Family AEGIDAE White, 1850

Syscenus springthorpei

© Copyright from Bruce 1997.

Museums

Regional Maps

• Aegidae White, A. 1850. List of specimens of British animals in the collections of the British Museum, Part IV, Crustacea. London : British Museum (Natural History) 141 pp. [78].

  Type genus:

   Aega Leach, 1815.

Introduction

Aegidae are associates of fishes, almost exclusively attaching temporarily to the external skin surface. A small number of species are associated with other invertebrates, notably sponges, which might be used as refugia. Aegids are regarded as micropredators rather than parasites, feeding on blood or mucus temporarily and never attaching permanently (Bruce, 2009). Many species are relatively large (1 to 7 cm) and can be recognised as belonging to this family by the prehensile dactyli on pereopods 1–3 and the large dark eyes meeting, or almost meeting, at the front of the head. Species of the family are occasionally pests of aquaculture fishes. The family is almost exclusively marine, with the monotypic Alitropus H. Milne Edwards, 1840 the only genus occurring in fresh water.

Earlier keys to genera included Barybrotes, now in its own family (Bruce, 2009).

The family is cosmopolitan with numerous species. Brusca (1983) and Bruce (1983) have provided introductions to the literature. Bruce et al. (1982) and Bruce (1985, 1993) gave keys to separate this family from similar families. Bruce (1993, 2009) provided keys to the genera. Seven genera and 33 species are known from Australia, with Alitropus (freshwater) and Syscenus (mesopelagic), each represented only by a single species.

Excluded Taxa

Misidentifications

AEGIDAE: Aega punctulata Miers, 1881 [Occurrence in Australia based on a misidentification in Hale (1937) from off Maria Island, TAS, see Bruce (2009).] — Bruce, N.L. 2009. The marine fauna of New Zealand: Isopoda, Aegidae (Crustacea). NIWA Biodiversity Memoir 122: 1-252 [235-236]

Diagnosis

Eyes large, often medially united. Mouthparts forming buccal cone; maxillula styliform, with terminal and mesial robust setae; maxilla with single distomesial basal endite; maxilliped palp with conspicuous recurved (‘hooked’) robust setae. Pereopods 1–3 robust, with dactylus as long as or longer than propodus, usually strongly recurved.

General References

Bruce, N.L. 1983. Aegidae (Isopoda: Crustacea) from Australia with descriptions of three new species. Journal of Natural History 17: 757-788

Bruce, N.L. 1985. Calyptolana hancocki, a new genus and species of marine isopod (Cirolanidae) from Aruba, Netherlands Antilles, with a synopsis of Cirolanidae known from the Caribbean and Gulf of Mexico. Journal of Crustacean Biology 5: 707-716

Bruce, N.L. 1993a. Two new genera of marine isopod crustaceans (Flabellifera: Sphaeromatidae) from southern Australia, with a reappraisal of the Sphaeromatidae. Invertebrate Taxonomy 7: 151-171

Bruce, N.L. 2009. The marine fauna of New Zealand: Isopoda, Aegidae (Crustacea). NIWA Biodiversity Memoir 122: 1-252

Bruce, N.L., Brusca, R.C. & Delaney, P.M. 1982. The status of the isopod families Corallanidae Hansen, 1890, and Excorallanidae Stebbing, 1904 (Flabellifera). Journal of Crustacean Biology 2: 464-468

Bruce, N.L., Brusca, R.C. & Delaney, P.M. 1982. The status of the isopod families Corallanidae Hansen, 1890, and Excorallanidae Stebbing, 1904 (Flabellifera). Journal of Crustacean Biology 2: 464-468

Brusca, R.C. 1983. A monograph on the isopod family Aegidae in the tropical eastern Pacific. I. The genus Aega. Allan Hancock Monographs in Marine Biology 12: 1-39

History of changes