Chinese Mitten Crab
The Chinese mitten crab is native to East Asia, where they are a delicacy. They have funny-looking, hairy claws which distinguish them from other crabs. Populations of this crab have invaded Europe and the United States and are causing concern due to potential ecological damage.
The Chinese mitten crab is most easily distinguished by its claws, which are white-tipped and covered in brown hair. The shell, or carapace, of this crab is up to 4 inches wide and light brown to olive green in color. They have eight legs.
Other names for this crab are the Shanghai hairy crab and big binding crab.
The Chinese mitten crab is (not surprisingly) native to China, but expanded its range during the 1900s and is now considered an invasive species in many areas.
According to the Global Invasive Species Database, the Chinese mitten crab is one of the 100 “World’s Worst” invaders. If established in an area, the crab will compete with native species, foul fishing gear and water intakes, and can intensively burrow into shorelines and increase erosion problems.
Ectothermic
An ectothermic animal is one who cannot regulate its own body temperature, so its body temperature fluctuates according to its surroundings.
Ectothermic animals, or ectotherms, are commonly referred to as "cold-blooded." Examples of ectotherms are: reptiles, amphibians, and fish.
The opposite of an ectotherm is an endotherm.
Notochord
A notochord is often described as a primitive backbone. It is a rigid, cartilaginous rod that is present at some stage of development in all chordates. In some chordates, the notochord is present as a rod of cells that lies beneath and parallel the nerve cord, giving it support.
In vertebrates, the notochord is typically present only in the embryo stage.
The word notochord comes from the Greek words (Source) notos (back) and chorde (cord).
Seals and Sea Lions
Seals, sea lions and walruses are all in the order Carnivora and suborder Pinnipedia, thus they are called “pinnipeds.”
There are three families of pinnipeds: the Phocidae, the earless or ‘true’ seals; the Otariidae, the eared seals, and the Odobenidae, the walrus. This article focuses on the difference between the earless seals (seals) and the eared seals (sea lions).
Phocidae (Earless or 'True' Seals)
Earless seals:
Have no external ear flaps.Swim with their hind flippers. Their hind flippers always face backward and are furred.Have 2 or 4 teats.Can be found in both marine and freshwater environments.Examples of earless (true) seals: harbor (common) seal (Phoca vitulina), grey seal (Halichoerus grypus), hooded seal (Cystophora cristata), harp seal (Phoca groenlandica), elephant seal (Mirounga leonina), and monk seal (Monachus sp.).
Otariidae (Eared Seals, Including Fur Seals and Sea Lions)
Eared seals:
Have external ear flaps.Swim with their front flippers. Unlike earless seals, their hind flippers can turn forward, and they are better able to “walk” on their flippers.Have 4 teats.Are only found in marine environments.Examples of eared seals: Steller’s sea lion (eumetopias jubatus), California sea lion (Zalophus californianus), and Northern fur seal (Callorhinus ursinus).
Sources: NOAA Office of Protected Resources. 2008. ”Pinnipeds: Seals, Sea Lions and Walruses” (Online). NOAA. Retrieved November 23, 2008.Waller, Geoffrey, ed. 1996. SeaLife: A Complete Guide to the Marine Environment. Smithsonian Institution Press. Washington, D.C.Elasmobranch
The term elasmobranch refers to the sharks, rays and skates - cartilaginous fishes. These animals have a skeleton made of cartilage, rather than bone.
These animals are collectively referred to as elasmobranchs because they are in the Class Elasmobranchii (older classification systems refer to these organisms as Class Chondrichthyes, listing Elasmobranchii as a subclass.) According to the World Register of Marine Species (WoRMS), elasmobranch comes from elasmos (Greek for "metal plate") and branchus (Latin for "gill").
: Skeleton made of cartilage5-7 gill openings on each sideRigid dorsal fins (and spines if present)Spiracles to aid in breathingPlacoid scales (dermal denticles)The upper jaw of elasmobranchs is not fused to their skull.Elasmobranchs have several rows of teeth which are continually replaced.Species in Class Elasmobranchii, which includes over 1,000 species, include the southern stingray, whale shark, basking shark, and the shortfin mako shark.
Elasmobranchs reproduce sexually with internal fertilization and either bear live young or lay eggs.
Biggest Ocean Animal
Blue whales are thought to be the largest animal ever to live on the Earth. They reach lengths up to about 100 feet and weights of an amazing 100-150 tons.
Blue whales are a type of baleen whale known as a rorqual. Their skin is a beautiful gray-blue color, often with a mottling of light spots.
Blue whales are found in all the world's oceans. After the invention of the grenade-tipped harpoon in the late 1800's, blue whales were subjected to relentless hunting. The blue whale was given protection from hunting in 1966 by the International Whaling Commission and today there are an estimated 10,000-15,000 blue whales in the world.