Coralliocaris sandyi, Mitsuhashi, Masako & Takeda, Masatsune, 2008

Mitsuhashi, Masako & Takeda, Masatsune, 2008, Identity of the coral-associated pontoniine shrimp species, Coralliocaris nudirostris (Heller, 1861) and C. venusta Kemp, 1922 (Crustacea: Decapoda: Palaemonidae), with descriptions of two new species, Zootaxa 1703, pp. 1-24 : 11-16

Coralliocaris sandyi new species

(figs 1C, D; 6C, D & 8–10)

Coralliocaris venusta: Patton, 1966: 277 (in part).

Coralliocaris venusta: Bruce, 1976a: 32 –35, fig 12.

Coralliocaris venusta: Bruce ,?1977b: 73 (colour illust); 1978a: 282, fig 42 (in part).

Coralliocaris venusta: Bruce, 1980: 339 (tab), 342 (text);?1983: 201 (text).

Coralliocaris venusta b: Bruce, 1998: 32 (text), 37 (key). — Mitsuhashi, 2000; 5, 6, fig 9 (colour illust). Coralliocaris nudirostris: Kamezaki et al., 1988 ; 158 (colour illust). — Mitsuhashi, 2000; 3, fig 3 (colour illust) (same specimen as Kamezaki et al.).

Material examined. Holotype: Off Kuro-shima Island, Ryukyu Islands, 8m depth, from Acropora sp., Jun. 29, 1998, coll. K. Nomura and M. Mitsuhashi, ov.Ψ(CL 2.73 mm), NSMT-Cr 1928.

Allotype: Paired with holotype, 1ɗ(CL 1.74 mm), NSMT-Cr 1955.

Paratypes: Japan: Tomino, Ishigaki-jima Island, Ryukyu Islands, low tide, 1m depth, from Acropora sp., Jun. 22, 1998, coll. M. Mitsuhashi, 1ov.Ψ(CL 2.86 mm) (damaged), NSMT-Cr 1918; same locality data, from Acropora digitifera (Dana) , 1ov.Ψ(CL 2.15 mm) (parasitized by a bopyrid isopod), NSMT-Cr 1919; Tomino, Ishigaki-jima Island, Ryukyu Islands, low tide, 1m depth, Jun. 25, 1998, coll. M. Mitsuhashi, 1ov.Ψ(CL 2.67 mm), NSMT-Cr 1920; off Anadomari, Kuroshima Island, Ryukyu Islands, 8m depth, from Acropora sp., Jun. 27, 1998, coll. K. Nomura and M. Mitsuhashi, 1ov.Ψ(CL 2.67 mm), NSMT-Cr 1921; off Kuroshima Island, Ryukyu Islands, 8m depth, from Acropora sp., Jun. 29, 1998, coll. K. Nomura and M. Mitsuhashi, 1ɗ(CL 2.23 mm), NSMT-Cr 1961; off Hori, Kuroshima Island, Ryukyu Islands, patch reef, 3m depth, from Acropora gemmifera (Brook) , Oct. 5, 1987, coll. K. Nomura, 1ov.Ψ(CL 3.46 mm), 1ɗ(CL 2.85 mm), NSMT-Cr 1933. Paracel Islands: Macclesfield Bank, Pygmy Shoal, 12fms., 16°25.0’S, 114°45.0’E, 1ov.Ψ(CL 2.16 mm), 1ɗ(CL 1.38 mm), QM-W28262. Palau: Aulong Island, the Rock Islands, Dec. 1, 1997, coll. M. Takeda, 1Ψ(CL 3.21 mm), NSMT-Cr 1956. Australia: Heron Island, Capricorn Islands, Queens Lane, from Acropora sp., Dec., 1951, coll. W. Patton, 1Ψ(CL 2.19 mm), AM P. 13250; lagoon, 0.1m depth, from Acropora sp., Aug. 6, 1976, coll. D. Fisk, 1Ψ(CL 2.54 mm), 1ɗ(CL 2.19 mm), QM-2434; Ashmore Reef, Western Australia, 12°13.4’S 122°59.0’E, channel into lagoon, 8m depth, from coral, Jul. 26, 1986, coll. C. Johnson et al., 1ɗ(CL 2.02 mm), 1ov.Ψ(CL 2.37 mm), NTM-Cr. 0 12660. Ile Europe: Jun., 1952, 1ov.Ψ(CL 3.10 mm), MNHN-Na 11083. Data unknown: 1ov.Ψ(CL 2.28 mm), KMNH IvR 300030.

Description of holotype. Medium-sized ovigerous female (CL 3.05 mm), carrying early eyed eggs (fig 7A). General morphology closely resembling C. nudirostris . Rostrum (fig 7A–C) shallow, tapers to sharp point, just reaching intermediate segment of antennular peduncle; upper and lower margins without perceptible tooth, but each margin with setae near tip; supraorbital eave regularly expanded posteriorly, not angled.

