Atractus guentheri ( Wucherer, 1861 )
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publication ID |
https://doi.org/ 10.11646/zootaxa.2364.1.1 |
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persistent identifier |
https://treatment.plazi.org/id/0390751B-3D7C-FFD9-FF61-FA92FA85BFD8 |
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treatment provided by |
Felipe |
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scientific name |
Atractus guentheri ( Wucherer, 1861 ) |
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Atractus guentheri ( Wucherer, 1861)
Figs. 2D View FIGURE 2 , 3D View FIGURE 3
Geophis Güntheri Wucherer, 1861 ; Proc. Zool. Soc. London 1861:115.
Atractus guentheri – Boulenger, 1894; Catalogue of the Snakes in the British Museum 2:305. (part.).
Atractus guentheri – Roze, 1961; Acta Biol. Venez. 3:117
Atractus guentheri – Peters & Orejas-Miranda 1970; U.S. Nat. Mus. Bull. 297:29. (part).
Atractus guentheri – Vanzolini, 1986; Adenda and Corrigenda Part 1 Snakes, Catalogue of Neotropical Squamata :3. Atractus guentheri – Fernandes & Argôlo, 1999; Bol. Mus. Nac. Nov. Ser. Zool. 397:2.
Holotype: Adult male, BMNH 1946.1 .1.76 (formerly BMNH 61.3.23.16), municipality of Canavieiras (15º41’S, 38º57’W, sea level), state of Bahia, Brazil (specimen examined). GoogleMaps
Diagnosis: Atractus guentheri is distinguished from all congeners by the following combination of characters: (1) 17/17/17 smooth dorsal scale rows; (2) two postoculars; (3) moderate to long loreal; (4) temporals 1+2; (5) seven supralabials, third and fourth contacting orbit; (6) seven infralabials, first four contacting chinshields; (7) seven to eight maxillary teeth; (8) three gular scale rows; (9) three preventrals; (10) 147–149 ventrals in females, 136–145 in males; (11) 20–23 subcaudals in females, 29–32 in males; (12) dorsum beige or brown, with a dark brown vertebral (three scales wide) and two dorsolateral lines (one scale wide); (13) venter uniform creamish white in preserved and creamish red to pink in living specimens; (14) moderate body size, females reaching 437 mm SVL and males 313 mm SVL; (15) moderate tail size in females (9.6–11.1% SVL) and long (16.9–18.1% SVL) in males; (16) moderately bilobed, semicapitate, and semicalyculate hemipenis.
Comparisons: Among all congeners, A. guentheri shares 17 dorsal scale rows and dorsum with three conspicuous longitudinal stripes only with A. emigdioi . Atractus guentheri differs from A. emigdioi by having seven to eight maxillary teeth (vs. 10–14).
Description: Head twice as long as wide, flattened in lateral view, round in dorsal view; cervical constriction indistinct; snout truncate in lateral view, round in dorsal view; rostral sub-triangular in frontal view, about twice as broad as high, poorly visible in dorsal view; internasal as long as wide; internasal suture sinistral with respect to prefrontal suture; prefrontal about as long as wide; supraocular sub-rectangular, about twice as long as wide; frontal sub-triangular or pentagonal, broader than long; parietal twice as long as wide; nasal divided; nostril located between prenasal and postnasal; prenasal twice as high as long; postnasal twice as high as long; loreal moderate or long, contacting second and third supralabials; pupil round; usually two postoculars of similar size; upper postocular slightly longer than lower postocular; temporals 1+2; anterior temporal twice as long as high; upper posterior temporal elongate, four times as long as wide; seven supralabials, third and fourth contacting orbit; second supralabial higher than first and shorter than third; sixth higher and seventh longer than remaining supralabials; symphisial triangular, twice as broad as long; usually seven infralabials, first four contacting chinshields; first pair of infralabials in contact behind symphisial, preventing symphisial/ chinshield contact; chinshields three times longer than wide; three gular scale rows; three preventrals; 17/17/ 17 smooth dorsal scale rows; dorsals lacking apical pits, supra-anal tubercles, and keels; caudal spine moderate, conical, and acuminate.
Maxillary arch: Arched in dorsal view, with five to six prediastemal and two postdiastemal teeth; first two prediastemal teeth slightly smaller and closely spaced, remaining prediastemal teeth large and moderately spaced; prediastemal teeth curved posteriorly, angular in cross section, robust at base, and narrower on the apices; maxillary diastema moderate spaced; postdiastemal teeth smaller than last prediastemal tooth; lateral process of maxilla poorly developed, lacking posterior projection.
Colour in preservative: Dorsum of head generally dark brown or black; head occasionally beige, with dark brown lateral stripes on posterior region of parietals, connected posteriorly on the mid portion, forming anterior end of the vertebral line; lateral of head brown anteriorly to mid portion of supralabials, frequently with brown covering last three supralabials; lower margin of supralabials, infralabials, chinshields, gular region, and preventrals creamish white scattered with small brown dots; venter uniformly creamish white; venter occasionally with dark brown dots concentrated medially; tail creamish white, with small dark brown dots on lateral margins of subcaudals; dorsal ground colour beige or brown reticulated with small dark brown dots; dark pigment concentrated on lateral margins or restricted to anterior part of dorsals; dorsum with three or five longitudinal stripes; vertebral line (three scales wide) black or dark brown, extending from posterior region of parietals to tip of the tail; dorsolateral stripes (one scale wide) black or dark brown above third and fourth scale rows; occasionally there are two additional longitudinal stripes above fifth and sixth scale rows; longitudinal stripes indistinct on melanic specimens ( Fig. 2D View FIGURE 2 ).
