Epictia munoai ( Orejas-Miranda, 1961 )

Francisco, Bárbara Cristina S., Pinto, Roberta R. & Fernandes, Daniel S., 2012, Taxonomy of Epictia munoai (Orejas-Miranda, 1961) (Squamata: Serpentes: Leptotyphlopidae), Zootaxa 3512, pp. 42-52 : 43-49

Epictia munoai ( Orejas-Miranda, 1961)

Leptotyphlops munoai Orejas-Miranda 1961 , Act. Biol. Venezuelica, Caracas, 3: 83–97

Epictia munoai —Hedges, Adalsteinsson and Branch in Adalsteisson et al. 2009, Zootaxa, 2244:11.

Holotype. MBUCV 4547, Pozo Hondo, Tambores (31º57’S, 056º15’W), Tacuarembó Department, Uruguay, M.A. Klappenback and P.R. San Martin, 12 October, 1956.

Paratypes. MBUCV 4548-49, 4551, Pozo Hondo, Tambores, Tacuarembó Departament, Uruguay, M.A. Klappenback and P.R. San Martin, 12 October, 1956. MHNM 0 63 Pozo Hondo, Tambores, Tacuarembó Departament, Uruguay, M.A. Klappenback and P.R. San Martin, September, 1956. MHNM 0 68, Pozo Hondo, Tambores, Tacuarembó Departament, Uruguay, M.A. Klappenback and P.R. San Martin, September, 1956. MHNM 2771-96, Pozo Hondo, Tambores, Tacuarembó Departament, Uruguay, M.A. Klappenback and P.R. San Martin, September, 1956. AMNH 91508 ( MHNM 063H), Pozo Hondo, Tambores, Tacuarembó Departament, Uruguay, M.A. Klappenback and P.R. San Martin, September, 1956. CM 38970 (This specimen belongs to MHNM 0 63 sample; however, no additional information could be found [S.P. Rogers, pers. comm.]), Pozo Hondo, Tambores, Tacuarembó Departament, Uruguay, M.A. Klappenback and P.R. San Martin, September, 1956. MNRJ 3306 ( MHNM 068C; Fig. 02), Pozo Hondo, Tambores, Tacuarembó Department, Uruguay, M.A. Klappenback and P. R. San Martin, 12 October, 1956. MHNM 0 71, Pozo Hondo, Tambores, Tacuarembó Department, Uruguay, M.A. Klappenback and P.R. San Martin, 22 September, 1957. MHNM 2765-70, Pozo Hondo, Tambores, Tacuarembó Department, Uruguay, M.A. Klappenback and P.R. San Martin, 22 September, 1957. CAS 93104 ( MHNM 0107G), Pozo Hondo, Tambores, Tacuarembó Departament, Uruguay, M.A. Klappenback and P.R. San Martin, 12 October, 1957. USNM 163506 ( MHNM 0107J), Pozo Hondo, Tambores, Tacuarembó Departament, Uruguay, M.A. Klappenback and P.R. San Martin, 12 October, 1957. MHNM 2797-2809, Pozo Hondo, Tambores, Tacuarembó Department, Uruguay, M.A. Klappenback and P.R. San Martin, 12 October, 1957. MHNM 0 871, Arroyo Cuaró (30°35’S, 056°50’W), Artigas Departament, Uruguay, A. Y. Ximénez, February, 1960. MHNM 0 872, no specific locality, Montevideo Departament, Uruguay 1891. MHNM 0 873, no specific locality, Cerro Largo Departament, Uruguay, Lucas, 1925. MHNM 0 874, Sierra de la Aurora (31°03’S, 055°43’W), Rivera Departament, Uruguay P.R. San Martin, 24 March, 1961. MACN 1048, San Isidro (34°28’S, 058°30’W), San Isidro Department, Buenos Aires Province, Argentina, J. Plinch, 1895. MACN 12487, Sierra de la Ventana (38°07’S, 061°58’W), Torniquist Department, Buenos Aires Province, Argentina, M. Biraben and I. Scott, February, 1948.

Diagnosis. Distinguished from all congeners by the following combination of characters: (1) snout truncate or rounded in dorsal view, and rounded in ventral and lateral views; (2) two supralabials (1+1); (3) three infralabials; (4) supraocular scale present, not in contact with first supralabial; (5) rostral scale subtriangular or triangular in dorsal view; (6) ocular subpentagonal, with pointed apex; (7) eyes positioned on midanterior portion of ocular; (8) temporals not distinct; (9) occipitals extend to the level of second supralabial; (10) fused caudals absent; (11) middorsal scales 184-225 in males and 202-226 in females; (12) ventral scales 178-219 in males and 184-211 in females; (13) subcaudals 10-13 in males and 10-14 in females; (14) 10 scales around the middle of the tail; (15) striped pattern RB with ground color whitish-cream; and venter light brown.

