Wolffogebia nhatrangensis, Ngoc-Ho & Ngoc-Dung & Phi-Hung, 2001

Ngoc-Ho, Nguyen, Ngoc-Dung, Duong & Phi-Hung, Tran, 2001, The genus Wolffogebia Sakai, 1982 (Crustacea, Decapoda, Thalassinidea, Upogebiidae) with a new species from Vietnam, Zoosystema 23 (1), pp. 101-108 : 103-104

Wolffogebia nhatrangensis n. sp.

TYPE MATERIAL. — Holotype, Vietnam, Binh An , Nhatrang, about 20-30 cm in mud, near a shrimp pond, Tran-Phi-Hung & Duong-Ngoc-Dung coll., 24.XI.1999, 1 cl 10 mm, tl 27.5 mm ( MNHN Th 1385). Paratypes, 1 cl 9.5 mm, tl 26.5 mm ( MNHN Th 1386) ; 2, 1 ovigerous cl 7-10 mm, tl 21.5-29 mm ( MNHN Th 1387); 17 cl 7-9 mm, tl 20-25 mm; 15 (1 ovig.) cl 6.5-7.5 mm, tl 20-23.5 mm ( MNHN Th 1388); 2, 2 (NHML 2000.1656-1659); 2, 2 ( NHMW 19457 ) ; 2, 2 ( NMV J 4714 ) ; 2, 2 ( RMNH D 48593) ; 2, 2 ( SMF 25785) .

TYPE LOCALITY. — Nhatrang, Vietnam.

ETYMOLOGY. — The species is named after its type locality.

OTHER MATERIAL EXAMINED. — Binh An. Nhatrang, Vietnam, about 20-30 cm in mud, near a shrimp pond, Tran-Phi-Hung & Duong-Ngoc-Dung coll., 24.XI.1999, 23 cl 5-8.5 mm ( MNHN Th 1389) ; 18 cl 6-9 mm; 14 cl 6.5-7 mm ( MNHN Th 1390) ; 6.II.2000, 5, 1 ovigerous cl 7.5-9 mm, 91 juveniles cl 4-6 mm ( MNHN Th 1394) .

Mouth of Lô River. Nhatrang, Pham thi Du coll., 7.X.1998, 2 cl 6.5 and 7 mm (MNHN Th 1391). DIAGNOSIS. — Rostrum semicircular distally, with three to four small round tubercles on each lateral bor- der, distal border unarmed; eight to nine very small tubercles on lateral ridges of gastric region. Slight median carina on anterior region of carapace extending distally to almost entire rostrum; anterolateral bor- der of carapace with minute spine. Telson slightly broader than long, posterior border straight. Pereiopod 1 subcheliform: merus with upper subdistal spine; carpus with upper mesial subdistal and lower distal spine; propodus, with upper proximal spine and eight to twelve fine oblique crests on lower anterior half of mesial surface, crests distinct in large males, faint or absent in younger males, absent in females; fixed finger with small proximal round tooth on cutting edge. Dactylus with two to three small round teeth over mesial proximal half in large males. Pereiopods 2 and 3 with lower proximal spine on merus. Exopod of uropods about as long as telson.

DESCRIPTION

Rostrum (Fig. 1A) semicircular distally, about 1.5 time as long as broad at base, with three to four small rounded tubercles on each lateral bor- der, distal border unarmed; lateral ridges of gastric region with eight to nine very small tubercles, the two or three proximal of which hardly visible. Anterior region of carapace with slight broad non-setose median carina extending to nearly tip of rostrum; anterolateral border of carapace (Fig. 1B) with minute spine. Tergites of abdominal segments 3 and 4 ( Fig. 2A ) bearing dense setae on lateral distal border. Telson (Fig. 1C) approximately 1.2 time as broad as long, lateral borders slightly convex, distal border straight, a faint longitudinal groove medially.

Antennular and antennal peduncles ( Fig. 2B, C ) unarmed. Maxillipeds 1-3 ( Fig. 2 D-F) as figured. Arthrobranchs with single row of large lamellae on each side of rachis.

Pereiopod 1 in large males (cl> 7-7.5 mm) (Fig. 1D, E), stouter than in younger males and females. Ischium with spinule on proximal lower border. Merus with upper subdistal spine and sometimes lower proximal spinule. Carpus with large upper mesial subdistal spine and slightly smaller lower distal spine. Propodus about twice as long as broad, with upper proximal spine, and mesially a series of 10 to 12 fine oblique crests on lower anterior half, the longest near fixed finger, decreasing in size both distally and proximally; fixed finger subdistal, about half as long as dactylus, a proximal round tooth on cutting edge. Dactylus with corneous tip and two small triangular teeth near proximal and distal third of cutting edge; mesial surface with two or three round teeth over proximal half.

Pereiopod 1 in younger males ( Fig. 3C ) with propodus about three times as long as broad. Among the males examined, 14 specimens (cl 5-7.5 mm) bear no crest on mesial surface of propodus; in nine others (cl 6.5-8.5 mm), crests are shorter, fewer (6-8) than in large males and sometimes hardly visible. No round teeth on proximal mesial surface of dactylus.

Pereiopod 1 in females ( Fig. 3A, B ) slender, propodus about four times as long as broad, narrowing distally, fixed finger small, dactylus approximately five times as long, both unarmed.

Pereiopod 2 ( Fig. 3D ) with lower proximal spine on merus and sometimes upper distal spinule on carpus.

Pereiopod 3 ( Fig. 3E ) with lower proximal spinule on merus.

Pereiopod 4 unarmed. Pereiopod 5 subcheliform. Two ovigerous females bearing large eggs of 1-1.4 mm in diameter.

Uropod (Fig. 1C) basipod unarmed; exopod triangular, about as long as telson, endopod approximately trapezoidal, both unarmed, posterior border slightly convex.

Figures

FIG. 2. — Wolffogebia nhatrangensis n. sp.; A, paratype, ovig. tl 24 mm (MNHN Th 1387), lateral view; B-F, paratype, tl 26.5 mm (MNHN Th 1386); B, C, antennule and antenna; D, E, F, maxillipeds 1, 2 and 3 respectively. Scale bars: A-C, F, 1 mm; D, E, 0.5 mm.

FIG. 3. — Wolffogebia nhatrangensis n. sp.; A, paratype, ovig. tl 24 mm, pereiopod 1 in lateral view; B, paratype, ovig. tl 24 mm, distal part of pereiopod 1 in mesial view; C, paratype, tl 21.5 mm, distal part of pereiopod 1 in mesial view; D, E, paratype, tl 29 mm (MNHN Th 1387) pereiopod 2 and 3 respectively. Scale bars: 1 mm.