Indoreonectes radhanagari, Jadhav & Karuthapandi & Jaiswal & Shankar & Dinesh & Raghunathan & Banerjee, 2024

Indoreonectes radhanagari sp. nov.

( Figures 7 View Figure 7 , 8 View Figure 8 , Table 1)

Type material: Holotype: 32.1 mm SL. India, Western Ghat, Maharashtra State, Kolhapur District, Radhanagari Wildlife Sanctuary , Rautwadi waterfall, 16.4319 N;

73.9550 E, 626 m asl, 23.xi.2020, coll. Shrikant Jadhav and M. Karuthapandi (ZSI/ FBRC /F/4041) . Paratypes: 6 exs, 25.3–29.3 mm SL; same locality and label data as holotype (ZSI/ FBRC /F/4042); 3 exs., 26.2-31.1 mm SL. India, Western Ghat, Maharashtra State, Kolhapur District, Radhanagari Wildlife Sanctuary , a stream near Kariwade village , 16.4187 N; 73.9198 E, 608 m asl,

23.xi.2020, coll. Shrikant Jadhav and M. Karuthapandi (ZSI/FBRC/F/4043).

Type depository: The type specimens are deposited in the museum collections of the Zoological Survey of India, Freshwater Biology Regional Centre, Hyderabad, India (ZSI/ FBRC) .

Diagnosis: Indoreonectes radhanagari can be distinguished from all other congeners by having the lateral and inter-bar spaces equal (vs. lateral bars wider than inter-bar spaces in I. neeleshi , lateral bars narrower than inter-bar spaces in I. keralensis , I. telanganaensis , I. evezardi , I. kalsubai , and I. rajeevi , and black blotches in I. amrabad ). Further, Indoreonectes radhanagari can be distinguished from I. rajeevi by the absence (vs. presence) of a conspicuous black marking on the lower lip; presence (vs. absence) of dorsal hump behind nape; caudal peduncle as long as deep (vs. slightly longer than deep); maxillary barbel not reaching the posterior border of operculum (vs. reaching to the posterior border of operculum); presence (vs. absence) of a dark brown to black spot at the base of first dorsal-fin ray and distinct spots on the dorsal side of the head.

Indoreonectes radhanagari can be distinguished from I. neeleshi by having the lateral and inter-bar spaces equal (vs. lateral bars wider than inter-bar spaces), and inner rostral barbel reaching the middle of the eye (vs. reaching the middle of the nostril). Indoreonectes radhanagari can be distinguished from I. telanganaensis by the absence (vs. presence) of spots on the cheek below the eye; lateral and inter-bar spaces equal (vs. lateral bars narrower than inter-bar spaces); and inner rostral barbel reaching the middle of the eye (vs. reaching anterior margin of the eye).

Indoreonectes radhanagari can be distinguished from I. evezardi by having a caudal peduncle bar not divided into two spots (vs. divided into two spots); caudal peduncle as long as deep (vs. deeper than long); lateral and inter-bar spaces equal (vs. lateral bars narrower than inter-bar spaces); and dorsal-fin origin vertical from pelvic-fin base (vs. posterior to vertical at pelvic-fin base).

Indoreonectes radhanagari can be distinguished from I. amrabad by having the lateral bar and inter-bar (vs. blotches) on the body; caudal peduncle as long as deep (vs. deeper than long); three to four rows of dark-brown spots on the caudal-fin rays (vs. five to six rows of dark-brown spots); spots on the cheek below eye absent (vs. present); and dorsal-fin origin vertical from pelvic-fin base (vs. posterior to vertical from pelvic-fin base).

Indoreonectes radhanagari can be distinguished from I. kalsubai by the presence (vs. absence) of a dark brown to black spot at the base of the first dorsal-fin ray and distinct spots on the dorsal side of the head; lateral bar and inter-bar spaces equal (vs. lateral bars narrower than inter-bar spaces); and inner rostral barbel reaching the middle of the eye (vs. reaching up to nostril).

