Copidognathus mangrovorum Chatterjee, Marshall & Pešić, 2012, sp. nov.

Copidognathus mangrovorum sp. nov.

(Figs. 2, 3)

Material examined: Holotype, Ƥ, Brunei Darussalam, Kota Batu, Sungai Brunei Estuary and Bay, 4º56'N, 115º1'E, 10.iii.2011, mud flat and algae covering the pneumatophores of Avicennia marina mangrove trees, leg. T. Chatterjee & D. J. Marshall. Paratypes: one 3 and one Ƥ, same data as holotype.

Description: Female: Idiosoma 312 µm long. All dorsal plates separate. Areolae and costae on dorsal plates with rosette pores, remainder of plate foveate. AD 90 µm long, 86 µm wide. AD with two areolae, one anterior and one transverse median, paired ds1 anterior to middle areola. OC 126 µm long, 80 µm wide (length to width ratio about 1.60), posteriorly small tail like extends beyond the insertion of leg III, each with two corneae, areola with rosette pores between cornea ventromedially and also on posterior side, pore canaliculas laterally distal to posterior cornea; ds2 located at anteromedial edge of OC. PD 194 μm long, 132 μm wide; paired costae two-to three- rosette pores wide; ds3-ds5 on PD lateral toporose costae.

All ventral plates separate. AE 96 µm long, 173 µm wide; with three pairs of setae and a pair of epimeral pores. EPI coxal in origin. Paired marginal areolae posterior to insertion of leg I, a pair of areolae posterior to vs2, remain- der of plate reticulately panelled, canaliculi arranged within polygons. Each PE with three ventral setae and one dorsal seta, marginal areola present on PE ventrally. GA longer than AE. GA 166 µm long, 119 µm wide. GO 68 µm long. Paragenital areolae present. Ovipositor surpassing anteriorly about 38 µm of GO, extending beyond anterior PGS. Distance between anterior end of GO and that of GA 72 µm, almost as long as length of GO. Three pairs of PGS present, anterior pair 26 µm away from anterior end of GO and 46 µm away from anterior margin of GA; middle pair just above the level of anterior margin of GO; third pair near posterior side of GO. Pair of SGS located at the anterior end of genital sclerites.

Gnathosoma 98 µm long, 59 µm wide, about 1.66 longer than wide. Rostrum 48 µm long, about 0.48 of gnathosomal length; rostrum tip extending just at the anterior end of P2. Palp consisting of four segments. P1 and P3 without a seta, P2 with one dorsal seta distally. P4 with three long proximal setae and one minute distal seta. Proto- and deuto-rostral setae situated at the tip of rostrum; tritorostral setae (long maxillary setae of rostrum) located on the posterior half of rostrum (0.69 of rostrum length from tip of rostrum); gnathosomal base with a pair of setae (basirostral setae) near the middle of the gnathosomal base. Gnathosomal base ventrolaterally porose; rostral sulcus long but not extending up to the level of tritorostral setae.

Chaetotaxy of legs: trochanters I–IV, 1-1-1-0; basifemora I–IV, 2-2-2-2; telofemora I–IV, 5-5-2-2; genua (patella) I–IV, 4-4-3-3; tibiae I–IV, 7-7-5-5; tarsi (PAS excluded) I–IV, 7-4-4-4. Telofemora III–IV with two dorsal setae and devoid of a ventral seta. Length and width ratio of telofemora I–IV approximately 1.7, 1.8, 2.0, 2.2, respectively. Dorsal side of telofemora I–II with few rosette pores. Tibiae I–IV with 2-2-1-0 bipectinate and 1-1-1- 2 smooth slender ventral setae. Tarsus I with three dorsal setae, one solenidion, three ventral setae (two distal ventral setae, eupathidium present near the tip), two doublet eupathidia PAS. Tarsus II with three dorsal setae, a solenidion, two single eupathidia PAS. Tarsi III –IV each with four dorsal setae (distance between two basidorsal setae almost equal with the height of tarsus) and two PAS (one small spur-like and one pointed seta like). All legs with two lateral claws and a bidentate median claw. Lateral claws with accessory process dorsally. Lateral claws of tarsi II–IV with very delicate pecten ventrally.

