An Animal A Day
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Giant Neotropical Toad
The Giant Neotropical Toad (Bufo marinus) is native to the Americas from southern Texas to northern Argentina. It has been introduced to many locations in the belief it will control agricultural pests, particularly of sugarcane. Introduced populations now occur in Australia, Florida, Papua New Guinea, the Philippines, the Ogasawara Islands and Ryukyu Islands of Japan, most Caribbean islands and many Pacific islands including Hawai'i and Fiji.
Giant Neotropical Toad, Bufo marinus
Some individuals reach exceptional sizes for an anuran. A preserved specimen in the museum of Queensland is 24 cm long and weighed 1.36 kg. They can live as long as twenty years in captivity, but usually don't live as long in the wild.
Adults possess enlarged paratoid glands behind the eyes and other glands across the back. When the animal is harassed these glands secrete a milky-white fluid known as bufotoxin. Bufotoxin contains components which are dangerous to many animals. There are reported deaths of humans after consumption of toads. Ill-effects from contact with toads have also been reported and they should be handed with caution. However they are sometimes kept as pets.
Adults are omnivores which is unusual for an anuran. Their prey includes small vertebrates, a wide range of invertebrates, carrion and plant material. They even been known to attempt to eat ping pong balls. They are active primarily at night, ranging far away from water.
Females lay from 4,000 to 36,000 eggs per clutch, and breed at least twice per year. Both eggs and tadpoles are toxic to many animals. This toxic protection is lost for a period after metamorphosis until the paratoid glands develop.
Introduction to Hawaii
This toad was introduced into Hawai'i in 1932 from Puerto Rico to control injurious insects in the sugarcane fields.
Introduction into Australia
101 toads were brought to Australia from Hawai‘i in June 1935 in an attempt to control pests to sugarcane crops. They bred immediately in captivity and by August 1935 over 3000 young toads had been released in areas around Cairns, Gordonvale and Innisfail in northern Queensland. Releases were temporarily limited due to environmental concerns, but resumed in other areas after September 1936. Since their release, toads have steadily expanded their range through Queensland, reaching the border with New South Wales in 1978 and the Northern Territory in 1984.
There are grave concerns that toads might affect Australia's native fauna by predation, competition, conveying diseases and by poisoning animals that attempt to prey on toads. The long-term impact of toads on the Australian environment is difficult to determine. Precipitous declines in populations of the Northern Quoll have been observed after toads have invaded an area. There are also a number of reports of goanna and snake populations collapsing after the arrival of toads. See link.
A number of native species have been reported as successfully preying on toads. Some birds, such as the Torresian Crow and the Black Kite, have learned to attack a toad's belly, avoiding the venom-producing glands on the behind the head. Recent reports by researchers in the Northern Territory indicate that a native frog Litoria dahlii is apparently able to eat the tadpoles and live young of the toad without being affected by the poison that often kills other predators. This is believed to account for slower than expected infestations of toads in certain areas of the Northern Territory.
The saga of the Cane toad in Australia was popularized by the film Cane Toads: An Unnatural History (1987) which tells the tale with a humorous edge and is often shown in Environmental Science courses.
Other names
The Giant Neotropical Toad is also known by the following names:
- Aga Toad (German, origin unknown)
- Cane Toad
- Dominican Toad
- Giant Marine Toad
- Giant Toad
- Marine Toad
- Sapo gigante (Spanish)
- South American Cane Toad
- Spring Chicken (in Belize)
- Sapo Cururu (in Brazil)
Issue #87 -
hey this is good stuff,i like reading this
keep it up.will be back for more -
Desert locust
Plagues of the desert locust (Schistocerca gregaria) have threatened agricultural production in Africa, the Middle East and Asia for centuries. The livelihood of at least one-tenth of the worldÂ’s human population can be affected by this hungry insect. The 2004 desert locust plague is predicted to cause significant crop losses in West Africa and have a negative impact food security in the region.
Desert locust ecology
The desert locust lives a solitary life, until it rains. Rain causes vegetation growth and spurs the development of eggs that have been laid in the sandy soil. The new vegetation provides food for the newly hatched locusts and provides them with shelter as they develop into winged adults.
When vegetation is distributed in such a way that the locusts have to congregate to feed, and there has been sufficient rain for a lot of eggs to hatch, forced physical contact causes the insect's hind legs to bump up against one another. This triggers a cascade of metabolic and behavioral changes that signal the insectÂ’s transformation from solitary behaviour to gregarious behavior. When the locusts become gregarious they change from green coloured to yellow and black, their bodies become shorter, and they give off a hormone that causes them all to be attracted to the same location, enhancing swarm formation.
Solitary (top) and gregarious (bottom) desert locusts, Schistocerca gregaria
During quiet periods, called recessions, locusts are confined to a 16-million-square-kilometer belt that extends through the Sahara Desert in northern Africa, across the Arabian Peninsula, and into northwest India. When conditions are right swarms invade countries on all sides of the recession area, as far north as Spain and Russia and as far east as India and southwest Asia. As many as 60 countries can be affected.
Swarms regularly cross the Red Sea between Africa and the Arabian Peninsula and are even reported to have crossed the Atlantic Ocean from Africa to the Caribbean. A single swarm can cover 1,200 square kilometers and can contain between 40 and 80 million locusts per square kilometer. The locust can live between three to six months, and there is a tenfold increase in locust numbers from one generation to the next.
Crop loss
Desert locusts can consume the approximate equivalent of their body mass each day (2 g) in green vegetation: leaves, flowers, bark, stems, fruit, and seeds. Nearly all crops, and non crop plants, are at risk, including millet, rice, maize, sorghum, sugarcane, barley, cotton, fruit trees, date palm, vegetables, rangeland grasses, acacia, pines, and banana.
Desert locusts feeding
Crop loss from locusts was noted in the Bible and Qur'an. During the twentieth century, Desert Locust plagues occurred in 1926-1934, 1940-1948, 1949-1963, 1967-1969 and 1986-1989. The significant crop losses caused by swarming desert locusts, exacerbate problems of food shortage, and are a threat to food security.
Control
NASA has developed methods for detecting conditions and regions likely to give rise to swarms by satellite. Satellite data, combined with weather information and ground surveys, are used by the FAOs Desert Locust Information Service to produce forecasts published on the Web and in regular locust bulletins. They also provide information and training to affected countries and arrange for funding from donor agencies in case of major upsurges and plagues.
The desert locust is a difficult pest to control, and control measures are made more difficult by the large and often remote areas (16-30 million sq. km) where locusts can be found. Undeveloped basic infrastructure in some affected countries, limited resources for locust monitoring and control and political turmoil within and between affected countries further reduce the capacity of a country to prevent swarms.
At present the primary method of controlling desert locust swarms is with organophosphate insecticides applied in small concentrated doses by vehicle-mounted and aerial sprayers. The insecticide must be applied directly to the insect. Control is undertaken by government agencies in locust affected countries or by specialised organisations like the Desert Locust Control Organisation for East Africa (DLCO-EA).
A biological control product has been available since the late nineties. It is based on a naturally occurring entomopathogenic (i.e. infecting insects) fungus, Metarhizium anisopliae var. acridum. The species M. anisopliae is widespread throughout the world infecting many groups of insects, but it is harmless to humans and other mammals and birds. The variety acridum has specialised on short-horned grasshoppers, to which group locusts belong, and has therefore been chosen as the active ingredient of the product.
