Tuesday, August 31, 2010

August 31, 2010 : Nothosaurus (Extinct)


Nothosaurus 

Nothosaurus (meaning false reptile) is an extinct genus of sauropterygian reptile from the Triassic period, approximately 240-210 million years ago, with fossils being distributed from North Africa and Europe to China. It is the best known member of the nothosaur order.

A complete skeleton of the species Nothosaurus raabi can be seen in the Natural History Museum in Berlin. 

Nothosaurus was a semi-oceanic animal which probably had a lifestyle similar to that of today's seals. It was about 4 metres (13 ft), with long, webbed toes and possibly a fin on its tail. When swimming,
Nothosaurus would use its tail, legs, and webbed feet to propel and steer it through the water. The skull was broad and flat,with long jaws, lined with needle teeth, it probably caught fish and other marine creatures.  Nothosaurus hunted by sneaking up slowly on prey, such as shoals of small fish, then putting on a last-minute burst of speed. Once caught, few animals would be able to shake themselves free from the mouth of Nothosaurus.

In many respects its body structure resembled that of the much later plesiosaurs, but it was not as well adapted to an aquatic environment. It is though that one branch of the nothosaurs may have evolved into plesiosaurs such as Liopleurodon and the long-necked Cryptoclidus.

Monday, August 30, 2010

August 30, 2010 : Bermuda Triangle


Bermuda Triangle

The Bermuda Triangle, also known as the Devil's Triangle, is a region in the western part of the North Atlantic Ocean where a number of aircraft and surface vessels allegedly disappeared mysteriously. Popular culture has attributed these disappearances to the paranormal or activity by extraterrestrial beings. Documented evidence indicates that a significant percentage of the incidents were inaccurately reported or embellished by later authors, and numerous official agencies have stated that the number and nature of disappearances in the region is similar to that in any other area of ocean.

The boundaries of the triangle cover the Straits of Florida, the Bahamas and the entire Caribbean island area and the Atlantic east to the Azores. The more familiar triangular boundary in most written works has as its points somewhere on the Atlantic coast of Miami, San Juan, Puerto Rico; and the mid-Atlantic island of Bermuda, with most of the accidents concentrated along the southern boundary around the Bahamas and the Florida Straits.

The area is one of the most heavily traveled shipping lanes in the world, with ships crossing through it daily for ports in the Americas, Europe, and the Caribbean Islands. Cruise ships are also plentiful, and pleasure craft regularly go back and forth between Florida and the islands. It is also a heavily flown route for commercial and private aircraft heading towards Florida, the Caribbean, and South America from points north.

Sunday, August 29, 2010

August 29, 2010 : Slender Snipe Eel


Slender Snipe Eel

The slender snipe eel, Nemichthys scolopaceus, sometimes referred to as the deep sea duck, is a fish that can weigh only a few ounces, yet reach 5 feet or 1.5 m in length. Features include a bird-like beak with curving tips, covered with tiny hooked teeth, which they use to sweep through the water to catch shrimp and other crustaceans. It has a lifespan of ten years.

It has more vertebrae in its backbone than any other animal, around 750. However, its anus has moved forward during its evolution and is now located on its throat. Its larvae are shaped like leaves, which actually get smaller before transforming into adults.

Many specimens found in museums were spat up from larger fish that were caught in trawls.

Saturday, August 28, 2010

August 28, 2010 : Pigbutt Worm


Pigbutt Worm 

The pigbutt worm or flying buttocks (Chaetopterus pugaporcinus) is a newly discovered species of worm found by scientists at the Monterey Bay Aquarium Research Institute. The worm is round in shape, approximately the size of a hazelnut, and bears a strong resemblance to a disembodied pair of buttocks. Because of this, it was given a Latin species name that roughly translates to "resembling a pig's rear." 

The worm has been recently observed residing just below the oxygen minimum zone between 900 and 1,200 metres (3,000 to 4,000 feet) deep — even when the sea floor is significantly deeper. The worms have also been observed floating with their mouths surrounded by a cloud of mucus. Current theories suggest that they reside in this area of the ocean because of its cornucopia of detritus and marine snow, and that the worms use these mucus clouds to capture particles of food and "snow." 

The worm has a segmented body, but the middle segments are highly inflated, giving the animal a round shape. These morphological characteristics are unique among chaetopterids. It is unknown whether the specimens found to date were adult or larval forms. Their unusual size (five to ten times larger than any known chaetopterid larvae) might indicate they were adults, but all known species of chaetopterid adults live in parchment-like tubes on the sea floor. Comparison to larval morphology has indicated that the specimens have a close relationship to either genus Chaetopterus or genus Mesochaetopterus, and a phylogenetic tree constructed from mitochondrial and ribosomal DNA sequences from twelve different Chaetopteridae worms found them to be most closely related to other worms of the  Chaetopterus genus.

Friday, August 27, 2010

August 27, 2010 : Basking Shark


Basking Shark

The basking shark (Cetorhinus maximus) is the second largest living shark, after the whale shark. It is a cosmopolitan species, found in all the world's temperate oceans. It is a slow moving and generally harmless filter feeder.

