Black squirrel

Black squirrel

The black squirrel is a melanistic subgroup of the eastern gray squirrel. Melanism is a development of the dark-colored pigment melanin in the skin or its appendages and is the opposite of albinism. Historically, it was also the medical term for black jaundice. The word melanism is deduced from the Greek: μελανός, meaning “black pigment”.

There are also pure white and pure black squirrels but both are variations of the gray squirrel.”  Biologists surmise that the black fur more readily absorbs the rays of the sun, thereby keeping its owner warmer during cold winters. Selective genetics has given the black squirrel this survival advantage.

As a melanistic variety of the eastern gray squirrel, individual black squirrels can exist wherever grey squirrels live. Grey mating pairs cannot produce black offspring. Gray squirrels have two copies of a normal pigment gene and black squirrels have either one or two copies of a mutant pigment gene. If a black squirrel has two copies of the mutant gene it will be jet black. If it has one copy of a mutant gene and one normal gene it will be brown-black. In areas with high concentrations of black squirrels, mixed litters are common. The black subgroup seems to have been predominant throughout North America prior to the arrival of Europeans in the 16th century, as its dark color helped them hide in old growth forests which tended to be very dense and shaded. As time passed, hunting and deforestation led to biological advantages for grey coloured individuals. Today, the black subgroup is particularly abundant in the northern part of the eastern gray squirrel’s range. This is likely due to the significantly increased cold tolerance of black squirrels which lose less heat than greys. Black squirrels also enjoy concealment advantages in denser northern forests.

Distribution

Large natural populations of black squirrels can be found throughout Ontario and in several parts of Ohio, Maryland, Michigan, Indiana, Virginia, Washington, D.C., Wisconsin, Minnesota, and Pennsylvania. Populations of grey squirrels in which the black subgroup is predominant can be found in these six areas as well as in smaller enclaves in Missouri, New Jersey, Delaware, southern New York, Illinois and Connecticut

Large increase in our rodent population makes us a prime hangout for Eagles, Red-tailed Falcons and the like, as well as the Wiley Fox and other fleet of foot predetators which keeps natures balance in the proper order.

Photo;

JP TP ARTS Studio by Jasper

Attenborough’s long-beaked echidna (Zaglossus attenboroughi)

Looks Aren’t Everything

Attenborough’s long-beaked echidna (Zaglossus attenboroughi)

This animal is one of three species from the genus Zaglossus to occur in New Guinea. It is named in honor of Sir David Attenborough. It was considered extinct until recent expeditions have discovered tracks and locals have reported seeing the creature.

Status:

Given the ongoing anthropogenic disturbance of the Cyclops Mountain forest habitat, this has raised concern that Z. attenboroughi populations may already be endangered or even locally extirpated. However, biological surveys of Papua province are notoriously incomplete; it is possible that the animal still exists there or in related mountain ranges.

The echidna is endangered by hunting and habitat loss. In fact, in the 1900s, it was thought to be extinct until some of their “nose pokes” were found in the mountains of New Guinea. These “nose pokes” are very distinct and represent the echidna’s feeding techniques. This animal is so high in the endangered-species list that locals are being educated on this creature and asked to stop their tradition of hunting and killing it and sharing it with rivals as a peace offering. As reported on July 15, 2007, researchers from EDGE visiting Papua’s Cyclops Mountains had recently discovered burrows and tracks thought to be those of Zaglossus attenboroughi. Furthermore, communication with local people revealed that the species had perhaps been seen as recently as 2005. In 2007, Sir David’s long-beaked echidna was identified as one of the top-10 “focal species” by the Evolutionarily Distinct and Globally Endangered (EDGE) project.

Conservation Proposed:

Attenborough’s long-beaked echidna was believed extinct until EDGE team members uncovered evidence of its continued survival in 2007. The species is likely to be highly threatened and in need of urgent conservation action, which should include working with local communities to raise awareness of the species and enforcing the protection of the Cyclops Mountains Strict Nature Reserve. Further research into the species’ ecology and threats such as hunting pressure, coupled with regular monitoring will help to inform future conservation actions.

Additional research measures include carrying out surveys in areas of suitable habitat in the Foja Range and comparative genetic analysis of all currently recognized long-beaked echidna taxa in order to better understand the evolutionary status and conservation significance of the Cyclops Mountains long-beaked echidna population.

