A REVISION OF THE FAMILY EUMEDONIDAE DANA, 1853 (CRUSTACEA, DECAPODA, BRACHYURA, XANTHOIDEA)

Abstract

The family Eumedonidae, sensu Stevcic et al. (1988), contains nine genera and 26 species. On the basis of a large series of specimens from the Indo-West Pacific region and the examination of available type specimens, the family Eumedonidae Dana, 1853, is here revised. lt now contains 12 genera and 32 species. Of the 12 genera, three genera are new viz., Permanotus, Tauropus and Tiaramedon. Harrovia purpureus Gordon, 1934, Harrovia egeriae Gordon, 1947, and Harrovia spinosus Miers, 1879, are transferred to these new genera respectively. On the basis of the length of the second antennal segment, Harrovia frontodentata Shen, Dai & Chen, 1982, is transferred to Ceratocarcinus White, 1847. After a detailed comparison of Echinoecus Rathbun, 1894, and Proechinoecus Ward, 1934, the latter is synonymised under Echinoecus. The following five species are described as new viz., Eumedonus brevirhynchus, Eumedonus intermedius, Gonatonotus nasutus, Harrovia cognata and Zebrida brevicarinata. Three species, Echinoecus nipponicus Miyake, 1939, Harrovia japonica Balss, 1921, and Zebrida Longispina Haswell, 1880, have been resurrected from their previous synonymics under Echinoecus pentagonus (A. Milne Edwards, 1879), Harrovia elegans De Man, 1887, and Zebrida adamsii White, 1847, respectively. After examining a large series of specimens stretching across the Sunda and Sahul Shelves, Harrovia plana Ward, 1936, is shown to be a junior synonym of Harrovia longipes Lanchester, 1900. Harrovia bituberculata Shen, Dai & Chen, 1982, and Zebrida paucidentata Flipse, 1930, have also been synonymised under Permanotus purpureus (Gordon, 1934), new combination, and Zebrida adamsii White, 1847, respectively. The first zoeal stage or Permanotus purpureus is also described for the first time and compared with other known first zoeal stages or cumedonids, namely, Rhabdonotus pictus A. Milne Edwards, 1879 (fide Chia & Ng, 1995), Harrovia longipes Lanchester, 1900 (fide Lim & Ng, 1988), H. albolineata Adams & White, 1849 (fide Chia et al., 1993), Echinoecus pentagonus (A. Milne Edwards, 1879) (fide Van Dover et al., I 986), and Zebrida adamsii White, 1847 (fide Mori et al., 1991). Lectotypes are designated for Eumedonus zebra Alcock, 1895, and Harrovia Japonica Balss, 1921, respectively. Whereas a neotype has been established for Harrovia elegans De Man, 1887. The status and affliations of the family are also discussed with keys to all genera and species provided.