Microcaecilia butantan, Wilkinson, Mark, Antoniazzi, Marta Maria & Jared, Carlos, 2015

Wilkinson, Mark, Antoniazzi, Marta Maria & Jared, Carlos, 2015, A new species of Microcaecilia Taylor, 1968 (Amphibia: Gymnophiona: Siphonopidae) from Amazonian Brazil, Zootaxa 3905 (3), pp. 425-431 : 426-430

Microcaecilia butantan sp. nov.

urn:lsid:zoobank.org:act:F9BA7AF1-4C47-4A07-A265-41B42886D38D Figs. 1–2 ; Table 1

Holotype. Museu de Zoologia, Universidade Sao Paulo ( MZUSP) 143389, a female with small (c. 0.5 mm) nonyolky eggs, collected by Carlos Jared and Marta Maria Antoniazzi, dug from soil in a cupuaçu ( Theobroma grandiflorum ) plantation within APA (Área de Proteção Ambiental) Aramanaí [237'57.96"S, 5457'44.16"W, 152m asl], municipality of Belterra, Pará, in October 2010, maintained in captivity until fixed in December 2010.

Paratypes (n = 3). MZUSP 153204–6 collected by Carlos Jared and Marta Maria Antoniazzi, dug from soil at or near the type locality (within the same plantation) in May 2010 or May 2011.

Diagnosis. A Microcaecilia that differs from M. albiceps (Boulenger, 1882) , M. nicefori (Barbour, 1928) , M. supernumeraria Taylor, 1970 and M. unicolor (Duméril, 1863) in having elongate PM series that extend posterior to the level of the choanae, and from all other Microcaecilia ( M. dermatophaga Wilkinson, Starace, Gower & Sherratt, 2013 , M. iwokramae ( Wake & Donnelly, 2010), M. iyob Wilkinson & Kok, 2010 , M. grandis Wilkinson, Nussbaum & Hoogmoed, 2010 , M. marvaleewakeae Maciel & Hoogmoed, 2013 , M. pricei, (Dunn, 1944) M. rabei (Roze & Solano, 1963) , M. rochai Maciel & Hoogmoed, 2011 , M. savagei Donnelly & Wake, 2013, M. taylori Nussbaum & Hoogmoed, 1979 and M. trombetas Maciel & Hoogmoed, 2011 ) in having more than 135 PAs.

Description of the holotype. Some morphometric and meristic data are in Table 1 . Good condition, a 3 mm midventral incision c. 65 mm behind ST, a 9 mm midventral incision c. 35 mm anterior of TT, an opened scale pocket posteriorly, some skin damaged anteriorly by search for subdermal scales.

Body subcylindrical, slightly dorsoventrally flattened throughout (width and depth at midbody 4.0 x 3.7 mm), fairly uniform, slightly narrower anteriorly, narrowing posteriorly from just in front of the vent; L/W c. 40. In dorsal view, head intermediate between U- and V-shaped; sides of head fairly straight, converging gently from posterior to level of TAs, more curved and converging more strongly to level of nares, ST moderately pointed. In lateral view, top of head slightly convex; upper lip slightly concave, somewhat downturned anteriorly from just in front of TAs; ridge bearing vomeropalatine teeth visible close to CM; lower jaw robust, two-thirds the height of upper jaw at levels of CM and TA. In ventral view, snout projects strongly beyond recessed mouth, anterior margins of upper and lower jaws much more blunt than ST. Eyes not visible. TAs very slightly elevated, on indistinct, broad low papillae that are just visible dorsally and ventrally, much closer to CMs than to nares, distinctly above imaginary lines between nares and CMs. Nares small, dorsolateral, superficially they are ovate depressions, longer than wide/high, each with deeper, more ovate, wider than long, aperture anteriorly. Nares closer to ST than to level of AM, about one and a half times as far from bottom than from top of snout and from ST in lateral view, not visible from below.

Teeth pointed, gently recurved, lacking serrations or blade like flanges, last few elements of outer series much smaller posteriorly. OMs and PMs monocuspid, the former a little larger; VPs smaller, more uniform in size, bicuspid, vomerine series broadly rounded anteromedially, palatines extending posteriorly slightly further than premaxillary-maxillary series. Distance between vomeropalatine and premaxillary-maxillary series anteriorly much less (approximately half) AM–ST in ventral view; upper series extending posteriorly distinctly beyond choanae. Palate strongly arched transversely and longitudinally. Choanal apertures subcircular, separated from each other by about twice width of single choana, anterior margins approximately level with TAs. Tongue somewhat pointed at tip, attached anteriorly, smooth except for a medial longitudinal groove posteriorly.

