Neocallichirus Sakai, 1988

Ngoc-Ho, Nguyen, 2014, Six species of Axiidea and Gebiidea from the Indo-West Pacific (Crustacea, Decapoda), Zoosystema 36 (3), pp. 545-561 : 554-556

Genus Neocallichirus Sakai, 1988

Neocallichirus audax (de Man, 1911) ( Fig. 4 )

Callianassa audax de Man, 1911: 223 . — Dworschak 1992: 190, fig. 1a-d. — Tudge et al. 2000: 138, 143.

Callianassa (Callichirus) audax – de Man 1928: 1, 28, 113, 179, pl. 20, fig. 31-31i. — Rao & Kartha 1967: 279, figs 1, 2. — Timizi 1967: 151-154, figs 1, 2.

Callichirus audax – de Saint Laurent & LeLoeuff 1979: 97.

Neocallichirus audax – Sakai 1999: 95, fig. 21d, f, 2005:17. — Fatima & Kazmi 2008: 123-124, pl. 1.

MATERIAL EXAMINED. — Vietnam. Can-Gio, HochiMinh ville, 9-10 km off the coast, 10-15 m, entangling net, sandy bottom, coll. and don. Nguyen-van-Xuân 2000, 1 ♂, cl 32 mm, tl 113 mm, broken, 1 ♀, cl 16 mm, tl 54 mm, distal part of both pereopods 1 broken ( MNHN Th 1618).

DISTRIBUTION. — Strait of Malacca (de Man 1911; Dworschak 1992), West Pakistan ( Tirmizi 1967) Malabar coast, south west India ( Rao & Kartha 1967), East coast of India ( Dworschak 1992).

DESCRIPTION

Carapace with cervical groove and linea thalassinica well defined; anterior border ( Fig. 4A ) with three small prominences, median prominence making short obtusely angular rostrum. Eyestalks about twice as long as broad, with slightly pointed tip, overreaching base of first antennular article; cornea rounded, large in male, smaller in female, dark brown, situated dorso-laterally in proximal half of eyestalks. Telson ( Fig. 4G ) nearly half as long as broad, posterior border slightly undulated, posterolateral borders rounded, with few setae.

Antennular peduncle ( Fig. 4A ) reaching about half length of last article of antennal peduncle.

Other mouth appendages not differing from those described in previous accounts of the species (de Man 1928; Tirmizi 1967; Rao & Kartha 1967); maxilliped 3 ( Fig. 4H ) without exopod; endopod ischium-merus length less than twice merus width, propodus approximately quadrate, distal border feebly arcuate.

Major pereopod 1 massive ( Fig. 4B, D ) on the left in male as in female. Ischium slender, lower border with a few denticles; merus with a few proximal upper denticles and a toothed blade on lower border; carpus about as long as merus but broader with curved lower border; propodus 1.4 times longer than carpus, bearing fine tubercles distally and a dentate distal border; fixed finger slightly curved, with round tubercles proximally and on proximal half of cuttting edge; dactylus slightly longer than fixed finger with curved tip, cutting edge with a strong triangular tooth pointing below and a flat broad tooth behind it that is more prominent in the male.

Minor pereopod 1 ( Fig. 4C, E ) slender, mainly unarmed, with carpus over 1.6 times longer than propodus, fixed finger and dactylus nearly as long as propodus.

Pereopod 3 ( Fig. 4F ) propodus with an elongated posterior lobe.

Pereopod 4 ( Fig. 4M ) subchelate and pereopod 5 ( Fig. 4N ) chelate, distal articles of both bearing numerous setae.

Male pleopod 1 ( Fig. 4I ) two-segmented, last segment with a shallow distal depression and bearing long setae. Male pleopod 2 ( Fig. 4J ) biramous; outer ramus slender and shorter than inner, latter with a distal constriction, both ramus with long setae distally.

Female pleopod 1 ( Fig. 4K ) three-segmented, last segment finger-like and about half as long as second segment, all segments bearing long setae. Female pleopod 2 ( Fig. 4L ) biramous, outer ramus faintly segmented and nearly as long as inner; inner ramus with a distal minute knob as reported by Rao & Kartha (1967: 284, fig. 2H) and Sakai (1999: fig. 21f), both ramus carrying long setae. Third to fifth pleopods ( Fig. 4O ) biramous, foliaceous, both ramus lanceolate, appendix interna present, very faint on inner ramus.

Uropods ( Fig. 4G ) exopod with rounded outline and antero-dorsal plate; endopod slightly shorter than exopod, triangular, with largest width proximally, subacute tip turned postero-laterally.

REMARKS

Callianassa audax was established by de Man (1911) on two females from the Straits of Malacca and a full description was presented in 1928 along with the Decapoda of the Siboga Expedition.Two subsequent accounts of the species were by Tirmizi (1967) on a male from West Pakistan and Rao & Kartha (1967) on five specimens, four females and one male from the Malabar coast, southwest of India.

The specimens from Vietnam agree with materials of Neocallichirus audax previously studied, especially with the specimen from West Pakistan ( Tirmizi 1967: fig. 2B) in the shape of the pereopod 3 propodus with a long posterior lobe ( Fig. 4F ), longer than in the type (de Man 1928: fig. 31f). The discrepancy is considered here as a variation.

Other discrepancies can be found in the account by Rao & Kartha (1967), e.g., the shape of the telson, of the uropods, of maxilliped 3, which are probably due to the poor quality of the figures.

Figures

FIG. 4.— Neocallichirus audax (de Man,1911) (MNHN Th 1618):A-C, F-J, N, O, ♂, tl113 mm;D, E, K, L, M, ♀, tl 54 mm.A, anterior part of carapace; B, D, major pereopod 1; C, E, minor pereopod 1; F, pereopod 3; G, telson and uropod; H, maxilliped 3; I, K, pleopod 1; J, L, pleopod 2; M, N, distal part of pereopods 4 and 5. Scale bars: 1 mm.