Atractus francoi, Passos & Fernandes & Bérnils & De Moura-Leite, 2010

Passos, Paulo, Fernandes, Ronaldo, Bérnils, Renato S. & De Moura-Leite, Julio C., 2010, Taxonomic revision of the Brazilian Atlantic Forest Atractus (Reptilia: Serpentes: Dipsadidae) 2364, Zootaxa 2364 (1), pp. 1-63 : 12-15

publication ID	https://doi.org/ 10.11646/zootaxa.2364.1.1
DOI	https://doi.org/10.5281/zenodo.5323920
persistent identifier	https://treatment.plazi.org/id/0390751B-3D67-FFC5-FF61-FABEFD7CBD21
treatment provided by	Felipe
scientific name	Atractus francoi
status	sp. nov.

Treatment

Atractus francoi sp. nov.

Figs. 2B–C View FIGURE 2 , 3C View FIGURE 3 , 5 View FIGURE 5

Atractus sp. – Marques, Eterovic & Sazima, 2004; Snakes of the Brazilian Atlantic Forest: An Illustrate Field Guide for the Serra do Mar. Holos, Ribeirão Preto, 1–205:69.

Holotype: Adult male, MNRJ 17537 View Materials (formerly DZUFRJ 1742 ), collected 17 July 2006 by M. C. Carlo, locality Fazenda Recanto, Serra do Piloto (22°50’S, 44°03’W, ca. 600 m), municipality of Mangaratiba, state of Rio de Janeiro, Brazil. GoogleMaps

Paratypes: Six n specimens: adult male ( IBSP 72654 View Materials ), municipality of São José do Barreiro (22º38’S, 44º35’W, ca. 600 m), state of São Paulo GoogleMaps ; an adult male ( IBSP 74724 View Materials ), two juvenile females ( IBSP 53924 View Materials , 74723 View Materials ), and adult female ( IBSP 74648 View Materials ), collected by P. A. Hartmann, Núcleo SantaVirgínia, Parque Estadual da Serra do Mar, municipality of São Luís de Paraitinga (23º14’S, 45º20’W, ca. 770 m), state of São Paulo GoogleMaps ; adult female ( MNRJ 17536 View Materials ), collected on September 1989 by R. Schasse, municipality of Nova Friburgo (22º16’S, 42º32’W, ca. 915 m), state of Rio de Janeiro GoogleMaps .

Diagnosis: Atractus francoi is distinguished from all known congeners by the following combination of characters: (1) 17/17/17 smooth dorsal scale rows; (2) two postoculars; (3) moderate loreal; (4) temporals 1+2; (5) usually seven supralabials (six in one side), third and fourth contacting orbit; (6) seven infralabials, first four contacting chinshields; (7) eight or nine maxillary teeth; (8) two to four gular scale rows; (9) three or four preventrals; (10) 156–164 ventrals in females and 162–164 in males; (11) 14–19 subcaudals in females and 25–30 in males; (12) dorsum uniformly black in adults and brown with scattered small black dots in juveniles; (13) venter beige anteriorly, becoming gradually black after 15 th ventral in juveniles and adults; (14) moderate body size, females reaching 473 mm SVL and males 420 mm SVL; (15) tail short in females (6.3– 8.6% SVL) and moderate (12.6–13.6% SVL) in males; (16) moderately bilobed, semicapitate, and semicalyculate hemipenis.

Comparisons: Among congeners, A. francoi shares 17 dorsal scale rows, dorsal colour pattern uniformly black in adults, venter dark with posterior margin of ventral scales with pale (beige) pigmentation, seven to ten maxillary teeth, and semicapitate and semicalyculate hemipenis [unknown in A. caete ] only with A. caete , A. serranus , and A. trihedrurus . Atractus francoi differs from A. caete by usually having seven supralabials (six in one side of one specimen), eight or nine maxillary teeth, and juveniles dark brown with small black dots dorsally and having venter mostly brown (vs. usually six supralabials, seven maxillary teeth, and juvenile with dorsum uniformly black and venter mostly cream); from A. serranus and A. trihedrurus by having females attain maturity below 500 mm SVL, 152–154 ventrals in males and 162–164 in females, hemipenial lobes smaller than remaining capitulum, asulcate capitulum lacking medial and lobular crests, sulcus spermaticus narrow, basal region of hemipenis lacking moderate hooked spines, and barely distinct ontogenetic change of dorsal colouration (vs. mature females always more than 500 mm SVL, 141–147 ventrals in males and 150–163 in females of A. serranus and 136–150 in males and 146–159 in females of A. trihedrurus , hemipenial lobes longer than remaining capitulum, asulcate capitulum with conspicuous medial and lobular crests, sulcus spermaticus expanded laterally, basal region of hemipenial with moderate hooked spines, and juveniles of A. trihedrurus with banded colour pattern).

