Trachysalambria malaiana ( Balss, 1933 )

Chan, Tin-Yam, Cleva, Régis & Chu, Ka Hou, 2016, On the genus Trachysalambria Burkenroad, 1934 (Crustacea, Decapoda, Penaeidae), with descriptions of three new species, Zootaxa 4150 (3), pp. 201-254 : 207-209

Trachysalambria malaiana ( Balss, 1933)

( Fig. 1 )

Trachypenaeus curvirostris malaiana Balss, 1933: 234 [type locality: Indonesia].

Trachypenaeus fulvus Dall, 1957: 206 , fig. 23A–G [type locality: Queensland, Australia]; Hall, 1962: 29, figs. 112, 112a, b; Racek & Dall, 1965: 93; Racek & Yaldwyn, 1971: 212; Holthuis, 1980: 54; Motoh, 1980: 40, fig. 12; Grey et al., 1983: 120, pls. 43, 50.

Trachypenaeus asper .— Kubo, 1949: 395, figs. 7H’, 32K, L, 47L, 59B, 75R, X, 79D. [not Alcock, 1906]

Trachypeneus unicus Hall, 1961: 102 [type locality: south of Singapore].

Trachypenaeus curvirostris .— Holthuis, 1980: 53 (in part). [not Stimpson, 1860]

Trachypenaeus malaianus .— Motoh & Buri, 1984: 81, figs. 55-56; Chaitiamvong & Supongpan, 1992: 37, pl. 52.

Trachypenaeus malaiana .— Liu & Zhong, 1988: 193, fig. 119; Chan, 1998: 928, unnumbered figs.

Trachysalambria fulva .— Pèrez Farfante & Kensley, 1997: 149; De Grave & Fransen, 2011: 228.

Trachysalambria malaiana .— Pèrez Farfante & Kensley, 1997: 149; De Grave & Fransen, 2011: 228.

Trachypenaeus (Trachysalambria) fulvus .— Davie, 2002: 152.

Material examined. Philippines. Manilla market: 17.03.1976, 1 male cl 18.5 mm, 3 females cl 22.5–25.2 mm ( MNHN IU- 2014-12851 ), 1 female cl 24.0 mm ( MNHN IU- 2014-7060 ) ; 27.05.1985, 11 males cl 15.0– 18.5 mm, 18 females cl 15.5–24.8 mm (MNHN IU-2014-7061), 1 female cl 23.3 mm (MNHN IU-2014-7062). MUSORSTOM I, stn CP 0 1, 14°28.0’N, 120°42.0’E, 36–37 m, 18.03.1976, 8 males cl 16.0– 19.5 mm, 3 females cl 19.5–26.0 mm (MNHN IU-2014-7059), 1 male cl 18.2 mm, 1 female cl 25.5 mm (MNHN IU-2014-7064).

Vietnam. “ De Lanessan ”: Entrance of Port Dayot , Honi Cohé Bay, 0 9.08.1926, 4 females cl 20.5–24.0 mm ( MNHN IU- 2014-7068 ) ; Cap Saint Jacques, 18.12.1926, 28– 32 m, 1 female cl 21.8 mm (MNHN IU-2014-7074). No specific data, 1 male cl 16.5 mm, 1 female cl 24.2 mm (MNHN IU-2014-7069).

Singapore. Singapore Fisheries Research Station, stn B176, 23.11.1956, 3 males cl 13.0– 14.5 mm ( MNHN IU- 2014-7071 ) . Singapore market, 12.1995, 3 females cl. 17.0– 21.5 mm ( MNHN IU- 2013-14467 ) .

Thailand. Narathiwat, 18.10.1981, 1 female cl 18.2 mm ( MNHN IU- 2014-7070 ).

Indonesia. CORINDON II: stn CH 201, 01°11’S, 117°06’E, 21 m, 30.10.1980, 1 male cl 16.0 mm, 3 females cl 17.5–19.0 mm ( MNHN IU- 2014-7065 ) ; stn CH 203, 01°09’S, 117°08’E, 25 m, 30.10.1980, 1 male cl 15.2 mm ( MNHN IU- 2014-7073 ) . ANAMBAS, stn EA-TT-08, 03°56.01’N, 107°51.78’E, 41– 23 m, 18.03.2002, 10 males cl 13.5–17.5 mm, 4 females cl 20.5–23.0 mm (MNHN IU-2014-7067), 1 female cl 22.1 mm (MNHN IU-2014-7066).

South-East Asia. No specific data, 1 female cl 12.5 mm (MNHN IU-2014-7072).

Papua New Guinea. BIOPAPUA, stn CP 3702, 3°57’N, 144°40’E, 80–91 m, 0 1.10.2010, 2 males cl 12.0 and 12.4 mm ( MNHN IU- 2014-7103 ).

Australia. Queensland: Reef Point, Scarborough, 15.12.1967, 1 female not measured (QM W2782); Beacon , stn 222, 27°18’50 S, 153° 12.50 E, 8.2 m, 1967, 2 females cl 16.0 and 21.0 mm (QM W2821) ; Moreton Bay : stn 384, 12.8 m, 0 6.02.1968, 1 male cl 17.0 mm, 1 female cl 16.5 mm (QM W2973) ; 12.8 m, 26.06.1968, 1 male cl 11.5 mm, 1 female cl 18.0 mm (QM W3829); Hinchinbrook Is., 18°27.5’S, 146°22.7’E, 0 7.01.1986, 1 female cl 20.5 mm (QM W12843) . Northern Territory, Gove Peninsula ( Pools ), 11.01.1971, 1 male cl 8.7 mm, 1 female cl 8.2 mm ( MNHN IU- 2014-7077 ), 1 male cl 9.2 mm ( MNHN IU- 2014-7078 ) . Western Australia, Exmouth Gulf , 13 m, no date, 3 males cl 12.0-13.0 mm, 2 females cl 15.2 and 17.0 mm ( MNHN IU- 2014-7075 ), 1 female cl 17.5 mm ( MNHN IU- 2014-7076 ) .

