Helicoprion
Helicoprion ("Spiral Saw") was a long-lived genus of shark-like cartilaginous fish that first arose in the oceans of the late Carboniferous 280 million years ago, survived the Permian-Triassic Extinction Event, and eventually went extinct during the early Triassic some 225 million years ago.
The only fossils known are the teeth, which were arranged in a fantastic "tooth-whorl" strongly reminiscent of a circular saw. It was not until the discovery of the skull of a relative, Ornithoprion, that it was realized that the tooth-whorl was in the lower jaw. The tooth-whorl represented all of the teeth produced by that individual in the lower jaw, in that as the individual grew, with the older, smaller teeth being moved into the center of the whorl by the appearance of larger, newer teeth. Comparisons with other eugenodontids suggest that Helicoprion may have grown up to 10-15 ft long.
Lumpfish
Lumpsuckers or lumpfish are mostly small scorpaeniform marine fish of the family Cyclopteridae. They are found in the cold waters of the Arctic, North Atlantic, and North Pacific oceans. The greatest number of species are found in the North Pacific.
The family name Cyclopteridae derives from the Greek words κύκλος (kyklos), meaning "circle", and πτέρυξpectoral fins of most of the fish that comprise this family.
Lumpsuckers are named appropriately enough; their portly bodies are nearly spherical with generally drab coloration and lithic patterns. The "sucker" part refers to the fish's modified pelvic fins, which have evolved into adhesive discs (located ventrally, behind the pectoral fins); the fish use these discs to adhere to the substrate. Many species have bony, wart-like tubercles adorning the head and body; these are important taxonomic (pteryx), meaning "wing" or "fin", in reference to the circle-shaped features of the family.
Guitarfish
The guitarfish are a family, Rhinobatidae, of rays. The guitarfish are known for an elongated body with a flattened head and trunk and small ray like wings. The combined range of the various species is tropical, subtropical and temperate waters worldwide. They often travel in large schools.
Adult guitarfish grow to a length of between 1.5 metres (4.9 ft) and 1.8 metres (5.9 ft). These fish are bottom feeders, preferring small crustaceans. Their teeth are small and numerous, usually arranged in 65 or 70 rows. Guitarfish are ovoviviparous, with the young hatching out of the eggs after leaving the mother's body.
Guitarfish have a body form intermediate between those of sharks and rays. The tail has a typical ray-like form, but in many species the head has a triangular, or shovel-like shape, rather than the disc-shape formed by fusion with the pectoral fin found in other rays.
Notable species include the shovelnose guitarfish, Rhinobatos productus.
Mobula Ray
Mobula is a genus of ray in the family Myliobatidae (eagle rays). Their appearance is similar to that of Manta rays, which are in the same family. The Devil fish can attain a disc width of up to 5.2 meters (17 feet) and can probably weigh over a ton , second only to the Manta in size. Despite their size, little is known about this genus.
Mobula rays in the Gulf of California (Sea of Cortez) have been reported to breach as high as 2 metres above the sea.
Tongue-Eating Louse
Cymothoa exigua, or the tongue-eating louse, is a parasitic crustacean of the family Cymothoidae. It tends to be 3 to 4 centimetres (1.2 to 1.6 in) long. This parasite enters through the gills, and then attaches itself at the base of the spotted rose snapper's (Lutjanus guttatus) tongue. It extracts blood through the claws on its front, causing the tongue to atrophy from lack of blood. The parasite then replaces the fish's tongue by attaching its own body to the muscles of the tongue stub. The fish is able to use the parasite just like a normal tongue. It appears that the parasite does not cause any other damage to the host fish. Once C. exigua replaces the tongue, some feed on the host's blood and many others feed on fish mucus. This is the only known case of a parasite functionally replacing a host organ. It is currently believed that C. exigua are not harmful to humans unless picked up alive, in which case they can bite.
There are many species of Cymothoa, but only C. exigua is known to consume and replace its host's tongue.
In 2005, a fish parasitised by what could be Cymothoa exigua was discovered in the United Kingdom. As the parasite is normally found off the coast of California, this led to speculation that the parasite's range may be expanding, However, it is also possible that the isopod traveled from the Gulf of California in the snapper's mouth, and its appearance in the UK is an isolated incident. The animal in question will be put on display in the Horniman Museum.
Crown-of-Thorns Starfish
The crown-of-thorns starfish (Acanthaster planci) is a large nocturnal sea star that preys upon coral polyps. The crown-of-thorns receives its name from venomous thorn-like spines that cover its body.
The crown-of-thorns is endemic to tropical coral reefs in the Red Sea, the Indian Ocean, and the Pacific Ocean. As solitary animals, they feed alone and maintain constant distance between themselves and other members of their species.
The crown-of-thorns is the second largest sea star in the world. Only the Giant Sunstar is larger.
Dolphin Fish
The mahi-mahi (in Hawaiian) (Coryphaena hippurus) commonly known as dolphin-fish. In other languages it is known as rakingo, calitos, maverikos, dorado, or lampuka (in Maltese). These are surface-dwelling ray-finned fish found in off-shore temperate, tropical and subtropical waters worldwide. They are one of only two members of the Coryphaenidae family, the other being the pompano dolphinfish.
The mahi-mahi is not related to the Delphinidae family of mammals whose common name is simply dolphin. The English language adopted the Hawaiian word mahi-mahi without formalizing its spelling. The American Heritage Dictionary, fourth edition, cites the preferred spelling (occurring “more frequently”) as the hyphenated mahi-mahi. The secondary spelling is the single word mahimahi, with the identical Hawaiian word given as the derivative source. But Webster’s Unabridged Dictionary, second edition, reverses this preference order, preferring the single word to the hyphenated version, as does the Oxford English Dictionary (2000 draft entry).
Out of the water, the fish often change color among several hues (giving rise to their Spanish name, dorado maverikos, "golden maverick"), finally fading to a muted yellow-grey upon death.
