Latreille, 1806
Ostracoda are small maxillopodan crustaceans with a bivalved carapace or shell, resembling a clam shell, enclosing an unsegmented body with five to seven paired appendages. The shell shape is highly variable and its surface is smooth to ornate. As the animal grows, the shell is shed, growing again after each moult. Valves of the shell connected dorsally by a ligament. Shell penetrated by pores, bearing setae of various kinds. The shell is closed by muscles which leave attachment scars on the inner surface of the valves. First antenna (or antennule) and second antenna (or antenna) well developed. The maxilla (or fourth limb, maxillula, or first maxilla) is a variable feeding limb. Fifth limb (or maxilla, or first thoracic leg) generally with a large epipodial plate. Furca either anterior or posterior to the anus. Digestive system consisting of mouth and gut.
Most species have an antero-dorsal median eye, which sometimes receives light through a translucent spot in the shell. Other species have paired compound lateral eyes.
There is an open circulatory system; a heart may be present or absent. Respiration is by diffusion through the thin cuticle that covers the entire body.
Sexes usually separate; fertilization internal, accomplished by a complicated copulatory apparatus.
Embryos are brooded in the postero-dorsal section of the shell, or the eggs released into the water. There are four to nine instar larvae with bivalve shells, thus resembling the adults. The key to adult ostracods starts at Page 157: Ostracoda.
Most ostracods live burrowed in the substrate or are epibenthic crawlers, others are planktonic.
Four recent orders are recognised, based primarily on the nature of the second antenna. Myodocopa, Cladocopa, Platycopa and Podocopa. About 2000 recent species.
The key to the pelagic ostracods of the North Sea starts at Page 157: Ostracoda.
[Adapted from Angel, 2000]
The following ostracod species are included in this volume:
Order Myodocopida
Suborder Halocypridina
Family Halocyprididae
Subfamily Halocypridinae
Boroecia borealis
Halocypria globosa
Subfamily Conchoecinae
Mikroconchoecia curta
Conchoecilla daphnoides
Mikroconchoecia echinulata
Discoconchoecia elegans
Orthoconchoecia haddoni
Conchoecia hyalophyllum
Conchoecissa imbricata
Boroecia maxima
Obtusoecia obtusata
Paraconchoecia spinifera
Metaconchoecia teretivalvata
Suborder Myodocopina
Family Cylindroleberidae
Asterope abyssicola
Synasterope norvegica
Family Cypridinidae
Doloria sarsi
Skogsbergia megalops
Vargula norvegica
Family Philomedidae
Euphilomedes interpuncta
Philomedes brenda
Philomedes lilljeborgi