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    • Zebra Danio

      The Zebra Danio or Zebrafish (Brachydanio rerio or Danio rerio) is a tropical fish belonging to the minnow family (Cyprinidae). Originating in Eastern India, it grows to about 2 inches (6 cm) and lives for around 5 years. There are long-finned and other color forms of this danio.

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      Zebra Danio, Danio rerio

      Like other danios it is omnivorous and a peaceful fish that gets along well with other fish in community tanks. A schooling fish, it prefers to be in groups of 6 or more. Zebra Danios prefer water with a 6.0–8.0 pH, a water hardness of up to 5.0–19.0 dGH, and a temperature range of 64–74°F (18–24°C).

      Males have gold stripes between the blue stripes and females have silver stripes instead of gold. An egg-scatterer, danios produce around 100 eggs in a single spawning.

      Zebra Danios serve as a common and useful model organism for studies of vertebrate development, because it reproduces very easily, passing from the egg to the larvae stage in less than three days. For genetic research groups, the Zebrafish is an excellent test subject and has already replaced rats and mice in many labs. Zebra danio is one of the few species of fish to have been flown into space. If researchers modify its genotype at the egg stage, they can see results on its organs barely three days later aided by the transparency of the embryos. A common reverse genetics technique is to knock down gene expression or modify splicing in Zebrafish using Morpholino antisense.

      Because of this interest it has been one of the first organisms to have its genome sequenced. The results of genetic engineering in these fishes have been used to produce the Glofish, an aquarium pet with fluorescent pigments.

      Zebra Danios are susceptible to Oodinium, or Velvet disease.

      Zebra Danios are omnivorous. Live/frozen flaked foods are suitable, especially brine shrimp. When conditioning zebras for breeding, it's advisable to feed them plenty of fresh foods.

      Zebrafishes are used as a model organism for genetic analysis of genes. These fishes have the advantage of fast and easy growth in the laboratory. See the external links for more information.

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      Issue #62

    • Sea anemone

      Named after a terrestrial flower, the anemone, the sea anemone is a group of water-dwelling, filter feeding animals of the order Actinaria. As a cnidarian, it is closely related to coral and jellyfish. The anemone is a (usually) solitary polyp with stinging cells (cnidocytes) in its tentacles. These stinging cells serve to paralyze and capture prey, which is then moved by the tentacles to the mouth for digestion inside a central cavity.

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      Giant Green Sea Anemone, order Actinaria, Southern California

      Other close relations to the sea anemone are the solitary, tube-dwelling anemones and the hydras.

      The sea anemone has a foot which in most species attaches itself to rocks or anchors in the sand. Some species attach to kelp and others are free-swimming. Although not plants and therefore incapable of photosynthesis themselves, many sea anemones form an important symbiosis with certain single-celled green algae species which reside in the animals' gastrodermal cells. These algae may be either zooxanthellae, zoochlorellae or both. The sea anemone benefits from the products of the algae's photosynthesis, namely oxygen and food in the form of glycerol, glucose and alanine; the algae in turn are assured a reliable exposure to sunlight, which the anemones actively maintain. The preponderance of species inhabit tropical reefs, although there are species adapted to relatively cold waters, intertidal reefs, and sand/kelp environments.

      Some sea anemones form symbiotic relationships with crabs and anemone fish, also known as clownfish. In the former situation, anemones will either attach or be attached to the shell of a hermit crab (by the crab's own volition), providing additional protection for the crab and allowing the anemone to eat scraps when the crab feeds. A similar relationship can be formed between a sea anemone and a clownfish. The clownfish presses itself into the anemone, living comfortably within the stinging tentacles: This is possible because of a protective slime that covers the clownfish. The clownfish benefits from this symbiotic relationship because it is protected by the anemone. The anemone benefits because the anemone gets food scraps from the clownfish.

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      Common Clownfish (Amphiprion ocellaris) in their Magnificent Sea Anemone (Heteractis magnifica) home.

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      Sea anemones at the aquarium in Bristol Zoo, Bristol, England.

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      Starfish and anemones in a cold water rocky community.

      Issue #63

      Edited by poon cho tang 03 Jul `05, 10:03AM
    • Dimetrodon

      Dimetrodon was a predatory synapsid (mammal-like "reptile") genus that flourished during the Permian period, living between 280 and 260 million years ago. It is more closely related to mammals than to true reptiles (Sauropsida) like dinosaurs, lizards and birds. Dimetrodon was not a dinosaur, despite being popularly grouped with them; rather, it is classified as a pelycosaur.

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      Fossil skeleton of Dimetrodon grandis at the National Museum of Natural History, Washington, DC

      Dimetrodon was a dominant carnivore, the largest of its day. It grew to up to 3 meters in length. Dimetrodon means "two-measures teeth"; it is so named because it had a large skull with two different types of teeth (shearing teeth and sharp canine teeth), as opposed to the dinosaurs. It walked on four side-sprawling legs and had a large tail.

      Dimetrodon's most distinctive characteristic is the spectacular sail on its back. The sail was probably used to regulate body temperature; the surface area would allow it to warm up or cool off more efficiently. It may also have been used in mating rituals and to ward off other predators. The sail was supported by neural spines, each one sprouting from an individual vertebra.

      Dimetrodon was discovered in Texas by Edward Drinker Cope.

      Conservation status: Fossil

      Issue #64

      Edited by poon cho tang 03 Jul `05, 10:06AM
    • Bengal cat

      The Bengal cat is a domestic cat breed with 'wild' characteristics and coloration, but a domestic temperament. They are medium sized cats - a male may weigh as much as 15 lb (7 kg), and a female commonly weighs 8 to 10 lb (4 to 5 kg). The closer the cat is to their Asian Leopard ancestors, the larger it is likely to be.

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      A Bengal kitten, aged 13 weeks

      Bengal cats are actually a hybrid between Asian Leopard Cats and domestic felines - mainly Egyptian Maus, American Shorthair, Abyssinian, Ocicat, and domestic shorthaired cats, as well as later generation Bengal males. Developed by Jean Mill of California in the 1970's, Bengal cats are labelled with an 'F' number to indicate how many generations they are removed from their wild ancestors. Kittens from an Asian Leopard Cat (crossed with a Bengal cat or domestic cat) would be called F1 Bengal cats, their offspring would then be called F2 Bengals and so on. Bengal cats from F1 to F3 are not allowed to be shown, due to their still semi-wild nature, although many F3 Bengal cats are very friendly. Asian Leopard cats or F1 and F2 Bengal cats may not be easily house-trained and need knowledgeable owners. They are often difficult to breed (F1 and F2 males are always infertile and F3 males are almost always infertile), with smaller litters. Consequently, when they are occasionally sold, they are much more expensive than later generation Bengal cats. A special breeders license is needed to care for F1 bengal cats or for their Asian leopard cat parents.

      Bengal cats are either spotted or have marbled patterns on their coats. The following colors and patterns are recognized: Brown Spotted Tabby, Brown Marbled Tabby, Seal Sepia Spotted Tabby, Seal Sepia Marbled Tabby, Seal Mink Spotted Tabby, Seal Mink Marbled Tabby, Seal Spotted Lynx Point and Seal Marbled Lynx Point only.

