Introduction

Tanaidaceans are common peracaridans of all marine benthic environments. They are recognised by the fusion of the head to the first and second thoracomeres thereby having always only six free thoracomeres. The second thoracopods (chelipeds) are chelate or subchelate and are followed by six pairs of pereopods.

The literature on the Tanaidacea is extensive. Bacescu (1974) provided a bibliography and Sieg (1983a) expanded this and catalogued all species known up to 1980 with complete synonymies and references. The evolution of the order was treated using phylogenetic principles by Sieg (1983b, 1984). He also discussed general morphology, distribution and sexual dimorphism. Sieg & Winn (1978) provided keys to all families and Gutu (1972, 1981) diagnosed families and gave keys to the 'Monokonophora'. More recent reviews have been provided by Gutu (1996) and by Gutu & Sieg (1999). The last discusses morphology and ecology, in French, and lists all genera and higher taxa.

All surveys of benthic marine communities in bays and on the shelf and slope of Australia have turned up numerous species of tanaidaceans, but few species have been described from waters surrounding the Australian mainland.

Our Catalogue includes species from the Australian subantarctic islands, Macquarie Island and Heard Island (Sieg 1986a). A few species have extensive synonymies which can be found in Sieg (1983a). Our synonymies list only those junior synonyms used for Australian records.

The systematic arrangement in this contribution largely follows Sieg (1984). Four suborders of Tanaidacea are currently recognised and replace the earlier division into Monokonophora and Dikonophora. Two, Apseudomorpha (equivalent to the Monokonophora) and Tanaidomorpha (which, with the Neotanaidomorpha, is equivalent to the Dikonophora), are represented in the known Australian fauna. The biogeography of the group was discussed by Sieg (1986b).

The name Tanaidacea was first introduced for the order by Hansen (1895). Spelling of family names derived from the genus Tanais are here brought into line with Latin usage, e.g. Tanaidae becomes Tanaididae.

This chapter of the Catalogue was initiated in Melbourne in the 1980s with the help of Jürgen Sieg in Osnabrück who contributed lists, diagnoses and opinions on higher classification. Dr Sieg died on 14 August 1996 and the work was completed by Gary Poore in 2000–2002 with the help of Richard Heard and Kim Larsen. The diagnoses written by Sieg have not been altered and may not be compatible with more recent interpretations, e.g. by Gutu (1996) and Gutu & Sieg (1999). Generic composition of some families may also differ too but these alternative views are highlighted.{47917:b}

Database Notes

Updated by Gary C.B. Poore, 30 April 2005.

General References

Bacescu, M. 1974. Bibliographia tanaidaceorum. Travaux du Muséum d'Histoire Naturelle "Grigore Antipa" 15: 69-90

Błażewicz-Paszkowycz, M. & Bamber, R.N. 2012. The shallow-water Tanaidacea (Arthropoda: Malacostraca: Peracarida) of the Bass Strait, Victoria, Australia (other than the Tanaidae). Memoirs of Museum Victoria 69: 1-235

Gutu, M. 1972. Phylogenetic and systematic considerations upon the Monokonophora (Crustacea - Tanaidacea) with the suggestion of a new family and several new subfamilies. Revue Roumaine de Biologie Zool. 17: 297-305

Gutu, M. 1981. A new contribution to the systematics and phylogeny ofthe suborder Monokonophora (Crustacea, Tanaidacea). Travaux du Muséum d'Histoire Naturelle "Grigore Antipa" 23: 81-108

Gutu, M. 1996. The synoptic table and key to the superspecific taxa of recent Apseudomorpha (Crustacea, Tanaidacea). Travaux du Muséum d'Histoire Naturelle "Grigore Antipa" 36: 135-146

Gutu, M. & Sieg, J. 1999. Ordre des tanaïdacés (Tanaidacea Hansen, 1895). pp. 353-389 in Forest, J. Traité de Zoologie. Anatomie, systématique, biologie … Tome 7 Crustacés. Fascicule 3A Péracarides. Mémoires de l'Institut Océanographique, Monaco 19: 1-450

Hansen, H.J. 1895. Isopoden, Cumaceen, und Stomatopoden der Plankton-Expedition. Ergebnisse der Hamburger Magalhaensischen Sammelreise 2(Gc): 1-105 pls 1-8

Larsen, K. 2005. Deep-Sea Tanaidacea (Peracarida) from the Gulf of Mexico. Leiden : Brill 381 pp.

Markham, J.C. 1985a. Additions to the bopyrid isopod fauna of Thailand. Zoologische Verhandelingen (Leiden) 224: 1-63

Sieg, J. 1983a. Crustaceorum Catalogus editus a H.-E. Gruner & L.B. Holthuis Pars 6. Tanaidacea. The Hague : Dr W. Junk 552 pp.