Male: Idiosoma 308 µm long. GA 159 µm long, 129 µm wide; GO 48 µm long. Distance between anterior end of GO and that of GA 71 µm, equaling about 1.48 times of GO length. Twenty four PGS present, four pairs of SGS present, arranged 2–2, anterior two pairs slender, third pair spur-like, fourth pair pointed and thicker than first two pairs. Paragenital areolae present. Spermatopositor large.

Etymology: Named after the habitat (pneumatophores of mangroves) where collected.

Remarks: The new species resembles the species of the ‘ oculatus group’ (Bartsch 1977, 1999a, 2002; Chatterjee & De Troch 2001; Pepato & Tiago 2005) in having a posteromedian areola on AD, ds1 anterior to the median areola on AD, OC posteriorly tail-like, PD with paired costae, ds2 inserted on anteromedian edge of OC, ds3-ds5 located on PD, gnathosoma with one pair of maxillary setae on its base (basirostral setae) and one pair on rostrum, trochanters III–IV without a distal spiniform process, telofemora III–IV devoid of ventral setae, solenidia on tarsi I–II setiform and dorsolateral in position, tarsi I, III, and IV with a pair of fossary setae inserted within fossal area. However, in the ‘ oculatus group’, the PGS in male are close to GO and arranged in a ring, whereas in the present species, the anterior PGS are away from the anterior margin of GO. Additionally, males of the ‘ oculatus group’ usually bear three pairs of SGS (one anterior pair and two posterior pairs), whereas in the present species the male has four pairs of SGS. The number of SGS is not always similar for each of the two genital sclerites in an individual (one sclerite may bear three SGS and the other, four), for example, this is found in C. hureaui Newell, 1984, C. levigatus Bartsch, 1999 and C. rasilis Bartsch, 1999 (Newell 1984; Bartsch 1999a). However, only single males have been examined for last two species and for the present species, giving little indication of the taxonomic importance of this variation in SGS number in males. Among the members of the ‘ oculatus group’, only C. hureaui Newell, 1984 from Kerguelen Islands (Newell 1984) has four dorsal setae on tarsus IV (as in the present species). In the described species of the ‘ oculatus group’, the tritorostral setae are located on the anterior to middle (or near middle) of the rostrum, while in the present new species these setae are located on the posterior half of this structure (on about 0.69 of rostrum length from tip of rostrum). C. hureaui has feebly developed medial costae on PD with scattered, irregularly formed rosette pores and coarse pores, the EPI is cervical in origin and the distance between anterior end of GO and that of GA about 1.91 times of the GO’s length in female and 2.83 times in male, while in the new species two- to three- rosette pores wide well developed costae are present on PD, the EPI is coxal in origin and the distance between anterior end of GO and that of GA almost as long as GO’s length in female and 1.48 times in male.

Copidognathus amalus Bartsch, 1999 from southwestern Australia (Bartsch 1999b) has two areolae on AD (one anterior and one posteromedian areolae), OC caudiform posteriorly extending beyond the insertion of leg III, ds2 on anteromedian edge of OC, PD with two costae, ds3-ds5 on PD, tibiae I–IV with 2-2-1-0 bipectinate setae and genu IV bearing three setae (Bartsch 1999b). It differs from C. mangrovorum sp. nov., in having three dorsal setae on tarsus IV, wider costae on PD (four to six rosette pores), and telofemur IV bearing one ventral seta. C. maculatus Bartsch, 1979 from the eastern United States, northwest Atlantic (Bartsch 1979), shares some features with the present species, but can be easily distinguished in having ds2 on the membranous cuticle between AD and OC, and OC posteriorly blunt and not extending beyond the insertion of leg III.