Physical World/Fish

	Hammerhead shark family Sphyrnidae So named for the unusual and distinctive structure of their heads, which are flattened and laterally extended into a hammer shape called a cephalofoil. The positioning of the eyes, mounted on the sides of the shark's distinctive hammer head give the shark good 360-degree vision in the vertical plane
	Wobbegong family Orectolobidae 12 species of carpet sharks Wobbegongs spend much of their time resting on the sea floor. They are well camouflaged with a symmetrical pattern of bold markings which resembles a carpet
	Whale shark Rhincodon typus A slow-moving filter feeding shark and the largest known extant fish species Their skin is marked with pale yellow spots and stripes which are unique to each individual
	Basking shark Cetorhinus maximus The second largest fish, after the whale shark. It is found in all the world's temperate oceans, and is a slow moving and generally harmless filter feeder. Known for its greatly enlarged mouth
	Thresher shark genus Alopias Named for and easily recognised by its exceptionally long, thresher-like tail or caudal fins which it lashes to stun prey
	Stingray suborder Myliobatoidei Most stingrays have one or more barbed stingers on the tail, which are used exclusively in self-defence. Fatal stings are very rare, but can happen, most famously in the death of Steve Irwin in 2006
	Manta ray genus Manta Manta ray is the largest of the rays and has the largest brain of any fish. It is in the family of eagle rays. Giant oceanic manta ray (pictured) can grow to a width of 7 m
	Moray eel family Muraenidae Moray eels are the only animals that use pharyngeal jaws (a second set of jaws) to actively capture and restrain prey. Most species lack pectoral and pelvic fins
	Electric eel Electrophorus electricus Capable of generating powerful electric shocks of up to 600 volts. Despite its name, it is not an eel, but rather a knifefish
	Giant oarfish Regalecus glesne Also called the king of herrings, it is the world's longest bony fish. Its shape is ribbon-like, narrow laterally, with a dorsal fin along its entire length
	Ocean sunfish Mola mola The world's heaviest bony fish, it can weigh up to 1000 kg. Sunfish can be as tall as they are long when their dorsal and ventral fins are extended
	Sailfish genus Istiophorus Sailfishes have a characteristic sail (dorsal fin) on top, which often stretches the entire length of the back. Another notable characteristic is the elongated bill, resembling that of a swordfish. Individuals have been clocked at speeds of up to 68 mph, making them the fastest fish in the ocean
	Swordfish Xiphias gladius Contrary to popular belief, the "sword" is not used to spear, but instead may be used to slash at its prey to injure the prey animal, to make for an easier catch. Mainly, the swordfish relies on its great speed and agility in the water to catch its prey
	Barracuda genus Sphyraena Known for its large size and fearsome appearance. Barracudas are snake-like in appearance, with prominent, sharp-edged, fang-like teeth. Known as the "tiger of the sea"
	Grouper subfamily Epinephelinae Groupers are teleosts, typically having a stout body and a large mouth. They are mostly protogynous hermaphrodites, i.e. they mature only as females and have the ability to change sex after sexual maturity
	Tarpon genus Megalops One of the great saltwater game fishes. They are prized not only because of their great size, but also because of the fight they put up and their spectacular leaping ability
	Anglerfish order Lophiiformes They are bony fishes named for their characteristic mode of predation, in which a fleshy growth from the fish's head (the esca or illicium) acts as a lure. Some deep-sea anglerfish emit light from their escae to attract prey
	Archerfish Family Toxotidae Known for their habit of preying on land-based insects and other small animals by shooting them down with water droplets from their specialized mouths
	Pufferfish Family Tetraodontidae Generally believed to be the second-most poisonous vertebrates in the world, after the golden poison frog. The meat of some species is considered a delicacy in Japan (as fugu) Pufferfish can fill its extremely elastic stomach with water until it is much larger and almost spherical in shape
	Ocellaris clownfish Amphiprion ocellaris Also known as the common clownfish. In the wild, they all form symbiotic mutualisms with sea anemones The main character in Finding Nemo is an A. ocellaris
	Candiru Vandellia cirrhosa Also known as the toothpick fish. a species of parasitic freshwater catfish native to the Amazon Basin It is attracted to blood and urine, and will (rarely) enter the body by swimming up the penis. It can only be removed by surgery
	Coelacanth genus Latimeria Coelacanths were thought to have gone extinct in the Late Cretaceous, around 66 million years ago, but were rediscovered in 1938 off the coast of South Africa Two species – West Indian Ocean coelacanth, and Indonesian coelacanth
	Seahorse genus Hippocampus (from Greek for "horse" and "sea monster") Fertilised eggs grow in the male’s brood pouch Seahorses rise by expelling water from a swim bladder
	Lamprey order Petromyzontiformes Jawless fish also known as lamprey eels The adult is characterised by a toothed, funnel-like sucking mouth. Lampreys are well known for those species which bore into the flesh of other fish to suck their blood
	Lungfish subclass Dipnoi Also known as salamanderfish Freshwater fish. Lungfish have the ability to breathe air. All lungfish have two lungs, with the exception of the Australian lungfish, which only has one
	Hagfish class Myxini Eel-shaped, slime-producing marine fish (also called slime eels). They are the only known living animals that have a skull but no vertebral column. Along with lampreys, hagfish are jawless