      Bengal cats can take a great deal of interest in running water and often don't mind getting wet. Most Bengal owners have stories about their cat's affection for running water or even jumping in a sink or tub. Additionally, Bengal cats are very intelligent and curious, and so are particularly interactive with their human housemates, wanting to be in the middle of whatever the human is engaged in, and often following the human around the house as household chores are performed. Bengals tend to vocalize to communicate with their humans, and are quite capable of jeoulousy and spitefulness if they feel that another feline is getting more attention. The other side of this coin is that they are also extremely affectionate towards and playful with their humans. Excellent hearing and highly developed instincts make Bengal cats excellent "watch dogs." Manx is yet another cat breed that share many of these similar traits with the Bengal cat.

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      A litter of Bengal kittens

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      Bengal kittens, at two weeks

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      An eight-month-old Bengal

      Country of origin: United States

      Issue #65

      Edited by poon cho tang 03 Jul `05, 10:07AM
    • Bumblebee Bat

      The Bumblebee Bat or perhaps more correctly Kitti's Hog-nosed Bat, (Craseonycteris thonglongyai) is the world's smallest species of bat at 29-33 mm in length and a weight of 2 grams (about as much as a dime). It is the only known species in its genus and is found in a tiny region of western Thailand, at Sai Yoke in the Kanchanburi province.

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      A Bumblebee Bat, Craseonycteris thonglongyai, hanging on a rocky outcropping.

      The bat is named a Bumblebee Bat because it is about the size of a bumblebee. It competes with the Etruscan Pygmy Shrew for the title of world's smallest mammal. At issue is whether skull size or mass defines "smallest"; the shrew is lighter but the bat's skull, shown below, is smaller at 11 mm.

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      The skull of the Bumblebee Bat, at 11 mm, is smaller than any other mammal.

      The Bumblebee Bat has reddish-brown upperparts, although the species seems to occur as another colour phase that has greyer upperparts. The underside is always a paler version of the top. The ears are relatively large and extend beyond the rather pig-like snout when lying forward.

      They are most active at dusk when they fly around the tops of bamboo clumps and teak trees to feed on insects. The wings are quite long and broad with pointed tips and dark membrane. They seem to be shaped for hovering flight and indeed gut contents of specimens do include spiders as well as other small insects that have been gleaned off foliage. Insects are also caught in straight flight.

      Bumblebee Bats roost in the hot upper chambers of caves in limestone hills, just about as far away from the entrance so that the small colony — up to 15 individuals — can fit without the bats being too close to each other.

      The bats are small both in size and in number. The species was unknown prior to 1974. Their already restricted habitat has been highly affected by deforestation and unsustainable levels of teak logging. In 1982, the Royal Forest Department of the Thailand Government only found 160 of them living in 3 caves, despite extensive surveys. Bumblebee bats are now considered one of the twelve most endangered species on the planet.

      Issue #66

      Edited by poon cho tang 03 Jul `05, 10:09AM
    • Peregrine Falcon

      The Peregrine Falcon (Falco peregrinus) is a medium-sized falcon about the size of a large crow: 38-53 cm (15 to 21 inches) long. It has a wingspan of about 1 metre (40 inches). Males weigh 570-710 grams; the noticeably larger females weigh 910-1190 grams.

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      Peregrine Falcon, Falco peregrinus

      Introduction

      Adult Peregrine Falcons have slate blue-grey wings and backs barred with black. Their undersides are white with light brown stripes. They have white faces with a black stripe on each cheek, and the head is blue-black. The subspecies vary in plumage; for instance immature males of the American tundra have pale crowns, while birds of the northwestern coast of North America are darker than others. All Peregrines have large dark eyes. The younger birds are darker below, browner, and streaked rather than barred.

      These birds are greatly prized in falconry, where the hen is known as a falcon and the cock as a tiercel.

      Peregrines eat mostly other birds such as pigeons, shorebirds, starlings, songbirds, parrots, and ducks. They attack their prey by flying high and diving ("stooping") at the victims.

      Although a Peregrine's speed in level flight is no greater than that of many other birds, its diving speed can exceed 320 km/h (200 Mi/h), arguably making it the fastest animal on earth.

      The bird's Latin name, peregrinus, means "foreigner" or "traveler". This is because wintering birds often wander far from their frequently bleak breeding areas.

      The call of this bird is a harsh repeated "cack".

      Range, habitat, and nesting

      Peregrine Falcons live mostly along mountain ranges, river valleys, and coastlines and, increasingly, in cities. They are widespread and common in Europe, Asia, North and South America, Australasia and Africa.

      In North America, Peregrine Falcons still breed in the Rocky Mountains, the Pacific Northwest, and the Arctic tundra, as well as the Midwest states. They used to be commonly found in parts of the Appalachian Mountains and nearby valleys from New England south to Georgia, the upper Mississippi River valley, and along the Pacific coast as far south as Mexico.

      Courtship displays include spectacular aerobatic flight and dives by the male and aerial pursuits. A pair may mate for life. These birds aggressively defend the nesting area.

      The nest is a scrape or depression dug in gravel on a cliff ledge. Sometimes if no cliff is available, Peregrines will nest in a tree cavity, an old stick nest, or even a tussock of grass on the tundra. These birds also nest on tall buildings in cities, which resemble their natural nesting sites. The female usually lays 3 to 5 eggs; the color ranges from reddish white to mottled brown.

      If a Peregrine Falcon lives through its first year, it can live up to 10 years. Most young birds do not survive their first year.

      Peregrines on the northwest coast of North America and other mild-winter regions are usually permanent residents. Other populations migrate; for instance, birds from Alaska, northern Canada and Greenland migrate to Central and South America. Migrating birds may travel far out over open ocean.

      Similarly, many birds from northern Eurasia move further south in winter, but in areas with less cold winters birds, especially adult males, will remain on the breeding territory.

      Recovery efforts

      Wildlife services around the world organized Peregrine Falcon recovery teams to breed Peregrines in captivity, among other places, at Cornell University and the renowned World Center for Birds of Prey located in Boise, Idaho.

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      Successful efforts at saving endangered species like the Peregrine were recognized by a U.S. postal stamp.

      The birds were fed through a chute so they could not see the human trainers. Then, when they were old enough, the box was opened. This allowed the bird to test its wings. As the bird got stronger the food was reduced because the bird could hunt its own food. This procedure is called hacking. To release a captive-bred falcon, the bird was placed in a special box at the top of a tower or cliff ledge

      Worldwide recovery efforts have been remarkably successful. In the United States, the banning of DDT, over time, made it possible for released birds to breed successfully. There are now dozens of breeding pairs of Peregrine Falcons in the northeastern USA. Many have settled in large cities, including New York, where they nest on skyscraper window ledges and the towers of suspension bridges. These structures typically closely resemble the natural elevated cliff ledges which the species prefers for nesting locations. During daytime the falcons have been observed swooping down to catch common city birds such as pigeons and starlings. In many cities, it has been credited with controlling the numbers of such common birds, which have often become pests, without resort to more controversial methods such as poisoning or hunting. The story in many other parts of the world has been similar.

      In Virginia, state officials working with students from the College of William and Mary in Williamsburg have successfully established nesting boxes high atop the George P. Coleman Memorial Bridge on the York River and the Benjamin Harrison Memorial Bridge and Varina-Enon Bridge on the James River and at other similar locations. 13 new chicks were hatched in this Virginia program during a recent year. The Peregrine Falcon was removed from the U.S. Threatened and Endangered Species list on August 25, 1999.