Redescription of the paratype (MNRJ 3306). Adult female, 149 mm TL, 8 mm TAL; 3.6 mm MB; 2.7 mm MT; 19.6 TL/TAL; 43.6 TL/MB; 2.9 mm HL, 2.5 mm HW; 2.2 relative eye diameter; 0.8 mm rostral width; body cylindrical; snout short and truncate in dorsal and ventral views, rounded and slightly pointed in lateral view.

Head distinguishable from neck; superior border of lip composed by rostral, infranasal, first supralabial, ocular and second supralabial; rostral subtriangular, reaching the anterior edge of ocular scale and supranasals overpassing this level; rostral contacting supranasal and infranasal laterally, and frontal dorsally; two supralabials (1+1); first supralabial overpassing nostril level and inferior edge of the eyes; first supralabial slightly shorter than second supralabial, not contacting supraocular; second supralabial overpassing nostril and eyes levels, contacting parietal and not contacting occipital; three infralabials, two previous rectangular and subequal in size and shape, posterior scale trapezoidal in shape, almost twice wider than first infralabial, as wide as second supralabial; sinfisial divided, two and a half times wider than long; ocular subhexagonal in shape with a narrow base, rectangular apex as high as long; ocular in contact with first supralabial and supranasal anteriorly, second supralabial and parietal posteriorly, and supraocular dorsally; supraocular scale present and not contacting first supralabial, three times longer than wide, rectangular in shape, in contact with supranasal and frontal anteriorly, parietal posteriorly, postfrontal laterally, and ocular ventrally; parietal subhexagonal in shape, elongated dorsoventrally, contacting ocular and supraocular anteriorly, temporal and occipital posteriorly, second supralabial ventrally, postfrontal and interparietal laterally; occipital in subhexagonal shape, elongated dorsoventrally, one and a half time smaller than parietal, contacting parietal anteriorly, first row of middorsal scales posteriorly, temporal ventrally and interparietal and interoccipital laterally, not reaching second supralabial level; temporal scale not differentiated from other dorsal scales, subhexagonal in shape, bordered by second supralabial, parietal and occipital anteriorly, and dorsal scale posteriorly; middle cephalic shields (frontal, postfrontal, interparietal, and interoccipital scales) similar in shape, subpentagonal; frontal almost one and a half time wider than long, contacting rostral and supranasals anteriorly, supraocular laterally, and postfrontal posteriorly; postfrontal almost two times wider than long, contacting frontal and supraoculars anteriorly, parietals laterally, and interparietal posteriorly; interparietal two times wider than long, contacting postfrontal and parietals anteriorly, occipitals laterally, and interoccipital posteriorly; interoccipital almost two times wider than long, wider than interparietal, contacting interparietal and occipital anteriorly, and first middorsal row posteriorly; nasal scale divided; supranasals higher than long, reaching eyes level, not contacting each other, base with same width than infranasals; supranasal contacting rostral anteriorly, first supralabial and ocular posteriorly, and supraocular dorsally; infranasal one and a half time smaller than supranasal, as high as long, contacting rostral anteriorly, first supralabial posteriorly, and supranasal dorsally; nostril obliquely oriented and placed anteriorly in the nasal suture; eyes well developed with domed structure externally, positioned on the anterior portion of ocular scale; cloacal shield rounded, almost three times wider than long; tail short, fused caudals absent; terminal spine short, wider than long; 14 scale rows around midbody; 10 scale rows around the tail; 218 middorsal scales; 203 ventral scales; 13 subcaudals.

Colour in preservative. Dorsal background whitish-cream and stripped pattern with brownish rectangular blotches (RB); venter light brown; head brown, without stripes; infralabials and cloacal shield with same color as the venter; rostral without blotches; terminal spine white.

Variation. Although no sexual dimorphism was found in any analyzed variables, results will be presented for females and males separately. Middorsal scales 184–225 (216.2 ± 10.6, n = 25) in males and 202–224 (210 ± 26.9, n = 18) in females; midventral scales 178–219 (202.4 ± 10.1, n = 25) in males and 182–221 (199.2 ± 7.7, n = 18) in females; subcaudal scales 10–13 (12.1 ± 1.0, n = 25) in males and 10–14 (12.4 ± 0.9, n = 18) in females; TL 71–184 (130.2 ± 26.5, n = 25) in males and 63–162 (104.3 ± 37.1, n = 18) in females; TL/TAL 15–23 (17.3 ± 2.3, n = 25) in males and 13–24 (18.1 ± 3.1, n = 18) in females; TAL/TL% 4.4–7.1 (5.9% ± 0.0, n = 25) in males and 4.1–7.6 (5.7% ± 0.0, n = 18) in females; TL/MB ratio 37.9–69.8 (52.1 ± 7.5, n = 25) in males and 37.9–71.6 (53.5 ± 9.1, n = 18) in females; TAL/MT ratio 2.7–5.2 (3.9 ± 0.6, n = 25) in males and 2.7–4.7 (3.7 ± 0.7, n = 18) in females; relative eye diameter 2.0–3.0 (2.5 ± 0.3, n = 25) in males and 1.9–3.3 (2.4 ± 0.3, n = 18) in females; rostral width 0.5–0.8 (0.6 ± 0.0, n = 25) in males and 0.5–0.8 (0.6 ± 0.1, n = 18) in females.

