Axianassa ngochoae Anker, 2010

Ngoc-Ho, Nguyen, 2014, Six species of Axiidea and Gebiidea from the Indo-West Pacific (Crustacea, Decapoda), Zoosystema 36 (3), pp. 545-561 : 556-558

publication ID	https://doi.org/ 10.5252/z2014n3a1
persistent identifier	https://treatment.plazi.org/id/03C187FC-FF85-6966-D294-FAF1FB8C9822
treatment provided by	Felipe
scientific name	Axianassa ngochoae Anker, 2010
status

Treatment

( Fig. 5 View FIG )

MATERIAL EXAMINED. — Vietnam. Cân gio, HochiMinh city, 4-7 m, Nguyên van Xuân coll., III.1998: 1 ♂, cl 7 mm, tl 20 mm ( MNHN Th 1571).

DESCRIPTION

Carapace ( Fig. 5A View FIG ) rounded dorsally, with linea thalassinica well defined but cervical groove faint.

Rostrum ( Fig. 5B View FIG ) unarmed, anteriorly rounded, slightly surpassing cornea of eyes.

Pleomere 1 ( Fig. 5A View FIG ) about half dorsal length of somite 2, pleuron tapering ventrally to a spiniform process; pleomeeres 2 and 3 subequal in length, pleomeres 4-6 shorter, pleura poorly defined in all, unarmed.Telson ( Fig. 5C View FIG ) with greatest width about one-third of middorsal length, posterior margin rounded not clearly separated from lateral margins.

Cornea terminal, pigmentation partly lost after preservation. Antennular peduncle ( Fig. 5A View FIG ) about half length of antennal peduncle; antennular articles 1 and 2 about 1/3 length of article 3, latter slender, elongate-cylindrical, lower flagellum with faintly differentiated articles, superior flagellum of about 30 articles, just reaching distal margin of antennal article 4. Antennal acicle ( Fig. 5B View FIG ) elongate with pointed tip, antennal article 4 elongate, cylindrical, flagellum about twice as long as peduncle.

Pereopod 1 ( Fig. 5A, D View FIG ) asymmetrical but similar in spinulation; both ischium and merus with one spine near anterior third of lower border; carpus and palm unarmed, fixed finger about as long as palm in minor pereopod 1, three-thirds as long as palm in major pereopod 1, cutting edge with small rounded teeth and a larger one near midlength. Dactylus about as long as fixed finger, with curved tip, a flat tooth on proximal third, a large round tooth near midlength and four or five smaller round teeth distally. Pereopod 2 ( Fig. 5A, E View FIG ) ischium unarmed, merus bearing about 22-24 stout setae on lower border, carpus and propodus with stiff setae on lower border and fine setae on upper border; dactylus about half as long as propodus, slender with fine setae on upper and lower border. Pereopod 3 ( Fig. 5A View FIG ) with setae on lower border of propodus, dactylus with pointed tip with five or six corneous spinules on upper border. Pereopods 4, both right and left missing. Pereopod 5 ( Fig. 1A View FIG ) flexed distally with lower border of propodus becoming dorsal bearing numerous setae; numerous short setae on lower border of dactylus.

Pleopod 1 absent. Pleopods 2-5 ( Fig. 5A View FIG ) biramous, rami lanceolate. Uropods with both exopod and endopod ( Fig. 5C View FIG ) ovate, unarmed.

REMARKS

The specimen studied is a young male with no pleopod 1 and small gonopores on the coxae of pereopod 5.

Nine species of Axianassa are known to date with six of them originating from the vicinity of the American continent: A. arenaria Kensley & Heard, 1990 (Gulf of Mexico), A. canalis Kensley & Heard, 1990 ( Panama canal), A. intermedia Schmitt, 1924 ( Curaçao) , A. jamaicensis Kensley & Heard, 1990 ( Jamaica) , A. mineri Boone, 1931 (Bay of Panama), A. australis Rodrigues & Shimizu, 1992 ( Brazil) . Except for A. mineri , the other species are from western Atlantic. The first five species were either established or redescribed by Kensley & Heard (1990).

Three species recently described are from southwestern Pacific: A. sinica W. Liu & R. L. Liu, 2010 from South China Sea, A. ngochoae Anker, 2010 from Polynesia, Axianassa heardi Anker, 2011 from off Queensland, Australia.

Of these last three species, A. sinica has a pointed rostrum (see Liu & Liu 2010: fig. 2A) while in A. ngochoae and A. heardi , the rostrum is obtuse ( Anker 2010: fig. 1C, D; 2011: fig. 9B, E). It is unarmed in A. ngochoae but bears teeth on lateral margins in A. heardi .

The specimen from Vietnam agrees with the type except for the pereopod 2 ( Fig. 5E View FIG ) that is provided with stout setae on the lower border of the merus.

Family UPOGEBIIDAE Borradaile, 1903