      In the UK, there has been a good recovery of populations since the crash of the 1960s. This has been greatly assisted by conservation and protection work led by the RSPB. Peregrines now breed in many mountainous and coastal area especially in the west and north. They are also using some city buildings for nesting, capitalising on the urban pigeon populations for food.

      Conservation status: Lower risk (lc)

      Issue #67

      Edited by poon cho tang 03 Jul `05, 10:11AM
    • Australian copperhead

      An Australian copperhead is any of three closely related species of snake in the genus Austrelaps. They are native to the relatively fertile temperate southern and eastern part of the continent.

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      A young Lowlands Copperhead, Austrelaps superbus

      Australian copperheads are usually of medium size, only rarely being more than about 1.8 metres long, and have a moderate build. Their colour varies a great deal, from a coppery mid-brown to yellowish, reddish, grey or even black, depending on the individual. The copper head colouring that gave rise to the common name is sometimes present, sometimes not. Some individuals also have visible markings just behind the head.

      Perhaps in consequence of this great variation, it was not realised until the second half of the 20th century that there were in fact three different species.

      -- The Lowlands Copperhead, Austrelaps superbus, is found throughout Victoria and Tasmania.
      -- The Highlands Copperhead, Austrelaps ramsayi, ranges from the rugged hills in north-eastern Victoria into New South Wales.
      -- The Pygmy Copperhead, Austrelaps labialis, is restricted to the small south-western part of South Australia that is relatively cool and well-watered.

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      Adult Lowlands Copperhead

      Copperheads are well adapted to cooler climates; they remain active after most reptiles have become dormant, and are the first to resume hunting at the end of winter. They are the only Australian snake found above the snowline. Their favoured habitat is near water. While they are moderately uncommon elsewhere, where conditions are suitable they congregate in substantial numbers. Copperheads are very much at home in the water: they swim well and often hunt tadpoles.

      They are diurnal at most times of year, but switch to night-time hunting in hot weather. They are generalised carnivores and will take any suitably-sized prey—including their own young—but the major diet item is frogs. Where frogs are common, so too are copperheads, and other snakes tend to be rare.

      Breeding starts in spring, and females give birth to about 14 live young, each a little under 20 cm long, in late summer.

      Like all elapids (members of the family Elapidae), Australian copperheads have fixed fangs mounted at the front of the jaw. They are shy and retiring by nature, and prefer to escape rather than fight where escape is possible, and their venom is, by Australian standards, only moderately toxic (equal on a per-mg basis to that of the Indian cobra). Nevertheless, they deliver a substantial quantity of venom and a copperhead bite left untreated can easily kill a healthy adult human. There is no specific copperhead antivenom, however the CSL-developed Tiger Snake antivenom is effective.

      Issue #68

    • European tree frog

      The European tree frogs (some members of the genus Hyla) are small frogs that can grow 5 cm in size at most. They are the only members of the wide-spread tree frog family (Hylidae) indigenous to Mainland Europe. Characteristic are the discs on the frog's toes which it uses to climb trees and hedges.

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      European tree frog, Hyla arborea

      Historically, tree frogs were used as barometers because they respond to approaching rain by croaking. In the breeding season, even when migrating to their mating pools, they croak as well. They are the loudest frogs of Europe, because of their large larynx (about one-fifth of the body length). Depending on subspecies, temperature, humidity, and the frog's 'mood', skin color ranges from bright to olive green, grey, brown and yellow.

      The head is rounded, the lip drops strongly, the pupil has the shape of a horizontal ellipse and the eardrum is clearly recognizable.

      Males can be distinguished from females by their browny-yellowy, large (folded) vocal sacs in the throat region. The amplexus is axillary (in the armpits).

      There are three or four species and many subspecies:

      - The Common or European tree frog, Hyla arborea (Linnaeus, 1758)
      - The Mediterranean tree frog or stripeless tree frog, Hyla meridionalis (Boettger, 1874)
      - The Italian tree frog, Hyla intermedia (Boulenger, 1882), not always considered a species)
      - The Sardinian tree frog, Hyla sarda (De Betta, 1853)

      The European tree frogs actually don't live in forests, but rather prefer sunny forest edges, bushy heaths, wet dune pans, wet scrubland and extensively used meadows and parks with ponds rich in submerged vegetation without fish nearby. These habitats are increasingly influenced by human activity. Hyla arborea, the common tree frog, is endangered in western Europe (nearly extinct in Belgium) while the more common Mediterranean tree frog lives in wet gardens, treegarths, vineyards, campings, and near pine trees.

      Common tree frog

      Both adult males and females reach sizes up to 30-40 mm, rarily longer than 45 mm. The smooth, shining, usually leaf-green back and the white-yellowish to grey belly are separated by a dark stripe on its flank reaching from the nostrils, over the eye and the eardrum, to the groin, contrasting the green, and forming a dark spot near the hips. The croaking sounds like a loud and rithmic 'creck-creck-creck...' and resemble the call of the Baillon's Crake (Porzana pusilla) and the Little Crake (Porzana parva).

      Spawn

      Eggs are deposited mostly during May, with the earliest spawn observed at the end of March. The clusters of spawn (each consisting of 10 to 50 eggs) are as big as walnuts and are deposited in shallow places grown with water plants. The top of every egg is brown and the bottom yellowy white. The diameter of an egg lies between 1.5 to 2 millimeter. After the deposition the eggs come together in clusters in order that the animal pole, which is pigmented brown and yellow, points upward and the vegetative pole, which is white and unpigmented, points downward.

      The time of development of the clutches depends on the prevailing water temperatures. Clusters that sink to the bottom of the water develop considerably slower than those which are exposed to the sunlight directly under the surface of the water.

      Distribution

      Widely distributed throughout Europe from the Ukraine and Belarus to the Balkan, Crete, Italy, the Benelux, Germany, most of France and the northwestern Iberian peninsula. Absent in the British Isles, the majority of Scandinavia and Denmark, the Alps and small northern parts of the Netherlands and Germany.

      Mediterranean tree frog

      Resembles the common tree frog, but is larger (some females up to 65 mm), has longer hindlegs, and the flank stripe only reaches to the front legs (often starting at the eyes, not at the nostrils). The croaking resembles that of the common tree frog, but it is deeper and slower: 'wroar... wroar... wroar'.

      Distribution

      Southern France, northern Catalonia, southern Portugal and Spain, and Menorca.

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      European tree frogs

      Issue #69

      Edited by poon cho tang 12 Jul `05, 11:49PM
    • Bumblebee

      The Bumblebee is a flying insect of the genus Bombus in the family Apidae. Like the common honeybee, of which it is a relative, the bumblebee feeds on nectar and gathers pollen to feed its young. They are very interesting creatures that are beneficial to humans and the plant world alike, and tend to be larger than other members of the bee family. Most, but not all, bumblebee species are gentle. From this comes their original name: "Humblebee".

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      Bumblebee, genus Bombus

      Bumblebees are social insects that are characterized by a black and yellow striped body, a commonality among the majority of the species of Bombus; however, some species are known to have orange or even red on their bodies. Another distinguishing characteristic is a hairlike substance, called pile, that covers their entire body, making them appear and feel fuzzy.

      A long-held myth of the bumblebee was that, in terms of theoretical aerodynamics, it did not have the capacity (in terms of wing size or beat per second) to achieve flight with the degree of wing loading necessary. This myth became popular after an aerodynamicist in the 1930s stated that a bumblebee was not capable of flight. The statement was based upon an assumption that the bee's wing could be treated as a static aerofoil. However, in reality the bumblebee's flight is characterized by an oscillating wing that shares more characteristics with a helicopter rotor than an aeroplane wing.