Geographic distribution. Southern Brazil, in the states of Rio Grande do Sul and Santa Catarina, Uruguay and Eastern Argentina ( Fig. 3 ).

Comparisons with other Cisandine species of the genus Epictia . Comparisons were made with all cisandine species: Epictia undecimstriata ( Schlegel 1839) , E. goudotii ( Duméril and Bibron 1844) , E. albipuncta ( Burmeister 1861) , E. signata ( Jan 1861) , E. columbi ( Klauber 1939) , E. subcrotilla ( Klauber 1939) , E. tenella ( Klauber 1939) , E. magnamaculata ( Taylor 1940) , E. nasalis ( Taylor 1940) , E. striatula ( Smith and Laufe 1945) , E.australis ( Freiberg and Orejas-Miranda 1968) , E. diaplocia ( Orejas-Miranda 1969) , E. collaris ( Hoogmoed 1977) , E. vellardi ( Laurent 1984) , E. borapeliotes ( Vanzolini 1996) , E. clinorostris ( Arredondo and Zaher 2010) . Although Epictia albifrons (Wagler in Spix 1824) is actually assigned as nomen dubium (see Franco and Pinto 2009), the validity of this name is under revision (V. Wallach in prep.). For this reason, we did not include this taxon in the comparisons. Epictia undecimstriata could not be compared to E. munoai because it is known only from the holotype, which is apparently lost according to Hahn (1980) and McDiarmid et al. (1999). Pinto et al. (2010) recognized Epictia phenops as a full species based on molecular data from Adalsteinsson et al. (2009). However, this taxon is currently diagnosed only through molecular data, and no specimens were available for morphological comparisons. Since E. phenops was formerly a subspecies of E. goudotti , we consider the latter taxon to represent the former when compared to E. munoai , concluding that E. phenops is morphologically distinct from E. munoai .

Epictia munoai differs from Epictia striatula and E. albipuncta by the presence of 10 scales around the middle of the tail (12 in the latter two), from E. tenella by the absence of contact between the supraocular and the first supralabial, and from E. vellardi , E. columbi , E. clinorostris , E. goudotti , E. magnamaculata , E. nasalis , and E. signata by the presence of three instead of four infralabials.

Epictia munoai differs from E. australis by lacking two black rings around the gular region and one around the tail. Although all species are predominantly brown, Epictia munoai has an RB striped pattern that differs from E. australis (LB), E. clinorostris (LB), E. borapeliotes (TB), and E. striatula (TB). Epictia nasalis has no striped dorsal pattern (uniform brown). Epictia vellardi and E. tenella has the same pattern of Epictia munoai . Meristic and morphological data are presented in Table 1.

Remarks. Recent taxonomic studies of Leptotyphlopidae focused on the elaboration of more objective diagnoses of taxa based on extensive morphological and meristic character data ( Passos et al. 2005; 2006; Arredondo and Zaher 2010; Pinto et al. 2010; Pinto and Curcio 2011; Pinto and Fernandes 2012).

Epictia munoai is currently diagnosed by some conflicting characters, since Leptotyphlops albifrons (= Epictia albifrons ) was assigned as nomen dubium by Franco and Pinto (2009). Some species of the Leptotyphlops albifrons species group (sensu Peters and Orejas-Miranda 1970) were distinguished from L. albifrons (= Epictia albifrons ) by the contact of supraocular and first supralabial scales. However, this character was considered variable by several authors ( Jan and Sordelli 1860; Boulenger 1893; Thomas 1965; Hoogmoed and Gruber 1983; Franco and Pinto 2009).

Despite the general conservative morphological features of Leptotyphlopidae , E. munoai has well-defined characters that distinguish it from the other congeners, such as low numbers of dorsal and ventral scales. Furthermore, this taxon occurs in sympatry with a few other species of Epictia ( E. australis and E. albipuncta ), and apparently is a common species that is relatively well represented in herpetological collections.

The 19 examined specimens from the Municipality of Corumbá, state of Mato Grosso do Sul, Brazil, previously identified as Epictia albifrons or Epictia munoai , was identified in this study as Epictia vellardi . Epictia vellardi was known only from the type specimens (FML00110 - Holotype and FML00295 - Paratype) from the Municipality of Formosa, Province of Formosa, Argentina, and the specimens reported herein represent the first record of this taxon in Brazil. According to Morrone (2006) and Morrone (2010), both regions ( Formosa, Argentina and Corumbá, Brazil) are included in the biogeographic Chaco province, which composes the open corridor of South America along with the biogeographic Cerrado and Caatinga provinces.

Figures

FIGURE 3. Geographic distribution of Epictia munoai. Triangle = type locality; rectangles = literature data; circles = specimens examined.