The product is available under different names in Africa and Australia. It is applied in the same way as chemical insecticides but does not kill as quickly. At recommended doses, the fungus typically takes two to three weeks to kill up to 90% of the locusts. For that reason, it is recommended for use mainly against hoppers, the wingless early stages of locusts. These are mostly found in the desert, far from cropping areas, where the delay in death does not result in damage. The advantage of the product is that it affects only grasshoppers, which makes it much safer than chemical insecticides. Specifically, it allows the natural enemies of locusts and grasshoppers to continue their beneficial work. These include birds, parasitoid and predatory wasps, parasitoid flies and certain species of beetles. Though they cannot always prevent plagues, they can limit the frequency of outbreaks and contribute to their control.
2004 Desert locust swarm
In 2004 West Africa faces the largest desert locust plague in 15 years. The costs of fighting the swarm are estmiated by the FAO to reach US$122 million and harvest losses are valued at up to US$2.5 billion which will have disastrous effects on the food security situation in West Africa.
The countries affected by the 2004 plague are Algeria, Benin, Burkina Faso, the Canary Islands, Cape Verde, Chad, Egypt, Gambia, Guinea, Libyan Arab Jamahiriya, Mali, Mauritania, Morocco, Niger, Nigeria, Saudi Arabia, Senegal, Sudan, Tunisia and Yemen.
Recently, large swarms of locusts traveled from Egypt into Jordan and Israel. It was reported that millions have reached the Gulf of Aqaba and the surrounding regions. Israel's Ministry of Agriculture reported sightings of individual insects as far north as Jerusalem and Tel-Aviv.
Large scale control efforts are underway, but most countries face serious shortages of pesticides and aircraft.
Issue #88 -
Ribbon eel
The ribbon eel (Rhinomuraena quaesita) is one of the most unique species of saltwater eels. It is a member of the Muraenidae (Moray eel) family of order Anguilliformes. What is now known as Rhinomuraena quaesita also includes the former Rhinomuraena amboinensis. R. quaesita was used for blue ribbon eels and R. amboinensis for black ribbon eels, but these are now recognized as the same species. The ribbon eel is native to the Indian Ocean and Pacific Ocean.
Ribbon eel, Rhinomuraena quaesita
The ribbon eel is an elegant creature with a long, thin body and high dorsal fins. Many feel that it resembles a brightly colored party streamer. The ribbon eel can easily be recognised by its expanded anterior nostrils. Juveniles and sub-adults are jet black with a yellow dorsal fin, whiel females are yellow with a black anal fin and white margins on the fins. The adult male can be black, fluorescent blue with yellow highlights, blue-green, or brilliant yellow.
R. quaesita grows to an overall length of approximately 100 cm (36 in), and has a life span of up to five years. The ribbon eel is the only moray eel that is not gonochoristic.
Behavior
Like many eels, the ribbon eel is sometimes thought to be angry or aggressive, because its mouth is often open, appearing ready to strike. In reality, the eel is simply breathing.
In the wild, the ribbon eel buries itself in sand or hides in rocks or reefs, dashing out to feed on small fishes. The ribbon eel is known as one of the most sociable and peaceful of all moray eels, and does not bother humans or get easily irritated.
In the aquarium
It is estimated that greater than 99% of ribbon eels do not live more than a month in captivity. Ribbon eels have been observed in nearly every case to stop eating after being captured.
Purchasing an animal of this species may be unwise, as it is extremely unlikely that the eel has continued eating since capture. It is always best to see it, in person, eat something while in captivity. Fish sellers have been known to hide or lie about the fact that the animal no longer eats. Some feel that this species should never be purchased under any circumstance, as when the demand dries up, these eels will no longer be caught and put up for sale. Capturing 100 of these animals to get 1 pet is not a very pleasant ratio for the species.
Issue #89 -
Millipede
Millipedes (Class Diplopoda, previously also known as Chilognatha) are very elongated arthropods with cylindrical bodies that have two pairs of legs for each one of their 20 to 100 or more body segments. These animals are herbivorous, slow and nonvenomous; unlike the somewhat similar and closely related centipedes (Class Chilopoda), which can be easily distinguished by their single pair of legs for each body segment. Most millipedes eat decaying leaves and other dead plant matter, moisturizing the food with secretions and then scraping it in with the jaws.
Rusty millipede, Trigoniulus corallinus
This class of arthropods is thought to be among the first animals to colonize land during the Silurian geologic period. These early forms probably ate mosses and primitive vascular plants.
Sri Lankan Giant Millipede (Spirostreptus sp.)
The millipede's most obvious feature is its large number of legs. In fact its name is a compound word formed from the Latin roots milli ("thousand") and ped ("foot"). Despite their name, these creatures do not have a thousand legs, although some rare species are close enough with an amazing 750. However, common species have between 80 and 400 legs.
Having very many short legs makes millipedes rather slow, but they are powerful burrowers. Waving their body length and with the legs moving in a wavelike pattern, they easily force their way underground, head first. They also seem to have some engineering ability, reinforcing the tunnel by rearranging the particles around it.
Millipedes, found under a rock
Due to their lack of speed, millipedes' primary defense mechanism is to curl into a tight coil—protecting their delicate legs inside an armored body exterior. Many species also emit a somewhat poisonous liquid secretion, or hydrogen cyanide gas, through microscopic pores along the sides of their bodies as a secondary defense. Some of these substances are acidic and can burn the exoskeleton of ants and other insect predators, and the skin and eyes of larger predators. As far as humans are concerned, this chemical brew is fairly harmless, although it should never be eaten or applied to the eyes. Because of this, caution should be used when handling millipedes.
Issue #90 -
Gorgosaurus
Gorgosaurus (Latin for "dragon lizard") is a genus of carnivorous dinosaur that reached 7 to 8 meters (27 to 30 feet) in length, and weighed 2.5 tonnes (2.75 short tons). It was first described by paleontologist Lawrence Morris Lambe in 1914, and has been found in western Canada and the United States. It lived about 70 million years ago in the late Cretaceous period.
Gorgosaurus, Gorgosaurus libratus, at the Royal Tyrrell Museum of Palaeontology
Over 20 Gorgosaurus skeletons have been recovered, making it the most well-represented tyrannosaurid in the fossil record. Generally similar to Tyrannosaurus and most other large tyrannosaurids (such as Daspletosaurus, and Albertosaurus), Gorgosaurus can be described as having a massive head, large curved teeth, tiny two-fingered front limbs, and powerful legs. Compared to the other tyrannosaurids, Gorgosaurus is most similar to its very close relative Albertosaurus.
Although it has been suggested that Gorgosaurus was a scavenger, its co-existence with the similarly sized, but more robust tyrannosaurid Daspletosaurus casts doubt on this theory. Another hypothesis proposes that Gorgosaurus, which was rather lean for a tyrannosaurid, actively hunted fleet-footed animals such as duckbills and ornithomimids ("ostrich-mimic" dinosaurs). According to this proposition, the more troublesome ceratopsians and ankylosaurians (horned and heavily armoured dinosaurs) would have been left to Daspletosaurus.
A juvenile Gorgosaurus
For years, the species Gorgosaurus libratus (the only species of Gorgosaurus currently recognized) was assigned to the Albertosaurus genus. However, recent work done by paleontologists suggest that enough differences exist between G. libratus and the other Albertosaurus species, to justify the original genus name of Gorgosaurus.
Conservation status: Fossil
Issue #91 -
Affenpinscher
The Affenpinscher is a terrier-like toy breed of dog.
