Anchistioides willeyi ( Borradaile, 1899 )

Marin, Ivan, 2009, On the presence of Anchistioides willeyi (Borradaile, 1899) (Decapoda: Caridea: Anchistioididae) in the Red Sea, Zootaxa 2243, pp. 53-56 : 53-55

Anchistioides willeyi ( Borradaile, 1899)

( Fig. 1 )

Palaemonopsis willeyi Borradaile, 1898: 410 , pls. 36, 37, fig. 7

Amphipalaemon willeyi Nobili, 1905: 5 ; Borradaile, 1917: 407, pl. 59, fig. 13.

Anchistioides willeyi Gordon, 1935: 344 , figs. 23a, 24a; Holthuis, 1952: 214, 215, figs. 106, 107; Bruce, 1971: 22, fig. 8.

Material examined. Red Sea: Sudan, Al Bahr al Ahmar, Sanganeb Atoll, 28 km NE of Port Sudan, S-Mole, SAN- 122, 30 m depth, from living Stylophora , 27.09.1992, leg. V. Neumann, 1 male, pcl. 3.1 mm ( SMF 33833).

Description. Carapace smooth, with antennal tooth, hepatic tooth absent, with blunt postorbital tubercle ( Fig. 1 A); rostrum deep at medial part, with 9 medium dorsal and 3 large ventral teeth, with proximal and distal parts toothless. Sixth abdominal somite ( Fig. 1 B) with posterodorsal angles rectangular bearing sharp dorsal projections, posteroventral angels sharply produced. Telson ( Fig. 1 C) with 2 pairs of dorsal spines, spines from an anterior pair situates on different levels; tip of the telson with 2 stout marginal and a pair of thin medial spines. Scaphocerite ( Fig. 1 D) slender, about 3 times as long as maximal width, with the distal blade rectangular, not overreaching distolateral tooth. Second pereiopod with merus slender, about 10 times as long as wide ( Fig. 1 E); propodus ( Fig. 1 F) smooth and stout, about 2.5 times as long as wide; fingers straight and slender, about 8 times as long as wide, about 1.2 times longer than palm, with straight cutting margins bearing several small triangular teeth in its proximal parts.

Remarks. The specimen described above agrees well with the previous descriptions of Anchistioides willeyi (e.g. Holthuis, 1952; Bruce, 1971). Morphological affinities given by Borradaile (1915) easily falls within interspecific variation known for other caridean shrimps (e.g. De Grave, 1999; Marin, 2007) and previous suggestion of conspecificity of A. willeyi , A. cooperi and A. gardineri ( Gordon, 1935; Bruce, 1971) seems to be actual. Besides two latter species were collected in the same type locality, Maldive Islands. Probably, interspecific variation in Anchistioides willeyi occurs in rostral formula (6-10/3) and length of fingers of second pereiopod (finger similar or slightly longer than palm). However, Bruce (1978) reported possibly undescribed species within the “ willeyi ” species group from Madagascar “ with long rostra, rostral formula 8-13/6, and unusual long fingers of second pereiopod ”.

Distribution. Anchistioides willeyi is reported from the Red Sea for the first time. The species (if a senior synonym of A. cooperi and A. gardineri ) is also known from Maldives (type locality of A. cooperi and A. gardineri ), Borneo Bank, South Philippines, Aru Island in Indonesia, the Great Barrier Reef of Australia and New Britain ( Papua New Guinea) (type locality of A. willeyi ) (see Bruce, 1971). However, the zoogeographical distribution of Anchistioides willeyi can be given only after verification of taxonomical status of all synonymized species.

Figures

FIGURE 1. Anchistioides willeyi (Borradaile, 1899), SMF 33833, male: A—carapace; B—sixth abdominal somite and telson, lateral view; C—telson, dorsal view; D—scaphocerite; E—second pereiopod; F—same, chela.