Ciliopagurus galzini, Poupin & Malay, 2009

Poupin, Joseph & Malay, Maria Celia, 2009, Identification of a Ciliopagurus strigatus (Herbst, 1804) species-complex, with description of a new species from French Polynesia (Crustacea, Decapoda, Anomura, Diogenidae), Zoosystema 31 (2), pp. 209-232 : 222-225

Ciliopagurus galzini n. sp.

( Figs 1D ; 3D ; 4D ; 5-9 )

Ciliopagurus tricolor – Poupin 2005: 9, 23 [not Ciliopagurus tricolor Forest, 1995 ].

TYPE MATERIAL. — French Polynesia. Tuamotu Is, Rangiroa I., off Motu Maeherehonae, 14.9287°S, 147.8578°W, outer slope under rocks, 6-12 m, coll. G. Paulay, 10.IX.2001, ♂ 3.8 mm, in Conus ? pertusus (holotype, UF Crust 10901). — Same, in Cypraea sp. , 1 ♂ 2.9 mm (paratype, MNHN Pg 6347, DNA H284- EF683570 ); 1 ♀ 2.2 mm, 1 ♀ 3.2 mm (paratype, UF Crust 1339, DNA H282- EF683568 , DNA H283- EF683569 ). — Same, in cavern and wall, 3-12 m, coll. G. Paulay, 10.II.2001, 1 ♂ 3.2 mm (paratype, UF Crust 1742, DNA H32- EF683560 ).

SHELLS. — Cypraeidae : Cypraea helvola Linnaeus, 1758 ; Cypraea scurra Gmelin, 1791 ; Cypraea schilderorum (Iredale, 1939) . Conidae : Conus pertusus Hwass in Bruguière, 1792.

TYPE LOCALITY. — French Polynesia (Tuamotu Is, Rangiroa I.), 3- 12 m.

ETYMOLOGY. — This species is dedicated to Professor René Galzin, director of CRIOBE biological research station at Moorea I. René Galzin has constantly supported our research on coral reef fauna in French Polynesia and other places in the Indo-West Pacific.

DISTRIBUTION ( Fig. 9 ). — Known from type locality only, French Polynesia (Tuamotu Is, Rangiroa I.), outer reef slope between 3 and 12 m.

DIAGNOSIS. — Ocular peduncles 0.68-0.77 (average 0.72) times as long as shield. Distal segment of antennular peduncle 0.21-0.30 (average 0.25) times as long as shield. Ocular acicles each with 3 or 4 terminal spines (unusually 2). Chelipeds equal; outer face of chela with 3 complete transverse striae, plus an additional stria proximally partly hidden behind anterior margin of carpus; striae smooth or with minute spinules. Chela 0.77-1.00 (average 0.92) times as long as shield; fingers 0.49-0.56 (average 0.52) times as long as chela. Main stridulating area with 10-12 parallel corneous crests, distally acute. Merus of cheliped without prominent tubercle on ventral face. Dactyl of third ambulatory leg 0.99-1.07 (average 1.04) times as long as propodus. Posterior lobes of telson subequal, unarmed or with 1-6 inconspicuous spines on terminal margins.

COLORATION ( Fig. 1D ). — Antennular, antennal and ocular peduncles bright orange, cornea yellow. Chelipeds ( Fig. 3D ) and ambulatory legs ( Fig. 4D ) with composite coloured rings, comprised of one white median band, flanked by two bright red rings; these composite rings are set against a bright orange background. Chelipeds with composite rings on meri, carpi, and chelae including fingers. Ambulatory legs with composite coloured rings disposed on meri, carpi, propodi and dactyls; terminal claws black. Shield white; live coloration of the abdomen not known, cream after several months in preservative.

DESCRIPTION

Shield slightly wider than long ( Fig. 5A ). Rostrum rounded, slightly overreaching level of broadly subtriangular lateral projections; anterior margins between rostrum and lateral projections slightly concave; anterolateral margins strongly convex.