This shark is called the basking shark because it is most often observed when feeding at the surface and appears to be basking in the warmer water there. It is the only member of the family Cetorhinidae. Gunnerus was the first to describe and name the species Cetorhinus maximus from a specimen found in Norway. The genus name Cetorhinus comes from the Greek, ketos which means marine monster or whale and rhinos meaning nose, the species name maximus is from Latin and means "greatest". The following centuries featured more attempts at naming: Squalus isodus, in 1819 by Macri; Squalus elephas, by Lesueur in 1822; Squalus rashleighanus, by Couch in 1838; Squalus cetaceus, by Gronow in 1854; Cetorhinus blainvillei by Capello in 1869; Selachus pennantii, by Cornish in 1885; Cetorhinus maximus infanuncula, by Deinse & Adriani 1953; and finally Cetorhinus maximus normani, by Siccardi 1961.

The largest accurately-measured specimen was trapped in a herring net in the Bay of Fundy, Canada in 1851. Its total length was 12.27 metres (40.3 ft), and it weighed an estimated 19 short tons (17 t). There are dubious reports from Norway of three basking sharks over 12 metres (39 ft), the largest at 13.7 metres (45 ft), dubious because few anywhere near that size have been caught in the area since. Normally the basking shark reaches a length of between 6 metres (20 ft) and a little over 8 metres (26 ft). Some specimens surpass 9–10 metres (30–33 ft), but after years of large-scale fishing, specimens of this size have become rare.

Thursday, August 26, 2010

August 26, 2010 : Cavefish


Cavefish

The cavefish (commonly: blindfish, swampfish) is found in caves and adapted to life in the dark. Notably, it lacks functional eyes and pigmentation. There are more than 80 known varieties of cavefish.

Cavefishes are generally small, ranging up to 11 centimetres (4.3 in) in length. Most do not have pelvic fins, although Amblyopsis spelaea has small ones with up to six rays. Externally, they resemble killifishes in many respects, although their internal anatomy more closely resembles the trout-perches, with which they are currently classified.

Although some species have tiny, vestigial, eyes, three have no eyes at all. Cavefishes do, however, have rows of sensory papillae on their skin, which they use to help navigate their lightless environment. The majority of cave fish have little to no pigment in their skin. These features are an example of regressive evolution. Cavefishes can only be found in caves that have streams running into them; a cave with no inlets (such as Blanchard Springs Caverns in Arkansas) will not contain cavefishes. One species, the swampfish Chologaster cornuta, inhabits above-ground swamps, rather than caves.

They are believed to have evolved from their aboveground counterparts.

Wednesday, August 25, 2010

August 25, 2010 : Sea Robin


Sea Robin

Sea robins, also known as gurnard, are bottom-feeding scorpaeniform fishes in the family Triglidae. They get their name from their large pectoral fins, which, when swimming, open and close like a bird's wings in flight.

They are bottom dwelling fish, living at depths of up to 200 m (660 ft). Most species are around 30 to 40 cm (12 to 16 in) in length. They have an unusually solid skull, and many species also possess armored plates on the body. Another distinctive feature is the presence of a "drumming muscle" that makes sounds by beating against the swim bladder. When caught, they make a croaking noise similar to a frog.

Sea robins have six spiny "legs," three on each side. These legs are actually flexible spines that were once part of the pectoral fin. Over time, the spines separated themselves from the rest of the fin, developing into feeler-like "forelegs." The pelvic fins have been thought to let the fish "walk" on the bottom, but are really used to stir up food. The first three rays of the pectoral fins are membrane free and used for chemoreception.

Sea robins have sharp spines on their gill plates and dorsal fins that inject a mild poison, causing slight pain for two to three days.

Tuesday, August 24, 2010

August 24, 2010 : Lancetfish


Lancetfish

Lancetfishes are large oceanic predatory fishes in the genus Alepisaurus ("Scaleless lizard"), the only living genus in the family Alepisauridae.

Lancetfishes grow up to 2 metres (6.6 ft) in length. Very little is known about their biology, even though they are widely distributed in all oceans, except the polar seas. Specimens have been recorded as far north as Greenland. They are often caught as by-catch for vessels long-lining for tuna.

The generic name is from Greek a- meaning "without", lepis meaning "scale", and sauros meaning "lizard".

Lancetfishes possess a long and very high dorsal fin, soft-rayed from end to end, with an adipose fin behind it. The dorsal fin has 41 to 44 rays and occupies the greater length of the back. This fin is rounded in outline, about twice as high as the fish is deep, and can be depressed into a groove along the back. The body is slender, flattened from side to side, deepest at the gill covers, and tapers back to a slender caudal peduncle.

The mouth is wide, gaping to the back of the eye, and each jaw has two or three large fang-like teeth, in addition to numerous smaller teeth. The caudal fin is very deeply forked; its upper lobe is prolonged as a long filament, although most lancetfishes seem to lose this when captured. The anal fin originates under the last dorsal ray, and is deeply concave in outline. The ventral fins are about halfway between the anal and the tip of the snout, while the pectoral fins are considerably longer than the body is deep and are situated very low down on the sides. There are no scales, and the fins are exceedingly fragile.