Indoreonectes radhanagari can be distinguished from I. keralensis by having a long nasal barbel reaching the middle of the eye (vs. short nasal barbel barely reaching the anterior margin of the eye); presence (vs. absence) of dorsal hump behind nape; caudal peduncle as long as deep (vs. longer than deep); spots on the cheek below eye absent (vs. present); and dorsal-fin origin vertical from pelvic-fin base (vs. posterior to vertical from pelvic-fin base).

Description: Morphometric data of the holotype and nine paratypes are provided in Table 1. Body elongate, slender, its length 7.1–8.8 times depth; Dorsal profile rising evenly from the tip of snout to head, a distinct dorsal hump behind nape, gradually rising to dorsal-fin origin, sloping gently to origin of adipose crest on caudal peduncle; moderately high adipose crest on dorsal aspect of caudal peduncle. The ventral profile is almost straight.

Head small, moderately depressed. Snout rounded; shorter than postorbital length; eye moderately large dorso-laterally placed, not visible from ventral view. Mouth semicircular in ventral aspect, with thick fleshy lips, upper lip with a shallow median incision, and lower lip interrupted medially by a deep groove ( Figure 9C View Figure 9 ). Barbels well developed, four pairs; two rostral barbels almost equally long, inner one extending to the middle of the eye, outer reaching slightly beyond posterior margin of eye; maxillary barbel longest, extending up to middle between the posterior border of eye and tip of operculum; nasal barbel reaching the middle of eye. Lips and barbels covered with unculi.

Dorsal fin with 3 (10) soft unbranched rays and 7 (10) branched rays, origin nearer to caudal-fin base than to tip of snout, posterior edge rounded, shorter than head length. Anal fin with 3 (10) unbranched and 5 (10) branched rays, tip not reaching caudal-fin base when depressed. Pectoral fin with 2 (10) unbranched and 9 (10) branched rays, reaching midway between pectoral-fin origin and pelvic-fin origin when adpressed. Pelvic-fin with 1 (10) unbranched and 7 (10) branched rays, opposite to dorsal-fin origin, tip not reaching anus, longer than half of distance between pelvic and anal-fin origin; axillary pelvic lobe absent. Distance from anus to anal-fin origin is almost equal to eye diameter. Caudal fin rounded, with 18(7) or 19(3) principal rays (with 3*–5 unbranched and 14–15* branched rays); dorsal and ventral procurrent rays subdermal. The caudal peduncle is about as long as deep, its length-to-depth ratio 1.0–1.1. Lateral line incomplete, with 8–11* pores, short, ending middle of pectoral fin. Scales minute. Cephalic lateral-line system with 3*(3), 4(6), 5(1) supraorbital, 3*(6), 4(4) + 7*(5), 8(5) infraorbital, 3(5), 4*(5) supratemporal pores. Preoperculomandibular canal pores are not visible.

Colouration: In life ( Figure 7 View Figure 7 ), Body colour is pale yellowish-white to grey with almost vertical brownish-black bars laterally, extending to the ventral side behind the dorsal fin; inter-bar space is yellowish-white equal to vertical bars. Dorso-lateral area of the head with irregular large dark-brown spots. Dark brown to black spot on base of first dorsal-fin ray; dorsal fin interradial membrane hyaline with two rows of black spots on rays; pectoral, ventral and anal fin hyaline, lacking spots; caudal fin interradial membrane hyaline, with three to four rows of dark-brown spots on rays; dark-brown vertical bar on caudal-fin base. Ventral surface without any markings. In preservatives ( Figure 8 View Figure 8 ), colouration is similar to that in life but faded.

Habitat: Indoreonectes radhanagari inhabits shallow, moderately fast-flowing streams with bedrock, sand, boulders and gravels as substrates. The stream was observed to flood during monsoon, thereafter reducing inflow during summer. Co-occurring species are Rasbora daniconius , Schistura denisoni , Devario aequipinnatus , Parapsilorhynchus sp. and Garra mullya .

Etymology: The specific epithet is named after ‘Radhanagari Wildlife Sanctuary’, the type locality for the species and a protected area in Maharashtra. The species epithet is a noun in apposition to the generic name.

Distribution: Indoreonectes radhanagari is currently known only from the surroundings of the Radhanagari Wildlife Sanctuary, northern Western Ghats, Maharashtra ( Figure 1 View Figure 1 ).

Common name: Radhanagari loach