A synopsis of Typhlocarcinops Rathbun, 1909 (Crustacea: Decapoda: Brachyura: Pilumnidae), with descriptions of nine new species from the Indo-West Pacific Author Ng, Peter K. L. Author Rahayu, Dwi Listyo text Zootaxa 2020 2020-06-05 4788 1 1 100 journal article 10.11646/zootaxa.4788.1.1 1175-5326 3878222 7A461DBA-00B7-48DB-9320-4775DA8F21B2 Typhlocarcinops lapillus n. sp. ( Figs. 72–75 ) Material examined . Holotype : male (6.0 × 4.2 mm ) ( NMCR ), station T19, Cortes , Bohol Island , 9°42.2’N , 123°50.8’E , Philippines , coll. PANGLAO 2004, 20 June 2004 . Paratypes : 5 females (2.5 × 2.0 mm, 2.7 × 1.8 mm , 4.0 × 2.7 mm , 5.8 × 4.0 mm, 5.8 × 4.2 mm ) ( ZRC 2018.0280 ), same data as holotype. Others : 1 female (4.5 × 2.8 mm ) ( ZRC 2018.0281 ), Tanimbar , Indonesia , 20 m , coll. October 1994 . FIGURE 72 . Typhlocarcinops lapillus n. sp . A–E, holotype male (6.0 × 4.2 mm) (NMCR), Bohol, Philippines. A, overall habitus; B, dorsal view of carapace; C, frontal view of cephalothorax; D, anterior thoracic sternum and pleon; E, outer view of right chela. Diagnosis . Carapace ( Figs. 72A, B , 74A, D, F, G , 75A, B ) 1.3−1.6 times broader than long, carapace surface smooth, shiny, sparse plumose setae on lateral and frontal margins, regions indistinct; anterolateral margin arcuate, lined with small granules, two shallow indentations anteriorly; posterolateral margin subparallel, entire. Front deflexed, broadly triangular ( Figs. 72B, C , 75B, C ). Orbit ( Figs. 72C , 73G , 75C ) short, bulbous ocular peduncles filling orbit, immovable, cornea small, pigmented. Epistome ( Figs. 72C , 75C ) relatively broad, posterior margin straight, with median suture. Antennal peduncles long. Third maxilliped ( Fig. 73A, H ) with outer surface of merus covered with small granules on distal margin, outer margin straight, anteroexternal angle protruding, auriculiform; ischium squarish, longer than merus; exopod broad. Chelipeds subequal in both sexes ( Figs. 72A, E , 74A, D, F , 75A, F ), smooth, sparse setae on upper and lower margins of fingers and palm; outer lower surface of palm with longitudinal ridge of small tubercles continued to tip of fixed finger, cutting edges of fingers with prominent broad teeth; carpus and merus smooth, margins with long setae; inner angle of carpus with sharp spiniform tooth ( Fig. 74E ). P2−P5 proportionally long ( Figs. 72A , 74A, D, F , 75A ), dorsal and ventral margins fringe with long setae; dactylus straight; merus of P5 not reaching front when folded. Fused thoracic sternites 1, 2 broadly triangular ( Fig. 72D ), proportionally narrow; thoracic sternites 3, 4 partially fused, with only lateral suture discernible. Male pleon ( Figs. 72D , 73B ) relatively broad, telson relatively long, 1.7 times length of somite 6, subtriangular. G1 ( Fig. 73 C–F) slender, curved, upper half shorter, sinuous, distal part curved, tip pointed, one large seta subdistally. Female pleon ( Figs. 74B , 75D, E ) broad, somite 1 reaching coxae of fourth ambulatory legs, tapering to pointed edge; telson subtriangular; vulva ( Fig. 74C ) relatively broad, rounded. FIGURE 73 . Typhlocarcinops lapillus n. sp . A–F, holotype male (6.0 × 4.2 mm) (NMCR), Bohol, Philippines; G, H, female (4.5 × 2.8 mm) (ZRC 2018.0281), Tanimbar Islands. A, right third maxilliped; B, male pleon; C, left G1 (ventral view); D, left G1 (dorsal view); E, distal part of left G1 (ventral view); F, distal part of left G1 (dorsal view); G, frontal view showing epistome, antennae and orbits (antennules not drawn); H, left third maxilliped. Scales: A, B = 1.0 mm; C, D, G, H = 0.5 mm; E, F = 0.25 mm. FIGURE 74 . Typhlocarcinops lapillus n. sp . A–C, paratype female (5.8 × 4.2 mm) (ZRC 2018.0280), Bohol, Philippines; D, paratype female (4.0 × 2.7 mm) (ZRC 2018.0280), Bohol Philippines; E, holotype male (6.0 × 4.2 mm) (NMCR), Bohol, Philippines; F, G, paratype female (2.5 × 2.0 mm) (ZRC 2018.0280), Bohol, Philippines. A, D, F, overall habitus; B, anterior thoracic sternum and pleon; C, sternopleonal cavity and vulvae; E, right carpus of cheliped; G, dorsal view of carapace. FIGURE 75 . Typhlocarcinops lapillus n. sp . , female (4.5 × 2.8 mm) (ZRC 2018.0281), Tanimbar Islands. A, overall habitus; B, dorsal view of carapace; C, frontal view of cephalothorax; D, anterior thoracic sternum and pleon; E, posterior thoracic sternum and pleon; F, outer view of left chela. Variation . In the smallest female, the indentations on anterolateral margin form two strong teeth ( Fig. 74G ), while in the large females and males, the anterolateral margin is entire lined with sharper granules ( Figs. 72B , 75B ). The carapace proportions also appear to vary, with one specimen having a proportionately broader carapace ( Fig. 74D ). Etymology . The name is derived from the Latin “ lapillus ” for a small gemstone, alluding to the small shiny appearance of the species. Remarks . Typhlocarcinops angustipes and T. lapillus n. sp. both have auriculiform anterolateral angle of the third maxilliped with a broad exopod. There are, however, many differences: the merus of the third maxilliped of T. angustipes is proportionately broader and almost the same length as the ischium ( Fig. 77B ) (versus the merus of the third maxilliped is slightly narrower and much shorter than the ischium ( Fig. 73A, H ) in T. lapillus n. sp . ); the male pleon is relatively more narrow with the telson short and semicircular ( Fig. 77C ) (versus the male pleon is relatively broader with the telson long and subtriangular ( Fig. 73B ), in T. lapillus n. sp . ), and the upper and lower halves of G1 are subequal, gently curved with scattered setae subdistally ( Fig. 77D, E ) (versus the upper half G1 is shorter, distinctly curved with a large seta subdistally ( Fig. 73 C–E) in T. lapillus n. sp. ). The carapace of T. angustipes is also subovate, 1.2–1.4 times broader than long, fringe with long setae on its margin, and with tubercles on the posterolateral surface ( Fig. 76A, B ) (versus the carapace is more ovate 1.3–1.6 times broader than long, sparse setae on its margin and the surface is completely smooth ( Figs. 72B , 75B ) in T. lapillus n. sp. ). Type locality . Bohol , Philippines . Distribution . Bohol , Philippines ; and Tanimbar Islands, Moluccas , Indonesia . From depths of 10– 26 m .