Gonodactyloideus rubrus, Ahyong, Shane T., 2004

Ahyong, Shane T., 2004, New species and new records of stomatopod Crustacea from the Philippines, Zootaxa 793, pp. 1-28 : 4-6

Gonodactyloideus rubrus sp. nov. ( Figure 1 )

Material examined. ZRC 2002.0470, 1 female (TL 48 mm), Balicasag Island, 200–400 m, P. Ng & P. Clark from local fishermen, Jul 2002.

Diagnosis. Telson with 5 mid­dorsal carinae in addition to carinae of primary teeth; accessory median carinae extending anteriorly to midlength of median carina, each with 2 short posterior spines; anterior submedian carina with posterior spine and upright tubercle; carina of intermediate tooth extending anteriorly almost to anterior margin of telson.

Description. Cornea expanded laterally, flattened dorsally, slightly broader than stalk, extending anteriorly beyond midlength but not end of antennal peduncle segment 2. Ophthalmic somite anterior margin with median tubercle. Ocular scales separate, rounded, slightly broader than high.

A1 peduncle length 0.54 CL. A1 somite dorsal processes low, truncate, with low truncate lobe at A1 peduncle articulation. A2 protopod without papillae; with fixed, laterally flattened mesiodorsal projection; with short anteroventral tooth. A2 scale length 0.42 CL.

Rostral plate slightly broader than long; anterolateral angles blunt; lateral margins strongly divergent anteriorly; median spine longer than basal portion.

Raptorial claw propodus with long movable, proximal spine; occlusal margin sparsely pectinate proximally.

Mandibular palp 3­segmented. MXP1–5 each with epipod.

TS6–7 with truncate lateral margins; margin of TS6 slightly broader than that of TS7. TS8 lateral margin obtusely rounded; sternal keel obsolete.

AS 1–5 posterolateral angle blunt. AS 6 with armed submedian, intermediate and lateral carinae; without ventrolateral spine anterior to uropodal articulation margin. AWCLI 741.

Telson slightly broader than long, with 3 pairs of primary teeth; with 11–14 submedian denticles either side of midline; with 5 mid­dorsal carinae in addition to carinae of primary teeth; median carina with proximal pit and posterior spine; accessory median carinae extending anteriorly to midlength of median carina, each with 2 posterior spines; anterior submedian carina with posterior spine and upright tubercle; carina of intermediate tooth extending anteriorly almost to anterior margin of telson; ventral surface smooth.

Uropodal protopod terminating in two slender, flattened spines, outer longer; exopod proximal segment outer margin with 10 or 11 movable spines and fixed distal spine; endopod with dorsolateral carina laterally, entire margin with single row of setae.

Colour in life. Overall colour red at fixation in formalin. Almost completely faded in alcohol but with small, faint, uniformly distributed spots. Dactylus of raptorial claw pink.

Measurements of holotype. TL 48 mm, CL 11.20 mm, A1 peduncle length 6.10 mm, A2 scale length 4.75 mm, width at AS 5 8.30 mm.

Etymology. From the Latin rubrus , red, alluding to the colour­in­life of the species.

Remarks. Gonodactyloideus rubrus sp. nov. is the third species of the genus to be recognised. It resembles the type species, G. c r a c e n s Manning, 1984 and differs from G. tricarinatus Ahyong, 2002 in having five mid­dorsal carinae on the telson (median, paired accessory median and paired anterior submedian carinae). Gonodactyloideus rubrus differs from G. c r a c e n s in having shorter accessory median carinae on the telson and two instead of one posterior spinules or tubercles on the accessory median and anterior submedian carinae of the telson. In G. c r a c e n s, the accessory median carinae of the telson are of similar length to the anterior submedian carinae and extend anteriorly beyond the proximal pit of the median carina. Conversely, in G. r u b r u s, the accessory median carinae of the telson are less than two­thirds the length of the anterior submedian carinae and do not extend anteriorly to the proximal pit of the median carina.

The presence of five posteriorly armed, mid­dorsal carinae in G. rubrus and G. c r a c e n s means that small specimens of either species could be confused with the superficially similar Gonodactylellus affinis (de Man, 1902). Gonodactylellus affinis is readily distinguished from species of Gonodactyloideus at all sizes by having the lateral margin of TS6 distinctly wider than, instead of subequal to, that of TS7. (See key to the species of Gonodactyloideus below).

Distribution. Presently known only from Balicasag Island, Philippines; 200– 400 m.

Figures

FIGURE 1. Gonodactyloideus rubrus sp. nov., female holotype TL 48 mm (ZRC 2002.0470). A, anterior. B, ocular scales. C, right antennal protopod, lateral. D, right raptorial claw, lateral. E, propodus, carpus and merus of raptorial claw, right medial. F, TS 6 – 8, right lateral. G, AS 4 – 5, right, lower lateral. H, AS 5 – 6, telson & uropod, dorsal. I, uropod, right ventral. J, telson, left lateral. Scale = 1.5 mm.