Alicellidae and Valettiopsidae - Two new callynophorate families of amphipod crustaceans
Contents
Abstract
Two new families, the Alicellidae fam. nov. and the Valettiopsidae fam. nov., are described based on genera traditionally considered as lysianassoid amphipods. The Alicellidae fam. nov. are deep-sea scavengers often associated with thermal vents. They are distinguished from all other amphipods by a combination of characters which includes a callynophore on antenna 1; a broad, serrate left lacinia mobilis (occasionally narrow or vestigial) and a reduced or vestigial right lacinia mobilis (occasionally broad and serrate); simple or subchelate gnathopod 1; an elongate ischium, rectolinear carpus and propodus and a small dactylus on gnathopod 2 (not mitten-shaped); absence of apical robust setae on uropods 1 and 2 and a deeply cleft telson. The family contains 6 genera: Alicella Chevreux, 1899; Apotectonia Barnard & Ingram, 1990; Diatectonia Barnard & Ingram, 1990; Paralicella Chevreux, 1908; Tectovalopsis Barnard & Ingram, 1990; Transtectonia Barnard & Ingram, 1990. The Valettiopsidae fam. nov. are deep-sea scavenging amphipods defined by a combination of characters which includes a callynophore on antenna 1; serrate, curved incisors; a well developed, serrate lacinia mobilis on each mandible, an oblique setal row on the inner plate of maxilla 2, an elongate ischium on gnathopod 2; the absence of robust setae on the apices of uropods 1 and 2 and a deeply cleft telson. The family contains two genera, Valettiopsis Holmes, 1908 and Valettietta Lincoln & Thurston, 1983.
Key words: Crustacea, Amphipoda, new families, taxonomy, Alicellidae, Valettiopsidae
