Austinogebia monospina, Liu, Wenliang & Liu, Ruiyu, 2012

Liu, Wenliang & Liu, Ruiyu, 2012, A new species of the genus Austinogebia Ngoc-Ho, 2001 (Crustacea, Decapoda, Gebiidea, Upogebiidae) from northern China, Zootaxa 3243, pp. 59-64 : 60-64

Austinogebia monospina sp. nov.

( Figs 1–4 )

Material examined. Holotype: 3 (cl. 8.5 mm), stn 130-6, Bohai Sea, 20 m, medium sand, coll. Guangyu Lin, 1 Nov 1958. Paratype: Ƥ (cl. 8.0 mm), stn 080720 -1, Jiaozhou Bay, Yellow Sea, 22 m, muddy sand, coll. Wei Jiang, Wenliang Liu & Junlong Zhang, 20 Jul 2008; 2ƤƤ (cl. 6.2–8.0 mm), stn 080720 -1, Jiaozhou Bay, Yellow Sea, 22 m, muddy sand, coll. Wei Jiang, Wenliang Liu & Junlong Zhang, 20 Jul 20081; 3 (cl. 7.8 mm), stn 130-6, Bohai Sea, 20 m, medium sand, coll. Guangyu Lin, 1 Nov 1958.

Description. Rostrum ( Fig. 2 A, B) triangular, about 1.8 times as long as basal width; tip blunt, projecting far beyond eyes, with 1 infrarostral spine; dorsal surface with dense setae but without small tubercles. Carapace with gastric region covered with dense setae and many small tubercles; lateral ridges terminating in small spine distally; dorsal surface with dense setae but without conspicuous tubercles; anterolateral border with 5 spines; cervical groove long and deep, with 3 or 4 small spines laterally; postorbital region with 2 small spines.

Eyestalks stout, unarmed; cornea darkly pigmented. Antennular peduncle reaching article 4 of antennal peduncle, unarmed. Antennal peduncle unarmed; article 3 with ovate scale on upper surface.

Maxilliped 3 ( Fig. 2 C) moderately stout; exopod consisting of 1 article, reaching to distal margin of ischium.

Male pereopod 1 subchelate, slender ( Fig. 3 A, B). Basis unarmed. Ischium with 2 ventral spines. Merus about 2.8 times as long as high, with row of about 5–7 ventral spines and 1 subterminal spine on dorsal margin. Carpus triangular, about 0.4 length of merus, with 1 small upper and 1 strong lower subdistal spines, mesial face with 1 upper spine near to basal third and two strong upper spines near to distal end. Propodus 3.0 times as long as high, 1.7 length of carpus, with row of 5 or 6 spines on upper margin; fixed finger triangular, narrow and sharply pointed; cutting edge slightly curved, with an inconspicuous tooth. Dactylus slender, terminating in corneous tip, about 0.7 length of palm; opposable margin slightly arched, smooth, unarmed; lateral surface carinate medially. Female pereopod 1 ( Fig. 3 C, D) generally similar to male, but more slender.

Pereopod 2 ( Fig. 4A ) with ischium unarmed; merus with 6 lower spines and 2 upper subdistal spines; carpus with 1 spine each on lower and upper margin; propodus about 2 times as long as high, unarmed; dactylus slender, 0.8 length of propodus.

Pereopod 3 ( Fig. 4 B) with ischium unarmed; merus with 3 lower spines, 5 rows of small corneous spines on outer face; carpus unarmed; propodus about 0.75 length of carpus, outer face with two rows of longitudinal setae; dactylus slender and elongate, slightly longer than propodus.

Pereopod 4 ( Fig. 4 C) unarmed; dactylus elongate, 1.5 length of propodus.

Pereopod 5 ( Fig. 4 D) subchelate, unarmed; dactylus elongate and curved.

Abdominal tergites smooth. Telson ( Fig. 2 D) subrectangular, slightly wider than long, 0.75 times as wide as long and about 0.8 length of abdominal somite 6; posterior margin broadly convex, unarmed.

Male pleopod 1 absent; pleopod 2–5 biramous, with exopods larger than endopods. Female pleopod 1 present, uniramous, consisting of 2 articles. Uropodal protopod bearing posterolateral spine; exopod subtriangular, about 1.1 times as long as wide, truncate on posterior margin; endopod shorter than exopod, about 0.75 times as long as wide, with prominent knob on proximal shoulder.

Remarks. Austinogebia monospina sp. nov. is readily distinguished from the other species of the genus by having only one infrarostral spine. In the other congeneric species, there are 2–4 infrarostral spines. It is closely related to A. spinifrons ( Haswell, 1881) in the form of rostrum, pereopod 1 and telson. Austinogebia monospina differs markedly from the A. spinifrons , however, in the lower margin of antennal peduncle being unarmed (versus armed with numerous ventral spines on the third and fourth segments), lower spines on the ischium of pereopod 1 relatively broad and short; and the posterior margin of telson broadly convex (versus slightly concave).

Etymology. The species name is based on the presence of only one infrarostral spine of rostrum.

Coloration. Body whitish overall; first pereopod ivory white; corneal spot brown; setae on appendages light brown.

Distribution and habitat. Presently only known from Bohai Sea and Yellow Sea. At depths of 20–22 m on medium sand and muddy sand.

Figures

FIGURES 1. Austinogebia monospina sp. nov. Holotype male, 130 - 6, entire animal, lateral view. Scale = 1 mm.

FIGURES 2. Austinogebia monospina sp. nov. Holotype male, 130 - 6. A. anterior carpace, dorsal view; B. anterior carapace, lateral view; C. maxilliped 3, outer view; D. abdominal somite 6, telson and uropods, dorsal view. Scale = 1 mm.

FIGURES 3. Austinogebia monospina sp. nov. A, B. Holotype male, 130 - 6. C, D. Paratype female, 080720 - 1. A. male pereopod 1, outer view; B. male pereopod 1, inner view; C. female pereopod 1, outer view; D. female pereopod 1, inner view. Scale = 1 mm.

FIGURES 4. A ustinogebia monospina sp. nov. Holotype male, Holotype male, 130 - 6. A. pereopod 2, outer view; B. pereopod 3, outer view; C. peorepod 4, outer view; D. pereopod 5, outer view. Scale = 1 mm.