Oziotelphusa wagrakarowensis ( Rathbun, 1904 )

Sudha Devi, S. K. Pati P. S. Sujila A. R., 2019, New records of two species of freshwater crabs (Decapoda: Gecarcinucidae) from Kerala, India, with notes on their distribution, Nauplius (e 2019006) 27, pp. 1-8 : 2-5

Oziotelphusa wagrakarowensis ( Rathbun, 1904)

( Fig. 1 )

Potamon (Potamon) wagrakarowensis Rathbun, 1904: 292 .

Paratelphusa (Oziotelphusa) hydrodromus — Alcock, 1910: 97 (part; not Cancer hydrodromus Herbst, 1794 ).

Oziotelphusa senex senex — Bott, 1970a: 100 (part; not Cancer senex Fabricius, 1798 ).

Oziotelphusa wagrakarowensis — Bahir and Yeo, 2005: 87. – Ng et al., 2008 (list): 70. — Pati and Sharma, 2012a: 126 (list). — Pati and Sharma, 2012b: 365 (list). — Pati and Sharma, 2014: 35.

Oziotelphusa senex senex — Srivastava, 2007: 35 (not Cancer senex Fabricius, 1798 ). — Srivastava, 2013: 77 (not Cancer senex Fabricius, 1798 ).

Material examined. INDIA. Kerala: Wayanad district — 4 males (cw 29.18–33.92 mm, cl 20.76–22.20 mm, ch 14.35–15.81 mm, fw 8.91–9.15 mm) and 1 female (cw 32.50 mm, cl 22.28 mm, ch 17.21 mm, fw 9.67 mm), Ondayangadi, near Mananthavady (11.823°N, 76.026°E; altitude 767 m), 17 September 2018, coll. Ammini (ZSI-WRC C.1830) .

Comparative material. INDIA. Karnataka: Bangalore Rural district — 7 males and 3 females, Vijayapura Tank, Vijayapura (13.295°N, 77.801°E; altitude 885 m), 19 March 1978, coll. M. Babu Rao et al. (ZSI-WRC C.451). Chamarajanagar district — 3 males and 2 females, Pdoddane Katte and Karigondu Katte, Bandipur Tiger Reserve (11.769°N, 76.448°E; altitude 839 m), 21 September 1989, coll. G.M. Yazdani (ZSI-WRC C.606). Chikballapura district — 8 males and 2 females, Kanepalli Tank, Chintamani (13.381°N, 78.037°E; altitude 882 m), 13 March 1978, coll. M. Babu Rao et al. (ZSI-WRC C.457) ; 6 males and 1 female, Gavana Tank, Siddalghata (13.392°N, 77.865°E; altitude 890 m), 15 March 1978, coll. M. Babu Rao et al. (ZSI-WRC C.566) ; 7 males, Appayya Kunta, Chikballapura (13.426°N, 77.730°E; altitude 905 m), 17 March 1978, coll. M. Babu Rao et al. (ZSI-WRC C.449) ; 12 males and 9 females, Manchanpani Tank, Chikballapura (13.464°N, 77.747°E; altitude 904 m), 18 March 1978, coll. M. Babu Rao et al. (ZSI-WRC C.565). Kolar district — 11 males and 5 females, Malekar Tank, Katerpalem (13.136°N, 78.133°E; altitude 837 m), 3 March 1978, coll. M. Babu Rao et al. (ZSI-WRC C.445) ; 6 males and 12 females, Malekar Tank, Katerpalem (13.136°N, 78.133°E; altitude 837 m), 4 March 1978, coll. M. Babu Rao et al. (ZSI-WRC C.567) ; 3 males and 1 female, Malur Tank, Malur (13.007°N, 77.927°E; altitude 898 m), 5 March 1978, coll. M. Babu Rao et al. (ZSI-WRC C.450) ; 9 males, Abdul Ali Garden, Bangarpet (12.993°N, 78.179°E; altitude 824 m), 6 March 1978, coll. M. Babu Rao et al. (ZSI-WRC C.564) ; 28 males and 7 females, Mashid Basalguntha Tank, Mulbagal (13.162°N, 78.390°E; altitude 839 m), 8 March 1978, coll. M. Babu Rao et al. (ZSI-WRC C.444) ; 9 males and 2 females, Dodda Hassala Lake, Dodda Hassala (13.099°N, 78.166°E; altitude 812 m), 10 March 1978, coll. M. Babu Rao et al. (ZSI-WRC C.563). Uttara Kannada district – 6 males and 15 females, Hosur, Siddapur (14.295°N, 74.853°E; altitude 583 m), 18 September 1991, coll . R.M. Sharma et al. (ZSI-WRC C.456).

