Hemichordata is a phylum which consists of triploblastic, enterocoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. They appear in the Lower or Middle Cambrian and include two main classes: Enteropneusta, and Pterobranchia. A third class, Planctosphaeroidea, is known only from the larva of a single species, Planctosphaera pelagica. The class Graptolithina, formerly considered extinct, is now placed within the pterobranchs, represented by a single living genus Rhabdopleura.
Nereis is a genus of polychaete worms in the family Nereididae. It comprises many species, most of which are marine. Nereis possess setae and parapodia for locomotion and gas exchange. They may have two types of setae, which are found on the parapodia. Acicular setae provide support. Locomotor setae are for crawling, and are the bristles that are visible on the exterior of the Polychaeta. They are cylindrical in shape, found not only in sandy areas, and they are adapted to burrow. They often cling to seagrass (posidonia) or other grass on rocks and sometimes gather in large groups.
William Bateson was an English biologist who was the first person to use the term genetics to describe the study of heredity, and the chief populariser of the ideas of Gregor Mendel following their rediscovery in 1900 by Hugo de Vries and Carl Correns. His 1894 book Materials for the Study of Variation was one of the earliest formulations of the new approach to genetics.
Holothuria is the type genus of the marine animal family Holothuriidae, part of the class Holothuroidea, commonly known as sea cucumbers. Members of the genus are found in coastal waters in tropical and temperate regions. They are soft-bodied, limbless invertebrates which dwell on the ocean floor and are usually detritivores. They resemble a cucumber in form. The genus contains some species that are harvested and sold as food.
Octopus is the largest genus of octopuses, comprising more than 100 species. These species are widespread throughout the world's oceans. Many species formerly placed in the genus Octopus are now assigned to other genera within the family. The octopus has 8 arms, averaging 20 cm (8 in) long for an adult.
Zoarcoidei is a suborder of marine ray-finned fishes belonging to the order Scorpaeniformes. The suborder includes the wolffishes, gunnels and eelpouts. The suborder includes about 400 species. These fishes predominantly found in the boreal seas of the northern hemisphere but they have colonised the southern hemisphere.
Saccoglossus is a genus of acorn worm. It is the largest genus in this class, with 18 species.
Euspira is a genus of medium-sized sea snails, marine gastropod molluscs in the subfamily Polinicinae of the family Naticidae, the moon snails.
Astralium, common name star snails, is a genus of sea snails, marine gastropod mollusks in the family Turbinidae, the turban snails and star snails.
Branchiostoma is one of the few living genera of lancelets. It is the type genus of family Branchiostomatidae.
Conus ventricosus mediterraneus is a subspecies of sea snail, a marine gastropod mollusk in the family Conidae, the cone snails and their allies.
Raphitoma is a genus of sea snails, marine gastropod mollusks in the family Raphitomidae.
Harrimaniidae is a basal family of acorn worms. A taxonomic revision was undertaken in 2010, and a number of new genera and species found in the Eastern Pacific were described. In this family the development is direct without tornaria larva, and circular muscle fibers in their trunk is missing. There is some indication that Stereobalanus may be a separate basal acorn worm lineage, sister to all remaining acorn worms.
Ptychoderidae is a family of acorn worms.
Cerianthus is a genus of tube-dwelling anemones in the family Cerianthidae. Members of the genus are found worldwide. They are predators, scavengers and omnivores.
The carpet flatworm is a polyclad flatworm in the family Pseudocerotidae.
John Dow Fisher Gilchrist (1866–1926) was a Scottish ichthyologist, who established ichthyology as a scientific discipline in South Africa. He was instrumental in the development of marine biology in South Africa and of a scientifically based local fishing industry.
Arthur Willey FRS was a British-Canadian zoologist.