Appearance
Weighing 7 to 8 pounds (3-4 kg) and not exceeding 10.25 inches (26-27 cm) in height at the withers, the Affenpinscher has bushy eyebrows, shaggy hair, and a monkey-like appearance. The coat is medium long and is harsh and wiry in texture. The FCI breed standards specifies that the coat must be black, but the AKC also allows gray, silver, red, black and tan, and beige; other clubs have their own lists of acceptable colours, with black always being the preference.
Black is the most common coat colour of the Affenpinscher.
Temperament
The Affenpinscher has a personality that some associate with terriers. They're different from terriers, however, in that they often get along with other dogs and pets. They are active, adventurous, curious, and stubborn, but they are also fun-loving and playful. The breed is confident, lively, affectionate towards family members and also very defensive of them. This friendly little dog enjoys being with its family. It needs consistent, firm training because some can be quite difficult to housebreak. The training should be varied because the dog can easily become bored. This breed learns quickly but its stubbornness might make it difficult to train.
Affenpinschers are somewhat territorial when it comes to their toys and food, so they are not recommended for very small children. This dog is mostly quiet but can become very excited if attacked or threatened and shows no fear toward any aggressor. It is best suited for a family who likes a show and has a sense of humor.
Health
The breed can be expected to live about 14-15 years. It is one of the healthiest breeds, with no known genetic health problems.
History
The breed is European in origin and dates back to the seventeenth century. Its name is derived from the German affe ("ape", "monkey") and pinscher ("terrier"). The breed predates and is ancestral to the Griffon Bruxellois (Brussels Griffon) and Belgian Griffon. Dogs of the Affenpinscher type have been known since about 1600 but these were somewhat larger, about 12 to 13 inches, and came in colors of gray, black, fawn, black and tan, gray and tan, and even red. White feet and chest were also common. The breed was created to be a ratter, working to remove rodents from kitchens, granaries, and stables.
Alternative name: Monkey Dog
Country of origin: Germany
Issue #92 -
Pygmy Hippopotamus
The Pygmy Hippopotamus (Hexaprotodon liberiensis) is a large mammal native to the forests and swamps of western Africa (the species name, meaning "of Liberia", reflects this). It is one of only four animals in the hippopotamus family. Unlike its largest relative, the Hippopotamus, relatively little is known about the Pygmy Hippo's diet or behavior, although it is clear that the Pygmy Hippo is adapted to forest environments rather than the more open plains and grasslands that the Hippopotamus prefers.
Pygmy Hippopotamus, Hexaprotodon liberiensis
Pygmy Hippos stand about 75 cm (30 inches) high at the shoulder and weigh 180 kilograms (400 pounds). They are more solitary than their larger relatives and considerably less aquatic. The skin is greenish-black, shading to a creamy gray on the lower body. The average lifespan is 35 years, and one in captivity reached the age of 42. The gestation period ranges from 190-210 days, and usually a single young is born. Pygmy Hippos live either alone or in small groups, typically a mated pair and one calf.
All species of hippo spend most of their time in the water, emerging mainly at night in order to feed on land. The Pygmy Hippo is half as tall as the Hippopotamus and weighs 1/10 as much as a small member of the larger hippo species. The fossil record suggests that the Pygmy Hippo is closer in form and possibly behavior to the common ancestor.
Issue #93 -
\Originally posted by poon cho tang:For all nature lovers....
Keeps the doctor at bay. Yummy. -
Rhea
Rheas, also known as nandus (pronounced nyandus) are large flightless birds native to South America. The name was given in 1752 by Paul Mohring; his reason for choosing this name, from classical mythology, is not known.
Rhea, genus Rhea
Rheas are polygamous, with males courting between two and twelve females. After mating, the male builds a nest, in which each female lays her eggs. The male incubates from ten to sixty eggs; the chicks hatch within 36 hours of each other. The females, meanwhile, may move on and mate with other males. While caring for the young, the males will charge at anyone — including humans and female rheas — who approaches the chicks.
Rheas are omnivorous, preferring broad-leafed plants, but also eating seeds, roots, fruit, insects, and small vertebrates.
American Rhea
Rhea americanus (called the Gray, Common or American Rhea) is not only the largest species of rhea but the largest American bird, with adults averaging 30 kilograms (66 lb).
The distribution of Rhea americanus
Farmers sometimes consider them pests, because they will eat almost any crop plant. Because of this habit, farmers sometimes kill the birds. This, along with egg gathering and habitat loss, has led to a sharp population decline; the species is listed as being of "special concern." They do not eat most crop plants, but they will eat brassicas (cabbage, and baby chard and bok choi) if very hungry soybean leaves. Rheas disdain grasses.
American Rheas live in grassland, savanna, scrub forest, chaparral, and even desert, but prefer areas with at least some tall vegetation. During breeding season (which ranges from August to January in South America, April to August in North America), they stay near water.
Male rheas are very territorial during breeding season. The infant chicks are highly intolerant of toxins, having high mortality in typical farming situations. Baby chicks under optimum conditions will grow to four feet tall by their fifth month.
Rheas have an incredible immune system that allows injured birds to heal rapidly with little intervention. This is reflected in the commercial uses of the animal. The fat of the birds is used as an anti-inflammatory salve. Use of the meat as an energy supplement is patented in the U.S. and Canada by an American woman who has spent 12 years working to reduce chick mortality and provide a commercial basis for the species, trying to ensure its long-term survival.
The American Rhea is a threatened species as listed in CITES.
Darwin's Rhea
Rhea pennatus (Darwin's Rhea, syn. R. darwini) is 90 to 100 centimeters (3 ft to 3 ft 4 in) tall, and has larger wings than other ratites, enabling it to run particularly well. They can reach speeds of 60 km/hour, enabling them to outrun predators. The strong claws at the end of each wing are effective weapons.
The distribution of Pterocnemia pennatus
The males of this species become aggressive once they are incubating eggs. The females thus lay the later eggs near the nest, rather than in it. Most of the eggs are moved into the nest by the male, but some remain outside, where they rot and attract flies. The male, and later the chicks, eat these flies.
Outside the breeding season, Darwin's rheas are quite sociable: they live in groups of from 5 to 30 birds, of both sexes and a variety of ages.
Darwin's Rhea lives in areas of open scrub in the grasslands of Patagonia and on the Andean plateau. It is classified as endangered throughout its range.
The "Lesser Rhea" (Pterocnemia pennata, formerly R. macrorhyncha) appears to be a synonym for R. darwini.
Conservation status: Vulnerable
Issue #94 -
Gila monster
The Gila monster (Heloderma suspectum) is one of the two known species of venomous lizards. (The other is the Mexican beaded lizard.) The Gila (pronounced heela) monster lives in the deserts of the southwestern USA and northwestern Mexico. It is a heavy, slow moving lizard, up to 60 cm (2 feet) long. Its skin has the appearance of beads in the colours black, pink, orange, and yellow, laid down in intricate patterns across the animal's body.
Gila monster, Heloderma suspectum
Unlike a snake, the Gila monster envenomates its victim not by means of hollow teeth, but through grooves in the teeth of its lower jaw. It produces only small quantities of the neurotoxic venom, which is secreted into the lizard's saliva. By chewing its prey, however, it tries to put as much of the poison into the bloodstream of its victim as possible.
The Gila monster's bite is normally not fatal to humans (there are no reliable reports of fatalities), but it can bite quickly and is known to hold on strongly.
The name "Gila monster" refers to the Gila River Basin in Arizona.
In 2005 the Food and Drug Administration of the United States approved a drug for the management of Type 2 diabetes, Byetta (exenatide), a synthetic version of a protein derived from the Gila monster's saliva.