Description:

The species was described from a single damaged specimen collected in the Dutch colonial era (c. 1961), and has apparently not been collected since then

It weighs from 5 to 10 kilograms (11 to 22 lb). It is the smallest member of the genus, being closer in size to the short-beaked echidna than are the other members of the genus. The male is larger than the female, and can be differentiated by the spurs on its hind legs. Found in tropical montane moss forest. Its altitudinal range is approximately 166 to 1,600 m.

Behavior:

Not much is known about the ecology of this species, since its behaviour has never been recorded.

The creature is nocturnal, and can roll up into a spiny ball when it feels threatened, somewhat in the manner of a hedgehog. The echidna is not a social animal, and comes together with its own kind only once a year, in July, to mate. The female will lay the eggs after about eight days, and the babies will stay in the mother’s pouch for around eight weeks or until their spines develop.

Photo credit:

Photo 1

Long-beakedEchidna.jpg ‎(391 × 299 pixels, file size: 50 KB, MIME type: image/jpeg)

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.

Photo 2

Sources:

: http://news.nationalgeographic.com/news/2007/07/070718-echidna.html

http://www.edgeofexistence.org/mammals/species_info.php?id=2

Bongo antelope Boocercus eurycerus

Bongo antelope  Boocercus eurycerus facts

The bongo is known for its graceful, spiraled horns and beautiful striped hide. Timid, well camouflaged, and mostly nocturnal, it is one of Africa’s most mysterious animals. The largest of all forest antelopes, bongos measure up to four feet at the shoulder.

Distribution:

Bongos are found in tropical jungles with dense undergrowth up to an altitude of 4,000 meters (12,800 ft) in Central Africa, with isolated populations in Kenya, and these West African countries: Angola, Benin, Burkina Faso, Cameroon, the Central African Republic, the Republic of the Congo, the Democratic Republic of Congo, the Ivory Coast, Equatorial Guinea, Ethiopia, Gabon, Ghana, Guinea, Guinea-Bissau, Kenya, Liberia, Mali, Niger, Sierra Leone, South Sudan, Togo, and Uganda.

Description:

Bongos are one of the largest of the forest antelopes. In addition to the deep chestnut colour of their coats, they have bright white stripes on their sides to help with camouflage. Adults of both sexes are similar in size. Adult height is about 1.1 to 1.3 m (3.6 to 4.3 ft) at the shoulder and length is 2.15 to 3.15 m (7.1 to 10.3 ft), including a tail of 45–65 cm (18–26 in). Females weigh around 150–235 kg (331–518 lb), while males weigh about 220–405 kg (485–893 lb). Its large size puts it as the third-largest in the Bovidae tribe of Strepsicerotini, behind both the common and greater elands by about 300 kg (660 lb), and above the greater kudu by about 40 kg (88 lb). The pigmentation in the coat rubs off quite easily; anecdotal reports suggest rain running off a bongo may be tinted red with pigment. The smooth coat is marked with 10–15 vertical white-yellow stripes, spread along the back from the base of the neck to the rump. The number of stripes on each side is rarely the same. It also has a short, bristly, and vertical brown ridge of hair along the spine from the shoulder to the rump; the white stripes run into this ridge.

A white chevron appears between the eyes, and two large white spots grace each cheek. Another white chevron occurs where the neck meets the chest. The large ears are to sharpen hearing, and the distinctive coloration may help bongos identify one another in their dark forest habitats. Bongos have no special secretion glands, so rely less on scent to find one another than do other similar antelopes. The lips of a bongo are white, topped with a black muzzle.

Lifestyle

The Bongo is a shy and elusive creature that is seldom seen by people due to it’s highly nocturnal lifestyle. As with many other antelope species, Bongos turn and flee almost immediately when they feel threatened and can disappear quickly into the surrounding forest, running with their horns laid back against their body to prevent them from getting tangled up in the vegetation. Male Bongos are solitary and will only come into contact with other Bongos to breed, whereas although females can be found on their own, they often form herds that can contain up to 50 members and consist of the females and their young (for protection). Bongos produce a variety of different calls so they are able to communicate including grunts, snorts, moos and bleating to warn others of approaching danger or when they are in distress. In many areas throughout their natural range, Bongos have been hunted by people for meat but also became a prize target for big-game trophy hunters which devastated local populations. The biggest impact that people have had on the Bongo though is the fact that vast areas of their natural habitats have disappeared to make room for agriculture and to provide grazing for livestock. This increasing closeness to Humans has led to outbreaks of disease in Bongos, along with severe population declines due to their dwindling habitats and therefore, an increasing lack of both food and suitable forest cover which Bongos heavily rely on.

