Halmyrapseudes killaiyensis (Balasubrahmanyan, 1962)

Kakui, Keiichi & Angsupanich, Saowapa, 2013, Description of three species of Halmyrapseudes (Crustacea: Tanaidacea: Parapseudidae), with a discussion of biogeography, Zootaxa 3736 (4), pp. 345-367 : 356-358

Halmyrapseudes killaiyensis (Balasubrahmanyan, 1962)

Figure 7

Apseudes killaiyensis Balasubrahmanyan, 1962 , 280–282, figs. 1, 4, 6. Halmyrapseudes killaiyensis: Băcescu & Guţu 1974 , 100; Băcescu & Guţu 1975, 112; Guţu 2008, 51. Apseudes srilankaensis Băcescu, 1981 , 78–80, figs. 2A–H, K, L, 3J, M–P.? Halmyrapseudes killaiyensis: Soemodinoto et al. 1995 , 64.

Apseudes srilankaensis: Bamber et al. 1997 , 139.

Halmyrapseudes srilankaensis: Bamber et al. 2002 , 287, 288, figs. 1–5.

Material examined. One adult male (NHM 2000.1451, BL 3.49, CW 0.63, 4 slides and 1 vial); 3 subadult males (NHM 2000.1452–1461.1, 2000.1452–1461.4, 2000.1452–1461.5: BL 3.19, CW 0.59, 3 slides and 1 vial; BL 3.47, CW 0.62, 3 slides and 1 vial; BL 2.72, CW 0.51, 3 slides and 1 vial); 1 preparatory female (NHM 2000.1452– 1461.2, BL 3.34, CW 0.59, 2 slides and 1 vial); 1 ovigerous female (NHM 2000.1452–1461.3, BL 3.52, CW 0.62, 5 slides and 1 vial). Bamber et al. (2002) gives collection information for these specimens.

Diagnosis. Lacinia mobilis with 4 teeth. Mandibular palp article 2 without dorsal simple setae. Pereopod 1 carpus with 2,1 or 1,1 ventral simple setae proximal to each spiniform seta.

Limited redescription of adult male (NHM 2000.1451). Left mandible ( Fig. 7 A) with lacinia mobilis bearing four teeth.

Cheliped generally similar to that of male H. gutui . Basis with one proximal and three distal simple setae in inner region. Merus with one mid-ventral simple seta. Carpus with 15 outer and 15 inner simple setae in dorsal region; ventral region with eight simple setae on digitiform process. Propodal palm with four ventroproximal simple setae; insertion of dactylus with 10 simple setae and one serrate seta. Fixed finger with four ventral simple setae.

Pereopod 1 ( Fig. 7 B) generally similar to that of male H. gutui . Merus with six dorsal, one outer, eight inner ventral, six ventral, and one ventrodistal short simple setae, and one inner dorsal and one ventral spiniform setae. Carpus with three outer simple setae in dorsal region; ventral region with one inner proximal, two inner distal, one distal, and one outer simple setae, two spiniform setae, and two, one simple setae proximal to each spiniform seta. Propodus with seven simple setae in dorsal region; ventral region with three spiniform setae, and three, two, two simple setae proximal to each spiniform seta.

Pereopods 2 – 6, pleopods, and uropod generally similar to those of male H. gutui , except the number of setae is slightly different; pereopod 4 basis lacks mid-ventral seta; and the pereopod 5 ( Fig. 7 C) propodus has three ventral simple setae, two long and one short distal simple setae, two distal conical setae, one inner distal setulate seta (ca. 2.6 times longer than serrate seta), and one inner distal serrate seta.

Limited redescription of female (NHM 2000.1452–1461.2, NHM 2000.1452–1461.3). Cheliped generally similar to that of female H. gutui . Basis with one proximal and one distal simple setae in inner region. Merus with one mid-ventral simple seta. Carpus with 14 outer and 13 inner simple setae in dorsal region. Propodal palm with eight simple setae at insertion of dactylus.

Variation. Numbers of simple setae in the ventral region of the pereopod 1 propodus and carpus are variable: the propodus has 3,2,2 (NHM 2000.1451, 1452–1461.2, 1452–1461.4), 3,1,2 (1452–1461.3, 1452–1461.5), or 2,2,3 (1452–1461.1) simple setae; the carpus has one (NHM 2000.1452–1461.3, 1452–1461.5) or two (in the other four specimens) simple setae, proximal to the more proximal of the two ventral spiniform setae. The ventral spiniform seta on the pereopod 5 propodus is a conical seta in two individuals. The numbers of simple setae and conical setae in most positions, and of plumose setae on the pereopod 6 and the pleopodal rami, are variable.

The number of articles in the antenna and the outer flagellum of antennule is variable: antenna has nine articles in females and 8–10 in males; the antennule outer flagellum has five or six articles in females and 8–10 in males.

Marked sexual dimorphism is present, as with H. gutui .

Remarks. Guţu (2008) considered H. srilankaensis (Băcescu, 1981) to be a junior synonym of H. killaiyensis because they are similar in morphology and their known localities are close (western and northern Sri Lanka for H. srilankaensis ; southeastern India for H. killaiyensis ). This might be correct, but the original description of H. killaiyensis is not detailed enough for adequate comparison, and it remains possible they are separate species. Unfortunately, Balasubrahmanyan (1962) did not indicate the type depository for H. killaiyensis , and there are no specimens in the Marine Biological Station, Porto Novo, where Balasubrahmanyan worked (now called The Centre of Advanced Study in Marine Biology, Annamalai University) (Olivia Fernando, Annamalai University, pers. comm.). To further examine the synonymy, therefore, topotypes need to be collected for H. killaiyensis . For now, we regard H. srilankaensis as a junior synonym for H. killaiyensis , following Guţu (2008).

Soemodinoto et al. (1995) reported material attributed to this species from bodies of brackish water in Java, Indonesia, but did not describe the specimens in detail, and the specimens are no longer available (Bamber et al. 2002). Therefore, the identity of the Java material is not clear.