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      A bumblebee in flight

      Bumblebees are typically found in higher latitudes that range from warm to cold climates where other bees might not be found. One reason for this is that bumblebees are one of the few insects that can regulate their body temperature, via both solar radiation and via internal mechanisms of "shivering" and radiative cooling from the abdomen.

      Bumblebees form colonies like honeybees, however, their hives are usually much less extensive than that of honeybees, because of the small size of the nest. Often, bumblebee nests will hold fewer than 50 individuals.

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      Bubblebee nest

      Unlike honeybees, bumblebees only store a few days' worth of food and so are much more vulnerable to food shortages. However, because bumblebees are much more opportunistic feeders than honeybees, these shortages may have less profound effects. Bumblebees mostly do not preserve their nests through the winter, though some tropical species live in their nests for several years. The last generation of summer includes a number of queens who overwinter separately in protected spots.

      In the autumn, young queens mate with male drone bees and hibernate over the winter in a sheltered area, whether in the ground or in a manmade structure. In the early spring, the queen awakens and finds a suitable place to create her colony, and then builds wax pots in which to lay her fertilized eggs from the previous winter. The eggs that hatch are female workers, and in time the queen populates the colony, with workers feeding the young and performing other duties similary to honeybee workers.

      Bumblebees are beneficial to human beings because they can pollinate plant species that other pollinators cannot. For example, bumblebee colonies are often emplaced in greenhouse tomato production, because the frequency of buzzing that a bumblebee exhibits effectively pollinate tomatoes.

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      Bumblebee collecting pollen from a sunflower.

      The agricultural use of bumblebees is limited to pollination. Because bumblebees do not overwinter the entire colony, they are not obligated to stockpile honey, and are therefore unuseful as honey producers, although the honey is delicious.

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      A buff-tailed bumblebee

      Bumblebees are in danger in many developed countries due to habitat destruction and collateral pesticide damage. In Britain, there are 21 species of native bumblebee and six varieties of cuckoo bees — bees that dupe other bumblebees into looking after their young. Of these, only six bumblebees remain widespread; five are in serious decline and at least three are extinct.

      Bumblebees are increasingly cultured for agricultural use as pollinators.

      Species

      - Small Garden bumblebee, Bombus hortorum
      - Large Garden bumblebee, Bombus ruderatus
      - Cullem's bumblebee, Bombus collamanus
      - Short-haired bumblebee, Bombus subterraneus
      - Great Yellow bumblebee, Bombus distinguendus
      - Shrill Carder bee, Bumbus silvarum
      - Bombus terrestris
      - Bombus lucorum
      - Bombus lapidarius
      - Bombus pascuorum
      - Bombus pennsylvanicus
      - Bombus pratorum

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      Bombus hortorum queen

      Issue #70

      Edited by poon cho tang 03 Jul `05, 10:19AM
    • Perch

      A perch is a freshwater bony fish belonging to the family Percidae. Perch, of which there are three species, lend their name to the largest order of vertebrates: the Perciformes, from the Greek perke meaning perch, and the Latin forma meaning shape. All perciform fish share the perch's general morphology.

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      Yellow perch, Perca flavescens

      The European perch (Perca fluviatilis) is found in Europe and northern Asia. It is 15-60 cm long, and may weigh up to 10.4 kg. It is usually dark green with red fins. It has been successfully introduced in New Zealand and Australia where it is called redfin perch.

      The Balkhash perch (Perca schrenkii) is found in Kazakhstan; in Lake Balkhash and Lake Alakol. It is very similar to the European perch, and grows to a comparable size.

      In the United States and Canada there is the smaller (10-25 cm long, 1.4-4.5 kg in weight) and wider-mouthed species, the yellow perch (Perca flavescens). It is paler and yellowish and its fins are not as red; although recognized as a distinct species, the yellow perch may be a subspecies of the European perch (in which case its binomial name would be Perca fluviatilis flavescens). This view is supported by successful cross-breeding of the two species, which has generated faster growing offspring. However, this may be an example of interspecies hybrid vigor and it is unclear whether or not these hybrids are viable.

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      Yellow perch

      Perch have ctenoid scales. When looking through a microscope, the scale look like a plate with growth rings and spikes on the top edges. Externally the anatomy of perch is simple enough. On the dorsal side of the fish, there consists a upper maxilla and lower mandible for the mouth, a pair of nostrils, and two lidless eyes. On the posterior sides are the operculum, which are used to protect the gills. Also there is the lateral line system which is sensitive to vibrations in the water. They have a pair of pectoral and pelvic fins. On the anterior end of the fish, there are two dorsal fins. The first one is spiny and the second is soft. There is also a caudal fin and anal fin. Also there is a cloacal opening right behind the anal fin.

      The perch spawns at the end of April or beginning of May, depositing it upon weeds, or the branches of trees or shrubs that have become immersed in the water; it does not come into condition again until July.

      The best time for fishing for perch is from September to February; it haunts the neighborhood of heavy deep eddies, camp sheathings, beds of weeds, with sharp streams near, and trees or bushes growing in or overhanging the water. The baits for perch are, minnows, red, marsh, brandling or lob worms and shrimps. The tackle should be fine but strong, as with a fish bait a trout or pike may frequently be hooked. Perch, unlike fish of prey, are gregarious, and in the winter months, when the frosts and floods have destroyed and carried away the beds of weeds, congregate together in the pools and eddies, and are then to be angled for with greatest success from 10 to 4 o'clock, at the edge of the streams forming such eddies.

      Issue #71

    • Black widow spider

      The Black widow spider (Latrodectus mactans) is notorious for its neurotoxic venom. It is a large widow spider found throughout the world and commonly associated with urban habitats or agricultural areas. Although the common name 'black widow spider' is used to refer specifically to L. mactans it is occasionally also applied to several members of the Latrodectus (widow spider) genus in which there are 31 recognised species including the Australian red-back and brown widow spider.

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      Black widow spider, Latrodectus mactans

      Adult black widow spiders are shiny black with a reddish hourglass shape marking on the bottom of its abdomen. Female black widow spiders are about 1.5 inches (38 mm) with legs spread. Without its legs, they are about 0.5 inches (13 mm). Male black widow spiders are half the size of the female, but with longer legs.

      Though its venom is toxic, deaths from Latrodectus bites are rare, only sixty-three having been reported in the United States between 1950 and 1959 (Miller, 1992). Black widow venom acts by causing a localized release of the neurotransmitter acetylcholine, which is involved in muscular contraction.

      The mechanism of the venom relates to the toxin initially being carried by the lymphatic system until it reaches the blood stream. Once in the blood, the toxin is moved by the circulation and depositied in the nerve ends where they insert into the muscle. Most strongly affected are back, abdomen, and thigh muscle areas. The venom acts at the nerve ends to prevent relaxation of the muscle, causing tetany - or constant, strong, painful contractions of the muscles. Standard treatments usually involve symptomatic therapy with pain medication, muscle relaxants, and - rarely -antivenin. The venom does not typically cause problems at the bite site itself, unless a secondary skin infection occurs.

