Gegeneophis pareshi, Giri, Varad, Gower, David J., Gaikwad, Kshamata & Wilkinson, Mark, 2011

Giri, Varad, Gower, David J., Gaikwad, Kshamata & Wilkinson, Mark, 2011, A second species of Gegeneophis Peters (Amphibia: Gymnophiona: Caeciliidae) lacking secondary annular grooves, Zootaxa 2815, pp. 49-58 : 50-56

Gegeneophis pareshi sp. nov.

( Figs. 1–5 ; Table 1 )

Holotype. BNHS 5264, adult female, collected in the village of Kuske near Cotigaon Wildlife Sanctuary, Canacona Taluka, South Goa District, Goa (15˚ 01’ N, 74˚ 12.5 E, 140 m a.s.l.) by R. Bhambure, M. Bhise and R. Korgaonkar on 11 August, 2009.

Paratypes (n = 15). BNHS 5263 collected from the type locality, Kuske, by R. Bhambure, M. Bhise and R. Korgaonkar on 12 August, 2009. BNHS 5373, 5375–5378, collected from the type locality, Kuske, by R. Bhambure, A Norohna and H. Kulkarni on 6 August, 2010. BNHS 5198–5200 collected from Hatipaul, Poinguinim, Canacona, South Goa District, Goa (14˚ 59.1 N, 74˚ 0 6.5 E, 48 m a.s.l.) by V. Giri, P. Porob, R. Bhanbure and K. Gaikwad on 25 June, 2009. BNHS 5265 collected from Poinguinim by R. Bhambure, M. Bhise and R. Korgaonkar on 13 August, 2009. BNHS 5331 collected from Poinguinim by R. Bhambure and V. Giri on 29 June, 2010. BNHS 5370-5372 collected from Poinguinim by R. Bhambure, A Norohna and H. Kulkarni on 5 August, 2010. BNHS 5289 collected from Neturlim, Sanguem, South Goa District, Goa (15˚ 0 5.8 N, 74˚ 12.7 E, 67 m a.s.l.) by R. Bhambure, M. Bhise and H. Ogale on 31 August, 2009. The three localities are all within 20 km of each other.

Diagnosis. A Gegeneophis differing from G. seshachari Ravichandran, Gower & Wilkinson, 2003 in having many more primary annuli (> 140 vs <130) and in having a largely unpigmented and very pale head and anterior of body, and from all other nominal species of Gegeneophis in lacking scales and secondary annular grooves, and in having the vent situated within an unsegmented terminal ‘shield’.

Description of holotype. Some meristic and morphometric data presented in Table 1 . Condition good; 10 mm midventral incision into coelom c. 40 mm anterior to the vent; mouth preserved slightly open, some tooth crowns broken, small piece of tissue missing from front of lower jaw. Overall shape fairly cylindrical and uniform throughout, very slightly dorsoventrally compressed. Head bullet-shaped in dorsal view; sides converge, particularly so anterior to TAs. In ventral view, lower jaw more bluntly rounded than snout. In lateral view, margins of mouth not strongly curved. Eyes not visible. TAs on imaginary lines between nares and CMs. In lateral view, nares approximately equidistant from top, front and bottom of snout. Nares barely visible in dorsal view, not in ventral view. TA slightly larger than naris on right, subequal on left; on raised bulges visible in dorsal and ventral views.

Teeth broken in several places, especially outer rows, but do not appear to differ notably from those of paratypes. Clear diastema between vomerine and palatine teeth at position of choana on right, small tooth sits within what would otherwise be a left diastema. Choanae subcircular, separated by just over the width of single choana. Tongue pigmented; narial plugs obvious with encircling grooves.

Nuchal region scarcely more massive than head and anterior body. C1 shorter than C2. Collar grooves faint but seemingly orthoplicate, probably incomplete middorsally and complete midventrally. Single TG faintly indicated on dorsum of each collar. Midventral crease extends from behind mandibular symphysis onto C1. AGs well marked laterally; mostly incomplete middorsally and midventrally, sporadically complete, slightly more so posteriorly, last few notably shorter, confined to dorsolateral surface. Each groove with single row of enlarged granular glands posterior to a narrow darker band on some. No scale pockets or scales. Granular glands more dense and conspicuous on posterior annuli.

Bounds of terminal shield not associated with marked change in shape; end of body gently tapers before bluntly rounded terminus, blunter than head. End of terminus including vent slightly upturned. Terminal keel absent. Disc around vent weakly circumscribed; subcircular; vent more or less transverse; denticulations approximately symmetrical about long axis, six anteriorly, five posteriorly.