Status:

The eastern bongo is arguably one of the most threatened large mammals in Africa, with recent estimates numbering less than 140 animals, below a minimum sustainable viable population. The situation is exacerbated because these animals are spread across four isolated populations. Whilst the bongo endangered species program can be viewed as having been successful in ensuring survival of this species in Europe, it has not yet become actively involved in the conservation of this species in the wild in a coordinated fashion. The plan is to engage in conservation activities in Kenya to assist in reversing the decline of the eastern bongo populations and genetic diversity in Africa, and in particular, applying population management expertise to help ensure the persistence of genetic diversity in the free ranging wild populations. To illustrate significance of genetic diversity loss, assume the average metapopulation size is 35 animals based on 140 animals spread across four populations (140/4=35). Assuming stable populations, these populations will lose 8% of their genetic diversity every decade. By managing all four populations as one, through strategic transfers, gene loss is reduced from 8% to 2% per decade, without any increase in bongo numbers in Kenya. By managing the European and African populations as one – by strategic exports from Europe combined with in situ transfers, gene loss is reduced to 0.72% every 100 years, with both populations remaining stable. If populations in Kenya are allowed to grow through the implementation of effective conservation, including strategic transfers, gene loss can be effectively halted in this species and its future secured in the wild.

In 2002, the IUCN, listed the western/lowland species as Near Threatened. These bongos may be endangered due to human environmental interaction, as well as hunting and illegal actions towards wildlife. CITES lists bongos as an Appendix III species, only regulating their exportation from a single country, Ghana. It is not protected by the US Endangered Species Act and is not listed by the USFWS. The IUCN Antelope Specialist Group considers the western or lowland bongo, T. e. eurycerus, to be Lower Risk (Near Threatened), and the eastern or mountain bongo, T. e. isaaci, of Kenya, to be Critically Endangered. Other subspecific names have been used, but their validity has not been tested.

Sources:

Photo credit :

Photo by Greg Hume P-1 Photo by Bodlina P-2

http://en.wikipedia.org/wiki/File:TragelaphusBongo.jpg

Blue crab facts

Blue crab

The Chesapeake blue crab or Atlantic blue crab, Callinectes sapidus

The blue swimmer crab, Portunus pelagicus

The blue king crab, Paralithodes platypus

The Japanese blue crab, Portunus trituberculatus

The blue crab is so named because of its sapphire-tinted claws. Its shell, or carapace, is actually a mottled brownish color, and mature females have red highlights on the tips of their pincers. Prized by humans for their sweet, tender meat, these wide-ranging, ten-legged crustaceans are among the most heavily harvested creatures on the planet. Their scientific name, Callinectes sapidus, means “savory beautiful swimmer.”

Blue crabs are found in brackish coastal lagoons and estuaries from Nova Scotia, through the Gulf of Mexico, and as far south as Uruguay. Close relatives of the shrimp and lobster, these bottom-dwelling omnivores have a prickly disposition and are quick to use their sharp front pincers. Large males can reach 9 inches (23 centimeters) in shell width.

They feed on almost anything they can get hold of, including mussels, snails, fish, plants, and even carrion and smaller blue crabs. They are also excellent swimmers, with specially adapted hind appendages shaped like paddles.

Atlantic blue crab  (Callinectes sapidus)

Atlantic blue crab, or the Chesapeake blue crab, is a species of crab native to the waters of the western Atlantic Ocean and the Gulf of Mexico, and introduced internationally.  Callinectes sapidus may grow to a carapace width of 230 mm (9.1 in). It can be distinguished from a related species occurring in the same area by the number of frontal teeth on the carapace; C. sapidus has four, while C. ornatus has six

After showing signs of a big comeback, the Chesapeake Bay’s blue crab population has plunged by more than half. The results of a winter survey, released Friday, showed that crab numbers fell 61 percent, from an estimated 765 million last year to 300 million crabs in 2013 — the lowest number in five years.