      Black widow spiders live in temperate and tropical zones (McCorkle, 2002). They typically prey on a variety of insects, but occasionally they do feed upon wood lice, diplopods, chilopods and other arachnids (McCorkle, 2002). When the prey is entangled by the web, L. mactans quickly comes out of its retreat, wraps the prey securely in its strong web, then punctures and poisons its prey (Foelix, 1982). The poison takes about 10 minutes to take effect, meanwhile the prey is held tightly by the spider (Foelix, 1982). When movements of the prey cease, digestive enzymes are released into the wound (Foelix, 1982). The black widow spider then carries its prey back to its retreat before feeding (Foelix, 1982).

      As is characteristic of all arthropods, black widow spiders have a hard exoskeleton composed of chitin and protein. When a male is mature, he spins a sperm web, deposits semen on it, and charges his palpi with the sperm. Black widow spiders reproduce sexually when the male inserts his palpus into the female's spermathecal openings. The females often kill and eat the male after mating; however, some males do escape under circumstances wherein the female is already well-fed. The female deposits her eggs in a globular silken container which they remain camouflaged and guarded. A female black widow spider can produce nine egg sacs in one summer, each containing about 400 eggs. Usually, eggs incubate for 20-30 days, but rarely do more than 12 survive through this process, due to cannibalism. It takes two to four months for black widow spiders to mature. The female live on for 180 days after maturing, while a male only lives on for another 90 days.

      According to a widely-reported media story (Wigmore, 2003), Chilean scientists were using part of Latrodectus venom to synthesize a drug that will not only serve as a male contraceptive, but will also work in a fashion similar to Viagra; however, this has not been reported in any mainstream peer-reviewed scientific journal.

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      Female black widow from the upper front showing mouthparts.

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      Female black widow from below showing red "hourglass" marker.

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      Female black widow from the upper rear showing pattern.

      Issue #72

    • Falkland Island fox

      The Falkland Island Fox (Dusicyon australis, formerly named Canis antarcticus), also known as the Warrah and occasionally as the Falkland Island Wolf or Antarctic Wolf and by Argentine writers as the Malvinas Zorro, was the only native land mammal of the Falkland Islands. This endemic canid became extinct in 1876, the only known canid to have gone extinct in historical times. Its most closely related species in the genus Dusicyon of southern-hemisphere foxes is Dusicyon griseus, the culpeo or Patagonian fox.

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      Falkland Island fox, Dusicyon australis, by John Gerrard Keulemans (1842-1912).

      The fur of the Falkland Island Fox had a tawny colour. The diet is unknown. Due to the absence of native rodents, it probably consisted of ground-nesting birds such as geese and penguins, grubs and insects, as well as seashore scavenging (Allen 1942).

      When Charles Darwin visited the islands in 1833, he named the species Canis antarcticus and described it as common and tame. The settlers regarded the fox as a threat to their sheep and organised poisoning and shooting on a massive scale. The absence of forests led to a speedy success of the extermination campaign.

      Conservation status: Extinct (1876)

      Issue #73

      Edited by poon cho tang 03 Jul `05, 10:21AM
    • Yorkshire Terrier

      The Yorkshire Terrier, also known as a Yorkie, is a breed of small dogs, one of many toy dog breeds. Yorkies can be very small indeed, usually not weighing more than about 5 or 6 pounds (less than 3kg).

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      Yorkshire Terrier puppy

      Appearance

      The breed standard calls for a long, blue and tan coat that hangs straight and parts down the middle. However, many yorkies do not conform directly to the stardard. Some coats are black or grey on the body. Brown and gold on the faces and legs is most common. The fur in a show dog is usually straight and can grow very long. Yorkies can also have somewhat wavy fur, although clubs do not recognize this variation for dog shows. In either case, Yorkie fur is soft, fine, and high-maintenance, and must either be trimmed short or washed and brushed frequently.

      Temperament

      The Yorkshire Terrier, though a Toy Breed, still retains much of its Terrier ancestry in terms of personality. Though personalities differ from dog to dog generally Yorkies are Intelligent, Independent and Spunky. Yorkies, especially males, are very territorial and are known for their disregard for the limitations of their own size. They will often attack much larger dogs despite their extreme size disadvantage.

      Yorkies typically get along well with cats or other dogs, and love to play together in groups. However, they are still terriers, and even an old, sedentary lap dog will eagerly hunt rodents. Because they are so small, they are easily injured, so while they will get along very well with children, it can be dangerous for the Yorkie to keep it in a house with small or abusive children. Also, despite their small size, if continually provoked or if attacked, like all dogs, they pack a surprisingly powerful bite.

      Yorkies may seem rather vapid and unintelligent at times (perhaps due to their yapping and playfulness), but they can easily be trained to perform simple tasks.

      Health

      Yorkies tend to develop cataracts in their old age, but their small size limits the effects of conditions such as arthritis. There is also the possibility of Trachea collapse, the cause of which is thought by many to be genetic. As with many purebred dogs, the Yorkshire Terrier is prone to certain genetic disorders. Most common is the liver shunt (portosystemic shunt). In this condition some of the dog's blood bypasses the liver and as such does not get cleaned of those toxins that the liver is responsible for removing. A Yorkie with this condition might exhibit some or all of the following symptoms: small stature, poor muscle development, behavioral abnormalities, unresponsiveness, seizures, and so on. However, if treated by a veterinarian, in time, the condition is most often reversible.

      History

      Most believe that the Yorkshire Terrier is the product of comingling Scottish and English terriers when many Scots were displaced by the Industrial Revolution and settled in England. Though pedigrees are not available for the first Yorkshire Terrier ancestors, several breeds have been suggested including (for the Scotish contribution) the Waterside Terrier, the Clydesdale Terrier, and the Paisly Terrier. English contributions to the bloodline of the Yorkshire Terrier may have included, according to many sources, the Manchester Terrier, the Maltese, and the Dandie Dinmont Terrier.

      The original Yorkshire Terrier, known as the "Broken-Haired Scotch Terrier" was a 12-to-14 pound dog with wire hair whose intended purpose was the catching of rats and other vermin that lived in small spaces.

      In 1870, the breed was renamed the Yorkshire Terrier, after the town of Yorkshire England where the breed is believed to have originated. The father dog of the breed is considered to be Huddersfield Ben, who was born in 1865, the inbred offspring of a mother and son. Huddersfield Ben was bred by Mr. W. Eastwood Huddersfield, who died in 1871. A multiple champion, Huddersfield Ben set the foundation for what would develop into the modern Yorkie.

      Miscellaneous

      A newly proposed breed, the Biewer, might or might not be a variation of the Yorkie or an entirely new breed.

      Famous Yorkies

      - Chow Mein from Gypsy

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      Common nickname: Yorkie
      Country of origin: United Kingdom

      Issue #74

    • Desert Cottontail

      The Desert Cottontail, Sylvilagus audubonii, is a New World cottontail rabbit, a member of the family Leporidae.

      Desert Cottontails are found throughout the central United States from eastern Montana to western Texas, and in northern Mexico. Westwards their range extends to central Nevada and southern California and Baja California. They are found at heights of up to 2,000 meters. They are particularly associated with the dry near-desert grasslands of the American south west, though they are also found in less arid habitats such as pinyon-juniper forest.