Maharashtra: Kolhapur district — 1 male, Nadi Kinara, Vannur (16.546°N, 74.243°E; altitude 527 m), 13 September 2012, coll. S.S. Kamble (ZSI-WRC C.1084). Nanded district — 2 males and 2 females, Kabarali (19.153°N, 77.306°E; altitude 355 m), 16 August 1971, coll. K. R. Rao (ZSI-WRC C.1002). Sangli district — 2 males, Mhaisal, approximately 15 km from Miraj (16.752°N, 74.704°E; altitude 537 m), 27 September 1984, coll. A.S. Mahabal et al. (ZSI-WRC C.916). Solapur district — 3 males, Sind River , near Sindkhed (17.501°N, 75.930°E; altitude 407 m), 22 November 1978, coll. A.S. Mahabal (ZSI-WRC C.803); 1 male, Nagamma Tank, on Vizapur road (17.460°N, 75.851°E; altitude 441 m), 24 November 1978, coll. A.S. Mahabal (ZSI-WRC C.810); 2 males and 4 females, Pimpaldara Nalla, near Padasali-Madha (18.030°N, 75.508°E; altitude 488 m), 24 August 1983, coll. A.S. Mahabal (ZSI-WRC C.809); 1 male and 1 female, Banegaon, near Nannaj, Great Indian Bustard Sanctuary (17.777°N, 75.882°E; altitude 483 m), 4 October 2011, coll. P.S. Bhatnagar et al. (ZSI-WRC C.521) .

Diagnosis. Carapace broader than long (cw/cl = 1.4–1.5), moderately deep (ch/cw = 0.5); dorsal surface distinctly convex fore and aft; frontal median triangle complete, not as broad as frontal margin; epigastric and postorbital cristae well developed; external orbital angle triangular, with short outer margin, approximately 2 times length of inner margin; epibranchial tooth moderate in size, sharp; branchial regions moderately inflated; epistomal median lobe with distinct, sharp median tooth ( Fig. 1A, B ). Suture between male thoracic sternites s2/s3 indistinct; suture between male thoracic sternites s3/s4 visible as groove medially, not reaching edge of sternum ( Fig. 1C ). Male pleon narrowly triangular, with strongly concave lateral margins; pleonal somite 6 trapezoidal, slightly broader than long, as long as telson, with strongly concave lateral margins ( Fig. 1C ). G1 highly stout, with downwardly curved, hook-like terminal segment; terminal segment subcylindrical, short, approximately 0.3–0.4 times length of subterminal segment, tip subacute; subterminal segment highly stout ( Fig. 1D ). G2 longer than G1, approximately 1.1–1.2 times length of G1; distal segment short, approximately 0.2–0.3 times length of basal segment ( Fig. 1E ).

Remarks. Bahir and Yeo (2005) noted that the G1 terminal segment of O. wagrakarowensis is about 0.3 times the length of the subterminal segment. The male lectotype of O. wagrakarowensis from Andhra Pradesh, however, has a slightly longer G1 terminal segment (approximately 0.4 × length of the subterminal segment) (see Bahir and Yeo, 2005: fig. 12C). The present specimens from Wayanad districts of Kerala also have a long G1 terminal segment, approximately 0.4 times the length of the subterminal segment ( Fig. 1D ). While our specimens resemble the lectotype in most of the carapace features, they only differ in the relative length between G2 and G1, i.e., the G2 length is about 1.2times the length of the G1 ( Fig.1D, E ) (vs. the G2 length is about 1.1 times the length of the G1; see Bahir and Yeo, 2005: fig. 12C, E). Other comparative material from Karnataka and Maharashtra also showed the following small variations:the G1 terminal segment is about 0.3–0.4 times the length of the subterminal segment; the G2 length is about 1.1–1.2 times the length of the G1; and the G2 distal segment is about 0.2–0.3 times the length of the basal segment. These small variations may be due to the differences in size (cw 17.30–37.92 mm) and age of the crabs.

Geographical distribution. Oziotelphusa wagrakarowensis is currently known from Andhra Pradesh (Anantapur district), Karnataka (Bangalore Rural, Bangalore Urban, Chamarajanagar, Chikballapura, Hassan, Kolar, Mysore, and Uttara Kannada districts), Kerala (Wayanad district), and Maharashtra (Kolhapur, Nanded, Sangli, and Solapur districts) of the Indian peninsula ( Fig. 1F ). The precise geographic range of O. wagrakarowensis is difficult to understand based on the known locality records. The species, however, seems to be restricted only to the highlands of the Deccan plateau and the Central Western Ghats. The wider distribution of O. wagrakarowensis in the highlands of the Indian peninsula — unlike the congeners with a relatively restricted distribution in lowland areas — could be associated with the geological history of the Deccan plateau and the formation of the Western Ghats. In fact, the Western Ghats are not true mountains but are faulted edge of the upraised Deccan plateau ( Kuriakose and Sebastian, 2016). It is possible that O. wagrakarowensis was actually present in the Deccan plateau and later able to occupy some parts of the Western Ghats. Furthermore, the anthropogenic introduction of the species to newer localities cannot be overlooked since these crabs are generally associated with rice crops. If this is true, then these crabs might have been introduced to further south of Kerala as well. In these situations, more surveys need to be conducted in the remaining part of Kerala.

Figures

Figure 1. Oziotelphusa wagrakarowensis (Rathbun, 1904), male (29.18 × 20.76 mm) (ZSI-WRC C.1830). A, overall dorsal view; B, frontal view of cephalothorax; C, overall ventral view; D, dorsal view of left G1; E, left G2; F, map showing distribution of O. wagrakarowensis in the Indian peninsula. Scale bar = 10 mm (A–C), 1 mm (D, E).