Bivalvia, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. The class includes the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim. Shipworms bore into wood, clay, or stone and live inside these substances.
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea. Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish live on the seabed in all the world's oceans, from warm, tropical zones to frigid, polar regions. They are found from the intertidal zone down to abyssal depths, at 6,000 m (20,000 ft) below the surface.
The red knot or just knot is a medium-sized shorebird which breeds in tundra and the Arctic Cordillera in the far north of Canada, Europe, and Russia. It is a large member of the Calidris sandpipers, second only to the great knot. Six subspecies are recognised.
Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms suspended in water, typically by having the water pass over or through a specialized filtering organ. Filter feeders can play an important role in condensing biomass and removing excess nutrients from the local waterbody, and are therefore considered water-cleaning ecosystem engineers. They are also important in bioaccumulation and, as a result, as indicator organisms.
A siphon is an anatomical structure which is part of the body of aquatic molluscs in three classes: Gastropoda, Bivalvia and Cephalopoda.
The redear sunfish, also known as the shellcracker, Georgia bream, cherry gill, chinquapin, improved bream, rouge ear sunfish and sun perch) is a freshwater fish in the family Centrarchidae and is native to the southeastern United States. Since it is a popular sport fish, it has been introduced to bodies of water all over North America. It is known for its diet of mollusks and snails.
Charonia is a genus of very large sea snail, commonly known as Triton's trumpet or Triton snail. They are marine gastropod mollusks in the monotypic family Charoniidae. They are one of the few natural predators of the crown-of-thorns starfish.
The pie crust crab, is a species of crab found around New Zealand and south-eastern Australia.
The African openbill is a species of stork from the family Ciconiidae. It is widely distributed in Sub-Saharan Africa and western regions of Madagascar. This species is considered common to locally abundant across its range, although it has a patchy distribution. Some experts consider there to be two sub-species, A. l. lamelligerus distributed on the continent and A. l. madagascariensis living on the island of Madagascar. Scientists distinguish between the two sub-species due to the more pronounced longitudinal ridges on the bills of adult A. l. madagascariensis. The Asian openbill found in Asia is the African openbill’s closest relative. The two species share the same notably large bill of a peculiar shape that gives them their name.
Evisceration is a method of autotomy involving the ejection of internal organs used by animals as a defensive strategy. Sea cucumbers (Holothuroidea) eject parts of the gut in order to scare and defend against potential predators such as crabs and fish. The organs are regenerated in a few days by cells in the interior of the sea cucumber.
The common starfish, common sea star or sugar starfish is the most common and familiar starfish in the north-east Atlantic. Belonging to the family Asteriidae, it has five arms and usually grows to between 10–30 cm across, although larger specimens are known. The common starfish is usually orange or brownish in color, and sometimes violet; specimens found in deeper waters are pale. The common starfish is found on rocky and gravelly substrates where it feeds on mollusks and other benthic invertebrates.
Atrina rigida, commonly called the rigid pen shell, is a species of bivalve mollusc in the family Pinnidae.
Durophagy is the eating behavior of animals that consume hard-shelled or exoskeleton-bearing organisms, such as corals, shelled mollusks, or crabs. It is mostly used to describe fish, but is also used when describing reptiles, including fossil turtles, placodonts and invertebrates, as well as "bone-crushing" mammalian carnivores such as hyenas. Durophagy requires special adaptions, such as blunt, strong teeth and a heavy jaw. Bite force is necessary to overcome the physical constraints of consuming more durable prey and gain a competitive advantage over other organisms by gaining access to more diverse or exclusive food resources earlier in life. Those with greater bite forces require less time to consume certain prey items as a greater bite force can increase the net rate of energy intake when foraging and enhance fitness in durophagous species.
Mollusca is the second-largest phylum of invertebrate animals, after Arthropoda; members are known as molluscs or mollusks. Around 76,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied.
Pisaster brevispinus, commonly called the pink sea star, giant pink sea star, or short-spined sea star, is a species of sea star in the northeast Pacific Ocean. It was first described to science by William Stimson in 1857. The type specimen was collected on a sandy bottom, 10 fathoms (18 m) deep, near the mouth of San Francisco Bay.
Evasterias troschelii is a species of starfish in the family Asteriidae. Its common names include the mottled star, false ochre sea star and Troschel's true star. It is found in Kamchatka and the north western coast of North America.
The Astropecten articulatus, more commonly known as the Royal Starfish, is a West Atlantic sea star of the family Astropectinidae.
Leptasterias tenera is a species of starfish in the family Asteriidae. It is found on the eastern coast of North America.
Polinices bifasciatus, or two-banded moon snail, is a species of gastropod mollusc. The animal was first described to science in a work authored by English biologists Edward Griffith and Edward Pidgeon. This was a multi-volume translation of George Cuvier's, Le Règne Animal (1830). The Griffith and Pidgeon work went beyond translation and added a supplement that included the description of Polinices bifasciatus. The description of Polinices bifasciatus is attributed to John Edward Gray. It reads, in its entirety, "Pale brown, with two narrow bands".