Subspecies
There exist two subspecies:
-- Heloderma suspectum cinctum, the banded Gila monster
-- Heloderma suspectum suspectum, the reticulate Gila monster
Issue #95 -
Jefferson Salamander
The Jefferson Salamander (Ambystoma jeffersonianum) is a mole salamander native to the north-eastern United States, southern and central Ontario, and south-western Quebec. It was named for Jefferson College in Pennsylvania, which in turn was named for Thomas Jefferson.
Jefferson Salamander, Ambystoma jeffersonianum
It is typically dark gray, brown, or black on its dorsal surface, but a lighter shade on its anterior. Some individuals may also have silver or blue specks on their sides; the area around the vent is usually gray. These salamanders are slender, with a wide nose and distinctive long toes, and range in size from 11 to 18 cm.
Like other mole salamanders, Jefferson Salamanders are burrowers; they have well developed lungs suited for this purpose. Nocturnal by nature, they can be spotted by day during the mating season. Breeding occurs in early spring, after the snow in the area has melted.
Habitat
The secretive adults tend to hide under stones or logs, or in leaf litter and other underbrush in deciduous forests. Migration to their breeding area is quick, since breeding sites are usually close to the over-wintering burrows. The breeding sites they choose are fishless ponds.
Reproduction
Eggs are laid in small agglomerations attached to submerged twigs or other natural support at the pond's edge. Clutches can contain between 5 to 60 eggs, averaging about 30. The age at which they first breed, and the frequency with which they breed are unknown; estimates are that females will first breed at 22 months, and males at 34 months. Eggs develop rapidly, and may hatch within 15 days. Larvae stay in the pond from two to four months, during which time they grow to between 3 and 8 times their hatching size.
The Jefferson Salamander is known to hybridize with the Blue-spotted Salamander. The offspring are always triploid females, possessing two of each chromosome from the Jefferson Salamander and one of each chromsome from the Blue-spotted Salamander. The presence of these triploid hybrids makes it difficult to identify which species an individual may be, skewing population measures for both species.
The triploid females will mate with either species, but any eggs it lays will not incorporate any genetic information from the sperm. Hence, its offspring will also be a triploid female.
Food
The larvae are carnivorous, typically consuming aquatic invertebrates. An insufficient food supply may result in cannibalistic behaviour. Adults are also carnivorous, eating a variety of small invertebrates.
Issue #96 -
Cockchafer
The Cockchafer or "May bug", as it is colloquially called, is a European beetle of the family of the dung beetles, the Scarabaeidae. Once abundant throughout Europe and a major pest in the periodical years of "mass flight", it has been decimated significantly in the middle of the 20th century through extensive use of pesticides and has even been locally exterminated in many regions. However, since a change in pest control beginning in the 1980s, its numbers have started to grow again.
Cockchafer, genus Melolontha
Taxonomy
There are three species of European cockchafers:
-- The Common Cockchafer, Melolontha melolontha (Linnaeus 1758)
-- The Forest Cockchafer, Melolontha hippocastani (Fabricius 1801)
-- Melolontha pectoralis (Megerle von Mühlfeld 1812; or Germar 1824), which is very rare and occurs only in south-western Germany.
Note: there are many more species of Melolontha, but these do not occur in Europe.
The cockchafer should not be confused with the similar European Chafer (Rhizotrogus majalis), which has a completely different life cycle, nor with the June Beetles (Phyllophaga spp.), which are native to North America, nor with the Summer Chafer (or "European June Bug", Amphimallon solstitiale), which emerges in June and has a two-year life cycle. (All of these are Scarabaeidae, have white grubs and are turf pests, too.)
Description
Imagines (i.e. adults) of the Common Cockchafer reach sizes of 25 to 30 mm, the Forest Cockchafer is a bit smaller (20-25 mm). The two species can best be distinguished by the form of their Pygidium (the back end): it is long and slender in the Common Cockchafer, but shorter and knob-shaped at the end in the Forest Cockchafer. Both have a brown colour.
The M. pectoralis looks similar, but its Pygidium is rounded.
Male cockchafers have seven "leaves" on their antennas, whereas the females have only six.
Life cycle
Adults appear at the end of April or in May and live only for about five to seven weeks. After about two weeks, the female begins laying eggs, which she buries about 10 to 20 cm deep in the earth. She may do this several times until she has laid between 60 and 80 eggs. The Common Cockchafer lays its eggs in fields, whereas the Forest Cockchafer stays in the vicinity of the trees. The preferred food for adults are oak leaves, but they will also feed on conifer needles.
The larvae, known as "white grubs" or "chafer grubs", hatch after some four to six weeks. They feed on plant roots, for instance potato roots. The grubs develop in the earth for some three to four years, in colder climates even five years, and grow continually to a size of about 4 to 5 cm, before they pupate in early autumn and develop into a cockchafer in some six weeks.
The cockchafer imagines overwinter in the earth at depths between 20 and 100 cm and work their way to the surface only in spring.
Because of their long development time as larvae, cockchafers appear in a cycle of every three or four years; the years vary from region to region. There is a larger cycle of some 30 years superimposed, in which they occur (or rather, used to occur) in unusually high numbers.
Pest control and History
Both the grubs and the imagines have an enormous appetite and thus were/are a major problem in agriculture and forestry. In pre-industrialized times, the main mechanism to control their numbers was to collect and kill the adult beetles, thereby interrupting the cycle. They were once very abundant: in 1911, more than 20 million individuals were collected in 18 km² of forest.
Collecting adults was an only moderately successful method. In the Middle ages, pest control was rare and people had no effective means to protect their harvest. This gave rise to events that seem completely ludicrous from a modern perspective. In 1320, for instance, cockchafers were brought to court in Avignon and sentenced to withdraw within three days onto a specially designated area, otherwise they'd be outlawed. Of course, the cockchafers didn't obey, and were collected and killed. (Similar trials also occurred for mice.)
In some areas and times, cockchafers even served as food. A 19th century recipe from France for cockchafer soup is handed down to us as "roast 1 pound (500 g) of cockchafers without wings and legs in sizzling butter, then cook them in a chicken soup, add some veal liver and serve with chives on a toast"! And a German newspaper from Fulda from the 1920s tells of students eating sugar-coated cockchafers. Today, only cockchafers made of chocolate are eaten.
Only with the modernization of agriculture in the 20th century and the invention of chemical pesticides did it become possible to effectively combat the cockchafer. Combined with the transformation of many pastures into agricultural land, this has resulted in a decrease of the cockchafer to near-extinction in some areas in Europe in the 1970s. Since then, agriculture has generally reduced its use of pesticides. Because of environmental and public health concerns - pesticides may enter the food chain and thus also the human body - many chemical pesticides have been phased out in the European Union and worldwide. In recent years, the cockchafer's numbers have been increasing again, causing damage to over 1,000 square kilometres of land all over Europe. While this may be due to the reduced use of chemicals, some scientists also argue that, since the cockchafer thrives in warm and dry soils, the current increase in abundance may be related to climate change.
Today, only biological measures are available for control. For instance, pathogenic fungi or nematodes that kill the grubs are applied to the soil.
Issue #97 -
Electric Yellow Cichlid
Electric Yellows (Labidochromis caeruleus) are freshwater perciform fish, peculiar cichlids native to Lake Malawi, Africa. Their bodies are strikingly bright yellow, with males having dark black streaks on their dorsal, pelvic, and ventral fins. While any Labidochromis caeruleus in the aquarium hobby should be the usual bright yellow with black markings, specimens from different areas of Lake Malawi will exhibit different coloring. In fact their quality is determined mostly on appearance, with brighter yellow, less white, and minimal appearance of the bars along their broad side making a better cichlid. Males and females are sexually monomorphic, the only true way to sex them would require examining their vents, while behaviour can provide reliable hints. In their natural habitat, Electric Yellows grow to about 9 cm in length, and have been known to reach 15 cm in captivity.