Sieg, J. 1983b. Evolution of Tanaidacea. Crustacean Issues 1: 229-256

Sieg, J. 1984. Neuere Erkenntnisse zum natürlichen System der Tanaidacea. Eine phylogenetische Studie. Zoologica (Stuttgart) 136: 1-132

Sieg, J. & Winn, R.N. 1978. Keys to the suborders and families of Tanaidacea (Crustacea). Proceedings of the Biological Society of Washington 91: 840-846

History of changes

Introduction

The classification of this suborder is the subject of controversy (Gutu 1981, 1996; Sieg 1980, 1984, 1986, 2001). The systematic position of Whiteleggiidae and Cirratodactylidae is especially uncertain. We follow Sieg (1984, 1986), Gutu (1996) and Gutu & Sieg (1999) and accept Whiteleggiidae as a separate family while Cirratodactylidae is considered a synonym of Kalliapseudidae. There are currently 14 families, eight of which are recorded from Australian waters. These eight (Apseudidae, Kalliapseudidae, Metapseudidae, Numbakullidae, Parapseudidae, Pagurapseudidae, Tanzanapseudidae and Whiteleggiidae) occur more or less commonly along the mainland coasts and on the shelf of the subantarctic islands. Gutu (1996) provided a key to families and genera.

Diagnosis

With or without eyes. Dorsoventrally depressed, body more or less semicircular in cross-section. Pereonites quite often with lateral processes (spine- or peak-like structures). Pleon typically formed by 5 pleonites and elongate pleotelson, pleonites often with pleurites. Antenna 1 biramous (except Tanapseudidae), 3–articled peduncle and multiarticled outer flagellum, inner flagellum 3– to 4–articled. Antenna 2 with 5–articled peduncle and multiarticled or reduced flagellum. Squama sometimes reduced or lacking. Mandibles of monocondyle type, typically with 3–articled palp which is sometimes reduced or lacking. Maxilla 1 with 2 endites, with or without palp. Maxilla 2 well developed, with several distinct lobes. Labium always with distal palp. Epignath cup-shaped. Maxillipeds never fused medially. Cheliped typically with semicircular coxa. Coxae of pereopods articulating laterally at the pereonites (visible dorsally). Pereopods show all kinds of specialisation (e.g., fossorial, ambulatory, climbing). Pleopods present or absent, endopod 1–articled, sometimes 2–articled. Uropods biramous, endopod typically long and multiarticled, exopod short and 2– to 8–articled. Marsupium formed by 4 pairs of sheet-like oostegites (in several families a reduced fifth pair of oostegites on the cheliped). Gonochoristic. Sexual dimorphism expressed in various degrees, but affecting only morphology of antenna 1 and cheliped. Mouthparts never lacking in the male.

General References

Gutu, M. 1981. A new contribution to the systematics and phylogeny ofthe suborder Monokonophora (Crustacea, Tanaidacea). Travaux du Muséum d'Histoire Naturelle "Grigore Antipa" 23: 81-108

Gutu, M. 1996. The synoptic table and key to the superspecific taxa of recent Apseudomorpha (Crustacea, Tanaidacea). Travaux du Muséum d'Histoire Naturelle "Grigore Antipa" 36: 135-146

Gutu, M. 2001. New changes in the systematics of the suborder Apseudomorpha (Crustacea: Tanaidacea). Travaux du Muséum d'Histoire Naturelle "Grigore Antipa" 43: 65-71

Guţu, M. 2006. New Apseudomorph Taxa of the World Ocean: Crustacea, Tanaidacea. Bucharest, Romania : Curtea Veche 318 pp.

Gutu, M. 2007. Contribution to the knowledge of the Indo-West-Pacific Apseudomorpha (Crustacea: Tanaidacea). Travaux du Muséum National d´Histoire Naturelle "Grigore Antipa" 50: 47-86

Gutu, M. & Sieg, J. 1999. Ordre des tanaïdacés (Tanaidacea Hansen, 1895). pp. 353-389 in Forest, J. Traité de Zoologie. Anatomie, systématique, biologie … Tome 7 Crustacés. Fascicule 3A Péracarides. Mémoires de l'Institut Océanographique, Monaco 19: 1-450

Larsen, K. 2005. Deep-Sea Tanaidacea (Peracarida) from the Gulf of Mexico. Leiden : Brill 381 pp.

Sieg, J. 1980. Sind die Dikonophora eine Polyphyletische gruppe? Are the Dikonophora a polyphyletic group? Zoologischer Anzeiger 205: 401-416

Sieg, J. 1984. Neuere Erkenntnisse zum natürlichen System der Tanaidacea. Eine phylogenetische Studie. Zoologica (Stuttgart) 136: 1-132

Sieg, J. 1986. Crustacea Tanaidacea of the Antarctic and Subantarctic 1. On material collected at Tierra del Fuego, Isla de los Estados, and the West Coast of the Antarctic Peninsula. Antarctic Research Series 45: 1-180

History of changes