Nuchal region a little wider than adjacent body. Two nuchal collars clearly marked by three nuchal grooves; NG1 and NG2 completely encircling body, NG3 widely incomplete and curving posteriorly on the venter. NG1 notably oblique laterally; substantial TG on C2, visible laterally; much shorter TG on C1. TGs, NG2 and NG3 bending slightly anteromedially on dorsum. NG1 with a ventral transverse groove a little longer than that on the dorsum. A small mid-ventral crease extends from between the CMs to just past the ventral TG on C1. Behind collars, 157 PAGs, mostly complete or very narrowly incomplete dorsally, mostly narrowly incomplete ventrally except for approximately the anteriormost 20 and posteriormost 12; PAs longest at midbody, shorter anteriorly and more so posteriorly. First SAG short, dorsolateral on 139th PA; SAGs dorsally complete from 142nd PA; more posterior SAGs gradually extending further ventrolaterally, none complete ventrally; SAGs absent from last two PAs, last PA (155th) divided by a SAG slightly in front of the level of the vent; last PAG just posterior to vent. AGs slightly raised in places. Vent region interrupts last four PAGs. Body ends in a short terminal cap c. 1.5 times the length of the last PA (viewed laterally), approximately the same length as the last PA with a SAG, a little shorter than midbody PAs. Body terminus slightly acuminate in lateral view, more so in dorsal view, narrowing only over last five PAs. In lateral view, ventral surface strongly upturned behind vent. Vent rather transverse, with perhaps five main denticulations anterior and four posterior, but with some irregular subdivisions, the interdenticular creases shorter anteriorly; vent slighty elevated but not in an obvious ‘disc’ and seemingly without papillae. Distinct terminal keel on dorsal surface of terminal cap. Scales in shallow (<0.5 mm deep, less than half length of PA in this region) pockets in posteriormost AGs, a single main row plus occasional supernumerary scales both anterior and posterior to the main row. No indications of scales in subdermal connective tissue. Three vertebrae in the nuchal region, no post-cloacal vertebrae.

In preservative, body mostly faint tan, with slightly darker middorsal band (3 mm wide), fairly abrupt transition to much paler lateral flanks and more gradual transition to slightly darker venter. Little regional differentiation in colour, darker dorsal coloration extends a little more ventrally on posteriormost annuli especially where there are SAGs. Head and ventral surface of nuchal region pale, almost pigmentless. Paler (whitish) immediately anterior to and around vent and on ventral surface of terminal cap. AGs with whitish edge and more or less well-developed adjacent line of darker pigment, appear darker than the intervening skin macroscopically. Numerous whitish glands visible scattered in the skin with many large glands aligned along AGs.

Variation and additional information from paratypes. Variation in some meristics and morphometrics is summarised in Table 1 . The paratypes, which are all males, are similar in most respects to the holotype except for notably fewer PAs (143–145), narrower bodies at the level of the vent and smaller heads, all of which might be indicative of sexual dimorphism. Only one (the last) terminal PA lacks a SAG in MZUSP 153205. MZUSP 153206 has three SAGs that are complete ventrally just anterior to the vent (on PAs 139, 140, and 141). In life, body colour is pink to purple ( Fig. 2 A).

Remarks. A total of 21 specimens of this species were encountered at the type locality or in nearby forests within the limits of APA Aramana in three expeditions: May 2010 (16 specimens, in three days, including eight in approximately four hours on the first day, and six in about two and a half hours on the second day) and 2011 (four specimens) during the rainy season and October 2010 (the holotype) during the dry season. Only four of these specimens were fixed for use as taxonomic vouchers. Some other specimens are being used in histological studies at the Instituto Butantan .

Etymology. The specific epithet is in honour of the Instituto Butantan , which enabled the discovery of the species through the Butantan na Amazônia ( Butantan in Amazon) project. To promote stability the species epithet is considered to be noun in apposition for nomenclatural purposes.

Suggested English name. Butantan microcaecilia .

Figures

FIGURE 1. MZUSP 143389, holotype of Microcaecilia butantan sp. nov. Scale bars in mm. Photo by Harry Taylor (Natural History Museum, London).

FIGURE 2. Microcaecilia butantan sp. nov. (A) Specimen in life dorsal view. Bar = 5 mm. (B) Specimen in life ventral view. Bar = 5 mm. (C) Habitat at type locality.

Tables

TABLE 1. Morphometric (in mm) and meristic data for the type series of Microcaecilia butantan sp. nov. * = holotype. Tooth counts for the paratype specimens are approximate and tentative. Empty cells are missing data. L = lip; N = naris; other abbreviations given in text.

	MZUSP	MZUSP	MZUSP	MZUSP
	143389*	153205	153206	153204
Sex	F	M	M	M
Length	159	208	191	202
Width at mid-body	4.0	4.5	3.7	3.3
Circumference	13	16	14	17
PAGs (= PAs)	157	143	145	143?
First PA with SAG	139	129	116	116
Last PA with SAG	155	142	143
SAGs	17	14	26	c. 25
SAGs complete ventrally	0	0	3	3 or 4
Vertebrae	162
CM–ST	3.5	4.5	4.2	4,0
NG1–ST	4.5	5.5	4.8	5.2
Width at occiput	3.2	3.5	3.3	3.1
Depth at occiput	2.7	2.8	2.4	2.3
Width at vent	2.4	2.7	2.8	2.9
Length of body behind vent	1.0	1.3	1.3	1.3
AM–ST	1.1	1.2	1	1.2
N–N	1.2	1.1	1.3	1.2
CM–N	3.0	4	3.6	3.7
L–N	1.0	0.9	0.9	0.9
N–TA	1.8	2	2	2.1
TA–TA	2.6	2.9	2.8	2.9
CM–TA	1.3	1.7	1.7	1.7
L–TA	0.5	0.4	0.4	0.4
Length of C1	1.3	1.8	1.4	1.5
Length of C2	1.5	1.9	2	1.8
PMs	22	21	18	20
VPs	24
OMs	19		13	16