Class OSTRACODA Latreille, 1802

Ostracoda (Podocopa).

© Copyright Ivana Karanovic. Western Australian Musem.

A marine ostracod from southern Australia.

© Copyright Anna Syme

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Introduction

Ostracods are one of the most speciose groups of living Crustacea. There are an estimated >20,000 living species, of which approximately 8,000 have been described. Ostracods have the best fossil record of any arthropods dating to >425 million years. This group of crustaceans is essentially aquatic, inhabiting both marine and non-marine environments. Some taxa are adapted to a semi-terrestrial life, for example, living in damp leaf-litter. The majority are free living, but some are commensal on other crustaceans, echinoderms and sharks. Approximately 2000 species are non-marine (Martens et. al. 2008). The two ostracod subclasses — Myodocopa and Podocopa — might not be closely related. The Myodocopa contains the Halocyprida (marine, mostly planktonic) and the Myodocopida (marine, benthic or living at various depths). The Podocopa contains the Podocopida (freshwater or marine) and Platycopida (marine). More information on general ostracod morphology can be found in Cohen et al. (2007). A database of all fossil and living world species is presented in Kempf (1986 and later editions).

Diagnosis

Small crustaceans, characterised by a bivalved carapace that totally encloses the body and appendages. The body shows reduced trunk segmentation and 5–8 pair of limbs, which are protruded from the gaping valves for locomotion. They are typically 0.5–2.0 mm long in the adult stage; however, some interstitial forms are as small as 0.2 mm, some freshwater species attain 8.0 mm and the pelagic marine genus Gigantocypris reaches 32 mm.

Diagnosis References

Horne, D.J., Cohen, A. & Martens, K. 2002. Taxonomy, morphology and biology of Quaternary and living Ostracoda. Geophysical Monograph 131: 5-36

General References

Cohen, A.C., Peterson, D.E., & Maddocks, R.F. 2007. Ostracoda. pp. 417-446 in Carlton, J.T. The Light & Smith Manual: Intertidal Invertebrates from Central California to Oregon. Berkeley & Los Angeles : University of California Press 4.

Karanovic, I. 2012. Recent Freshwater Ostracods of the World. Springer 1, 608 pp.

Kempf, E.K. 1986. Index and bibliography of marine Ostracoda Part 1: Index A. Cologne : Geologisches Institut der Universitat Koeln, Sonderveroffentlichungen. [and later editions]

Martens, K., Shon, I., Meisch, C. & Horne, D.J. 2008. Global diversity of ostracods (Ostracoda, Crustacea) in freshwater. Hydrobiologia 595: 185-193

Martens, K. & Savatenalinton, S. 2011. A subjective checklist of the Recent, free-living, non-marine Ostracoda (Crustacea). Zootaxa 2855: 1-79

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