Virginia and Maryland have been working hard to bring crabs back, and largely succeeding, since the population nearly crashed in 2007, prompting a federal disaster declaration. Officials called the latest findings disappointing, but they emphasized that crab numbers fluctuate a lot naturally.

Crabs responded quickly. The population jumped from an estimated 251 million in 2007 to last year’s 765 million — the highest total since the early 1990s.

Conservation efforts

Unique expertise and facilities for broodstock, hatchery and juvenile production of blue crabs. ARC is a 1,800-square-meter, state-of-the-art, environmentally responsible marine core facility that operates on recirculating artificial seawater. The Gulf Coast Marine Life Center will implement and build upon their infrastructure and technologies to successfully mass-produce blue crab juveniles for stock enhancement efforts along the Gulf coast region. The University of Maryland (ARC) has published abundant amount of information on the effective stock enhancement, including releasing large batches of individually tagged juvenile hatchery crab and monitoring them through DNA fingerprinting as well as developing optimal release strategies. Studies leading to a better understanding of the Blue Crab biology and life cycle are helping wildlife officials develop new policies for managing this economically vital fishery.

University of Maryland Institute of Marine and Environmental Technology’s Aquaculture Research Center (ARC

The blue swimmer crab, Portunus pelagicus

Portunus pelagicus, also known as the flower crab, blue crab, blue swimmer crab, blue manna crab or sand crab, and alimasag in Tagalog, is a large crab found in the intertidal estuaries of the Indian and Pacific Oceans (Asian coasts) and the Middle-Eastern coast of the Mediterranean Sea. The name “flower crab” is used in east Asian countries while the latter names are used in Australia. The crabs are widely distributed in eastern Africa, Southeast Asia, East Asia, Australia, Persian Gulf and New Zealand. The males are bright blue in colour with white spots and with characteristically long chelipeds, while the females have a duller green/brown, with a more rounded carapace. The carapace can be up to 20 centimetres (7.9 in) wide.

They stay buried under sand or mud most of the time, particularly during the daytime and winter, which may explain their high tolerance to ammonium (NH4+) and ammonia (NH3). They come out to feed during high tide on various organisms such as bivalves, fish and, to a lesser extent, macroalgae. They are excellent swimmers, largely due to a pair of flattened legs that resemble paddles. However, in contrast to another portunid crab (Scylla serrata), they cannot survive for long periods out of the water.

1. pelagicus commonly enters estuaries for food and shelter. Its life cycle is dependent on estuaries as the larvae and early juveniles use these habitats for growth and development. Prior to hatching, the female moves into shallow marine habitats, releases her eggs and the newly hatched zoea I larvae move into estuaries. During this time they feed on microscopic plankton and progress from the zoea I stage to the zoea IV stage (approximately 8 days) and then to the final larval stage of megalopa (duration of 4–6 days). This larval stage is characterised by having large chelipeds used to catch prey. Once the megalopa metamorphoses to the crab stage they continue to spend time in estuaries which provides a suitable habitat for shelter and food. However, evidence has shown that early juveniles cannot tolerate low salinities for extended periods, which is likely due to its weak hyper-osmoregulatory abilities. This may explain their mass emigration from estuaries to seawater during the rainy season. Male Portunus pelagicus are believed to become more territorial in colder water. This may explain why male crabs are rarely sighted within a close proximity to each other in more temperate waters; it also may explain why their female counterparts seem more prolific in these such areas.

The blue king crab  Paralithodes platypus

Species of king crab which lives near St. Matthew Island, the Pribilof Islands, and the Diomede Islands, Alaska, with further populations along the coasts of Japan and Russia. Blue king crabs from the Pribilof Islands are the largest of all the king crabs, sometimes exceeding 18 pounds (8.2 kg) in weight.

