Isometrus (Reddyanus) problematicus, Kovařík, 2003

Kovařík, František, 2003, A review of the genus Isometrus Ehrenberg, 1828 (Scorpiones: Buthidae) with descriptions of four new species from Asia and Australia, Euscorpius 10 (10), pp. 1-19 : 11-12

Isometrus (Reddyanus) problematicus sp. n.

(Figs 1 and 6, Table 1)

TYPE LOCALITY AND TYPE REPOSITORY. India, south, Pondichery State , Karaikal ; FKCP.

TYPE MATERIAL. India, south, Pondichery State, Karaikal, T.R.S.N. coll., 2002, 1♀ (holotype), FKCP; south, Tamil Nadu State, Coimbatore , IX.1957, 1♀ (paratype), leg. P. Susai Nathan, CASC (Stahnke colection); Nilgiri Hills, Kallas, XI.1958, 1♀ (paratype), leg. P. Susai Nathan, CASC (Stahnke colection) .

ETYMOLOGY. The name reflects past identification problems (see affinities).

DIAGNOSIS: Total length 22 mm (female). Pedipalps, legs and metasomal segments yellow to reddish brown with black spots. First metasomal segment bears 10 carinae, second through fourth segments bear eight carinae, fifth segment bears five carinae. Telson bulbous, without carinae. Subaculear tooth large, obliquely triangular, dorsally with three pairs of granules. Pectinal teeth number 9–12.

DESCRIPTION: The total length of the female holotype is 22 mm. Measurements of the carapace, telson, segments of the metasoma and segments of the pedipalps, and numbers of pectinal teeth are given in Table 1. There are 12 teeth in the pecten. The paratypes have 9–10 pectinal teeth. For the position and distribution of trichobothria on the chela of pedipalps see Fig. 6. The male is unknown.

COLORATION: The chelicera is reticulated. The carapace and mesosoma are dominantly black with a weak yellow pattern. The femur, patella and chela of pedipalps, legs and metasomal segments are yellow to reddish brown with black spots.

MESOSOMA AND CARAPACE: The carapace is without carinae but bears large granules. The mesosoma bears one median carina and is granulated. The ventral side of the seventh segment bears four carinae and is granulated. METASOMA AND TELSON: The first segment bears 10 carinae, the second through fourth segments bear eight carinae, and the fifth segment bears five carinae. The telson is bulbous, without carinae. The subaculear tooth is large, obliquely triangular, dorsally with three pairs of granules (Fig. 1).

PEDIPALPS: The femur and patella of pedipalps bear complete carinae and are weakly granulated. The manus of pedipalps is smooth, with only traces of carinae and several granules. The sixth cutting edge of movable fingers bears one external granule.

LEGS: The femur and patella bear complete carinae and are granulated. The legs are hirsute and without bristlecombs.

AFFINITIES. The described features distinguish I. problematicus sp. n. from all other species of the genus. They are recounted in the key below. The most similar species is I. basilicus Karsch, 1879 from Sri Lanka, from which I. problematicus sp. n. can be easily separated by smaller size and shorter/broader metasomal segments. One of the paratypes was originally labeled I. basilicus . The other paratype was labeled as I. brachycentrus , whose juveniles may be mistaken for I. problematicus sp. n. although they have markedly narrower manus of pedipalps and their legs and metasomal segments are conspicuously spotted in a way different from adults of I. brachycentrus .