Echinopericlimenes calcaratus ( Chace & Bruce, 1993 ) Chace & Bruce, 1993

Marin, Ivan & Chan, Tin-Yam, 2014, Deep water echinoid-associated pontoniine shrimp “ Periclimenes hertwigi Balss, 1913 ” species group (Crustacea: Decapoda: Caridea: Palaemonidae): species review, description of a new genus and species from Philippines, Zootaxa 3835 (3), pp. 301-324 : 308-312

Echinopericlimenes calcaratus ( Chace & Bruce, 1993) comb. nov.

( Figs. 5 , 6 , 14 b, c)

Periclimenes calcaratus Chace & Bruce, 1993: 104 , fig. 21 [type locality; Albay Gulf, Philippines, 267 meters].

Material examined. Philippines: 1 male (pcl. 5.0 mm) (lacking p-p II) ( NTOU M01742 ), PANGLAO 2004, stn. T35, 9°36.4’N 123°45.5’E, Panglao Island, Looc, depth 90 meters, 21 June 2004; 1 juvenile male (pcl. 3.4 mm) ( NTOU M01743 ), PANGLAO 2004, stn. T31, 9°33.0’N 123°42.0’E, between Panglao and Balicasag Island, depth 100–140 meters, sandy and hard bottom, 2 July 2004; 1 ovigerous female (pcl. 3.4 mm) ( NTOU M01744 ), 1 ovigerous female (lacking both pereiopods II) (pcl. 4.8 mm) ( NTOU M01745 ), PANGLAO 2004, stn. L42, 9°31.2’N 123°40.7’E, Balicasag Island, depth 80–90 meters, 2 July 2004; 1 ovigerous female (pcl. 5.0 mm) ( NTOU M 01746 ), AURORA 2007, stn. CP2741, 16°03’N 121°55’E, east part of Luzon Island, depth 194 meters, 1 June 2007.

Diagnosis. Medium-sized species with subcylindrical body ( Fig. 5 ). Carapace smooth, non pitted, swollen, with antennal and hepatic teeth; hepatic tooth larger than antennal, situated close to pterygostomial margin of carapace ( Figs. 6 a, b; 7 a–c) with tip overreaching it. Rostrum slender, compressed, slightly turned downward, reaching the distal margin of antennular peduncle; dorsal rostral carina armed with 5–6 small dorsal teeth, the most proximal tooth situated anterior to the level of orbit; ventral rostral margin feebly marked, with 1 small subapical tooth situated at the level of the most distal dorsal tooth; tip of rostrum small, triangular; proximal lateral rostral lamina feebly developed; pterygostomial angle rounded ( Figs. 6 a, b; 7 a–c). Abdominal somites smooth; pleurae of abdominal somites I–V rounded ( Fig. 5 ). Telson ( Fig. 6 c) stout, about 2.5 times longer than proximal width, narrowing distally, with 2 pairs of small dorsal marginal spines at 0.5 and 0.8 of telson length; distal margin of telson armed with 3 pairs of spines including 1 pair of short stout lateral spines, 1 pair of long slender intermediate spines and 1 pair of simple medial spines about twice shorter than intermediate spines. Eyes ( Fig. 6 a, b) large, with large hemispherical cornea and stout conical eyestalk. Antennula well developed, compressed; basal segment with distolateral angle bearing large tooth and medial rounded projection, with small ventromesial tooth. Antenna normal; basal segment armed with small lateral tooth reaching the distal margin of the segment; with long slender carpocerite; scaphocerite wide, well developed, with sharp distolateral tooth slightly overreaching the blade. Mouthparts are typical for the genus, without specific features. Pereiopod I ( Fig. 6 d) with slender segments; palm about twice longer than wide, equal to fingers; dactylus and fixed finger simple, with entire cutting margins and simple tips; polex furnished with several tufts of simple setae along ventral margin ( Fig. 6 e). Pereiopods II (chelipeds) similar in shape and slightly unequal in size ( Figs. 6 f, g; 7 d–g); major pereiopod II with slender merus and ischium bearing small teeth along ventral margin, smooth dorsally ( Fig. 7 h, i); carpus small, triangular in shape, slightly overlapping carpo-propodal articulation, with straight lateral margins; propodus ( Figs. 6 f, g; 7 d–g) cylindrical, covered with small blunt tubercles, about 3 times as long as wide; fixed finger (polex) about twice as long as wide, about twice shorter than palm, with ventral margin covered with blunt tubercles, with large triangular tooth proximally and well developed slightly convex cutting edge distally, with curved, simple tip; movable finger (dactylus) relatively stout, slightly longer than polex, with large triangular tooth proximally and well developed slightly concave cutting edge distally, tip curved, simple; minor pereiopod II similar to major pereiopod II but smaller. Pereiopod III relatively slender, with unarmed proximal segments; carpus slender, about 4 times as long as wide, unarmed, with dorsal margin produced distally overlapping carpo-propodal articulation; propodus slender, about 6–7 times as long as wide, with straight lateral margins, with 5–6 separate slender spines situated along ventral margin and several slender spines at distoventral angle ( Figs. 6 h; 7 j, k), with tuft of stout flattened setae at dactylo-propodal articulation; dactylus relatively stout, about twice longer than wide, with straight ventral margin, with distoventral margin serrated ( Figs. 6 i, j; 7 l); unguis small and curved, serrated ventroproximally, distal part smooth, unarmed. Uropods normal, well developed; distolateral angle of exopod sharply produced, with single movable spine.