Atractus francoi occurrs sympatrically with A. zebrinus along the coastal mountains of the states of Rio de Janeiro and São Paulo, but differs from it by having the dorsum and venter mostly black (vs. dorsum beige to creamish red with wide transversal black blotches, venter immaculate creamish white).

Description of the holotype: Adult male, SVL 420 mm, CL 53 mm (12.6% SVL); body diameter 9.0 mm (2% SVL); head length 18.2 mm (4.3% SVL); head width 10.8 mm (59.3% head length); interorbital distance 6.9 mm; rostro-orbital distance 4.9 mm (70% interorbital distance); naso-orbital distance 3.7 mm; cervical constriction barely distinct; head slightly arched in lateral view, round in dorsal view; snout truncate in lateral view, round in dorsal view; rostral sub-triangular in frontal view, 3.0 mm wide, 1.0 mm high, little visible in dorsal view; internasal 1.3 mm long, as long as wide; internasal suture sinistral with respect to prefrontal suture; prefrontal 2.2 mm long, 3.5 mm wide; supraocular sub-rectangular, 1.9 mm long, 1.3 mm wide; frontal sub-pentagonal, 4.2 mm long, 4.4 mm wide; parietal 7.1 mm long, 4.0 mm wide; nasal divided; nostril located between prenasal and postnasal; prenasal 1.2 mm high, 0.6 mm long; postnasal 1.5 mm high, 0.9 mm long; loreal 2.5 mm long, 1.0 mm high, contacting second and third supralabials; eye diameter 2.0 mm; pupil subelliptical; two postoculars; upper postocular 1.1 mm high, 0.9 mm long, similar in height and slightly longer than lower postocular; temporals 1+2; anterior temporal 3.5 mm long, 1.3 mm high; upper posterior temporal fragmented into small occipital-like scales and elongate (on the left side), 5.1 mm long, 1.9 mm wide; six (left) and seven (rigth) supralabials, third and fourth contacting orbit; second supralabial higher than first and lower than third; sixth supralabial higher and seventh longer than remaining supralabials; symphisial triangular, 2.6 mm wide, 1.2 mm long; seven infralabials, first four contacting chinshields; first pair of infralabials in contact behind symphisial, preventing symphisial/chinshield contact; chinshields 5.1 mm long, 2.1 mm wide; two (left) and three (right) gular scale rows; two preventrals; 152 ventrals; 29 (left) and 30 (right) subcaudals; 17/17/17 smooth dorsal scale rows; dorsals lacking apical pits, supra-anal tubercles, and keels; eight dorsal scale rows at the level of second subcaudal; anal gland three subcaudals long; caudal spine short, robust, and rhomboid; retracted hemipenis extends to the level of 11 th and bifurcates at 10 th subcaudal; six prediastemal and two postediastemal teeth; maxillary diastema moderate ( Fig. 5 View FIGURE 5 ).

Maxillary arch: Arched in dorsal view, with six prediastemal and two postdiastemal teeth; prediastemal teeth large, similar in size, curved posteriorly, angular in cross section, robust at base, narrower on the apices; first five teeth generally closely spaced, space between fifth and sixth tooth moderate; maxillary diastema moderate; postdiastemal teeth about half size of prediastemal teeth; lateral process of maxilla moderately developed, lacking posterior projections.

Colour in preservative: Dorsum of head dark brown, except for pale brown spots on distal portion of prefrontals; head dark brown, except for irregular pale brown dots covering anterior portion of loreal and fourth to sixth supralabials; symphisial and first three infralabials spotted with brown, remaining infralabials, chinshields, and preventrals beige coloured; gulars with dark brown dots; venter uniform beige anteriorly, with brown blotches on lateral portions of ventrals from 15 th scale; lateral blotches increase progressively in size, collapsing at level of 20 th ventral; posterior to this point venter becomes uniform brown, with only the posterior margin pale (creamish brown); tail brown with beige dots on posterior suture of subcaudals; dorsum of body uniformly dark brown ( Fig. 2B View FIGURE 2 ).