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      Desert Cottontail, Sylvilagus audubonii

      The Desert Cottontail is quite similar in appearance to the Eurasian Rabbit, though its ears are larger and are more often carried erect. It is also much less of a social animal, and makes much less use of burrows. Like all the cottontail rabbits, the Desert Cottontail has a rounded tail with white fur on the underside which is visible as it runs away. They are a light grayish-brown in colour, with almost white fur on the belly. Adults are 33 to 43 cm long and weigh up to 1.5 kg. The ears are long (8 to 10 cm), and the hind feet are large (7.5 cm in length). There is little sexual dimorphism, but females tend to be larger than the males, but have much smaller home ranges, about 4,000 m² (1 acre) compared with about 60,000 m² for a male.

      Desert Cottontails are not usually active in the middle of the day, but they can be seen in the early morning or late afternoon. They mainly eat grass, but will eat many other plants, even cacti. They rarely need to drink, getting their water mostly from the plants they eat or from dew. Like most lagomorphs, they reingest and chew their own feces; this allows more nutrition to be extracted.

      Many desert animals prey on cottontails, including eagles, owls, hawks, mustelids, coyotes, bobcats and humans. Southwestern Native Americans hunted them for meat but also used their fur and hides. The cottontail's normal anti-predator behavior is run away in zig zags; they can reach speeds of over 30 km/h. Against small predators they will defend themselves by kicking.

      The young are born in a shallow burrow or above ground, but they are helpless when born, and do not leave the nest until they are three weeks old. Where climate and food supply permit, females can produce several litters a year. Unlike the Eurasian rabbit, they do not form social burrow systems, but compared with some other leporids, they are relatively tolerant of other individuals in their vicinity.

      Conservation status: Lower risk (lc)

      Issue #75

      Edited by poon cho tang 03 Jul `05, 10:22AM
    • Andean Flamingo

      The Andean Flamingo (Phoenicopterus andinus) is a bird species in the Flamingo family restricted to the Chilean Andes. It is closely related to James's Flamingo (Phoenicopterus jamesi).

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      Andean Flamingos, Phoenicopterus andinus, at Slimbridge Wildfowl and Wetlands Centre, Gloucestershire, England.

      Like all flamingos it lays a single chalky white egg on a mud mound. Its population in Northern Chile was badly hit hit by drought, which cause the breeding lagoon areas to dry up, either preventing nest building, or allowing predation especially from the Culpeo Fox, Pseudolopex culpaeus.

      Andean Flamingos, like all the group, feed by filtering small items from water with their specialised bills. They have a deep, narrow lower mandible, which allows them to eat small foods such as diatoms, in contrast to the wider bill of larger species, which take bigger prey items.

      Most of the plumage is pinkish white. The Andean Flamingo is the only species that has yellow legs and feet.

      Conservation status: Vulnerable

      Issue #76

    • Carolina Anole

      The Carolina Anole (Anolis carolinensis), also known as the Green Anole, is an aboreal lizard found primarily in the southeastern parts of the United States and some Caribbean islands. It was described by Voigt in 1832 and Carolus Linnaeus in 1758 (as Lacerta principalis). Common synomyns include the American Anole and Red-throated Anole. It is sometimes referred to as the American chameleon due to its color-changing abilities, although it is not a chameleon.

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      Carolina Anole, Anolis carolinensis

      Description

      This lizard can reach a total length of about 22 cm. Females are slightly smaller (about 16 cm). The male has a dewlap -- pink or red in color -- that he can extend from his chin as a courtship or territorial display. This dewlap display is often accompanied by head bobbing and "pushups". Green Anoles can have a green or a brown body color, depending on mood and climate, with a white underbelly. Males are of solid color across the back, and females have a white stripe along the backbone.

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      Carolina Anole flashing his dewlap

      As a defense mechanism, their tails detach with mild force, but missing tails will regenerate. The lost tail piece is left twitching as a distraction as the lizard escapes. Also, like a chameleon, their eyes move independantly of one another.

      Distribution

      This species is native to the United States where it is found mainly in the southeastern parts of the country. They are sometimes kept as pets.

      Diet

      These lizards feed on various insects and other invertebrates. They may also eat pollen and nectar.

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      Carolina Anole eating a dronefly

      Behavior

      When caught and held, anoles will protest violently for the first few minutes by jumping around and holding their jaws open to bite; but thereafter they calm down and become rather compliant.

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      Male Anoles fighting

      Subspecies

      -- Anolis carolinensis carolinensis
      -- Anolis carolinensis seminolus


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      Anole shedding his skin

      Issue #77

      Edited by poon cho tang 03 Jul `05, 10:29AM
    • Palmate Newt

      The Palmate Newt (Triturus helveticus) is a species of newt found in parts of Great Britain, Western and Northern Europe. It can be found in ponds, lakes, canals, marshes, forests, pasture or agricultural land, sometimes in acid pools on upland moors or coastal areas. It spends the breeding season (February to May) in water laying 100 to 300 eggs which hatch into larvae in about 2 to 3 weeks and then metamorphose after a further 6-9 weeks. In colder areas the larvae often over-winter in the water and then metamorphose the next year. They become sexually mature in the second year, but neoteny is also known to occur in this species. Adults hibernate on land under logs and stones between November and March, or more rarely in water.

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      Palmate Newt, Triturus helveticus

      The base color of both sexes is olive-green or brown; males and some females have a dark spotting on the back. Sometimes confused with the Smooth newt, the palmate does not have the spotted throat of the smooth newt, but both sexes have a yellow or pale orange belly that can show some spotting. Males have webbed hind feet and a low, smooth crest along the back that continues into a slightly higher crest on the tail ending in a thread like tip during the breeding season of April - May. The crest and filament become less obvious and may disappear at other times when they become terrestrial. Males also have marked dorsolateral ridges, giving them a rather square cross-section. Females grow to 10 cm (4 in) and males to 8.5 cm (3.3 in). During the breeding season they are active during the day as well as night, but outside this period activity is restricted to rainy or humid nights.

      They feed on invertebrates, small crustaceans, planktonic animals, daphnia and also frog tadpoles. They are also known to display cannibalistic tendencies and they can live for up to 10 years. It is an endangered species and is protected by law in all countries where it occurs, but is thought to be extremely rare to endangered in the Netherlands, Belgium and Luxembourg and vulnerable in Germany, but common elsewhere. Related subspecies T. h. helveticus found in northern Germany to northeastern Spain, T. h. punctillatus in the Sierra de la Demanda area, Spain, and T. h. alonsoi (also known as T. h. sequeirai) occurs in the north-western corner of the Iberian peninsula.

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      Adult male

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      Adult female

      Issue #78

    • Asian Lady Beetle

      The Asian lady beetle (Harmonia axyridis), often known as the Asian multicolored lady beetle because of the species' tendency to vary in color from orange to yellow to even black, is now a common insect in North America. It is a non-native insect on the continent, introduced in the United States in an attempt to control the spread of aphids. After many years of trying to establish a North American population of these beetles brought from their native region in northeastern Asia, a group finally took root in Louisiana around 1988. Since then, the insect has spread throughout the United States and has succeeded in controlling aphid populations. However, many people are now coming to view the Asian lady beetle as a nuisance, probably partly due to the fact that they not only like to overwinter indoors, along with the fact that they emit an unpleasant odor and a defensive stain when squashed.

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      The Asian lady beetle, Harmonia axyridis, is easy to identify from its false "eyes"—twin white football-shaped markings behind the head. In color, the insects range from black to mustard, with zero to many spots. A common U.S. form is mustard to red and has 16 or more black spots.