Monday, August 23, 2010

August 23, 2010 : Sea Serpents (Myth)


Sea Serpents

Sightings of sea serpents have been reported for hundreds of years, and continue to be claimed today. Cryptozoologist Bruce Champagne identified more than 1,200 purported sea serpent sightings. Despite these numerous sightings, no credible physical evidence has been recorded and it is currently believed that the sightings can be best explained as misidentification of known animals such as oarfish and whales. Some cryptozoologists have suggested that the sea serpents are relict plesiosaurs, mosasaurs or other Mesozoic marine reptiles, an idea often associated with lake monsters such as the Loch Ness Monster.

Skeptics and debunkers have questioned the interpretation of sea serpent sightings, suggesting that reports of serpents are misidentifications of things such as cetaceans (whales and dolphins), sea snakes, eels, basking sharks, baleen whales, oarfish, large pinnipeds, seaweed, driftwood, flocks of birds, and giant squid.

While most cryptozoologists recognize that at least some reports are simple misidentifications, they claim that many of the creatures described by those who have seen them look nothing like the known species put forward by skeptics and claim that certain reports stick out. For their part, the skeptics remain unconvinced, pointing out that even in the absence of out-right hoaxes, imagination has a way of twisting and inflating the slightly out-of-the-ordinary until it becomes extraordinary.

Sunday, August 22, 2010

August 22, 2010 : Sea Spiders


Sea Spiders 

Sea spiders, also called Pantopoda or pycnogonids, are marine arthropods of class Pycnogonida. They are cosmopolitan, found especially in the Mediterranean and Caribbean Seas, as well as the Arctic and Antarctic Oceans. There are over 1300 known species, ranging in size from 1 to 10 millimetres (0.039 to 0.39 in) to over 90 cm (35 in) in some deep water species. Most are toward the smaller end of this range in relatively shallow depths, however, they can grow to be quite large in Antarctic waters.

Although "sea spiders" are not true spiders, or even arachnids, their traditional classification as chelicerates would place them closer to true spiders than to other well known arthropod groups, such as insects or crustaceans. However this is in dispute, as genetic evidence suggests they may even be an ancient sister group to all other living arthropods. 

These small animals live in many different parts of the world, from Australia, New Zealand, and the Pacific coast of the United States, to the Mediterranean Sea and the Caribbean Sea, to the north and south poles. They are most common in shallow waters, but can be found as deep as 7,000 metres (23,000 ft), and live in both marine and estuarine habitats. Pycnogonids are well camouflaged beneath the rocks and among the algae that are found along shorelines.

Sea spiders either walk along the bottom with their stilt-like legs or swim just above it using an umbrella pulsing motion. Most are carnivorous and feed on cnidarians, sponges, polychaetes and bryozoans. Sea spiders are generally predators or scavengers. They will often insert their proboscis, a long appendage used for digestion and sucking food into its gut, into a sea anemone and suck out nourishment. The sea anemone, large in comparison to its predator, almost always survives this ordeal.

Saturday, August 21, 2010

August 21, 2010 : Ocean Pout


Ocean Pout 

The ocean pout (Zoarces americanus) is an eelpout in the family Zoarcidae. It is found in the Northwest Atlantic Ocean, off the coast of New England and eastern Canada. The fish has antifreeze proteins in its blood, giving it the ability to survive in near-freezing waters.

Scientists have done studies wherein genes are taken from the ocean pout and implanted into salmon in an attempt to make the latter grow faster. Use of the promoter region from the ocean pout antifreeze protein gene, which regulates when and where the gene will be expressed, allows for the growth hormone gene it is attached to in transgenic salmon to be continually expressed, theoretically allowing for continuous production of growth hormone and thus, bigger fish faster. Controversy has arisen, as some view the altered fish as a potential threat to ordinary salmon if it is ever allowed to enter the wild. Nationwide, chefs, grocers and others have agreed not to sell the new fish over these concerns, though the fish is believed to be safe for human consumption.

In June 2006 the Unilever company announced that it would use genetically modified yeast to grow antifreeze proteins based on a gene from the ocean pout, and use it to improve the consistency and storage properties of its ice cream brands.

Friday, August 20, 2010

August 20, 2010 : Abyssobrotula galatheae


Abyssobrotula galatheae

Abyssobrotula galatheae is a species of cusk eel in the family Ophidiidae, and the only species in its genus. It is the deepest-living fish known; one specimen, trawled from a depth of 8,370 m (27,453 ft) in the Puerto Rico Trench in 1970, holds the record for the deepest fish ever captured. The first examples of this fish were misidentified by Staiger as Bassogigas profundissimus, before being described as a new species by Jørgen Nielsen in 1977. The species name refers to the research ship Galathea, which captured the first specimens.