Juvenile colouration in preservative: Dorsum of body dark brown with small (one scale long) black dots concentrated on paravertebral region, occasionally in a fragmented barely distinct vertebral black line; first four scale rows lacking marks on both sides of body; venter similar to adults with slightly paler colour.

Juvenile colouration in life: Dorsum of head almost black, with reddish brown blotches concentrated on anterolateral portion of prefrontals and temporal region; lower margins of supralabials beige; dorsal ground colour of body and tail dark reddish brown with small fragmented black dots ( Fig. 3C View FIGURE 3 ).

Hemipenis morphology (everted organs n = 2): Retracted organ bifurcates at level of eighth and extends to level of ninth subcaudal. Everted hemipenis moderately bilobed, semicapitate, semicalyculate; lobes distinct and restricted to distal portion of capitulum; lobes sub-cylindrical, of similar size, with round apices; lobes slightly centrifugally oriented, with length similar to remaining capitulum; lobes and capitulum covered with small papillate calyces; vertical walls of calyces well defined, not arranged in distinct calyculate flounces on both sides of organ; asulcate side of capitulum with irregular calyces lacking lobular and medial crests; capitular groove indistinct on the sulcate side and well defined on the asulcate side of hemipenis; capitulum located just above sulcus spermaticus bifurcation and slightly smaller than hemipenial body; sulcus spermaticus bifurcates at about middle of organ; sulcus spermaticus branches centrifugally oriented, running to tip of lobes; margins of sulcus spermaticus stout and narrow, bordered with papillae from the base to the apices of lobes; hemipenial body sub-cylindrical, covered with moderate hooked spines on laterodistal region of the sulcate side of hemipenis; basal portion of the hemipenial body with small spines only, lacking moderate hooked spines; basal naked pocket restricted to basal portion of hemipenial body; proximal region of hemipenis with an evident constriction with uniformly scattered longitudinal plicae and diffuse spinules ( Fig. 6A View FIGURE 6 ).

Variation: Largest male 420 mm SVL, 53 mm CL; largest female 475 mm SVL, 40 mm CL; tail 12.6– 13.6% (n = 2) SVL in males, 6.3–8.6% (x¯ = 7.6; SD = 3.5; n = 4) SVL in females; 152–154 (n = 2) ventrals in males, 162–164 (x¯ = 161; SD = 1; n = 3) in females; 25–30 (x¯ = 27.2; SD = 2.1; n = 3) subcaudals in males, 14–19 (x¯ = 16.9; SD = 2.1; n = 4) in females; 6 (n = 1 side) or 7 (n = 13 sides) supralabials; 2 (n = 2 sides), 3 (n = 8 sides), or 4 (n = 3 sides) gular scale rows; 2 (n = 1) or 3 (n = 6) preventrals; 8 (n = 6 sides) or 9 (n = 2 sides) maxillary teeth; 8–10 (x¯ = 8.9; SD = 0.7; n = 14 sides) dorsal scale rows at the level of second subcaudal; 7.2–9.2 mm (x¯ = 8.6; SD = 0.9; n = 4) body diameter; hemipenis bifurcates at level of seventh to 10 th and extends to level of eighth to 11 th (n = 2) subcaudal.

Etymology: This species is dedicated to our friend Dr. Francisco Luís Franco, Curator of Herpetology at Instituto Butantan in Brazil, for his contribution to the systematics of South American snakes, and also for calling our attention to this undescribed species.

Distribution: Highlands of the Serra da Bocaina and Serra dos Órgãos, in Southeastern Brazil between the states of Rio de Janeiro and São Paulo, ranging from Nova Friburgo to São Luís do Paraitinga. Atractus francoi inhabits Lower Montane Rainforest between 600–1000 m elevation ( Fig. 7 View FIGURE 7 ).

Remarks: Marques et al. (2004) identified and illustrate a juvenile female of A. francoi (IBSP 74723, actually paratype) as possibly an undescribed species (= Atractus sp. ). A female (MNRJ 17536, 473 mm SVL, CL 30 mm) layed six eggs in captivity (R. Fernandes pers. observ.), which corroborates that females of A. francoi attain maturity below 500 mm SVL.