Commercial blue king crab harvest around the eastern Bering Sea began in the mid-1960s and peaked in 1981 with a catch of 13,228,000 pounds (6,000 t). The Pribilof Island harvest by the United States peaked in 1980 at 10,935,000 lb (4,960 t) and was closed in 1988 due to population decline, then again in 1999 after being opened for three years. The St. Matthew fishery peaked in 1983 with 9,453,500 lb (4,288.0 t) but experienced a similar decline and was closed in 1999. It was opened in 2009, and was featured on the television show Deadliest Catch. The St. Matthew stock is rebuilding but the fishery remains closed, while the Pribilof stock has not drastically improved.  Diomede blue king crabs have never been harvested commercially, but support a subsistence fishery for the Native Village of Diomede, Alaska, population 170.

Colder water slows the rate of crab growth and crabs at northern latitudes are often smaller than more southern crabs. Commercial harvest of blue king crabs at the Pribilof Islands is limited to males with a carapace width (CW) over 6.5 inches (170 mm) and St. Matthew Island is limited to crabs with CW greater than 5.5 in (140 mm), corresponding to crabs over 4.7 in (120 mm) carapace length (CL). Diomede blue king crabs are similar in size to St. Matthew Island crabs.

Pribilof Island blue king crabs mate and produce eggs in late March to early May. Females generally brood their eggs externally for 12–14 months. Since blue king crabs need more than a year to brood their eggs, they miss a breeding cycle just before the larvae hatch and only produce eggs every other year, although first-time breeders can often produce eggs in subsequent years. Females release larvae around the middle of April in the Pribilof Islands, while those held at warmer temperatures in the laboratory may release larvae as early as February.

Female blue king crabs in the Pribilof Islands grow to the largest size before they are reproductively mature. About 50% of crabs are mature at 5 in (130 mm) CL. St. Matthew Island females can become sexually mature at 3 in (76 mm) CL and Diomede crabs are similar. Larger female crabs from the Pribilof Islands have the highest fecundity, producing 162,360 eggs or 110,033 larvae per crab. The reduction in fecundity is about 33% between the egg and larval stages. In Japan, an average of 120,000 larvae were released from each blue king crab. Diomede blue king crabs release an average of 60,000 larvae per female.

Environmental variables, such as tides, temperature, salinity, light, phytoplankton blooms, and predation, are seasonally pulsed and likely serve as cues for larval release. Release of larvae over a longer period may serve to give the female a larger window for larvae to correspond with any favorable environmental conditions that may exist, also known as “bet-hedging”. In the laboratory, Pribilof larvae hatch over the course of about one month, and Diomede larvae hatch over the course of 2–3 weeks. These differences may be due to water temperature in the laboratory, which has a clear effect on embryonic and larval development, and is probably slightly different from hatch timing in a natural environment.

The Japanese blue crab, Portunus trituberculatus

Portunus trituberculatus, the gazami crab, Japanese blue crab or horse crab, is the most widely fished species of crab in the world. It is found off the coasts of East Asia and is closely related to Portunus pelagicus.

The carapace may reach 15 centimetres (5.9 in) wide, and 7 cm (2.8 in) from front to back. P. trituberculatus may be distinguished from the closely related (and also widely fished) P. pelagicus by the number of broad teeth on the front of the carapace (3 in P. trituberculatus, 4 in P. pelagicus) and on the inner margin of the merus (4 in P. trituberculatus, 3 in P. pelagicus).  Carapace rough to granulose with regions discernible.  Front with 3 acutely triangular teeth with the central projected slightly forwards of the lateral ones; 9 teeeth on each anterolateral margin, the most external one much larger than the preceding.  Chelipeds elongate: larger chelae with conical tooth at the base of fingers; 4 spines on the inner margin of the merus. Legs laterally flattened to variyng degrees, last 2 segments of last pair paddle-like.  Carapace colour dull green to brown.

1. trituberculatus is the world’s most heavily fished crab species, with over 300,000 tonnes being caught annually, 98% of it off the coast of China.

Sources

http://www.nationalgeographic.com/

http://www.gcmlc.com/index.php

http://www.fao.org/fi/website/FIRetrieveAction.do?dom=topic&fid=3380&lang=en

Photo credit

http://en.wikipedia.org/wiki/

The Star-Nosed Mole (Condylura cristata)

The Star-Nosed Mole (Condylura cristata)

Star-nosed mole is a small mole found in wet low areas of eastern Canada and the northeastern United States, with records extending along the Atlantic coast as far as extreme southeastern Georgia. The star-nosed mole is easily identified by the twenty-two pink fleshy appendages ringing its snout, which is used as a touch organ with more than 25,000 minute sensory receptors, known as Eimer’s organs, with which this hamster-sized mole feels its way around. With the help of its Eimer’s organs, it may be perfectly poised to detect seismic wave vibrations.