Though uncommon, this species is known from the tropical and subtropical waters of all oceans. It occurs in the abyssal and hadal zones below a depth of 3,110 m (10,203 ft). It is bottom-dwelling in nature, although one individual has been captured from the water column in the Gulf of Panama. Its diet consists of polychaete worms and crustaceans, such as isopods and amphipods. Reproduction is oviparous, possibly with pelagic eggs floating in a gelatinous mass as in other members of the family. 

A. galatheae has a short head with a downward inflection, a swollen snout, and an inferior mouth. The body is soft, with a tapering tail and loose, transparent skin. Both the body and the head are covered with scales. The teeth are small and pointed, arranged in irregular rows; the two median and single pair of basibranchial (on the most ventral gill arch) tooth patches are distinctive for this species. The eyes are tiny, deep-set, and hidden. They are unlikely to be functional, but there is a well-developed system of sensory pores on its head. The lateral line is only visible on the frontmost part of the body and lacks developed pores.

Externally,
A. galatheae can be distinguished from other deep-sea ophidioids by its long pectoral fins, which contain only 10-11 fin rays each, and its flat, weakly developed opercular spine. The long dorsal and anal fins contain 97-116 and 76-96 rays respectively. The pelvic fins and caudal fin are small and contain 2 and 8 rays respectively. The coloration is yellowish; the branchial cavity is black and the peritoneum dark brown. The skeleton is well-ossified, consistent with a benthic lifestyle; there are 18-21 precaudal vertebrae. It grows to at least 16.5 cm (6.5 in) long.

Thursday, August 19, 2010

August 19, 2010 : Cretoxyrhina (Extinct)


Cretoxyrhina 

Cretoxyrhina mantelli was a large shark that lived during the Cretaceous period, about 100 to 82 million years ago. It was featured in the "Prehistoric Sharks" episode of Paleoworld.

This shark was first identified by a famous Swiss Naturalist, Louis Agassiz in 1843, as Cretoxyhrina mantelli. However, the most complete specimen of this shark was discovered in 1890, by a fossil hunter, Charles H. Sternberg. He published his findings of this specimen in 1907. This specimen comprising nearly complete associated vertebral column and over 250 associated teeth. Such kind of exceptional preservation of fossil sharks is rare because shark's skeleton is made of cartilage, which is not prone to fossilization. Charles dubbed this specimen Oxyrhina mantelli. This specimen represented a 20-foot-long (6.1 m) shark. It was excavated from Hackberry creek, Gove county, Kansas.

In later years, several other specimens have also been found. One such specimen was discovered in 1891 by George Sternberg, and was stored in a Munich museum. This specimen was also reported to be 20 feet long but was destroyed during a bombing raid on Munich in WWII.

This shark had no common name in the early literature (i.e. over 30 synonyms were assigned), and since it fed by slicing up its victims into bite-size pieces, paleontologists, K. Shimada and M. J. Everhart, assigned the title of the Ginsu Shark to Cretoxyhrina mantelli. The word Ginsu refers to slicing and dicing.

The Ginsu shark was the largest shark in its time and was among the chief predators of the seas. Fossil records revealed that it preyed upon a variety of marine animals such as, Mosasaurs, Plesiosaurs, Xiphactinus, and protostegid turtles.

Wednesday, August 18, 2010

August 18, 2010 : Eastern Emerald Elysia


Eastern Emerald Elysia
 

Elysia chlorotica, common name the eastern emerald elysia, is a small-to-medium-sized species of green sea slug, a marine opisthobranch gastropod mollusc. This sea slug superficially resembles a nudibranch, yet it does not belong to that suborder of gastropods. Instead it is a member of the closely-related suborder Sacoglossa. The suborder Sacoglossa are known as the 'sap-sucking Opisthobranchias'. Many members of this group use chloroplasts from the algae they eat; a phenomenon known as kleptoplasty. Elysia chlorotica is one of the "solar-powered sea slugs", utilizing solar energy via chloroplasts from its algal food. It lives in a subcellularendosymbiotic relationship with chloroplasts of the marine heterokont alga Vaucheria litorea. 

Elysia chlorotica feeds on the intertidal algae Vaucheria litorea by puncturing the algal cell wall with its radula. The slug then holds the algal strand firmly in its mouth and, as though it were a straw, sucks out the contents. Instead of digesting the entire cell contents, or passing the contents through its gut unscathed, it retains only the algal chloroplasts, by storing them within its own cells throughout its extensive digestive system. The acquisition of chloroplasts begins immediately following metamorphosis from the veliger stagejuvenile sea slugs begin to feed on the when the Vaucheria litorea cells. Juvenile slugs are brown with red pigment spots until they feed upon the algae, at which point they become green. This is caused by the distribution of the chloroplasts throughout the extensively branched gut. Initially, the slug needs to continually feed upon algae to retain the chloroplasts, but over time the chloroplasts become more stably incorporated into the cells of the gut enabling the slug to remain green without further feeding.