Abdomen (fig 7A) with broadly rounded pleurae; third segment longer than second segment. Telson (fig 7D) about as long as twice of greatest width; 2 pairs of dorsolateral spines situated at half length and posterior 1/3 length respectively; posterior margin with 3 pairs of terminal spines, intermediate pair thickest and longest, 1/7 of telson length, 3 to 4 times of outermost spine; innermost pair plumose, somewhat shorter than intermediate pair. Eyes (fig 7A, B) large; eyestalk length about 1.5 times of its width; cornea globular, slightly wider than eyestalk. Antennular peduncle (fig 7B) reaching 3/4 of lamella of scaphocerite; basal segment slightly shorter than greatest width, roundly convex on outer margin, terminating in small spine; stylocerite reaching to 3/4 of length of medial margin; fused part of upper flagellum composed of 8 articles. Antenna

(fig 7B) similar to that of C. nudirostris ; basicerite with wide, robust distolateral spine. Mouthparts based on left side. Mandible (fig 8A) armed with 4 teeth on distomedial margin of incisor process. Maxillula (fig 8B) with small seta on tip of anterior lobe of palp; upper lacinia with several short thick setae and fine longer setae on medial margin; lower lacinia slender, with fine longer setae distally. Maxilla (fig 8C) with short simple endite bearing small apical seta; palp twice as long as endite. First maxilliped (fig 8D) with short rounded basal endite, fringed with setae on medial margin. Second and third maxillipeds (fig 8E, F) generally similar to those of C. nudirostris ; carpus of third maxilliped slightly longer than terminal segment; arthrobranch of third maxilliped with 9 lamellae; exopod overreaching distal end of endopod when extended. First pereiopod (fig 9A, B) slender; dactylus about 1.6 times as long as palm, with several tufts of setae; medial surface of fingers regularly convex, without concavity on medial surface; palm with tufts of long setae on dorsolateral distal part; carpus slightly longer than merus. Second pereiopods (fig 9C, D) subequal to each other. Chela about 1.5 times as long as CL. Dactylus half as long as palm, slightly flanged, with distinct longitudinal ridge on medioventral face; cutting edge with 2 subtriangular teeth on proximal half. Fixed finger with 3 subtriangular teeth on cutting edge. Palm subcylindrical, slightly shorter than 3 times of greatest width. Carpus 0.3 times as long as palm; distoventral margin without perceptible tooth; medioventral process blunt. Merus compressed, somewhat longer than half of palm. Third to fifth pereiopods (fig 9E) similar to each other, robust. Dactylus short, distally blunt, each extensor surface with strongly curved hook-shaped protuberance. Propodus 4 times as long as dactylus, with 4 transverse rows of curved setae on distoventrally, covering dactylus, longer than ischium, with robust process at dorsodistal margin. Pleopod well developed; first pleopod with slender endopod, 2/3 of exopod in length; each appendix interna of second to fifth pleopods situating at proximal 1/3 of endopod, 1/4 length of endopod.

Notes of paratypes. Medium-sized females (CL 2.15–3.46 mm) and smaller, slender males (CL 1.38–2.85 mm).

Rostrum (fig 10A, B) reaching distal 1/3 of basal segment to first segment of antennular peduncle; dorsal margin unarmed or armed with 1 to 3 teeth, ventral margin unarmed or armed with a tooth (tab 1). First pereiopod (figs 6C, 10C) with a tuft of dense setae situated close to movable finger. Second pereiopod (fig 10D) relatively large, slender in male, chela 2.6 to 3.0 times as long as CL in males, 2.3 to 2.8 times as long as CL in females; cutting edge of movable finger normally with 2 teeth, except for an ovigerous female (NSMT- Cr 1933) which unusually bears only 1 tooth on left. Third to fifth pereiopods (fig 6D) with 4 to 5 rows of strongly curled setae on distoventral part of propodus. Pleopod (fig 10E) of male with small masculina.

Ovigerous female bearing about 70 early developmental eyed-ova, measuring 0.46 mm – 0.71 mm along axis.

Colour in life. Ground colour transparent. Carapace and abdomen with fine longitudinal black stripes made up of black dots in females (fig 1C). Males sparsely dotted with black dots (fig 1D), without distinct stripes. The colour patterns still remain in some specimens kept in alcohol with white dots, longitudinally striated. [Based on specimens: NSMT-Cr 1918; 1919; 1920; 1921; 1933; 1955; 1961.]

Remarks. This species is very similar to C. nudirostris in general morphology, but can be distinguished by the colour pattern (black striae on the body, fig 1C, D), and the fingers of the first pereiopod not forming a concavity (fig 6C). A further new species (described below) also lacks a concavity on the fingers of the first pereiopod, but can be separated from C. sandyi sp. nov. by the colour pattern and the roundly convex rostral base, relatively round cheliped of the first pereiopod, and usually has fewer number of rostral teeth ( Table 1 ). Dense tufts of setae on the dorsodistal part of the palm and thick, strongly curly setae on the third to fifth pereiopods (fig 6C, D) may be also diagnostic features of this species.

This species has been reported as the ‘black striated morph’ of C. venusta , corresponding to the black longitudinal striated form (‘ type’ of Bruce (1976a); ‘ type’ of Bruce (1980), and ‘a type’ of Bruce (1998) and Mitsuhashi (2000)). Bruce (1998) mentioned a third colour pattern of C. venusta , lacking conspicuous white patches, citing the photograph of Bruce (1977b: p 73). The only information on the specimen we have is a monochromatic photocopy of the photograph but from the features of the dark spots forming longitudinal lines on the body, it can also be considered to belong to this species.

One ovigerous female identified as C. venusta (MNHN-Na 11083) by Bruce (1978a) was examined in this study and identified as this new species based on the morphological features. The paper also reported some specimens of C. venusta from Geyer Reef of Madagascar and noted the colour pattern as ‘... heavily dotted and striated with patches of opalescent white’ that does not agree with the colour pattern of this species. Unfortunately, we could not access the specimen, but it is confidently assigned to this new species due to the same colour pattern.

Distribution. The type specimens were collected from the Ryukyu Islands. Widely distributed in Indo- West Pacific: Ryukyu Islands, Parcel Island, Palau Islands, Loyalty Islands, Western Australia, and Heron Island (Great Barrier Reef).

Etymology. This species is dedicated to Dr A. J. Bruce for his invaluable contributions to this species as well as the taxonomy of the subfamily Pontoniinae .