Typhlocarcinops hadrotes, Ng & Rahayu, 2020

Ng, Peter K. L. & Rahayu, Dwi Listyo, 2020, A synopsis of Typhlocarcinops Rathbun, 1909 (Crustacea: Decapoda: Brachyura: Pilumnidae), with descriptions of nine new species from the Indo-West Pacific, Zootaxa 4788 (1), pp. 1-100 : 61-63

publication ID	https://doi.org/ 10.11646/zootaxa.4788.1.1
publication LSID	lsid:zoobank.org:pub:7A461DBA-00B7-48DB-9320-4775DA8F21B2
DOI	https://doi.org/10.5281/zenodo.10564041
persistent identifier	https://treatment.plazi.org/id/03C05222-FF9E-FC32-FF35-D6A5FC63FCF1
treatment provided by	Plazi
scientific name	Typhlocarcinops hadrotes
status	sp. nov.

Treatment

Typhlocarcinops hadrotes View in CoL n. sp.

( Figs. 2B View FIGURE 2 , 50–52 View FIGURE 50 View FIGURE 51 View FIGURE 52 )

Typhlocarcinops marginata View in CoL — Serène 1964: 227, text fig. 10, pl. 20A (not Typhlocarcinops marginatus Rathbun, 1914 View in CoL ).

Material examined. Holotype: male (17.5 × 14.5 mm) ( MZB Cru 4813), station CP56, Pelabuhan Ratu, 7°00.429’S 106°24.407’E– 7°00.455’S 106°24.198’E, 269− 233 m, coll. SJADES 2018, 3 April 2018 GoogleMaps . Paratypes: 1 male (16.2 × 12.8 mm), 1 female (18.3 × 14.3 mm) ( ZRC 2018.0278 View Materials ) , 1 male (15.6 × 12.2 mm), 1 female (16.8 × 13.4 mm) ( MZB Cru 4814), same locality as holotype GoogleMaps ; 1 male (13.0 × 10.3 mm) ( ZRC 2018.0279 View Materials ), station CP 37, south of Cilacap , 8°07.462’S 109°05.639’E– 8°07.864’S 109°26.470’E, 163−166 m, coll. SJADES 2018, 30 March 2018 GoogleMaps .

Diagnosis. Carapace ( Figs. 50A, B View FIGURE 50 , 51B View FIGURE 51 ) about 1.2–1.3 times broader than long, surface finely pubescence, longer plumose setae on lateral margins, regions not demarcated, H-shaped gastro-cardiac grooves indistinct; anterolateral margin arcuate, lined with small granules obscured by long setae, posterolateral surface and margin with scattered tubercles. Front ( Fig. 50B, C View FIGURE 50 ) bilobed, with shallow median cleft, margin of each lobe convex. Orbit ( Fig. 50C View FIGURE 50 ) short, bulbous ocular peduncles filling orbit, immovable, cornea small, pigmented. Epistome ( Fig. 50C View FIGURE 50 ) relatively broad, posterior margin straight, with median suture. Antennal peduncles short. Third maxilliped ( Fig. 52A View FIGURE 52 ) with merus broad, outer margin straight, anteroexternal angle rounded, ischium squarish, much longer than merus, inner margin shorter than outer margin, lower margin slightly oblique; exopod relatively slender. Chelipeds unequal in males, subequal in females ( Fig. 50A, E View FIGURE 50 , 51B, E View FIGURE 51 ), finger of major chela smooth shallow longitudinal groove on surface, longitudinal ridge on fixed finger continued to base of palm, surface of palm smooth; cutting edges of fingers with prominent teeth; surface of carpus smooth, margin with short setae, inner angle low, with sharp granules ( Fig. 51A View FIGURE 51 ); dorsolateral margin of merus with row of large tubercles, margins covered with long setae. P2−P5 proportionally long ( Figs. 50A View FIGURE 50 , 51B View FIGURE 51 ), glabrous; merus of P5 not reaching front when folded. Fused thoracic sternites 1, 2 broadly triangular ( Fig. 50D View FIGURE 50 ), proportionally narrow; thoracic sternites 3, 4 partially fused, with only lateral suture discernible. Male pleon narrow ( Figs. 50D View FIGURE 50 , 52B View FIGURE 52 ), telson long, subtriangular, 1.7 times as long as somite 6. G1 slender ( Fig. 52 View FIGURE 52 C–H), slightly curved, upper half slightly sinuous, much longer than lower half, distal part straighter, directed upward, with tip slightly bent, pointed. Female pleon ( Fig. 51C View FIGURE 51 ) broad, somite 1 reaching coxae of fourth ambulatory legs, tapering to pointed edge; telson subtriangular; vulva ( Fig. 51D View FIGURE 51 ) slit-like, with flap-like sternal vulvar cover.

Etymology. The name is derived from the Greek “hadrótçs” which alludes to the thickness of the carapace of the species. The name is used as a Latin noun in apposition.

Remarks. Serène (1964: 227–228) referred a male specimen (8.3 × 6.4 mm) from 52 m in the Java Sea to “ T. marginatus Rathbun, 1914 ” but described the anterolateral margin as rounded and entire. Rathbun (1914: 152) states that the anterolateral margin has “three interruptions in the denticles forming three teeth”, and this is obvious in the type specimen ( Fig. 55B View FIGURE 55 ). But as has been discussed earlier, it is not always easy to see the low teeth unless the margins are carefully and completely cleaned, and from his figures ( Serène 1964: pl. 20A), his specimen does not appear to have been brushed clean. In addition, the third maxilliped figured by him ( Serène 1964: text fig. 10A) also does not agree in that the anteroexternal angle of the merus has no auriculiform structure as in the type of T. marginatus ( Fig. 56A View FIGURE 56 ). Instead, Serène’s (1964) figures and descriptions match what is here recognized as T. hadrotes n. sp. His specimen was not collected in the same area as the type locality but it was from the Java Sea and relatively shallower water (52 m). The type specimens were all from deeper than 100 m.

The long, slightly sinuous upper half and straight distal part of the G1 of T. hadrotes n. sp. superficially resembles those of T. ocularius Rathbun, 1914 , and T. hirtus n. sp. In T. hadrotes n. sp., however, it is twisted differently, with the upper half curved towards the surface of the sternum while the lower half is turned toward the pleonal surface ( Fig. 52C, D View FIGURE 52 ). From lateral view, the upper half of the G1 of T. hadrotes n. sp. is straighter with the tip directed upwards ( Fig. 52C, D View FIGURE 52 ). The G1 of T. ocularius on the other hand, evenly curves towards the sternum ( Fig. 46A, B View FIGURE 46 ) while in T. hirtus n. sp. it is slightly twisted laterally ( Fig. 64C, D View FIGURE 64 ). In addition, the tip of the G1 of T. hadrotes n. sp. is tapering, pointed and slightly bent ( Fig. 52 View FIGURE 52 C–H) while in T. ocularius , the tip is tapering and directed upwards ( Fig. 46 View FIGURE 46 ). In T. hirtus n. sp., the tip is broad and fluted ( Fig. 64 View FIGURE 64 C–F).