The incorporation of chloroplasts within the cells of Elysia chlorotica allow the slug to capture energy directly from light, as most plants do, through the process known as photosynthesis. This is significantly beneficial for Elysia chlorotica because during time periods where algae is not readily available as a food supply, the Elysia chlorotica can survive for months on the sugars produced through photosynthesischloroplasts. Kept within the slug's own cells, it has been found that the chloroplasts can survive and function for up to nine or even 10 months. In one study performed by their own Elysia chlorotica were deprived of alga ingestion for a period of eight months. After the eight month period, despite the fact that the Elysia chlorotica were less green and more yellowish in colour, the majority of the chloroplasts within the slugs appeared to have remained intact while also maintaining their fine structure. Although Elysia chlorotica are unable to synthesize their own chloroplasts, the ability to maintain the chloroplasts acquired from Vaucheria litorea in a functional state indicates that Elysia chlorotica must possess photosynthesis-supporting genes within its own nuclear genome; most likely acquired through horizontal gene transfer. Since chloroplast DNAproteins required for proper photosynthesis, scientists investigated the alone encodes for just 10% of the Elysia chlorotica genome for potential genes that could support chloroplast survival and photosynthesis. The researchers found a vital algal gene, psbO (a nuclear gene encoding for a manganese-stabilizing protein within the photosystem II complex) in the sea slug's DNA, identical to the algal version. They concluded that the gene was likely to have been acquired through horizontal gene transfer, as it was already present in the eggs and sex cells of Elysia chlorotica.

Tuesday, August 17, 2010

August 17, 2010 : Deep Sea Gigantism


Deep Sea Gigantism


In zoology, deep-sea gigantism, also known as abyssal gigantism, is the tendency for species of crustaceans, invertebrates and other deep-sea-dwelling animals to display a larger size than their shallow-water counterparts. Examples of this phenomenon include the giant isopod, the Japanese spider crab, the king of herrings (an oarfishSeven-arm Octopus, and a number of squid species: the Colossal Squid (up to 14 m in length), the giant squid (up to 13 m), the Robust Clubhook Squid, the Dana Octopus Squid, of up to 12 m), the Galiteuthis phyllura, Kondakovia longimana, and the bigfin squids.

It is not known whether this effect comes about as a result of adaptation for scarcer food resources (therefore delaying sexual maturity and resulting in greater size), greater pressure, or for other reasons. The Blue Planet series posited that larger specimens do well in the abyssal environment due to the advantages in body temperature regulation and a diminished need for constant activity, both inherent in organisms with a lower surface area to mass ratio (see the square-cube law).

One example for which scientists do have an explanation is the giant tube worm. These creatures live off hydrothermal vents, which supply them with enormous amounts of energy.

Monday, August 16, 2010

August 16, 2010 : Harlequin Shrimp


Harlequin Shrimp

Gnathophyllid shrimps (family Gnathophyllidae) are a taxon of tropical shrimp in the superfamily Palaemonoidea. They are colorful and very popular for aquariums. These animals dwell in coral reefs, where they live on a diet of starfish. This animal also has unusual front legs that are shaped like paddles. Harlequin shrimps grow only up to 2 inches.

The genus Hymenocera is sometimes separated to form family Hymenoceridae. Harlequin shrimp are completely reef safe, but should not be kept by beginners. Their diet is solely starfish. They will not harm any other tank inhabitants. Will hide most of the time until a starfish is added to the tank, when they will almost immediately come out from hiding and overpower their prey even at 10 times their size. Their front legs act as a pseudo needle type projection that temporarily paralyzes the prey, enabling the shrimp to flip them over and carry them off.

The shrimp consumes starfish alive. Usually working in pairs, the harlequin will keep the starfish alive by feeding on it for about a week, starting on the starfish's tube feet, until it is completely consumed. The shrimp enjoy fresh starfish, so they will keep their food alive by feeding it while in their captivity. Considering this, it is difficult to keep a constant food supply for this pet.

These shrimp are white or a peachy-cream with vibrantly colored spots or splotches. Harlequin found in and around the Indian Ocean typically have blue or purple splotches, whereas ones in the Pacific region have red and orange splotches.

Sunday, August 15, 2010

August 15, 2010 : Leatherback Turtle


Leatherback Turtle 

The leatherback turtle (
Dermochelys coriacea) is the largest of all living sea turtles and the fourth largest modern reptile behind three crocodilians. It is the only living species in the genus Dermochelys. It can easily be differentiated from other modern sea turtles by its lack of a bony shell. Instead, its carapace is covered by skin and oily flesh. Dermochelys coriacea is the only extant member of the family Dermochelyidae.

Leatherback turtles have the most hydrodynamic body design of any other sea turtle, with a large, teardrop shaped body. A large pair of front flippers power the turtles through the water. Like other sea turtles, the leatherback's flattened forelimbs are adapted for swimming in the open ocean. Claws are absent from both pairs of flippers. The Leatherback's flippers are the largest in proportion to its body among extant sea turtles. Leatherback's front flippers can grow up to 2.7 meters (9 ft) in large specimens, the largest flippers (even in comparison to its body) of any sea turtle. 