Electric Yellow, Labidochromis caeruleus
The Electric Yellow is also known as "Lemon Yellow" Labs, the "blue streak hap", the "electric yellow African", and is called the "yellow prince" in the Philippines. They are endemic to the northern coastal region of Lake Malawi, especially the Nkhata Bay area, in East Africa. It has become a popular commercial fish for aquarium enthusiasts.
This species is a Mouthbrooder, meaning the larvae are carried, hatch, and develop in the mother's mouth (buchal pouch), for about four weeks. These fish are breeding ovophiles, whereby the male will excavate a pit in the sand within his territory, in which to deposit his eggs; the female then takes these eggs into her mouth for fertilization.
Electric Yellows are peaceful compared to most other African cichlids. However, due to their aggressive nature toward non-cichlids Electric Yellows can be problematic for many standard freshwater aquarium keepers. In an aquarium setting, these fish thrive when provided numerous hiding places, such as rocks, plants, and caves.
Labidochromis caeruleus prefer water with a pH between 7.8 and 8.9 and a temperature range of 72 - 82 F (22 - 28 C). They prefer to breed in cooler temperature ranges (low 70s). Their diet consists mostly of prepared cichlid pellets or flakes, with supplemented with foods like krill, brineshrimp, spirulina flake, and veggies. A healthy diet and carotene rich foods like krill and spirulina will help your fish, in good lighting, to appear neon-like (hence the name Electric Yellow).
Issue #98 -
California sea slug
The California sea slug (Aplysia californica), also called the California sea hare, is a species of sea hare which belongs to the class Gastropoda in the phylum Mollusca.
It is a very large sea hare, growing to a record length of 75 cm. But most are smaller.
California sea slug, Aplysia californica
The California sea hare is herbivorous. Its diet consists primarily of red and brown seaweed, which gives the animal its typically dark coloration.
Life cycle
Like all sea hares, the California sea hare is hermaphroditic, acting as male and female simultaneously, even during mating. The eggs are yellow, but after 8 to 9 days change into a brown color before hatching into larvae. When this annual animal is laying eggs, it has reached the end of its life. Its lifetime depends somewhat on the temperature of the water: 14-25 degrees Celsius is best, but a somewhat cooler temperature delays spawning and extends its life somewhat.
Laboratory use
Aplysia californica has become a valuable laboratory animal, used in studies of the neurobiology of learning and memory. Its ubiquity in synaptic plasticity studies can be attributed to its simple nervous system, consisting of just a few thousand large, easily-identified neurons. Despite its seemingly simple nervous system, however, Aplysia californica is capable of a variety of non-associative and associative learning tasks, including sensitization, habituation, and classical and operant conditioning. Study typically involves a reduced preparation of the gill and siphon withdrawal reflex.
Issue #99 -
Steller's Sea Cow
The Steller's Sea Cow (Hydrodamalis gigas) is an extinct large sirenian mammal formerly found near the Asiatic coast of the Bering Sea. It was discovered in the Bering Strait in 1741 by the naturalist Georg Steller, who was traveling with the explorer Vitus Bering. A small population lived in the arctic waters around Bering Island and nearby Copper Island.
Steller's Sea Cow, Hydrodamalis gigas. From a drawing circa mid 18th century
The sea cow grew up to 35 feet (10.7 meters) long and weighed up to three-and-a-half tons, much larger than the manatee or dugong. It looked somewhat like a large seal, but had two stout forelimbs and a whale-like tail. According to Steller, "The animal never comes out on shore, but always lives in the water. Its skin is black and thick, like the bark of an old oak..., its head in proportion to the body is small..., it has no teeth, but only two flat white bones—one above, the other below." They fed on a variety of kelp. Wherever sea cows had been feeding, heaps of stalks and roots of kelp were washed ashore.
The population of sea cows was small in number and limited in range when Steller first described them. They were wiped out quickly by the sailors, seal hunters, and fur traders that followed Bering's route past the islands to Alaska, who hunted them both for food and for their skins, which were used to make boats. By 1768, less than 30 years after it had been discovered, the Steller's Sea Cow was extinct.
There are still sporadic reports of sea cow-like animals from the Bering area, however, so it has been suggested that small populations of the animal may have survived to the present day. This remains so far unproven.
Conservation status: Extinct (1768)
Issue #100 -
Ragdoll
The Ragdoll is a breed of longhaired cat. It is best known for its docile and placid temperament and affectionate nature. It is perhaps the gentlest and most easy-going of breeds. The name "Ragdoll" derived from the fact that many of these cats go completely limp and relax when picked up. Ragdolls have a sturdy body, short legs, and a long thick coat with Siamese-style points.
A sealpoint, bicolor Ragdoll
The breed had its origin in California in the 1960s with a cat named Josephine. Several wild and scientifically impossible stories were put out by the colorful breed founder regarding the origin and development of the Ragdoll breed, including extraterrestrials, kittens' traits and personality being affected by the mother's being hit by a car, and genetic alteration using human genes. None of these legends are scientifically supportable.
What is known is that this breed has been selectively bred over many years for desirable traits, such as large size, docility, and ability to go limp in the arms like a rag doll - hence the cat's name. Persians, Birmans, Burmese, and domestics had roles in early breeding programs. There have been attempts to establish several competing ragdoll-type cats, among them the RagaMuffin. Most of these attempted breeds are not recognised as there is little difference between them and the already-recognised Ragdolls, however the Ragamuffin is recognised by several registries.
The Ragdoll is a large, semi-longhaired cat, exhibiting the pointed (Siamese) pattern in three varieties: colorpoint, bicolor, and mitted. They are available in seal, blue, chocolate, and lilac point colors, either with or without markings on the face and feet. In some associations, they are also available in nonstandard colors, such as red and lynx point.
The Ragdoll is a large breed of cat. Adult males can weigh over 20 pounds (9 kg) in adulthood. Their long coats need minimal care.
Because of their good nature, Ragdolls make extremely good family pets, but care must be taken that they are not mishandled by young children.
Country of origin: United States
Issue #101 -
Ring-tailed Lemur
The Ring-tailed Lemur (Lemur catta) is a relatively large prosimian, a lemur belonging to the family Lemuridae. Ring-tailed Lemurs are the only species within the genus Lemur and are found only on the island of Madagascar.
Ring-tailed Lemurs, Lemur catta
Although threatened by habitat destruction and therefore listed as vulnerable by the IUCN Red List, Ring-tailed Lemurs are the most populous lemurs in zoos worldwide; they reproduce readily in captivity.
Physical description
Mostly grey with white underparts, Ring-tailed Lemurs have slender frames; their narrow faces are white with black lozenge-shaped patches around the eyes, and black vulpine muzzles. The lemurs' trademark, their long, bushy tails, are ringed in black and white. Like all lemurs, Ring-tailed Lemurs have hind limbs longer than their forelimbs; their palms and soles are padded with soft, leathery skin and their fingers are slender and dextrous. Ring-tailed Lemurs have claws on the second toe of the hind limb specialized for grooming purposes.
The very young animals have blue eyes while the eyes of adults are all a striking yellow. Adults may reach a body length of 46 centimetres (18 inches) and a weight of 5.5 kilograms (12 pounds). Their tails are longer than their bodies, at up to 56 centimetres (22 inches) in length.
