Metapenaeus elegans De Man 1907

Metapenaeus elegans De Man, 1907

(Figs. 2, 8b)

Metapenaeus elegans De Man 1907: 130 (type locality: Indonesia).— Miquel 1982: 83, figs. 31-32.— Lee et al. 1999: 445.

Penaeopsis elegans —De Man 1911: 58, pl. 6-fig. 16.

Material examined. Yilan County, Dasi fishing port, 14 Oct 1988, 1 male cl 19.1 mm (NTOU M02319).

Diagnosis. Rostrum with 8 (excluding epigastric tooth) teeth along entire dorsal border, generally straight and extending to tip of antennular peduncle. Pereiopod I with small ischial spine. In males, basial spine of pereiopod III not particular elongated, merus of pereiopod V with basal notch accompanied by carinated tubercle, which slightly bent outward. Telson with minute movable lateral spinules. Male petasma with distomedian projections semi-circular and flap-like, extending to tips of distolateral projections.

Coloration. Body somewhat pinkish grey and covered with dense dark dots. Antennal flagella and distal half of uropods reddish.

Distribution. Indo-West Pacific from Sri Lanka to Taiwan and Wallis and Futuna Islands, intertidal to 55 m deep (Miquel 1982; Pérez Farfante & Kensley 1997; Chan 1998).

Remarks. Although the list of Penaeoidea from Taiwan and adjacent areas by Lee et al. (1999) contained M. elegans as a new record, their sampling areas included many localities far from Taiwan in the South China Sea, East China Sea and northwest of the Philippines (Lee et al. 1999: fig.1). Moreover, Lee at al. (1999) only listed M. elegans with no further information how such record was based (e.g., no voucher specimen information provided). This work formally reports M. elegans from Taiwan for the first time and extends the northern geographical range of this species from the Philippines to Taiwan. This species is very rare in Taiwan and at present only one male has been collected from the northeastern coast of the island despite of the recent extensive surveys on the decapod crustacean fauna in Taiwan. Amongst the species of this genus in Taiwan, M. elegans is most similar to M. moyebi (Kishinouye, 1896). Nevertheless, their petasma are very different with the distomedian projections extending far beyond the distolateral projections in M. moyebi (Fig. 6b) but reaching as far as the tips of distolateral projections in M. elegans (Fig. 2b). According to Miquel (1982: fig. 31c), the thylcum of M. elegans has the anterior end of anterior plate smooth while the lateral margins of the lateral plates distinctly ridged (v.s. anterior end of anterior plate bearing three tubercles while lateral plates with margins not ridged in M. moyebi, Fig. 7c).