Remarks. All examined specimens are identical to the original description of the species given by Chace & Bruce (1993). Echinopericlimenes calcaratus comb. nov. mostly resembles E. hertwigi comb. nov. by having feebly developed lateral tooth on basal antennular segment. This feature separates these species from the remaining species of the genus ( E. dentidactylus comb. nov. and a new species described below) having well marked slender lateral tooth on basal antennular segment greatly overreaching distal margin of the segment (see below). Nevertheless, E. calcaratus comb. nov. can be readily separated from E. hertwigi comb. nov. by shorter rostrum armed with 1 ventral tooth situated at the level of the most distal dorsal tooth (vs. long rostrum usually armed with 2 ventral teeth in E. hertwigi comb. nov.) and shallower dorsal rostral carina (vs. deep dorsal rostral carina in E. hertwigi comb. nov.). At the same time, ovigerous female of E. hertwigi comb. nov. from Japan (CBM-ZC-3692) has 1 ventral rostral tooth resembling rostrum of E. calcaratus comb. nov. but also possesses deep dorsal rostral carina, especially in its proximal part, clearly differs from all examined specimens of E. calcaratus comb. nov. The taxonomic separation of these species is also satisfied by the analysis of barcoding gene COI showing the genetic differences between the species more than 7% (see Fig. 16).

Coloration. Body and appendages are uniformly deeply red without any white pigmentation ( Fig. 14 b, c).

Host. Exact host species of E. calcaratus comb. nov. remains unknown. Probably, the shrimp is associated with deep-water venomous sea urchin of the family Echinothuriidae (Echinodermata: Echinoidea) usually numerously presented in the same trawl catches (T.-Y. Chan, pers. comm.).

Distribution. The species is presently known only from the type locality, the Philippines, at the depth 80–267 meters ( Chace & Bruce, 1993; the present study).

Figures

FIGURE 5. Echinopericlimenes calcaratus (Chace & Bruce, 1993) comb. nov., male from Philippines, 90 m (NTOU M 01742) (above) and ovigerous female from Philippines, 80 – 90 m (NTOU M 01744), general lateral view.

FIGURE 6. Echinopericlimenes calcaratus (Chace & Bruce, 1993) comb. nov., ovigerous female from Philippines, 80 – 90 m (NTOU M 01744) (a – i), male from Philippines, 90 m (NTOU M 01742) (j): a, b — rostrum and carapace; c — telson; d — pereiopod I; e — same, chela; f — major pereiopod II; g — minor pereiopod II; h — distal propodus and dactylus of pereiopod III; i, j — same, distal part of dactylus, without scale.

FIGURE 7. Echinopericlimenes calcaratus (Chace & Bruce, 1993) comb. nov., male from Philippines, 100 – 140 m (NTOU M 01743) (a, d, e), ovigerous female from Philippines, 80 – 90 m (NTOU M 01745) (b), ovigerous female from Philippines, 194 m (NTOU M 01746) (c, g – l): a – c — rostrum and front of carapace, lateral view; d – g — pereiopods II, distal segments; h – i — pereiopods II; j, k — distal propodus and dactylus of pereiopod III; l — same, distal part of dactylus (without scale).

FIGURE 14. Echinopericlimenes dentidactylus (Bruce, 1984) comb. nov., male from Philippines, 679 – 740 m (NTOU M 01749) (a); Echinopericlimenes calcaratus (Chace & Bruce, 1993) comb. nov., non-ovigerous female from Philippines, 80 – 90 m (NTOU M 01745) (b), non-ovigerous female from Philippines, 194 m (NTOU M 01746) (c); Ecinopericlimenes aurorae sp. nov., holotype male from Philippines, 336 m (NMCR) (d, e), male from Philippines, 273 – 302 m (NTOU M 01742) (f), non-ovigerous female from Philippines, 357 – 367 m (NTOU M 01748) (g, h).