Habitat and diet
Found in the southwest of Madagascar and ranging the farthest into highland areas than any other lemur, Ring-tailed Lemurs inhabit deciduous forests with grass floors, or forests along riverbanks (gallery forests); some may also inhabit dry, open brush where few trees grow. Ring-tailed Lemurs are thought to require primary forest (that is, forests which have remained undisturbed by human activity) in order to survive; such forests are now being cleared at a troubling rate.
While primarily frugivores (fruit-eating), Ring-tailed Lemurs will also eat leaves, seeds, and the odd insect.
Behaviour and reproduction
Ring-tailed lemurs are diurnal and primarily arboreal animals, forming troops of up to 25 individuals. Social hierarchies are determined by sex, with a distinct hierarchy for each gender; females tend to dominate the troop, while males will alternate between troops. The lemurs claim a sizable territory which does not overlap with those of other troops; up to 5.6 kilometres (3.5 miles) of this territory may be covered in a single day's foraging. Despite being arboreal, they spend more time on the ground than any other lemur.
A female Ring-tailed Lemur carrying new-born twins.
Both vocal and olfactory signals are important to Ring-tailed Lemurs' communication: fifteen distinct vocalizations are used. A fatty substance is exuded from glands of the lemurs' anus and armpits, which the lemurs run their tails through; this scent is used by both sexes to mark territory, and to challenge would-be rivals amongst males. The males wave their tails vigorously high in the air in an attempt to overpower the scent of others.
Different alarm calls are given for aerial and terrestrial predators.
The breeding season runs from April to June, with the female in estrous for only one day. Gestation lasts for about 146 days, resulting in a litter of either one or two. The young lemurs begin to eat solid food after two months and are fully weaned after five months. Males reach sexual maturity at 2.5 years and females at just 19.5 months.
The Ring-tailed Lemur's social structure is multimale-multifemale with a single alpha female.
Females are highly dominant; they win all disputes with males.
Synonyms: Maki mococo, Muirhead, 1819
Conservation status: Vulnerable
Issue #102 -
Spotted Dove
The Spotted Dove (Streptopelia chinensis) is a pigeon which is a resident breeding bird in tropical southern Asia from India and Sri Lanka east to south China and Southeast Asia.
Spotted Dove, Streptopelia chinensis
It is a common and widespread species in open woodland, farmland and habitation over a good deal of its natural range, and this successful bird has also been introduced to the US, northern Indonesia, Australia and New Zealand.
This species builds a stick nest in a tree and lays two white eggs. Its flight is quick, with the regular beats and an occasional sharp flick of the wings which are characteristic of pigeons in general.
Spotted Dove is a long-tailed, slim pigeon, typically 33 cm in length. Its back, wings and tail are pale brown, heavily spotted with buff. In flight, it shows blackish flight feathers bordered on the inner edge with pale grey. Sexes are similar, but immatures are duller than adults.
The head and underparts are pinkish, shading to pale grey on the face and lower belly. There is a black neck patch finely spotted with white. The legs are red. The call is a low coo-coo-croo, with the emphasis on last note.
Spotted Doves eat grass seeds, grains and other vegetation. They are fairly terrestrial, foraging on the ground in grasslands and cultivation.
Like some other doves in this genus, they are not particularly gregarious, and are usually alone, or in pairs.
Issue #103 -
Leatherback Sea Turtle
The Leatherback Sea Turtle (Dermochelys coriacea) is the biggest of all turtles alive, reaching a length of 2 metres and a weight of up to 1500 lb (600 kg). One individual male weighed 916 kg, though other turtles of this size are rare. It is found in all tropic and subtropic oceans. It is the only species in the family Dermochelyidae.
Leatherback Sea Turtle, Dermochelys coriacea
This species has many unique features that distinguish it greatly from other sea turtles. Its metabolic rate is approximately 3 times higher than one would expect for a reptile of its size, which, coupled with counter-current heat exchangers and large size, allow it to maintain a body temperature above that of the surrounding water. It also has a shell that lacks the bony scutes of other turtles, being comprised mainly of connective tissue.
Physical Characteristics
The Leatherback is the largest of all the turtles and is very different from other turtles in both appearance and physiology. It has a smooth, blackish carapace with ridges running from head to tail. This shell is not made of bone plates but of soft connective tissue. The carapace does not meet the plastron at a sharp angle like in other turtles, but a gentle curve, giving the animal a semi-cylindrical appearance.
The front flippers of the Leatherback turtle are much larger than those of other turtles, both in proportion and in absolute size. Those of adults can span 270 cm from tip to tip.
The beak of the Leatherback turtle is specially hooked to help it bite jellyfish and its throat has backward-facing barbs to help it swallow them.
Diet
Leatherback turtles subsist on a diet of jellyfish. Because of the translucent nature of its prey, Leatherbacks are often fooled into eating floating plastic debris. Dead leatherbacks have been found with plastic bags, pieces of hard plastic, and monofilament fishing line in their stomachs.
Breeding
Leatherbacks mate at sea; males never leave the water once they enter it as hatchlings. Females mate every three or four years, returning to the beaches where they themselves were hatched to deposit their eggs. One female may lay as many as ten clutches in one breeding season. The interval between laying is about nine days. Mating only occurs after the age of ten years.
After encountering a female (who possibly exudes a pheromone to signal her reproductive status) the leatherback male uses head movements, nuzzling, biting or flipper movements to determine her receptiveness. Marine turtles often face a difficult and sometimes even dangerous task when attempting to reproduce. The male has to mount the female from behind and latch on in order to be able to copulate, but sometimes their shells obstruct this process. Mating can also become dangerous when the male is so desperately overeager to find a mate that he stays underwater for too long, and after encountering the female, he must spend another hour with no air. Fertilization is internal, and multiple males usually mate with a single female. This may be a development evolved to insure against male infertility, eliminate the risk of sperm depletion, allow females to select the highest quality sperm, and increase the genetic variation amongst offspring. However, studies have shown that the process of polyandry in sea turtles actually reduces fertilization success.
Cleavage of the cell begins within hours of fertilization, but development is suspended during the gastrulation period of movements and infoldings of embryonic cells, while the eggs are being laid. Development soon resumes, but the embryos remain extremely susceptible to movement-induced mortality in their nests until the membranes fully develop through the first 20-25 days of incubation, when the structural differentiation of body and organs (organogenesis) soon follows.
Nesting beaches must be comprised of soft sand and have a shallow approach angle from the sea. This is because their soft shells are easily damaged by hard rocks. This is a source of vulnerability for the turtles because these beaches are subject to erosion. Females excavate a nest above the high-tide line with their flippers. They then begin to lay their eggs, producing about 110 ova, 70 of which are large and fertile, the remaining 40 being smaller and sterile. The female carefully back-fills the nest, making sure to disguise it from predators with a scattering of sand.
The eggs hatch in about 60 days. Like some other reptiles, the ambient temperature of the nest determines the gender of the hatchlings. The eggs hatch while still buried under the sand. After nightfall, the hatchlings dig their way to the surface and make their way to the sea. Once the hatchlings reach the ocean they are generally not seen again until maturity. Very few of them survive this mysterious period to become adults. Most hatchlings are eaten by birds or even other reptiles before they have a chance to reach the water. When the lights of a city are visible from a hatching site, Leatherback hatchlings are attracted to the lights and away from the sea. Many of these hatchlings are struck by traffic or otherwise perish.
Atlantic Leatherback Turtles nest between February and July from Georgia in the United States to the U.S. Virgin Islands in the Caribbean.