Head cream to pale tan. Pigmentation largely absent on head and anterior of body, anteriormost approximately seven annuli very pale, pigmentation stronger posteriorly. Dorsum of body darker than venter, without abrupt transition laterally. Midventral darker narrow line on anterior half of body. Tip of body terminus pale. Disc around vent slightly paler but denticulations with some peripheral pigmentation. In preservative, colour pattern of holotype is more or less the same as in life (see below) except annular grooves on anteriormost part are more conspicuous.

Variation and additional information from paratypes. See Table 1 for meristic and morphometric data. The paratypes are mostly very similar to the holotype; PAs 145–151; L/W c. 50–80. The nuchal region is slightly more massive in some specimens. Visibility and completeness of nuchal grooves are variable, though they are never very well marked dorsally. In BNHS 5376 the nuchal grooves are more clearly marked, with N1 and N2 complete and N3 incomplete ventrally. In BNHS 5375 N1 is barely visible. In BNHS 5372 N1 and N2 are well marked and complete ventrally, but not dorsally. TGs are never well marked. A TG on the first collar is visible either clearly (e.g., BNHS 5372, 5373), or faintly (e.g., BNHS 5198, 5371). Similarly, a TG on C 2 may be very faint (BNHS 5373) or absent (BNHS 5236). A ventromedial groove on the throat extends to N2 on BNHS 5370 and 5378 but is not visible on BNHS 5375. In one paratype (BNHS 5377) the nares are not visible dorsally.

Eyes are just visible through the skin as minute dark dots in BNHS 5375-8, as small dark spots in BNHS 5370, and are more clearly visible in BNHS 5371 and BNHS 5372, where they are slightly larger than nares and TAs. Eye covered by bone even where clearly visible, as determined by probing with pin. TAs just below (touching) an imaginary line between eye and naris, more so (not touching) in BNHS 5370.

= circumference; D = dentary teeth; E = eye; HW = head width; IM = inner mandibular teeth; L = length; N = naris; PM = premaxillary-maxillary teeth; VP = vomeropalatine teeth.

BNHS 5289 ( Fig. 4 ), a male, is the largest known specimen of G. p a re s h i (228 mm). It matches the holotype closely except in having a notably curved upper lip (in lateral view), with the naris substantially further from the lip than from the top and front of the snout; and in having relatively more widely spaced choanae, approximately 1.5 times the width of each choana. The next largest male (BNHS 5371, 201 mm) has a similar head morphology. Smaller males BNHS 5377 and 3570 are more similar to the holotype. We interpret the differences between BNHS 5289 and 5371 and the rest of the type series as a combination of ontogenetic and sexually dimorphic variation. We did not detect any other notable sexual dimorphism.

Inside of mouth observed in more detail in some paratypes, especially those with broken jaws. All teeth stongly recurved. Dentary teeth most robust, recumbent and largest, largest of which are anterolateral; corresponding premaxillary maxillary teeth about two-thirds their size; teeth of inner rows substantially smaller. Vomerine and palatine teeth more uniform in size, small diastema at choanae generally present, four or five palatine teeth on each side. Teeth of outer series monocuspid, palatine and IMs bicuspid; accessory cusp not detected on vomerine teeth. Where more than one IM on either side, more lateral teeth very small and set close to larger inner teeth. In lateral view, tips of crowns of some vomerine and palatine teeth just visible posteriorly. Choanae generally separated by little more than width of each choana. Tongue darkly pigmented with pale, elongate narial plugs surrounded (except posteriorly) by well-defined grooves. Length of tongue anterior to narial plugs much less than behind, and about half width of each plug. Anterior of tongue with broad, free tip. Posterior of tongue with medial cleft and few longitudinal grooves (one on each side in BNHS 5265).

The vent is clearly transverse in most specimens but approaches a circular condition in BNHS 5377. Disc surrounding vent not strongly circumscribed in any specimens, denticulations often lightly pigmented. Paired papillae on anterolateral parts of disc variably present in some males (e.g., BNHS 5199, 5263, 5289) and some females (e.g., BNHS 5198). Area of vent not notably upturned in most specimens (e.g., BNHS 5373). Colour generally similar to holotype, though one specimen (BNHS 5371) is a clear outlier in being much darker throughout. Several specimens (BNHS 5199, 5200, 5265, 5331, 5370, 5371, 5372) differ from the holotype in having some pigmentation on the head and lower jaw, though this is generally faint and scattered and never encroaches onto the skin overlying the mandibles.

In most specimens the m. interhyoideus posterior are visible through the skin. The skin on the head was removed in BNHS 5198. The mesethmoid is not exposed middorsally. The eye is under the squamosal. The m. depressor mandibulae have a weakly developed and/or concealed posterior part. The m. intermandibularis and m. interhyoideus form a solid sheet. There is no middorsal fascial window or gap within the m. rectus lateralis.

