Mayericaprella, Guerra-García, 2006

Guerra-García, J. M., 2006, Caprellidae (Crustacea: Amphipoda) from the Great Barrier Reef and Adjacent Localities, Records of the Australian Museum 58, pp. 417-458 : 428

Mayericaprella n.gen.

Diagnosis. Flagellum of antenna 2 2-articulate. Gills present on pereonites 2–4. Pereopods 3 and 4 absent. Pereopod 5 four-articulate. Pereopods 6 and 7 six-articulate; propodus with two pairs of proximal grasping spines. Mandibular palp 3-articulate. Molar absent. Abdomen with two pairs of 2- articulate appendages.

Etymology. Mayericaprella is derived from “Mayer” and “ Caprella ” to dedicate the genus to P. Mayer for his valuable contributions to the knowledge of the Caprellidae during the last century. Gender: feminine.

Type species. Mayericaprella arimotoi n.sp.

Remarks. Mayericaprella n.gen. is close to Caprellina , especially to Caprellina bispinosa Müller, 1990 . The general shape of the body, the structure of the antennae, the distribution of the gills, the mouthparts (especially the maxilliped) and the abdomen are similar to that of species of Caprellina . However, the gnathopods and pereopods are different, especially pereopod 5 which is four-articulate in the new genus and 2- or 3-articulate in Caprellina (2- articulate in C. bispinosa and 3-articulate in C. longicollis and C. spiniger ). The only other genus in the subfamily Phtisicinae with four-articulate pereopods 5 is Quadrisegmentum . Although Mayericaprella shares with Quadrisegmentum the presence of four-articulate pereopod 5, the genera differ chiefly in pereopods 3 and 4, being present in the latter and absent in former. The number of articles on pereopod 5 is an important phylogenetic character in the Phtisicinae because they show progressive changes in segmentation of the limb (Hirayama, 1988). At present, the number of articles in the pereopods distinguishes genera (Mayer, 1903; Arimoto, 1976). For instance, genera close to Caprellina , such as Hircella , have been erected mainly on the basis of one-articulate pereopod 5. Nevertheless, Müller (1990) assigned C. bispinosa (having a 2-articulate pereopod 5) to Caprellina (characterized by a 3-articulate pereopod 5) instead of erecting a new genus for the species. Further study might show that C. bispinosa should be transferred to a different genus. The general morphology of Mayericaprella , with a four-articulate pereopod 5, is closer to Caprellina bispinosa with pereopod 5 2-articulate, than to the remaining species of Caprellina with a 3- articulate pereopod 5. Actually, the phylogenetic relationships among the species of the seemingly closely related genera Caprellina , Pseudocaprellina , Hircella and Liriarchus require study. The continuous gradient of variation in the characters of species of these genera makes generic distinctions difficult. A complete phylogenetic revision of the Caprellidae , necessary to address properly future taxonomic studies of this group, is required.