Range and Habitat
In the summer months, Atlantic Leatherback turtles are most common from the Gulf of Maine in the north to the coast of central Florida in the south. They have also been sighted as far north as the Gulf of St. Lawrence in Canada. Pacific Leatherback turtles are most often seen off the Hawaiian Islands, where they are known to congregate north of the archipelago.
The turtles prefer deep water but are most often spotted within sight of land. In the summer they are frequently seen basking near the surface, particularly in the Long Island Sound, where they have been injured by collisions with boat propellers.
Threats and Conservation
In the United States the Leatherback turtle has been classified as endangered across its range since 1970. It is also listed on Appendix 1 of the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES). This makes it illegal to harm or kill the turtles.
Adult Leatherback turtles are large animals that are not particularly vulnerable to natural predators. Eggs and hatchlings are most vulnerable to predation of all kinds. Birds, dogs, or other opportunists are known to dig up nests and consume eggs. New hatchlings are also vulnerable on their journey from nest to sea. Once they enter the water they become prey to many new predators and very few survive to adulthood.
Human activity endangers Leatherback turtles in many ways. Though it is forbidden, eggs are harvested by people in Puerto Rico, the surrounding islands, and possibly in other places. Development of beaches can disturb or destroy the particular kind of habitat that Leatherbacks need to nest, and the lights of development can cause hatchlings to move away from the sea rather than toward it. Human use of beaches can crush nests and hatchlings or bury eggs too deep for the hatchlings to emerge. Finally humans may disturb nesting females out of curiosity.
While adults are at sea their major threats are all from humans. Ingesting plastic, rubber, tar, oil, and other synthetic materials can kill an adult Leatherback or severly injure it. Many have been injured by colliding with boats, especially in shallow water. The equipment associated with commercial fishing, including lines, nets, ropes, and cables can entangle adult turtles and cause them to drown. Though "Turtle Exclusion Devices" are mandated on nets, they often fail to allow an animal the size of an adult Leatherback to escape. The NOAA estimates that about 640 adult Leatherback turtles are killed each year by commercial fishing enterprise.
Nets are purposely set for other kinds of sea turtles in some areas of Puerto Rico. Though they are not intended for Leatherbacks, some are occasionally caught. Despite its illegality, the practice continues.
Conservation status: Critical
Issue #104 -
Anise Swallowtail
The Anise Swallowtail, Papilio zelicaon, is a common swallowtail butterfly of western North America. Both the upper and lower sides of its wings are black, but the upper wing has a broad yellow stripe across it, which gives the butterfly an overall yellow appearance. There are striking blue spots on the rear edge of the rear wing, and the characteristic tails of the swallowtails. Its wingspan is 7-9 cm. Its body is somewhat shorter than the rather similar Western Tiger Swallowtail, with which its range overlaps; it also lacks the black stripes, converging towards the tail, of the latter. There is a somewhat darker subspecies, Papilio zelicaon nitra, which is rare throughout the range, though somewhat more often found at lower elevations.
Anise Swallowtail, Papilio zelicaon, on the San Francisco Bay Trail in Tiburon, California
The Anise Swallowtail is a butterfly of fairly open country, and is most likely to be seen on bare hills or mountains, in fields or at the roadside. It is often seen in towns, in gardens or vacant lots.
The caterpillar is green, with dark bands spotted with yellow. Its major food plants are members of the carrot family, Apiaceae, (including fennel), and also some members of the citrus family, Rutaceae. Like all swallowtail caterpillars, if disturbed, it will suddenly sprout bright orange osmateria or "stinkhorns" from just behind its head, which give off a foul odor. The caterpillar grows to around 5 cm in length before forming a chrysalis, which is brown or green in colour and about 3 cm long.
The normal range of the Anise Swallowtail extends from British Columbia and North Dakota at its northern extreme, south to the Baja California peninsula and other parts of Mexico. It is occasionally reported from the south-east United States, but its normal range does not extend east of New Mexico, and even in the south-western states it is uncommon in the desert regions. In the southern parts of its range, the adults can be seen year-round, but in the north-west coastal regions, there are two flights, in spring and fall, while in the coldest parts of its range, there is a single flight, between April and July. In all the more northerly parts of the range, the chrysalis hibernates.
Conservation status: Secure
Issue #105 -
Siamese fighting fish
The Siamese fighting fish (Betta splendens) is one of the most popular species of freshwater aquarium fish. It is a member of the gourami family (family Osphronemidae) of order Perciformes, but was formerly classified among the Anabantidae. It is native to the Mekong basin in Southeast Asia.
Siamese fighting fish, Betta splendens
The natural colouration of B. splendens is a dull green and brown, and the fins of wild specimens are relatively short; brilliantly-coloured and longer-finned varieties have, however, been developed by breeders (see In the aquarium, below.)
In the wild, the Siamese fighting fish inhabits standing or slow-moving water, including floodplains and rice paddys, at temperatures of 24–30°C (75–86°F). Carnivorous, it feeds on zooplankton and mosquito and other insect larvae.
B. splendens grows to an overall length of approximately 6 cm (2.5 in), and has a life span of up to two years.
The Siamese fighting fish is often called simply (if imprecisely) by its generic name, which is then treated as a common name ("betta").
Behaviour
Both instinctive and learned behaviours of B. splendens have been studied in considerable detail. Its characteristic aggressive responses are readily elicited by its own reflection in a mirror placed outside an aquarium. The capacity to turn aggressive behaviour on and off in this way, without putting the subject at the risk of physical damage inherent in staging an actual aggressive conflict, made the fish a popular subject of study by ethologists and comparative psychologists interested in studying aggression. There was a stream of research on the fish's aggressive behaviour from the 1970s, though this has reduced lately, partly because of new approaches to studying aggression arising out of sociobiology, and partly because it was realised that, even if no tissue damage was done, repeatedly eliciting aggressive responses in the fish might be a source of stress. Interesting results were obtained, however; for example was shown that the presentation of such an aggression-eliciting stimulus will act as an unconditional stimulus in classical conditioning, and as a reinforcer in operant conditioning. It is as if the fish finds the opportunity to attack another fish rewarding.
In the aquarium
Because of its beautiful colours and fin shapes, the Siamese fighting fish is popular with aquarists. In Asian countries they have long been used in a sport similar to cockfighting, where it was necessary to have aggressive short-finned fish. But today, by selective breeding, it is not uncommon to see males with an array of colors and tails. B. splendens specimens are bred for tail shapes ranging from the common veil-tail to the much-desired 180° "half-moon" tails, while still showing a stunning array of colors: marbled, Cambodian, butterfly, and chocolate are just a few examples.
To keep an individual B. splendens, a minimum tank size of 4 Litres (1 gallon) is recommended, if it will be kept in a warm room. A larger tank of 22 Litres (5 gallons) will allow use of a heater, to maintain a temperature of about 27°C (81°F). The floor of the tank should have, as a minimum, a thin (5 mm or 0.25 in) layer of gravel to increase the surface area for nitrifying bacteria to colonize. Decorations can provide hiding places, especially important when two males are housed in a divided tank, or when the betta is living in a community tank. Every decoration must be free of rough areas or sharp points which can damage the delicate fins of the betta—for this reason, silk rather than plastic plants are recommended. Live plants will improve the water quality.
In Canada and the United States, the Siamese fighting fish is sometimes sold in a vase with a plant, with the erroneous claim that the fish can feed on the roots of the plant. Betta species are carnivorous, though, and an appropriate food must be provided, such as dry "betta pellets" or live or frozen bloodworms or brine shrimp. When kept in a small container such as a vase, the fish need frequent water changes, and the container must be kept in a warm room. A larger tank with a heater will provide better living conditions. Wherever the fish is kept, water must be treated with an appropriate water conditioner before use.
