Family BRACHYSCELIDAE Stephensen, 1923
Introduction
The Brachyscelidae, a small tropical and temperate family of two genera, is very closely related to the Lycaeidae. Both genera and four of the six species have been reported from Australian waters. According to Laval (1980), species of Brachyscelus are mainly associated with salps. Nothing is known about the biology of Euthamneus species. Bowman & Gruner (1973) did not recognise the Brachyscelidae and the family needs revision. Vinogradov et al. (1982; in Russian) provided keys to genera and species and Zeidler (1992) provided a key to the species of Brachyscelus.
Diagnosis
Head as long as deep, longer than deep or deeper than long; anteroventral margin rounded; rostrum present or absent; eyes occupying most of lateral surface of head. Body laterally compressed. Antenna 1 shorter or longer than antenna 2; peduncle 1- or 2-articulate; peduncular article 1 longer than article 2; calceoli absent. Mandible molar absent; palp present or absent. Maxilla 1 inner plate absent. Gnathopod 1 carpochelate; carpus subequal to or longer than propodus. Pereopod 3 carpus shorter than propodus. Pereopod 5 shorter than, subequal to, or longer than pereopod 6; basis with posteroventral lobe; carpus linear. Pereopod 6 longer than pereopod 7; basis expanded. Pereopod 7 basis expanded. Uropod 2 inner ramus longer than outer ramus. Uropod 3 not sexually dimorphic; biramous.
General References
Bowman, T.E. & Gruner, H.E. 1973. The families and genera of Hyperiidea (Crustacea: Amphipoda). Smithsonian Contributions to Zoology 146: 1-64
Laval, P. 1980. Hyperiid amphipods as crustacean parasitoids associated with gelatinous zooplankton. Oceanography and Marine Biology Annual Reviews 18: 11-56
Stephensen, K. 1923. Crustacea Malacostraca. V. (Amphipoda I). Danish Ingolf-Expedition 3(8): 1-100
Vinogradov, M.E., Volkov, A.F. & Semenova, T.N. 1982. Amphipoda — Hyperiidea of the World Ocean. Nauka Leningrad U.S.S.R. Opred. po Faune S.S.S.R 132: 1-491 [in Russian]
Zeidler, W. 1992. Hyperiid amphipods (Crustacea: Amphipoda: Hyperiidea) collected recently from eastern Australian waters. Records of the Australian Museum 44(1): 85-133
Zeidler, W. 1998. Pelagic amphipods (Crustacea: Amphipoda: Hyperiidea) collected from eastern and south-eastern Australian waters by the CSIRO vessel "Warreen" during the years 1938–1941. Records of the South Australian Museum Monograph Series 4: 1-143