Ocular peduncles subequal or left slightly longer than right, 0.68-0.77 (average 0.72) times as long as shield, slightly constricted medially.Cornea diameter included 3.93-4.83 (average 4.55) times length of ocular peduncles. Ocular acicles well developed, subtriangular, distally truncated, armed with 3 or 4 terminal spines. Antennular peduncles reaching to distal 0.25 of ocular peduncles, when fully extended; ultimate segments 0.21-0.30 (average 0.25) times as long as shield. Antennal peduncles slightly shorter than antennular peduncles, reaching between middle and distal 0.30 of ocular peduncles. First segment unarmed. Second segment with laterodistal angle produced, terminating in bifid spine.Third segment with strong spine at ventrodistal angle. Fourth segment with dorsodistal spine.Fifth segment unarmed. Antennal flagellum overreaching outstretched chelipeds.Antennal acicle reaching well beyond proximal margin of fifth antennal segment, terminating in 2 strong pairs of terminal and sub-terminal spines; dorsomesial margin with 2 or 3 spines.

Chelipeds equal, distal margins of carpi slightly overreaching distal margins of ocular peduncles.Chela 0.77-1.00 (average 0.92) times as long as shield, ratio of height to length 0.63-0.73 (average 0.68). Cutting edges of dactyl and fixed finger with3 large calcareous teeth. Dactyl 0.49-0.56 (average 0.52) times as long as chela, outer face with 4 transverse striae each bearing stiff setae and minute corneous spines ( Fig. 5D ). Fixed finger with 3similar transverse striae.Outer face of palm with transverse striae set with stiff setae: 3 complete striae plus a proximal stria partly covered by anterior margin of carpus and shorter striae between as illustrated on Figure 3D . Dorsomesial surface of palm with stridulating apparatus in distal half composed of parallel corneous crests disposed on 4 main areas (numbered 1 to 4 on Fig.5D ). Distomesial area (no. 1) with 10-12 crests oriented obliquely to longitudinal axis of palm, distally acute; 6th-8th crest the longest being about 0.4 length of this area; dorsolateral side of area no. 1 with 3 or 4 additional small crests. Area no.2 much shorter,with only 4 or 5 crests near dorsal margin of palm. Areas nos 3 and 4 narrow, subparallel, each composed of 10-14 short crests, some of them reduced to corneous granules.Stria behind area no. 4 with few indistinct corneous denticles. Carpus shorter than palm bearing transverse striae set with stiff setae. Outer face with 3 main striae behind anterior margin plus an additional incomplete stria between the two first striae ( Fig. 3D ). Merus with 4 complete striae on outer face behind anterior margin and 1-3 additional posterior striae shorter and fragmented; ventral area depressed, without prominent tubercle; ventrolateral margin with 2 distal spines.

Ambulatory legs similar between left and right, overreaching outstretched chelipeds by length of dactyls. Relative length of segments and arrangement of striae, setae, and spines similar between second and third pereopods; transverse striae and distal margins of each segment set with stiff setae. Dactyl 0.99-1.07 (average 1.04) times as long as propodus, with strong terminal claw; ventral margin with 5-8 corneous spines, decreasing in size posteriorly, obscured by tufts of long setae; outer face with 3 or 4 main transverse striae plus a few shorter striae between. Propodus 0.76-1.02 (average 0.90) times as long as shield, with 5 or 6 main transverse striae and a few additional shorter striae between. Carpus 0.52-0.59 (average 0.55) times as long as propodus, with 3 or 4 transverse striae. Merus 0.81- 0.89 (average 0.85) times as long as propodus, with 5 or 6 main transverse striae and few shorter striae between; outer face convex, inner face flattened, dorsal margin angular set with long setae.

Fourth pereopod semichelate. Dactyl with long setae on dorsal margin. Propodus with broad rasp consisting of several rows of corneous scales, dorsodistal margin with long setae. Carpus with dorsodistal spine, dorsal margin with long setae. Merus with few striae on outer face, dorsal and ventral margins with long setae. Fifth pereopod chelate, with rasp on propodus and dactyl. Carpus and merus subovate in cross-section.

Abdomen with 4 unpaired biramous pleopods, on left side (verified in male only). First pleopod shortest, other 3 subequal in length. Sixth abdominal tergite calcified with a deep sub-median transverse groove and a weak longitudinal median furrow, more noticeable on posterior area.

Telson with distinct lateral indentations. Posterior lobes subequal to moderately asymmetrical, terminal margins with long setae at external angles. Left lobe rounded, only slightly longer than right, lateral margin unarmed, terminal margin with 2-6 spinules (sometimes missing or indistinct); right lobe rounded, terminal margin armed with 1-3 spinules.