Because of the aggressive nature of this species, tankmates must be chosen carefully, and two male B. splendens should not be housed in the same tank unless they are separated by a dividing wall. Females may or may not be able to coexist peacefully in the same tank depending on their temperaments. Before co-housing Siamese fighting fish with other species, their compatibility should be carefully researched, and the owner should have a back-up plan if the shared tank does not work.
Issue #106 -
Giant clam
The Giant Clam (Tridacna gigas) or traditionally, paÂ’ua, is the largest living bivalve mollusc. One of a number of large clam species native to the shallow coral reefs of the South Pacific and Indian oceans, they weigh an average of 440 pounds and can measure as much as 1.5 meters across.
Giant Clam, Tridacna gigas
Permanently sessile in adulthood, the creature's siphon and mantle tissues act as a habitat for the green algae on which it feeds. By day, its shell remains open unless disturbed, and in this way the symbiotic algae may receive sunlight they need to grow.
History
As is often the case with uncharacteristically large species, the giant clam has been historically misunderstood. Even reputable scientific and technical manuals once claimed that the great mollusk had caused deaths. In those days the Giant clam was also known as killer clam or man-eating clam. Versions of the U.S. Navy Diving Manual even gave detailed instructions for releasing oneself from its grasp by severing the adductor muscles used to close its shell.
Giant clams are the largest of all clam species and can grow until 1.5 meters in length.
Today, it is generally acknowledged that the giant clam is neither aggressive nor particularly dangerous; while it is certainly capable of holding one fast in its grip, the shell's closing action is actually a defensive response, and far too slow to pose any reasonable threat. No account of a human being trapped in this manner has ever been substantiated.
Conservation status
The IUCN lists the giant clams as vulnerable. There is concern among conservationists for the sustainability of practices among those who use the animal as a source of livelihood. The numbers in the wild have been greatly reduced by extensive harvesting for food and aquarium trade. Illegal trade in giant clam shells for use as decorative accoutrements abounds, and the meat, called Himejako in Japan, is prized as a delicacy.
Detail of the mantel of a Giant clam. The mantel contains light sensitive spots and if it senses danger the clam will close.
Conservation status: Vulnerable
Issue #107 -
Diplodocus
Diplodocus (Latin: "double-beam") is a type of dinosaur of subgroup Sauropoda. Diplodocus lived during the Jurassic period. Scientists gave the dinosaur its name due to the way part of its skeleton was formed.
The first Diplodocus skeleton was found at Como Bluff, Wyoming in 1878 and was named Diplodocus longus ("long double-beam") by paleontologist Othniel Marsh. Other species include D. carnegiei (named after Andrew Carnegie) and D. hayi.
A statue of Diplodocus carnegiei
Diplodocus remains have been found in the Western United States of Colorado, Utah, and Wyoming. Fossils of this animal are common, except for the skull, which is often missing from otherwise complete skeletons. The skull was very small compared to the huge size of the animal, which could reach up to 27 m. Instead of the way Diplodocidae were formerly portrayed, with their necks high up in the air, it is now believed by some that the animal could only keep its head very low to the ground (for grazing), and that the very long tail served as a counterbalance for the long neck. Others think the animal could stand on its hind legs.
Species
- D. carnegiei (Hatcher, 1901)
- D. hayi (Holland, 1924)
- D. longus (Marsh, 1878; holotype)
Conservation status: Fossil
Issue #108 -
Basenji
The Basenji is a breed of dog and a member of the sighthound family. The Basenji is a Congolese hunting dog that has no bark, but an odd yodelling sound. Recent DNA analysis confirms that this is one of the oldest breeds of dog. It was officially accepted into the AKC in 1943.
Basenji
Appearance
Basenjis are small, elegant-looking, short-haired dogs with erect ears, tightly curled tail, and graceful neck. Some people equate their appearance to that of a miniature deer. Their forehead is wrinkled, especially when young. Eyes are typically almond shaped, which gives the appearance of squinting with a serious look. It is not uncommon for a Basenji to stare down a person, which gives some people an unsettling feeling. The stare is not meant as an aggressive act; Basenjis feel that they are of equal stature with humans and are not intimidated by a human's interest in them.
Basenjis typically weigh around 20 to 24 pounds (9 to 11 kg) and stand about 17 inches (43 cm) tall at the withers. They are an athletic dog, and are deceptively powerful for their size. They have a graceful, confident gait like a trotting horse, and skim the ground in a "double-suspension gallop" when running flat out at their considerable top speed.
The AKC recognizes the following colorations: red/white, black/white, tricolor (red/black/white), and brindle (black stripes on a background of red)/white. There are additional variations, such as the "trindle", which is a tricolor and brindle, and several other colorations that remain in the Congo.
Tri-colored brindle (Trindle) Basenji at a hunt
Temperament
Most Basenjis have a strong dislike for contact with water, and will go to great, and sometimes amusing, lengths to avoid getting wet. On the other hand, they are extremely curious dogs, and can temporarily be completely oblivious to the pouring rain if something piques their interest. They are highly intelligent and learn quickly, but they also have a cat-like independence and "self-motivation" which can make them somewhat casual about obedience. A healthy Basenji is a mischievous and good-humored animal, and is not above testing the limits of its environment and owner just for sport. They can be aloof with strangers but form strong bonds with their owners. If not supervised or trained properly, Basenjis can become bored and destructive when left alone. Extremely quick and fast on its feet, the Basenji loves to run and chase, so much so that they are sometimes competitively raced in lure courses. There are few creatures the Basenji is likely to encounter (including its owner!) that it does not believe it can either outwit or outrun. This, combined with a virtually fearless approach to the world, make it a good idea not to allow a Basenji to run free in an unconfined area or where it may get into trouble. Basenjis can be very good with children if raised around them, but may not have much patience for them otherwise.
History
The Basenji is one of the most ancient breeds of dog. Originating on the continent of Africa, it has been venerated by humans for thousands of years. Basenjis can be seen on stele in the tombs of Egyptian pharaohs, sitting at the feet of their masters, looking just as they do today, with prick ears and tightly curled tail.
The Basenji had all but disappeared from civilization when it was rediscovered in the Congo region of Africa in 1895. There, the Basenji was highly prized by natives for its intelligence, courage, speed, and silence. They were invaluable assistants to the hunt, chasing wild game into nets for their masters. The Azande and Mangbetu tribes from the northeastern Congo region describe Basenjis, in the trade language of Lingala, as "embwa na bwasenji". Translated, this means "dogs from when we were wild" or "dogs from long ago".
Several attempts were made to bring the breed to England, but the earliest imports succumbed to disease. It was not until the 1930s that foundation stock was successfully established in England, and thence to the United States. So it is that nearly all the Basenjis in the western world are descended from these original imports. For a fascinating account of the importation of the Basenji from Africa, read The History of the Breed, a letter to the AKC in support of opening the stud book to admit new African imports.
Health
Some Basenjis are prone to Fanconi syndrome. Basenjis, along with certain other breeds of dog have been known to be carriers of a simple recessive gene which, when expressed, immediately causes Hemolytic Anemia. When lineage from a fully tested line (set of ancestors) is indefinite: a Basenji can be tested at any time before it is bred.
Alternative names:
- African Bush Dog
- African Barkless Dog
- Ango Angari
- Avuvi
- Congo Dog
- Zande Dog
Country of origin: Congo
Issue #109