The leatherback has several characteristics that distinguish it from other sea turtles. Its most notable feature is the lack of a bony carapace. Instead of scutes, thick, leathery skin with embedded minuscule osteoderms. Seven distinct ridges rise from the carapace, crossing from the anterior to posterior margin of the turtle's back. Leatherbacks are unique among reptiles in that their scales lack β-keratin. The entire turtle's dorsal surface is colored dark grey to black with a scattering of white blotches and spots. Demonstrating countershading, the turtle's underside is lightly colored. 

Instead of teeth, the leatherback turtle has points on the tomium of its upper lip, with backwards spines in its throat to help it swallow food.

Saturday, August 14, 2010

August 14, 2010 : Mimic Octopus


Mimic Octopus

The mimic octopus, Thaumoctopus mimicus, is a species of octopus that has a strong ability to mimic other creatures. It grows up to 60 cm (2 feet) in length. Its normal colouring consists of brown and white stripes or spots.

Living in the tropical seas of South East Asia, it was not discovered officially until 1998, off the coast of Sulawesi. The octopus mimics the physical likeness and movements of more than fifteen different species, including sea snakes, lionfish, flatfish, brittle stars, giant crabs, sea shells, stingrays, flounders, jellyfish, sea anemones, and mantis shrimp. It accomplishes this by contorting its body and arms, and changing colour.

Many octopus species are extremely flexible. For example, one octopus the size of a volleyball can actually squeeze its entire body into a soft drink can. If the mimic octopus has that flexibility, it would explain in part how it mimics other creatures.

Although all octopuses can change colour and texture, and many can blend with the sea floor, appearing as rocks, the mimic octopus is the first octopus species ever observed to impersonate other animals.

Based on observation, the mimic octopus may decide which animal to impersonate depending on local predators. For example, when the octopus was being attacked by damselfish, it was observed that the octopus appeared as a banded sea snake, a damselfish predator. The octopus impersonates the snake by turning black and yellow, burying six of its arms, and waving its other two arms in opposite directions.

The mimic octopus is often confused with Wunderpus photogenicus, another recently discovered species. The Wunderpus can be distinguished by the pattern of strong, fixed white markings on its body.

Friday, August 13, 2010

August 13, 2010 : Jawfish


Jawfish

Opistognathidae (opisto = "behind", gnath = "mouth"), commonly referred to as jawfishes, are classified within Order Perciformes, Suborder Percoidei. They are found throughout shallow reef areas of the Atlantic and Pacific Oceans, and the Gulf of Mexico.

Physically similar to blennies, jawfish are generally smaller-sized fish with an elongated body plan. Their heads, mouths, and eyes are large in size relative to the rest of their bodies. Jawfish possess a single, long dorsal fin with 9-12 spines and a caudal fin that can be either rounded or pointed.

Jawfish typically reside in burrows that they construct in sandy substrate. They will stuff their mouth with sand and spit it out elsewhere, slowly creating a tunnel. Utilizing the protection of these burrows, these fish will hover feeding on plankton or other small organisms, ready to dart back in at the first sign of danger. They are territorial of the area around their burrows.

Jawfish are mouthbrooders meaning that their eggs hatch in their mouths, where the new-born fry are able to be protected from predators.

Thursday, August 12, 2010

August 12, 2010 : Basket Star


Basket Star

Basket stars are a group of brittle stars. They are treated as a suborder Euryalina or order Euryalida. Many of them have characteristic many-branched arms. They generally live in deep sea habitats.The life span in the wild is up to 35 years. They weigh around 11 lbs, or 5 kg. Like other echinoderms, basket stars lack blood and achieve gas exchange via their water vascular system.

The basket stars are the largest ophiuroids with Gorgonocephalus stimpsoni measuring up to 70 cm in arm length with a disk diameter of 14 cm.

Wednesday, August 11, 2010

August 11, 2010 : Leviathan Melvillei (Extinct)


Leviathan Melvillei

Leviathan melvillei is an extinct species of physeteroid whale, which lived during the Miocene epoch.

In November 2008, fossil remains of Leviathan melvillei were discovered in the sediments of Pisco formation at Cerro Colorado, 35 km south-southwest of Ica, Peru. The remains include a partially preserved skull with teeth and mandible. Rotterdam Natural History Museum researcher Klaas Post stumbled across them on the final day of a field trip there in November 2008. Post was part of an international team of researchers, led by Dr Christian de Muizon, director of the Natural History Museum in Paris, and included other palaeontologists from Utrecht University and the natural history museums of Rotterdam, Pisa, Lima and Brussels.

The fossils have been dated at 12–13 million years old and were prepared in Lima, Peru, and are now part of the collection of the Natural History Museum there.

The skull of Leviathan melvillei is 3 metres (10 ft) long. Unlike the modern sperm whale, Physeter macrocephalus, L. melvillei had functional dentition in both of its upper and lower jaws. The jaws of L. melvillei were robust and its temporal fossa was also considerably larger than in the modern-age sperm whale. L. melvillei is one of the largest raptorial predators yet known, with whale experts using the phrase "the biggest tetrapod bite ever found" to explain their find. The teeth of L. melvillei are up to 36 centimetres (1.18 ft) long and are claimed to be the largest of any animal yet known. Larger 'teeth' (tusks) are known - walrus and elephant tusks, for example - but these are not used directly in eating (although, for example, walruses use their teeth to dredge shellfish, before eating them).