The star-nosed mole is covered in thick, blackish-brown, water-repellent fur, and has large, scaled feet and a long, thick tail, which appears to function as a fat storage reserve for the spring breeding season. Adults are 15 to 20 cm (5.9 to 7.9 in) in length, weigh about 55 grams (2 oz), and have 44 teeth. The mole’s most distinctive feature is a circle of 22 mobile, pink, fleshy tentacles (called rays) at the end of its snout, from which it derives its name. These are used to identify food by touch, such as worms, insects and crustaceans.

It is a good swimmer and can forage along the bottoms of streams and ponds. Like other moles, this animal digs shallow surface tunnels for foraging; often, these tunnels exit underwater. It is active day and night and remains active in winter, when it has been observed tunneling through the snow and swimming in ice-covered streams. Little is known about the social behavior of the species, but it is suspected to be colonial.

The star-nosed mole mates in late winter or early spring, and the female has one litter of typically four or five young in late spring or early summer. However, females are known to have a second litter if their first is unsuccessful. At birth, each offspring is about 5 cm (2 in) long, hairless, and weighs about 1.5 g. Their eyes, ears, and star are all sealed, only opening and becoming useful about 14 days after birth. They become independent after about 30 days, and are fully mature after 10 months. Predators include the red-tailed hawk, great horned owl, various skunks and mustelids, and large fish, as well as domestic cats.

Vanderbilt University neuroscientist Kenneth Catania, who has studied star-nosed moles for 20 years, recently turned his research to the study of star-moles as a route to understanding general principles about how human brains process and represent sensory information. He called star-moles “a gold mine for discoveries about brains and behavior in general—and an unending source of surprises”.

Comparing the mole’s snout to vision, his research showed that whenever the mole touched potential food it made a sudden movement to position the smallest rays, the twin rays number 11, over the object for repeated rapid touches. He reports: “The similarities with vision were striking. The star movements resembled saccadic eye movements—quick movements of the eyes from one focus point to another—in their speed and time-course. The two 11th rays are over-represented in primary somatosensory cortex relative to their size, just as the small visual fovea in primates—a small region in the center of the eye that yields the sharpest vision—is over-represented in primary visual cortex.” He notes that some bats also have an auditory fovea for processing important echolocation frequencies, suggesting that “evolution has repeatedly come to the same solution for constructing a high-acuity sensory system: subdivide the sensory surface into a large, lower-resolution periphery for scanning a wide range of stimuli, and a small, high-resolution area that can be focused on objects of importance”

Based on the circular organization of the nerve endings and its innervation pattern in Eimer’s organs, Marasco proposed by mapping experiments that nearly all receptors in the star-nosed mole have a preference for a particular direction of applied stimuli. Thus, while one receptor elicits a strong response if compressed in one direction, it may stay “silent” when compressed in another one.

Evolution[edit]

The development of the star-like appendages suggests precursors with proto-appendages on an ancestor’s snout which became elevated over successive generations. Although this theory lacks fossil evidence or supporting comparative data, nearly all extant moles have sheets of the Eimer’s organ making up the epidermis of their snout around the nares. Also, recent studies of Catania and colleagues identified one North American species (Scapanus townsendi) with a set of proto-appendages extending caudally on the snout which exhibit a striking resemblance to the embryonic stages of the star-nosed mole, although Scapanus townsendii has only eight subdivisions on its face rather than the 22 appendages found on the star-nosed mole. Such change is of common occurrence in evolution and is explained by the advantage of efficiently adding modules to the body plan without need to reinvent the regulatory elements which produce each module. Thus, although the star is unique in its shape and size, it seems feasible that the structure is based on a more ancestral bauplan as it comprises similarities found in a wide range of other moles and also in the molecular structure of other mammals.

