Fish and Crustaceans
Crustaceans form a large, diverse arthropod taxon which includes such animals as crabs, lobsters, crayfish, shrimps, prawns, krill, woodlice, and barnacles.[1] The crustacean group can be treated as a subphylum under the clade Mandibulata; because of recent molecular studies it is now well accepted that the crustacean group is paraphyletic, and comprises all animals in the clade Pancrustacea other than hexapods.[2] Some crustaceans are more closely related to insects and the other hexapods than they are to certain other crustaceans. The 67,000 described species range in size from Stygotantulus stocki at 0.1 mm (0.004 in), to the Japanese spider crab with a leg span of up to 3.8 m (12.5 ft) and a mass of 20 kg (44 lb). Like other arthropods, crustaceans have an exoskeleton, which they moult to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates, by the possession of biramous (two-parted) limbs, and by their larval forms, such as the nauplius stage of branchiopods and copepods.
Quick Facts
- Fish have been on the earth for more than 450 million years, whereas mammals have only been on earth for roughly 200 millions years
- There are over 27,000 identified species of fish on the earth and an estimated 15,000 fish species that have not yet been identified.
- There are more species of fish than all the species of amphibians, reptiles, birds and mammals combined.
- Sailfish, Swordfish, and Marlin are the fastest fish in the ocean, reaching speeds of up to 70 mph, which is faster than the speed limits on most highways!
- A female Sunfish may lay 300,000,000 eggs at a single spawning season
- Catfish have over 27,000 taste buds, whereas humans have only 9,000.
- Many crustaceans are extinct, extinct in the wild, or endangered or critical. Most are classified as Least Concern.
- A person who studies fish for a living is called an ichthyologist.