      In the U.S., the first attempts to introduce the beetle took place as far back as 1916. Repeated efforts were not very successful. In the early 1980s, aphids were causing significant problems for growers of pecan trees, so the United States Department of Agriculture again attempted to bring the insect into the country—this time in the southeastern United States. After a period of time, USDA scientists concluded that their attempts had been unsuccessful. However, a population of beetles was soon observed near New Orleans, Louisiana. In the following years, the beetle quickly spread to other states, being occasionally observed in the Midwest within about 5–7 years, and becoming common in the region by about 2000.

      Asian lady beetles hibernate in cooler months, though they will wake up and move around whenever the temperature reaches about 50°F (10°C). Because the beetles will use crevices and other cool, dry, confined spaces to hibernate, significant numbers may congregate inside walls if given a large enough opening. They often congregate in sunlit areas because of the heat available, so even on fairly cold winter days, some of the hibernating beetles will “wake up” because of solar heating. These large populations can be problematic because they can form swarms and hover in an area for a long time. Also, the bugs do not understand that glass cannot be penetrated by their small bodies, so many of the bugs will crash into window panes.

      These bugs will “reflex bleed” when agitated, releasing blood from their legs. The blood has a foul odor (similar to that of dead leaves) and can cause stains. It is believed that some people have allergic reactions when repeatedly exposed to lady beetles (especially dead ones). Sometimes, the beetles will bite humans, although many people feel a pricking sensation as a lady beetle walks across the skin. Bites are believed to do no more harm than cause irritation.

      image

      These beetles can sometimes be difficult to identify because of their variations in color, spot size, and spot count. The easiest way to identify an Asian lady beetle is to look at the pronotum and see if the black markings look like a letter “W” or “M” (depending on if the marking is viewed from the front or the back).

      Despite the troubles the Asian lady beetle causes, many biologists still view the bug as a beneficial insect. It is reported that the beetle has heavily fed on soybean aphids, which recently appeared in the U.S. after coming from China, supposedly saving farmers vast sums of money in 2001.

      Issue #79

      Edited by poon cho tang 03 Jul `05, 10:31AM
    • Rock bass

      The rock bass (Ambloplites rupestris) is a species of freshwater fish in the sunfish family (Centrarchidae) of order Perciformes. It is native to the Saint Lawrence River–Great Lakes system and the upper and middle Mississippi River basin in North America, from Québec to Saskatchewan in the north down to Missouri and northern Alabama and Georgia in the south.

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      Rock bass, Ambloplites rupestris

      The largest and commonest of the Ambloplites species, it has reached a maximum recorded overall length of 43 cm (17 in), and a maximum recorded weight of 1.4 kg (3.0 lb). It can live for as long as 10 years.

      The rock bass prefers clear, rocky, and vegetated stream pools and lake margins. Carnivorous, its diet consists of smaller fish, insects, and crustaceans.

      A. rupestris is sometimes called the redeye or redeye bass in Canada, but this name refers more properly to Micropterus coosae, a distinct species of Centrarchid native to parts of the American South.

      Rafinesque originally assigned the rock bass to Bodianus, a genus of marine wrasses (family Labridae).

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      Conservation status: Secure

      Issue #80

      Edited by poon cho tang 03 Jul `05, 10:33AM
    • Horseshoe crab

      The horseshoe crab (Limulus polyphemus), also known as king crab, is an arthropod that is more closely related to spiders than crabs. They are most commonly found in the Gulf of Mexico and along the northern Atlantic coast. They can grow up to 51 cm, on a diet of mollusks, worms, and other invertebrates. They find this prey under the sand, where they spend most of their lives. In captivity, its diet should be supplemented with meaty items such as pieces of squid and shrimp (Foster and Smith, 2004). Its mouth is located in the middle of the underside of the cephalothorax. A pair of pincers (chelicerae) for seizing food are found on each side of the mouth.

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      Horseshoe crabs, Limulus polyphemus

      Horseshoe crabs possess five pairs of book lungs (sometimes known as book gills) located just behind their appendages that allow them to breathe underwater, and can also allow them to breathe on land for short periods of time, provided the lungs remain moist. The outer shell of these animals consists of three parts. The carapace is the smooth frontmost part of the crab; it has on it the eyes, the walking legs, the chelicera (pincers), the mouth, the brain, and the heart. The abdomen is the middle portion where the gills are attached as well as the genital operculum. The last section is the telson which is used to flip itself over if stuck upside down.

      Limulus has been extensively used in research into the physiology of vision. It has four compound eyes, and each ommatidium feeds into a single nerve fibre. Furthermore the nerves are large and relatively accessible. This made it possible for electrophysiologists to record the nervous response to light stimulation easily, and to observe visual phenomena like lateral inhibition working at the cellular level. More recently, behavioural experiments have investigated the functions of visual perception in Limulus. Habituation and classical conditioning to light stimuli have been demonstrated, as has the use of brightness and shape information by male Limuli when recognising potential mates.

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      Pair of horseshoe crabs

      Since 1964 a substance in their blood called "Limulus amebocyte lysate" (LAL) has also been used to test for bacterial endotoxins in pharmaceuticals and for several bacterial diseases. The animals can be returned to water after extraction of a portion of their blood (except in Massachusetts, where their return is prohibited), so this is not necessarily a threat to the survival of horseshoe crabs. Horseshoe crabs have blue blood.

      Horseshoe crabs can live for sixteen to nineteen years. They migrate into the shore in late spring, with the male arriving first. The female then arrives and makes a nest at a depth of 15-20 cm in the sand. In the nest, females deposit eggs which are subsequently fertilized by the male. Studies conducted in Delaware have revealed an average of 3,650 eggs laid per nest. "Development begins when the first egg cover split and new membrane, secreted by the embryo, forms a transparent spherical capsule" (Sturtevant). The larvae form and these larvae swim for about five to seven days. After swimming they settle, and begin the first molt: this happens approximately twenty days after the formation of the egg capsule. As young horseshoe crabs grow, they move to deeper waters. During this time, molting still takes place for two to three years. They reach sexual maturity in five to seven years. The main cause of death during these days is the fish bait industry, which collects horseshoe crabs to make bait for lobsters and other catches.

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      Underside of a female showing the legs and book lungs

      Although most arthropods have mandibles, the horseshoe crab is jawless. The horseshoe crab's mouth is located in the center of the body.

      Horsehoe crabs are distant relatives of spiders and are probably descended from the ancient eurypterids (sea scorpions). They evolved in the shallow seas of the Paleozoic Era (540-248 million years ago) with other primitive arthropods like the trilobites. Horseshoe crabs are one of the oldest classes of marine arthropods, and are often referred to as "living fossils", as they have not changed much in the last 350 to 400 million years.

      No living species of horseshoe crab is endangered yet, but harvesting and habitat destruction have reduced their numbers at some locations and caused some concern for these animals' future.

      Conservation

      Since the 1970s, the horseshoe crab population has been decreasing, owing to several factors, including the use of the crab as bait in conch trapping.

      In 1995, the nonprofit Ecological Research and Development Group (ERDG) was founded with the aim of preserving the four remaining species of horseshoe crab. Since its inception, the ERDG has made significant contributions to horseshoe crab conservation. ERDG founder Glenn Gauvry designed a mesh bag for conch traps, to prevent other species from taking off with the bait. This has led to the amount of bait needed being decreased by approximately 50%. In the state of Virginia, these mesh bags are now mandatory in conch fishery.