Tuesday, August 10, 2010

August 10, 2010 : Piglet Squid


Piglet Squid

The animal, named because of its tuft of bristle-like arms and tentacles and rotund shape, is normally found more than 320 feet (100m) below the surface of the ocean.

Because of its deep water habit, little is known of the behaviour of the squid, although not surprisingly, judging by its body shape, it is known to be a sluggish swimmer.

The squids' bodies are almost completely clear except for some pigment-containing cells, or chromatophores, which give this specimen its distinctive appearance.

Properly called Helicocranchia pfefferi, the animals are also noted for the light producing organs known as photophores located beneath each of their large eyes.

This specimen, about the size of an orange, was collected by the Cabrillo Marine Aquarium where director Mike Schaat managed to capture it on film.

Monday, August 9, 2010

August 9, 2010 : Sea Angel


Sea Angel

Sea angels previously known as one kind of pteropod, are a large group of small swimming sea slugs in six different families. These are pelagic marine opisthobranch gastropod molluscs in the clade Gymnosomata within the larger clade
Heterobranchia.

Sea angels are also sometimes known as "cliones", but this is potentially misleading because the family Clionidae is just one of the families within this clade.

Recent molecular data suggests that the gymnosomata form a sister group to the Thecosomata, other planktonic, weakly- or non-mineralized gastropods, although this long-standing hypothesis has had some recent detractors.

In this clade, the foot of the gastropod has developed into wing-like flapping appendages (
parapodia) and their shells have been lost. These are both adaptations which suit their free-swimming oceanic lives. The adaptations also explain the common name sea angel and the New Latin name of the order; from Greek gymnos meaning "naked" and soma meaning "body."

The other suborder of pteropods, Thecosomata, are superficially similar to sea angels but are not closely related. They have larger, broader parapodia, and most species retain a shell; they are commonly known as sea butterflies.

Sea angels are gelatinous, mostly transparent and very small, with the largest species (
Clione limacina) reaching 5 cm. Clione limacina is a polar species; those found in warmer waters are far smaller. Some species of sea angel feed exclusively on sea butterflies; the angels have terminal mouths with the radula common to mollusks, and tentacles to grasp their prey, sometimes with suckers similar to cephalopods. Their "wings" allow sea angels to swim much faster than the larger (usually fused) wings of sea butterflies.

Sunday, August 8, 2010

August 8, 2010 : Cape Horn


Cape Horn 

Cape Horn island (Dutch: Kaap Hoorn, Spanish: Cabo de Hornos; named after the city of Hoorn in the Netherlands) is the southernmost headland of the Tierra del Fuego archipelago of southern Chile.

Cape Horn is the most southerly point of South America, and marks the northern boundary of the Drake Passage; for many years it was a major milestone on the clipper route, by which sailing ships carried trade around the world. However, the waters around the Cape are particularly hazardous, owing to strong winds, large waves, strong currents and icebergs; these dangers have made it notorious as a sailors' graveyard.

The need for ships to round the Cape Horn was greatly reduced by the opening of the Panama Canal in 1914. However, sailing around the Horn is widely regarded as one of the major challenges in yachting. Thus, a few recreational sailors continue to sail this route, sometimes as part of a circumnavigation of the globe, and almost all of these choosing routes through the channels to the north of the actual Cape (though many take a detour through the islands and anchor to wait for fair weather to actually visit Horn Island or even sail around it to replicate a rounding of this historic point). Several prominent ocean yacht races, notably the Volvo Ocean Race, the VELUX5OCEANS and the Vendée Globe, sail around the world via the Horn, and speed records for round-the-world sailing are recognized for following this route.

Saturday, August 7, 2010

August 7, 2010 : Pearlfish


Pearlfish 

Pearlfish is a general name for a variety of marine fish species in the Carapidae family. Pearlfish have been found in tropical waters of the Atlantic, Indian, and Pacific Oceans at depths up to 2,000 metres (6,600 ft) along oceanic shelves and slopes.

Pearlfish are slender fish, distinguished by having dorsal fin rays that are shorter than their anal fin rays. They have translucent, scaleless bodies reminiscent of eels. The largest pearlfish are about 50 centimetres (20 in) in length. They reproduce by laying oval-shaped eggs, about 1 millimeter in length.

Pearlfish are unusual in that the adults of most species live inside various types of invertebrate. Typically, they live inside clams, starfish or sea squirts, and are simply commensal, not harming their hosts. However, some species are known to be parasitic on sea cucumbers, eating their gonads. Regardless of the habits of the adults, the larvae of pearlfish are free-living among the plankton. Pearlfish larvae can be distinguished by the presence of a long filament in front of their dorsal fin, sometimes with various appendages attached.