Colour in life. Observations were made of BNHS 5331 in anaesthesia (MS222) and before fixation. Head unpigmented, pale pink. Tongue very pink. Body darker pink anteriorly, darkening posteriorly to purple and greylilac, slightly paler grey on terminal shield. Body slightly darker above than below, more notable posteriorly (including terminus) with weak, darker, broad middorsal stripe. Eye clearly visible; not within paler eye-tentacle stripe. Disc around vent pale pinkish grey. Short, slightly darker midventral streak just anterior to vent. Photographs of the species in life are shown in Fig. 5 . The smallest specimen (BNHS 5372, 115 mm; Fig. 5 ) seems to have had a more prominent middorsal stripe.

Etymology. Named in honour of Range Forest Officer Mr. Paresh Porob, in recognition of his dedicated efforts to conserve and promote a love and understanding of wildlife and the natural environment, especially in Goa. For nomenclatural purposes the species epithet is considered a noun in apposition.

Suggested common names. Paresh’s Gegeneophis (English) .

Distribution, conservation and natural history. BNHS 5263 has large and well-developed testicular lobes and lobules. The holotype (BNHS 5264) has yolky eggs, as does BNHS 5198 (1mm diameter). The holotype and paratopotypes were collected from moist soil under a large tree and under piles of compost in an open area behind houses in the village. The Poinguinim and Naturlim paratypes were dug from moist soil beneath compost around the bases of trees (mostly areca nut, coconut and banana) in gardens ( Fig. 6 ).

The occurrence of G. pareshi in human modified habitats (some close to the protected forest of Cotigaon Wildlife Sanctuary) is a source of optimism that it is not an immediate conservation concern, but until additional field surveys are carried out the species will likely need to be classified as Data Deficient under IUCN criteria. As with many caecilians, for which detailed ecological data are not immediately available or readily obtained (e.g., Gower & Wilkinson, 2005; Loader et al., 2011), the best prospect of G. pareshi being given some other IUCN categorization is to obtain better data on its distribution – either not occurring far beyond the type locality (threatened) or found over a substantially broader area (Least Concern). Finding the species in the nearby Wildlife Sanctuary would also improve its conservation status.

Figures

FIGURE 1. Preserved holotype (BNHS 5264) of Gegeneophis pareshi sp. nov.

FIGURE 2. Anterior end of preserved holotype (BNHS 5264) of Gegeneophis pareshi sp. nov. Scale bar in mm.

FIGURE 3. Posterior end of preserved holotype (BNHS 5264) of Gegeneophis pareshi sp. nov. Scale bar in mm.

FIGURE 4. Head end of preserved paratype male and largest specimen (BNHS 5298) of Gegeneophis pareshi sp. nov. Scale bar in mm.

FIGURE 5. Paratypes of Gegeneophis pareshi sp. nov. in life, BNHS 5377 (left, total length = 190 mm) and BNHS 5372 (right, total length 115 mm).

FIGURE 6. Mixed small plantation in walled garden at Poinguinim, collection locality of eight paratypes of Gegeneophis pareshi sp. nov.

Tables

TABLE 1. Some morphometric (in mm) and meristic data for the type series of Gegeneophis pareshi sp. nov. Measurements were made to the nearest 0.1 mm with dial callipers, except for length and circumference, which were measured with a ruler and piece of thread. * indicates holotype; all other specimens are paratypes. The number of denticulations forming the vent is given for the anterior and posterior halves separately (separated by a comma). Abbreviations other than those listed in Material and Methods:

BNHS no. 5264* 5198 5199	5200	5263	5265	5289	5331	5370	5371	5372	5373	5375	5376	5377	5378
Sex f f m	f	m	m	m	m	m	m		f	f	f	m	f
Total L 210 178 186	170	154	173	228	161	172	201	115	190	140	198	190	182
Primary annuli 145 150 147	146	150	145	151	149	148	148	148	148	147	148	149	149
ST-NG1 4.5 4.1 4.1	3.8	3.5	4.0	5.3	4.0	4.0	4.7	3.2	4.3	3.6	4.5	4.5	3.9
ST-CM 3.3 3.2 3.2	3.0	2.5	2.9	4.1	2.9	2.8	3.4	2.2	3.2	2.5	3.4	3.4	2.9
C1 L 1.1 1.1 1.0	1.0	0.9	1.1	1.6	1.1	1.1	1.1	0.8	1.0	1.1	1.1	1.0	1.1
C2 L 1.7 1.6 1.5	1.4	1.5	1.6	1.9	1.4	1.4	1.5	1.2	1.7	1.5	1.6	1.6	1.7
CM-NG1 1.2 1.0 1.0	0.9	1.1	1.2	1.3	1.1	1.2	1.2	0.9	1.0	1.0	1.2	1.5	1.2
Tip lower jaw-NG1 3.8 3.4 3.4	3.2	2.8	3.3	4.7	3.3	3.3	3.9	2.5	3.4	2.8	3.7	3.7	3.2
Tip lower jaw-CM 2.7 2.5 2.5	2.5	2.0	2.3	3.5	2.4	2.4	3.0	1.8	2.6	2.0	2.8	2.5	2.2
HW at NG1 3.2 2.6 2.6	2.4	2.3	2.5	3.4	2.5	2.7	2.8	1.9	2.5	2.5	2.8	2.8	2.5
HW at CM 2.8 2.5 2.5	2.3	2.2	2.3	3.2	2.3	2.6	2.7	1.9	2.6	2.2	2.6	2.6	2.3
N-N 1.2 1.1 1.2	1.2	1.1	1.1	1.4	1.1	1.1	1.2	0.9	1.1	0.8	1.2	1.1	1.0
TA-TA 2.3 2.0 2.0	1.8	1.6	1.9	2.7	1.9	1.9	2.1	1.4	2.0	1.6	2.1	2.2	1.9
E-E 1.7 1.7	1.5	1.6	1.7			1.6	1.8	1.3		1.9	1.8	2.0	1.8
N-TA 0.8 0.8 0.9	0.7	0.7	0.8	1.2	0.8	0.8	0.9	0.5	0.8	0.7	0.9	1.0	0.8
E-N 1.4 1.5	1.4	1.2	1.4		1.4	1.4	1.7	1.0		1.3	1.6	1.6	1.4
E-TA 0.5 0.6	0.6	0.5	0.6		0.6	0.6	0.6	0.4		0.6	0.6	0.6	0.5
TA-lip 0.5 0.4 0.4	0.4	0.4	0.4	0.5	0.4	0.4	0.4	0.3	0.4	0.3	0.4	0.5	0.5
N-lip 0.8 0.7 0.7	0.7	0.6	0.7	0.9	0.7	0.7	0.7	0.5	0.7	0.5	0.7	0.7	0.6
N-CM 2.7 2.5 2.6	2.4	2.2	2.3	3.3	2.3	2.2	2.7	1.5	2.4	2.2	2.7	2.7	2.2
TA-ST 1.6 1.5 1.6	1.5	1.3	1.5	2.0	1.4	1.4	1.7	1.2	1.4	1.2	1.7	1.6	1.3
E-ST 2.0 2.1	2.0	1.8	2.0		2.0	1.9	2.4	1.6		1.9	2.3	2.2	1.7
TA-CM 1.8 1.6 1.7	1.5	1.3	1.4	2.1	1.5	1.4	1.9	0.9	1.9	1.5	1.7	1.7	1.5
E-CM 1.1 1.0	1.1	0.9	0.8		0.9	0.8	1.1	0.5		0.8	1.2	1.2	1.0
ST-lip 1.1 0.9 0.9	0.9	0.8	0.9	1.0	0.8	0.9	1.0	0.7	0.8	0.8	0.9	1.0	0.8
W at midbody 3.7 2.2 2.4	2.2	3.0	2.7	3.9	2.4	3.3	2.7	1.9	2.7	2.5	2.9	2.9	2.5
W at vent 2.2 1.6 1.7	1.0	1.7	2.1	2.3	1.8	2.4	2.1	1.3	1.5	1.6	2.1	2.1	1.4
Vent-terminus 0.8 0.8 0.8	0.9	0.9	0.8	1.1	0.9	0.8	1.0	0.7	0.7	0.7	1.1	1.1	0.7
C at midbody 13 8 10	9	11	11	13	8	10	12	8	10	9	11	10	10
L terminal shield 3.1 3.2 3.1	3.3	3.4	3.8	5.7	3.8	3.7	3.9	2.4	3.5	3.2	2.9	4.8	2.8
W disc around vent 1.3 0.6 0.9	1.0	1.0	0.8	1.1	1.1	1.4	1.1	0.7	1.3	0.8	0.9	1.2	1.0
Vent denticulations 6,5 6,6 or 6,7 4,6	5,7	5,5	6,6	5,6	4,6	5,6	4,6	3,5	5,6	4,5	4,4	3,4	5,5
PM 18 19 18	18	17	19	23	20
VP 15 16 17	14	13	15	16	15
D 17 18 15	16	16	15	15	15
IM 4? 2 2	4	3	2	2?	1