Description. Entire body densely pubescent. Rostrum with 7–10 (usually 8 or 9, excluding epigastric tooth) teeth along entire dorsal border; slightly curved upwards to almost straight in females, ventral border convex to straight, tip nearly straight and with ventral margin slightly convex, tips of rostral teeth aligned in concave to straight configuration; in males rostrum straight (mostly) or very slightly curving upwards, ventral border straight (mostly) or slightly convex, tips of rostral teeth aligned in a straight line or occasionally in a slightly convex configuration; reaching middle to tip of second segment of antennular peduncle (generally shorter in males). Postrostral carina generally extending to posterior carapace but occasionally indistinct in posterior half. Pereiopods I and II without epipod, only pereiopod III with epipod. Pereiopod I bearing small ischial spine, which often minute and sometimes even completely absent. Pereiopod IV in females with coxa not particularly expanded medially. Pereiopod V varying from nearly reaching tip of scaphocerite to far overreaching scaphocerite. Abdomen with dorsal carinae distinct, highly elevated on somites II to VI; that of somite II short but laminate; somite III generally with distinct dorsal carina at posterior 2/3 but occasionally with distinct dorsal carina along entire length; carinae on somites IV and V terminating posteriorly in small spines but posterior spine sometimes rather minute at somite IV. Telson with strong but blunt dorsolateral carinae; generally armed with 3 pairs of movable lateral spines, subapical pair distinct but other 2 pairs very minute. Male petasma with lateral margins of stem almost parallel; distolateral lobes with ventral margins straight or slightly convex, tips of dorsal and ventral flaps coinciding, forming wide angle. Female thelycum with anterior plate regularly convex, surface generally depressed; anterior margin of posterior plate distinctly concave, with median cleft.

Coloration. Coloration information of this species is based on the color photographs provided for the Philippines ( Motoh 1980), Thailand ( Chaitiamvong & Supongpan 1992) and Australian ( Grey et al. 1983) material. Body generally greyish blue to light brown. Eyes black-brown. Antennal flagella reddish brown. Pereiopods yellowish to reddish brown. Pleopods reddish brown with lateral surfaces whitish or yellowish. Uropods dark grey to red and often with yellowish margins.

Distribution. South China Sea south to northern Australia; from the Philippines, Southern China, Vietnam, Singapore, Thailand, Malaysia, Indonesia, New Guinea and northern Australia; at depths of 5– 91 m.

Remarks. The present species is unique in the genus by the epipod being absent on the pereiopods I and II and only present at the pereiopod III. There are three names described that clearly fit such criteria: T. malaiana ( Balss, 1933) from Indonesia, T. fulva ( Dall, 1957) from northern Australia and T. unica ( Hall, 1961) from Singapore. The type localities of these three nominal species are rather close. Trachysalambria unica was considered by the original author ( Hall 1961) as a synonym of T. fulva . The northern T. malaiana and the southern T. fulva (supposed to be restricted to Australia) are sometimes considered as separated species that differ mainly in the pereiopod length, which is generally shorter in the latter ( Dall 1957; Rack & Dall 1965; Racek & Yaldwyn 1971; Motoh & Buri 1984). Although it is true that the Australian material tends to have shorter pereiopods, the length ranges of the pereiopods overlap in both the Australian and Asian materials examined. Thus, further dividing the present form seems to be unwarranted as suggested by Dall & Rothlisberg (1990). Nevertheless, attempts to sequence the DNA of Australian material has failed. Future genetic comparison amongst the Australian specimens with the sequences from the Philippines and Indonesia (which only have <0.2% divergence in 12S and 16S rRNA genes, Tables 2, 3) can determine if the present synonymy between T. malaiana and T. fulva is valid.

Other than the development of the epipod on the pereiopods, T. malaiana also differs from the other members of the genus in the shape of the genitalia. The petasma has the stem with the lateral margins parallel in T. malaiana ( Fig. 1 D, E). In the other species of Trachysalambria , the lateral margins of the stem of the petasma are converging distally. The anterior plate of the thelycum is regularly convex in T. malaiana ( Fig. 1 G) but more or less semitriangular in the other species of the genus. Moreover, only T. malaiana and T. parvispina sp. nov. have the dorsal carinae on the abdominal somites IV and V terminating in small spines ( Figs. 1 B, 5E, F). The lateral spines on the telson only have the subapical pair distinct in the present species, the others are very minute and difficult to discern (see also Dall 1957). This had resulted in the inconsistency in the number of lateral telson spines reported for this species in literature (e.g., Kubo 1949; Dall 1957; Hall 1962; Motoh & Burni 1984; Liu & Zhong 1988). In the other species of Trachysalambria , the lateral telson spines, except the one abutting the subapical spine, are rather easily discernible.

Figures

FIGURE 1. Trachysalambria malaiana (Balss, 1933), the Philippines, MUSORSTOM I, stn CP 01: A, B, G, female cl 25.5 mm (MNHN IU- 2014 - 7064); C – F, male cl 18.2 mm (MNHN IU- 2014 - 7064). A, cephalothorax, lateral view; B, dorsal part of abdominal somites II to VI, lateral view; C, rostrum, lateral view; D – F, petasma, ventral, dorsal and upper views, respectively; G, thelycum, ventral view.