Friday, August 6, 2010

August 6, 2010 : Nautilus


Nautilus 

Nautilus (from Greek ναυτίλος, 'sailor') is the common name of marine creatures of cephalopod family Nautilidae, the sole extant family of the superfamily Nautilaceae and of its smaller but near equal suborder, Nautilina. It comprises six living species in two genera, the type of which is the genus Nautilus. Though it more specifically refers to species Nautilus pompilius, the name chambered nautilus is also used for any species of the Nautilidae.

Nautilidae, both extant and extinct, are characterized by involute or slightly evolute shells that are generally smooth, with compressed or depressed whorl sections, straight to sinuous sutures, and a tubular, generally central siphuncle. Having survived relatively unchanged for millions of years, nautiluses represent the only living members of the subclass Nautiloidea, and are often considered "living fossils."

The name "Nautilus" originally referred to the Argonauta, otherwise known as paper nautiluses, because the ancients believed these animals used their two expanded arms as sails (cf. Aristotle Historia Animalium 622b). However, this octopus is not closely related to the Nautiloidea.

Thursday, August 5, 2010

August 5, 2010 : Acorn Worm

Acorn Worm

The Acorn worms or Enteropneusta are a hemichordate class of invertebrates, closely related to the chordates. There are about 70 species of acorn worm in the world, the main species for research being Saccoglossus kowaleski.

All species are infaunal benthos that either may be deposit feeders or suspension feeders. Some of these worms may grow to be very long; one particular species may reach a length of 2.5 meters (almost eight feet), although most acorn worms are much, much smaller.

One genus,
Balanoglossus, is also known as the tongue worm.

Wednesday, August 4, 2010

August 4, 2010 : Giant Barrel Sponge


Giant Barrel Sponge

The Caribbean barrel sponge, Xestospongia muta, is a large and common member of the coral reef communities at depths greater than 10 m, and has been called the “redwood of the deep”. 

Despite its prominence, high biomass and importance to habitat complexity and reef health, very little is know about the basic biology of this massive sponge, including rates of mortality and recruitment, reproduction, growth and age.  Like reef corals, this sponge is subject to bleaching and subsequent mortality.

Tuesday, August 3, 2010

August 3, 2010 : Goblin Shark


Goblin Shark 

The goblin shark, Mitsukurina owstoni, is a deep-sea shark, the sole living species in the family Mitsukurinidae. The most distinctive characteristic of the goblin shark is the unorthodox shape of its head. It has a long, trowel-shaped, beak-like rostrum or snout, much longer than other sharks' snouts. Some other distinguishing characteristics of the shark are the color of its body, which is mostly pink, and its long, protrusible jaws. When the jaws are retracted, the shark resembles a pink grey nurse shark, Carcharias taurus, with an unusually long nose.

Mitsukurina owstoni is found in the deep ocean, far below where the sun's light can reach at depths greater than 200 m. They can be found throughout the world, from Australia in the Pacific Ocean to the Gulf of Mexico in the Atlantic Ocean. They are best known from the waters around Japan, where the species was first discovered.
 

Goblin sharks feed on a variety of organisms that live in deep waters. Among some of their known prey are deep-sea squid, crabs and deep-sea fish. Very little is known about the species' life history and reproductive habits, as encounters with them have been relatively rare. As seemingly rare as they are however, there seems to be no real threat to their populations and so they are not classified as endangered species by the IUCN.

Monday, August 2, 2010

August 2, 2010 : Sarcastic Fringehead



Sarcastic Fringehead 

The sarcastic fringehead (Neoclinus blanchardi) is a ferocious fish which has a large mouth and aggressive territorial behaviour. When two fringeheads have a territorial battle, they wrestle by pressing their distended mouths against each other, as if they were kissing. This allows them to determine which is the larger fish and so dominance is established.

They can be up to 30 cm wide and are mostly scaleless with great pectoral fins and reduced pelvic fins. With highly compressed bodies, some may be so widened as to appear eel-like. They tend to hide inside shells or crevices. After the female spawns under a rock or in clam burrows the male guards the eggs.

They are found in the Pacific, off the coast of North America, from San Francisco, California, to central Baja California and their depth range is from 3 to 73 m.

Sunday, August 1, 2010

August 1, 2010 : Pacific Munitions Dump


Pacific Munitions Dump 

Chemical weapons dumped in deep water five miles south of Pearl Harbor after World War II should remain at the site because moving them could pose more of a threat to people and the environment, the Army said Friday.

Records show the Army dumped 16,000 bombs at the site after the war; each of the bombs contained 73 pounds of the chemical agent mustard.

The spots where the military has dumped chemical weapons off Hawaii are too deep to normally be reached by the public. They're also marked on nautical charts and ships do not trawl in these areas.

The military's Explosives Safety Board believes the safest approach to underwater munitions is to leave them in place and to educate the public about what they should do when they find a shell. However, the board believes weapons that pose an imminent and substantial danger should be removed.

The military used the ocean as a dumping ground for munitions between 1919 and 1970.

Related Articles
: Great Pacific Garbage Patch