Juvenile colouration in preservative: Juveniles and sub-adults have a beige dorsal ground colour with distinct dorsolateral dark brown longitudinal stripes.
Colour in life: Dorsal ground colour reddish brown or red, with black longitudinal lines; ventral edge of supralabials and mental region creamish yellow or creamish red; venter and tail creamish red, with small black dots on lateral portion of ventrals ( Fig. 3D View FIGURE 3 ).
Hemipenis morphology (everted organ n = 1): Retracted organ bifurcates at level of ninth and extends to the level of 10 th subcaudal. Hemipenis moderately bilobed, semicapitate, and semicalyculate; lobes subcylindrical, similar in size, and with slightly centrifugal orientation; lobes restricted to distal portion and slightly smaller than remaining capitulum; capitular groove poorly distinct on the sulcate side and well marked on the asulcate side of hemipenis; capitulum located just above sulcus spermaticus bifurcation; capitulum distinct, of similar size to hemipenial body; lobes and capitulum uniformly covered with spinulate calyces; calyces arranged transversely forming well-defined transversal flounces on the asulcate side of capitulum; sulcate side of capitulum with irregular and concentrated calyces; sulcus spermaticus divides at middle of organ; sulcus spermaticus with centrifugal orientation, branches running to apices of lobes; sulcus spermaticus margins stout and moderately wide, bordered with spinules from the base to the tip of lobes; hemipenial body subcylindrical, covered with moderate hooked spines; basal naked pocket extends to middle of hemipenial body; basal region of hemipenis with longitudinal plicae and diffuse spinules ( Fig. 6B View FIGURE 6 ).
Variation: Largest male 313 mm SVL, 55 mm CL; largest female 437 mm SVL, 42 mm CL; tail 16.9– 18.1% (x¯ = 17.4; SD = 0.5; n = 4) SVL in males, 9.6–11.1% (x¯ = 10.1; SD = 0.8; n = 3) SVL in females; 136– 145 (x¯ = 139.7; SD = 3.8; n = 4) ventrals in males, 147–149 (x¯ = 148; SD = 1; n = 3) in females; 29–32 (x¯ = 31; SD = 1.5; n = 4) subcaudals in males, 20–23 (x¯ = 22; SD = 1.2; n = 4) in females; 6 (n = 2 sides) or 7 (n = 14 sides) infralabials; 1 (n = 1 sides) or 2 (n = 15 sides) postoculars; 6 (n = 4 sides) or 7 (n = 9 sides) maxillary teeth; 8–10 (x¯ = 8.9; SD = 0.7; n = 16 sides) dorsal scale rows on the level of second subcaudal; 4.3–11.3 mm (x¯ = 7.7; SD = 2.5; n = 7) body diameter; hemipenis bifurcates level with seventh (n = 1) to ninth (n = 1) and extends to the level of 10 th (n = 1) or 11 th (n = 2) subcaudal.
Distribution: A small portion of coastal Atlantic Rainforest in the southeast of the state of Bahia in Brazil, from Almadina (14º48’S, 39º38’W) eastward to Ilhéus (14º47’S, 39º02’W) and southeastward to Canavieiras (15º41’S, 38º57’W), between Contas and Pardo rivers. Atractus guentheri inhabits Lowland Rainforest between 0–300 m elevation ( Fig. 4 View FIGURE 4 ).
Remarks: Wucherer (1861) described Geophis guentheri based on a specimen from Canavieiras in southeastern Bahia, Brazil. Boulenger (1894) synonymized G. guentheri with Rhabdosoma univittatum Jan (described from Caracas, Venezuela), and associate with this species additional material from Rio de Janeiro previously referred to R. maculatum by Günther (1858, pp. 241). Subsequent authors (e.g., Amaral 1930a,b) followed Boulenger’s concept of A. univittatus . Roze (1961) removed A. guentheri from the synonymy of A. univittatus . Subsequent authors reported A. guentheri as a widespread South American species, occurring in the Andes, Amazon forest, and Cerrado ( Peters & Orejas-Miranda 1970; Amaral 1978; Pérez-Santos & Moreno 1988). Vanzolini (1986) suggested that A. guentheri was probably restricted to forest in eastern Brazil. Fernandes and Puorto (1993) examined the holotype of A. guentheri and considered that specimens from the Brazilian Cerrado belong to an undescribed taxon for which they proposed the name A. pantostictus (see below). Fernandes and Argôlo (1999) redescribed the holotype of A. guentheri and reported new specimens and localities from southeastern Bahia. Fernandes and Argôlo (1999) restricted the concept of A. guentheri to striped specimens occurring in the southeast of the state of Bahia of Brazil, which we corroborate herein.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