REMARKS

An unusual armament of the ocular acicle, only 2 terminal spines instead of the usual 3 or 4, is observed on a single specimen out of five (♂ 3.2 mm, UF Crust 1742).

Within the species of the “ strigatus complex” C. galzini n. sp. is most closely related to C. tricolor with a similar colour pattern made of composite coloured rings disposed on an orange background. Because of this resemblance, the specimens collected at Rangiroa were first attributed to C. tricolor by Poupin (2005). However, when more specimens of C. tricolor were later available from Réunion Island, with photographs of live coloration, it became obvious that the specimens from Rangiroa, described herein as C. galzini n. sp., differ consistently from those collected in the western Indian Ocean in the coloration of fingers of chelae and dactyls of ambulatory legs. In C. galzini n. sp., these segments have composite coloured rings instead of being uniformly pale orange as in C. tricolor (see Figs 1B, D ; 3B, D ; 4B, D ).

The few other morphological differences observed between some specimens of the two species, such as the aspect of transverse striae on chelae and ambulatory legs, number of spines on ventral margins of dactyls of pereopods or on terminal margins of telson, and relative length of the appendages (see morphometric analysis), are size related or within the range of intraspecific variations observed for the two species. They cannot be used confidently to separate them. A phylogenetic analysis of mitochondrial DNA sequences has been therefore undertaken to confirm the appraisal of these colour differences as valuable specific indicators (see discussion).

Figures

FIG. 1. — Live colorations: A, Ciliopagurus strigatus (Herbst, 1804), Futuna I., ♂ 7 mm (MNHN Pg 7762); B, C. tricolor (Forest, 1995), Réunion I., ovig.♀ 2.9 mm (UF Crust 5433);C, C. vakovako Poupin,2001, Marquesas Is, holotype ♂ 4.3 mm (MNHN 5896); D, C. galzini n. sp., Tuamotus, holotype ♂ 3.8 mm (UF Crust 10901).

FIG. 3. — Left cheliped colour pattern, outer view: A, Ciliopagurus strigatus (Herbst, 1804), ♂ 3.8 mm, Réunion I. (MNHN Pg 7759); B, C. tricolor (Forest,1995),ovig.♀ 3.3 mm,Réunion I. (MNHN Pg 7760);C, C. vakovako Poupin,2001, holotype ♂ 4.3 mm,Marquesas Is (MNHN Pg 5896); D, C. galzini n. sp., holotype ♂ 3.8 mm (UF Crust 10901). Scale bars: 1 mm.

FIG. 4. — Left third pereiopod colour pattern, outer view: A, Ciliopagurus strigatus (Herbst, 1804), ♂ 3.8 mm, Réunion I. (MNHN Pg 7759); B, C. tricolor (Forest, 1995), ovig. ♀ 3.3 mm, Réunion I. (MNHN Pg 7760); C, C. vakovako Poupin, 2001, holotype ♂ 4.3 mm, Marquesas Is (MNHN Pg 5896); D, C. galzini n. sp., holotype ♂ 3.8 mm (UF Crust 10901). Scale bars: 1 mm.

FIG. 5. — Ciliopagurus galzini n. sp., holotype ♂ 3.8 mm (UF Crust 10901): A, shield and cephalic appendages; B, ocular scales; C, left antenna, dorsal view; D, left chela, dorsomesial face, with detail of stridulating apparatus and identification of four main areas (1-4). Scale bars: 1 mm.

FIG. 6. — Length of ocular peduncle/shield length. Data from Table 1, means ± 1.00 or 1.96 standard deviation, calculated for species of the strigatus species complex and Ciliopagurus krempfi (Forest, 1952): * indicates a significant difference (ANOVA and paired tests, P<0.05).

FIG. 7. — Maximum likelihood phylogram based on COI mitochondrial DNA sequences. Values above the branches correspond to parsimony bootstraps (left), maximum likelihood bootstraps (middle), and Bayesian posterior probabilities (right).

FIG. 9. — Geographic distributions of the Ciliopagurus Forest, 1995 species included in the “strigatus complex” based on the material examined for this work and literature. Light gray area is the distribution of C. strigatus (Herbst, 1804) (●); dark gray areas are the distribution of C. tricolor (Forest, 1995) (▲) and C. vakovako Poupin, 2001 (★); asterisk (Å) is the distribution of C. galzini n. sp. A doubtful locality for C. tricolor is indicated by “▲?”.