The picture which emerges suggests that the star-nosed mole is an extreme in mammalian evolution, having perhaps the most sensitive mechanosensory system to be found amongst the mammals.[13] The evolutionary process which led to elaboration of this star-like nose is based on two theories. One proposes the development of the structure of the star as a consequence of the selective pressure of the star-nosed mole’s wetland habitat. Wetlands have a dense population of small insects, so exploiting this resource requires a higher resolution sensory surface than that of other moles. Thus, a shift to the wetland environment may have provided a selective advantage for a more elaborate sensory structure. Furthermore, in wild caught moles of many species, the Eimer’s organs show obvious signs of wear and abrasion. It appears that constant and repeated contact with the soil damages the sensory organs, which have a thin keratinized epidermis. Star-nosed moles are the only species which live in the moist, muddy soil of wetlands where the less abrasive environment has allowed the delicate star-shaped structure to evolve.

The sea pig – Scotoplanes (Scotoplanes globosa)

The sea pig – Scotoplanes (Scotoplanes globosa)

Scotoplanes globosa, ~3000 m below surface in outer portion of Monterey Canyon off coast of central California (USA)

The sea pig is a genus of deep-sea holothurian echinoderm of the family Elpidiidae, order Elasipodida.

The 7,000 species of echinoderms that live in today’s oceans also include the starfish, sea urchins, brittle stars, and sea lilies. The 1,500 species of sea cucumbers, or holothurians, can be found in all oceans and at all depths, in a great variety of habitats – some burrow deep into mud or sand, while others may spend their entire lives swimming in midwater. It is in the dark reaches of the deep sea where the sea cucumbers rule. Here, a group known as the elasipods, of which Scotoplanes globosa is an example, can be found in enormous numbers (Dave Pawson, in litt. December 2009).

The bizarre deep-sea sea cucumbers were first described in wonderful detail by Swedish zoologist Hjalmar Théel in 1882, when he wrote a monograph of the astonishing collections amassed by the British research ship HMS Challenger in her round-the-world cruise of 1872-1876. Théel described about 65 new species which he placed in a new Order, the Elasipoda. The so-called elasipods are restricted to deep and cold parts of the world ocean, where they are the dominant large animals in most areas, often comprising more than 95% of the total weight of animals on the deep-sea floor. They are of great importance in the general economy of the deep sea, for as they feed on sediments, and move along on the seafloor, they introduce oxygen into the sediments, thus making them habitable by myriad small animals (Dave Pawson, in litt. December 2009).

Members of the Elpidiidae have particularly enlarged tube feet that have taken on a leg-like appearance, and are the only instance of legged locomotion amongst the holothurians, using water cavities within the skin (rather than within the leg itself) to inflate and deflate the appendages. These legs, in conjunction with their large, plump appearance (about 6 inches/15 cm long) have suggested the common name “sea pig”. There are other genera of Elpidiidae with a similar appearance that have also been referred to as “sea pigs”.

Scotoplanes live on deep ocean bottoms, specifically on the abyssal plain in the Atlantic, Pacific and Indian Ocean, typically at depths of over 1000 meters. Some related species can be found in the Antarctic. Scotoplanes (and all deep-sea holothurians) are deposit feeders, and obtain food by extracting organic particles from deep-sea mud. Scotoplanes globosa has been observed to demonstrate strong preferences for rich, organic food that has freshly fallen from the ocean’s surface, and uses olfaction to locate preferred food sources such as whale corpses.

Scotoplanes, like many sea cucumbers, often occur in huge densities, sometimes numbering in the hundreds when observed. Early collections have recorded 300 to 600 individual specimens per trawl. Sea pigs are also known to host different parasitic invertebrates, including gastropods (snails) and small tanaid crustaceans.

The main threat against Scotoplanes is deep-sea trawling. A single trawler sweep can catch and kill as many as 300 Scotoplanes. Since these animals make up a substantial part of the nutrition of deep-sea predators, this bycatch represents a serious threat to deep-sea life. A secondary threat to “scotoplanes” is the consumption of the creature in areas of Japan where they are considered a delicacy. The large, plump bodies have been associated with the taste of chicken.

http://echinoblog.blogspot.ca/

http://eol.org/

http://blogspotarchive.blogspot.com/2009/07/echinoblog.html.