Blue Crabs

The blue crab is names because of its sapphire-tinted claws. Its shell, or carapace, is actually a mottled brown color, and mature females have red highlights on the tips of their pincers. Prized by humans for their sweet, tender meat, these wide-ranged, ten-legged crustaceans are among the most heavily harvested creatures on the planet. Their scientific name, Callinectes Sapidus, means "Savory Beautiful Swimmer". Blue Crabs are found in brackish coastal lagoons and estuaries, from Nova Scotia, to the Gulf of Mexico, and as far as southern Uruguay. Close Relatives of the shrimp and lobster, these bottom-dwelling omnivores have a prickly disposition and are quick to use their sharp front pincers. Large males can reach 9 in. (23 cm.) in shell width. They feed on almost anything they can get a hold of, including mussels, snails, fish, plants, and even carrion and smaller blue crabs. They are also great swimmers with specially adapted hind appendages shaped like paddles. Blue Crabs are extremely sensitive to environmental, and habitat changes, and many populations, particulary in the Chesapeake Bay in the eastern United States, have experienced severe declines. Blue Crabs also play a key roll in managing the populations of the animals they prey on, and constant over-harvesting has had wide-ranging negative effects on the ecosystems they inhabit. For this reason, comprehensive managment schemes are in place in several parts of the Blue Crab's range. Credits go to: National Geographic

Sea Slugs

The sea slug is a name for a marine gastropod mollusk that lacks a shell as an adult and is usually brightly colored. Sea slugs, or nudibranchs, are distributed throughout the world, with the greatest numbers and the largest kinds found in tropical waters. They creep along the bottom or cling to submerged vegetation, usually in water just below the low tide line. Members of a few species swim on the surface in open ocean. Most sea slugs are under 1 in. (2.5 cm) long, although the largest, found in the Great Barrier Reef of Australia, reaches 12 in. (30 cm). Regarded by many people as the most beautiful of marine animals, sea slugs display a great array of solid colors and patterns. Many have feathery structures (ceratia) on the back, often in a contrasting color. Most sea slugs have two pairs of tentacles on the head, used for tactile and chemosensory reception, with a small eye at the base of each tentacle. Sea slugs graze on small sessile animals such as coelenterates, sponges, and bryozoans. Certain sea slugs that feed on corals and sea anemones ingest the stinging cells of their prey without discharging them; these then pass from the slug's digestive tract to the ceratia, where they are used by the slug for its own defense. Sea slugs are classified in the phylum Mollusca , class Gastropoda, subclass Opisthobranchia, order Nudibranchiata. Credits go to: Encyclopedia.com

The Sea Urchin

The sea urchin is a spherical-shaped echinoderm with movable spines covering the body. The body wall is a firm, globose shell, or test, made of fused skeletal plates and marked by regularly arranged tubercles to which the movable spines are attached. Five rows of the skeletal plates are pierced by pores for the tube feet of the water-vascular system; these are typical of echinoderms and are used for locomotion. The mouth is centered on the lower side of the body and in many species is surrounded by a whorl of gills. A complex jaw and tooth apparatus in the mouth, known as Aristotle's lantern, is used to fragment food. Long, sharp spines are used for protection, and in some species are poisonous. The spines are also used as levers, aiding the tube feet in locomotion and, along with the teeth, are used by some species to dig burrows in hard rock. Sea urchins feed on all kinds of plant and animal material; some eat sand or mud, digesting out organic material that is present. Entirely marine, they occur in all seas and at all depths but prefer shallower waters and rocky bottoms. Arbacia and Strongylocentrotus are the most familiar American genera; one species of the latter, the red sea urchin ( S. franciscanus ) of the Pacific coast, is estimated to live for 200 years or more. Eggs and sperm are shed into the sea. After fertilization, a characteristic, free-swimming larva, called the pluteus larva, develops; it undergoes a profound metamorphosis to assume the adult form. Sea urchins have some economic significance. The roe is considered a delicacy, especially in Mediterranean regions and Japan, and burrowing species may damage sea walls. Credits go to: Encyclopedia.com