Pseudopontophilus serratus Komai, 2004

Komai, Tomoyuki, Ohtsuka, Susumu, Yamaguchi, Shuhei & Nakaguchi, Kazumitsu, 2018, New records of six deep-sea caridean shrimps (Crustacea: Decapoda) from the Ryukyu Islands and its adjacent waters, southwestern Japan, Zootaxa 4457 (1), pp. 114-128 : 116-117

Pseudopontophilus serratus Komai, 2004

[New Japanese name: Nokogiri-shinkai-ebi-jyako]

Figs. 2 , 3

Pseudopontophilus serratus Komai, 2004: 76 , figs. 1–6 [type locality: New Caledonia, 510 m].— De Grave & Fransen 2011: 465.

Material examined. T/RV “Toyoshio-maru”, 2009-3 cruise, stn 11, W of Amami-oshima Island, 28°23.93’N, 129°13.55’E, 623–635 m, 23 May 2009, sledge net, coll. T. Komai, 2 males (cl 4.1, 5.8 mm), 7 females (cl 4.0– 4.9 mm), CBM-ZC 11092.

Colouration in fresh condition ( Fig. 2 ). Body covered with orange-brown chromatophores, more numerous on carapace, much fewer on pleon. Corneas grayish. Antennal scale mottled with white and orange-brown. Pereopod 1 generally semi-transparent, distally orange-brown on palm. Pereopods 4 semi-transparent, with tinge of red proximally on merus and ischium. Pereopod 5 entirely semi-transparent. Telson and uropods with scattered orange-brown spots on transparent background.

Distribution. Previously known from New Caledonia, Vanuatu, Fiji and Tonga, at depths of 235–650 m ( Komai, 2004). The present specimens greatly extend the geographical range of this species to the west and north.

Remarks. The genus Pseudopontophilus Komai, 2004 is represented only by its type species, P. serratus Komai, 2004 , which is known from the South-West Pacific localities, including New Caledonia, Vanuatu, Fiji and Tonga. Diagnostic characters of Pseudopontophilus include the pair of lateral teeth on the rostrum ( Fig. 3B ), one to four spines on the dorsal midline of the carapace aligned with the epigastric spine ( Fig. 3A, B ), a longitudinal row of three spines on the postorbital ridge on the carapace ( Fig. 3A, B ), one or two spines posterior to the hepatic spine ( Fig. 3A, B ), dorsally rounded pleomeres 1–6 ( Fig. 2B ) and short, but chelate pereopod 2 with fingers distinctly longer than the palm ( Fig. 3C ) ( Komai, 2004). The present specimens agree well with the type description of the species (cf. Komai, 2004) and represent the second record of the species since the original description.

One of the female specimens (cl 4.9 mm) carries an unidentified bopyrid isopod under the pleomeres 1 and 2.

Figures

FIGURE 2. Pseudopontophilus serratus Komai, 2004, showing coloration in fresh condition. A, male (cl 5.8 mm), CBM-ZC 11092, habitus, lateral view; B, female (cl 4.9 mm), same lot, habitus, dorsal view.

FIGURE 3. Pseudopontophilus serratus Komai, 2004, female (cl 4.9 mm), CBM-ZC 11092. A, carapace and cephalic appendages, lateral view; B, same, dorsal view; C, right pereopod 2, lateral view.