      Every year, around 10% of the horseshoe crab's breeding population dies when rough surf flips the creatures onto their backs, a position from which they often cannot right themselves. In response, the ERDG launched a "Just Flip 'Em" campaign, in the hopes that beachgoers will simply turn the crabs back over.

      Issue #81

      Edited by poon cho tang 03 Jul `05, 10:35AM
    • Heath Hen

      The Heath Hen (Tymphanucus cupido cupido) was a distinctive subspecies of the Greater Prairie Chicken, Tymphanucus cupido, a large North American bird in the grouse family. Heath Hens lived in the scrubby barrens of New England, whereas the Prairie Chickens lived from Texas north to Indiana and the Dakotas. Heath Hens were once common in their habitat, but being a gallinaceous bird, they were hunted by settlers extensively for food.

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      Heath Hen, Tymphanucus cupido cupido

      Eventually, all heath hens were extirpated on the mainland. There were a few left on the island of Martha's Vineyard, off Massachusetts. These were protected, and the population grew to almost 3,000. However, severe winters combined with a destructive fire during the nesting season brought the numbers down quickly. Soon, there was only one left and he was lovingly nicknamed "Booming Ben." He died in 1937.

      Heath Hens were one of the first bird species that Americans tried to save from extinction. Although the effort was unsuccessful, it paved the way for conservation of other species. Also, there has been some talk that someday, Greater Prairie Chickens might be introduced into suitable habitat in the northeastern USA to try to recreate the Heath Hen of past.

      Conservation status: Extinct (1930s)

      Issue #82

      Edited by poon cho tang 03 Jul `05, 10:39AM
    • Abyssinian

      The Abyssinian is a natural breed of domesticated cat believed to originate from one Egyptian female kitten called Zula that was taken from a port in Alexandria Egypt, by a British soldier and brought to England where the breed was developed by being bred with an English tabby. It is believed all Abbys in Europe, America and Australia are descended from Zula, but there has been at least one and possibly as many as three Abyssinians introduced from Libya (or less likely Egypt) into the existing Abyssinian gene pool in the US. The Abyssinian has become one of the most popular shorthaired breed of cats in the United States. They are said to be still wild Abyssinians in some parts of North Africa.

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      Shorthaired Abyssinian

      The Abyssinian has a distinctly thick, tawny coat. The tail and paws may show tabby markings, but the body must not. It has large almond-shaped green or golden eyes, with a fine dark line around them, and large ears. The coat is generally a warm golden colour, but Abbys can also be blue, fawn, cinnamon and red. There is also a Silver Abyssinian variant whose coat shows shades of white, cream and grey.

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      An Abyssinian kitten

      Abyssinians are very active, friendly, curious and playful, but are usually not "lap cats"; they are too busy exploring and playing. They are highly intelligent, but probably the most independent of any domestic breed. There is a long-haired version of the Abyssinian, called the Somali.

      Common nickname: Abby
      Country of origin: Egypt

      Issue #83

      Edited by poon cho tang 03 Jul `05, 10:45AM
    • Burmeister's Porpoise

      Burmeister's Porpoise (Phocoena spinipinnis) is a species of porpoise endemic to the coast of South America. It was first described by Hermann Burmeister, for whom the species is named, in 1865.

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      Burmeister's Porpoise, Phocoena spinipinnis

      Population and distribution

      Whilst Burmeister's Porpoise seems to be relatively common in its range, little work has been done to survey the species. Its range appears to be continuous in coastal waters from northern Peru in the Pacific round Tierra del Fuego and upto southern Brazil in the Atlantic. The total population is at least in the tens of thousands. Whilst usually described as staying very close to the sure, individuals have been spotted as far as 50 km from the shore and in the freshwater Valivia River in southern Chile.

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      Range of Burmeister's Porpoise

      Physical description

      Most photographs of Burmeister's Porpoises are taken of dead specimens and show the animal to be coloured black. This phenomenon gave rise to the earlier common name, the Black Porpoise. However live individuals are typically a dark grey colour. They turn black in just a few minutes after death. The underside varies in colour but is usually a lighter grey. Burmeister's are about 150 cm long when fully mature and weigh 50-75 kg. The maximum recorded weight is that of a female at 105 kg. They have a shallow indentation at their blowhole set just in front of the eyes. The shape and placement of the dorsal fin is unusual for a cetacean - it is triangular rather than curved and points backwards more than upwards. It is located about three-quarters of the way along the back - further back than any other dolphin or porpoise. These features are sufficient to distinguish the porpoise from the similar-sized Chilean Dolphin which is found in the porpoise's Pacific range.

      Behaviour

      Burmeister's Porpoise is difficult to observe. It appears to be shy, shows little of its body when surfacing and will move quickly away from approaching boats. They are typically seen alone or in pairs with occasional larger groups. One report from Chile saw a group of 70 in number. The porpoise feeds on various pelagic fish such as anchovies, hake and mackerel.

      Conservation

      Like all porpoises, Burmeister's is vulnerable to accidental capture in fishing nets. This is common in Uruguay, Peru and Chile. The annual estimated catch is largest in Peru, at 2,000 individuals. Burmeister's are also harpooned deliberately for food and for use as shark bait. The IUCN lists the animal as data deficient in its Red List of Threatened Species and the long-term of these actions is unknown.

      Conservation status: Unknown

      Issue #84

      Edited by poon cho tang 03 Jul `05, 11:00AM
    • Common Myna

      The Common Myna, Acridotheres tristis, is a myna, a member of the starling family. This bird is a common resident breeder in tropical southern Asia from Afghanistan to India and Sri Lanka. It is also known as the Indian Myna.

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      Common Myna, Acridotheres tristis

      It has extended its range into southeast Asia, and has been introduced widely elsewhere, including South Africa, Hawaii, North America, Australia and New Zealand.

      This abundant passerine is typically found in open woodland, cultivation and around habitation. The Common Myna builds a nest in hole in a tree or wall. The normal clutch is 4-6 eggs.

      These 25 cm long birds have brown body and wing plumage, with large white wing patches obvious in flight. The head and throat are dark grey. The bill, bare skin around the eyes and strong legs are bright yellow. The sexes are similar. Mynas mate for life. They strut in walking, hopping usually only to jump up or down. Their songs include croaks, squawks, chirps, clicks and whistles and they often fluff their feathers and bob their heads in singing. They screech warnings to their mates or other birds in cases of predators in proximity.

      Like most starlings, the Common Myna is omnivorous.

      Issue #85

    • Gaboon Viper

      The Gaboon viper, Bitis gabonica, is a terrestrial snake found in the rain forests of equatorial Africa. An ambush predator, it spends most of its life camouflaged and motionless in the the leaf litter. The species is actually surprisingly docile in nature, but can strike with lightning speed in any direction.

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      Gaboon viper, Bitis gabonica

      One of the three giant vipers of Africa, this thick-bodied reptile can grow to over 2 meters in length and weigh over 10 kg. It is also listed in the Guinness Book of World Records as having the longest fangs of any venomous snake: 50 mm (2 in). The specimen above was found in a village and was about 1.38 metres long. Its head can measure nearly 15 cm across. Although it does not have a particularly toxic venom compared to some other notorious species, it more than makes up for this with volume: up to 1,000 mg of dried venom has been extracted -- 40% more than the eastern diamondback rattlesnake (Crotalus adamanteus) has been known to produce. The venom is haemotoxic.

      Issue #86

      Edited by poon cho tang 12 Jul `05, 11:52PM
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