Callianassa coriolisae, Ngoc-Ho, 2014

Ngoc-Ho, Nguyen, 2014, Six species of Axiidea and Gebiidea from the Indo-West Pacific (Crustacea, Decapoda), Zoosystema 36 (3), pp. 545-561 : 552-554

Genus Callianassa Leach, 1814 Callianassa coriolisae n. sp.

( Fig. 3 )

Callianassa sibogae de Man, 1905: 613 . – Ngoc-Ho 1994: 54, fig. 3.

Cheramus sibogae – Ngoc-Ho 2005: 77, fig. 15.

MATERIAL EXAMINED. — Philippines. NO “Corioli” MUSORSTOM 3, St. 119, 320- 337 m, 3.VI.1985. Holotype. ♂, cl 12 mm, tl 45.5 mm, major pereopod 1 absent ( MNHN Th 1228).

Paratypes. 2 ♂, one damaged, cl 11 mm, tl 36 mm, one broken, cl 14 mm, major pereopod 1 present ( MNHN Th 1229).

OTHER MATERIAL EXAMINED. — Indonesia. Java anchorage, Callianassa sibogae , holotype, Siboga Expedition: ♂, tl 22.8 mm ( ZMA De 102.439).

Western Australia. Callianassa sibogae , Northwest Shelf: ♀, tl 13 mm (MNHN Th 1248).

French Polynesia. Cheramus sibogae, Raiatea Is. , Society: ♀, tl 23.5 mm ( MNHN Th 1434).

DIAGNOSIS. — Rostrum laterally compressed with upturned pointed tip. Antennular peduncle shorter than antennal peduncle. Second pleomere broader than long, with terga expanded laterally. Telson longer than broad at base, posterior border convex with a median spine. Maxilliped 3 subpediform, merus approximately quadrate. Male major pereopod 1 with spinules on lower border of ischium, merus with proximal pointed hook, carpus with typical elongated proximal dorsal “neck”, fixed finger and dactylus slender with incurved tip. Minor pereopod 1 ischium with spinules on lower border; merus with a spine at midlength of lower border; fixed finger and dactylus unarmed with slightly curved tip. Pereopod 3 propodus slender, not expanded. Uropod exopod and endopod longer than telson. A digitiform appendix interna on endopod of pleopods 2-5.

ETYMOLOGY. — The species is named after the oceanographic vessel Coriolis that collected the studied material.

DESCRIPTION

Carapace ( Fig. 3A, B ) with laterally compressed upturned pointed rostrum; eyestalks slightly shorter than first article of antennular peduncle, with obtuse mesiodistal tip, corneas subterminal. First pleomere saddle-shaped, broader posteriorly than anteriorly, narrow in the middle,lateral margins concave; second and sixth segments of about same length. Telson ( Fig. 3C ) about as long as sixth pleomere, slightly longer than broad at base, posterior border convex with a median spine and two lateral spiniform setae on each lateroposterior angle.

Antennular peduncle ( Fig. 3A, B ) reaching approximately base of last segment of antennal peduncle. Third maxilliped ( Fig. 3D, E ) subpediform with ischium-merus length about two or three times merus width; merus approximately quadrate, mesial surface of ischium with crista dentata of six or seven large teeth and four or five smaller teeth.

Male major pereopod 1 ( Fig. 3F ) ischium with spinules on lower border, merus about as long as ischium bearing proximal pointed hook and distal denticles; carpus triangular with typical elongated dorso-proximal “neck”, rounded lower border and lower distal spinule; propodus approximately quadrate, 1.5 times longer than carpus, unarmed except for a distal spine between the bases of dactylus and fixed finger; both of the latter about 0.75 time length of propodus, with incurved tip, fixed finger with a small flat triangular tooth at midlength of cutting edge, cutting edge of dactylus with a round proximal tooth and dentate distally.

Male minor pereopod 1 ( Fig. 3G ) ischium with spinules on lower border; merus as long as ischium unarmed except for a spine at midlength of lower border; carpus 1.5 times as long as merus, unarmed; palm slightly shorter than fixed finger, latter and dactylus unarmed with slightly curved tip.

Pereopod 3 ( Fig. 3H ) propodus slender, not expanded ventrally.

Pleopod 3 ( Fig. 3I ) biramous, both endopod and exopod slender, endopod bearing small finger-like appendix interna.

Uropods ( Fig. 3C ) both exopod and endopod longer than telson, with rounded posterior border, small dorsal setose lobe on exopod.

REMARKS

This material was firstly assigned to C. sibogae de Man, 1905 to which it is similar in: 1) the laterally compressed pointed upturned rostrum; 2) the antennular peduncle shorter than that of the antennae; 3) the morphology of the secod pleomere; and 4) the morphogy of the telson (de Man 1928: 124-126, pl. XI, fig. 17-17e).

Nevertheless, Poore (personal communication) pointed out the differences between the two species: 1) C. sibogae rostrum appears with a sharp upper edge (de Man 1928: fig. 17) that is absent in the new taxon; 2) C. sibogae maxilliped 3 merus shows an accused squarish distomesial corner which it is weak in C. coriolisae n. sp.; 3) the posterior border of the telson is unarmed in C. sibogae , bearing a median spinule in C. coriolisae n. sp.; and 4) the uropod.

Exopod is slender about 1.8 time as long as wide in C. sibogae , 1.4 times as long as wide in C. coriolisae n. sp.

The materials previously assigned to Callianassa sibogae from Western Australia, Northwest Shelf, ( MNHN Th 1248), and Cheramus sibogae from French Polynesia, Raiatea Is. Society ( MNHN Th 1434) are likely to belong to this new taxon.

Callianasa sibogae was established by de Man (1905) on a much damaged male of the Siboga Expedition of tl 22.8 mm without pereopods 1, 3 and 4. No large male of this species or those closely related has been subsequently studied and the morphology of major pereopod 1 reported in C. cariolisae n. sp. with a dorso-proximal “neck” in the carpus is unique.

The species sibogae is placed by Tudge et al. (2000) and WORMS (World Register of Marine Species) ( Poore 2013) in the genus Cheramus Bate, 1888 due to the presence of a rostral spine, and finger-like appendix interna on pleopods among other caracteristics. Nevertheless, considering the definition of the genus Cheramus as given by Manning & Felder (1991), a few discrepancies can be noted: male pereopod 1 bears a meral hook instead of being without; uropods are moderately elongated instead of “extremely elongate”.

Poore (personal communication) considers that Cheramus sibogae (and the new taxon) is within a group of a dozen or more species that are similar and diverse, and that probably should not be called Cheramus . Pending another revision of the group, the new taxon is here placed in the classic genus Callianassa .

Figures

FIG. 3. — Callianassa coriolisae n. sp.: A-E, G, H, holotype ♂, tl 42.5 mm (MNHN Th 2228); F, I, paratype ♂, broken, cl 14 mm (MNHN Th 1229). A, whole specimen; B, anterior part of carapace; C, telson and uropods; D, E, maxilliped 3 and inner view of ischium; F, pereopod 1; G, H, pereopod 2 and 3; I, pleopod 3. Scale bars: 1 mm.