Amerotyphlops arenensis, Graboski, Roberta, Filho, Gentil Alves Pereira, Silva, Ariane Auxiliadora Araújo Da, Prudente, Ana Lúcia Da Costa & Zaher, Hussam, 2015

Graboski, Roberta, Filho, Gentil Alves Pereira, Silva, Ariane Auxiliadora Araújo Da, Prudente, Ana Lúcia Da Costa & Zaher, Hussam, 2015, A new species of Amerotyphlops from Northeastern Brazil, with comments on distribution of related species, Zootaxa 3920 (3), pp. 443-452 : 444-447

Amerotyphlops arenensis sp. nov.

Fig. 1

Holotype. An adult male, MZUSP 20042, collected by Gentil P. Filho on 19th November 2008 from the Reserva Ecológica Mata do Pau Ferro (06° 58'12'' S, 35° 42'15'' W; ca. 600 m), municipality of Areia, state of Paraíba, Brazil.

Paratypes. Eighteen specimens all collected in the type locality by Gentil P. Filho. MZUSP 20037–38 collected in 16th October 2008, MZUSP 20039 collected in 17th October 2008, MZUSP 20040–41 collected in 19th November 2008, MZUSP 20136 collected in 19th November 2008, MZUSP 20043–45 collected in 17th December 2008, MZUSP 20046 collected in 18th December 2008, MZUSP 20047 and MZUSP 21273 collected in 21st January 2009, MZUSP 20048 collected in 28th February 2009, MZUSP 20049–50 and MZUSP 21274 collected in 27th March 2009, MZUSP 20051 collected in 23rd April 2009, and MZUSP 20052 collected in 21st May 2009.

Diagnosis. Amerotyphlops arenensis is distinguished from all other South American species by the following combination of characters: nasal suture incomplete; rostral scale oval; supralabial scales four; infralabial scales three; rows scales around the body 18/18/18; middorsal scales 204 to 225; rows of dorsal scales dark brown 12–13th; rows of ventral scales yellowish cream and immaculate 4–5; caudal spine dark brown; subcaudal scales 8–10 in female and 11–13 for males; and maximum TTL 233 mm.

The new species differs from Amerotyphlops lehneri by having an incomplete nasal suture (vs. complete nasal suture); from A. brongersmianus , A. reticulatus , and A. minuisquamus by having 18/18/18 rows scales around the body (vs. 18/16/14, 18/18/14, 20/18/14 or 20/18/ 15 in A. minuisquamus ; 20/20/18 or 20/20/ 20 in A. brongersmianus and A. reticulatus ); from A. yonenagae by having less than 250 middorsal scales (vs. more than 250 middorsal); from A. amoipira by having highly pigmented cephalic scales with a dark brown dorsum (vs. few pigmented cephalic scales, creamish brown dorsum with a fine darker brown paravertebral line concentrated in the anterior part of the body) and from A. paucisquamus by having a largest number of middorsal, between 204–225 (vs. fewer number of middorsal, between 162–209).

Description of the holotype. Adult male, TTL 191 mm, TL 7 mm, TTL/MBD 28.08, and TTL/TL 27.28. Head slightly depressed dorsoventrally, not distinct from neck. Snout round in dorsal and ventral views. Rostral oval, longer than wide, narrow at anteroposterior region and wider at medial region; visible in dorsal view, extending ventrodorsally without reaching the imaginary transverse line between anterior borders of eyes. Rostral contacting nasal (anterior and posterior) dorsolaterally, and first supralabial and anterior nasal scales ventrally. Nasal suture incomplete, only partially dividing the anterior and posterior portions of nasal scale. Suture begins in the upper edge of second supralabial, pass through nostril, but fails to reach rostral. Anterior nasal in contact with first infralabial and upper edge of second infralabial. Posterior nasal longer than wide, contacting upper margin of second supralabial and preocular. Supralabials four, fourth twice longer than third supralabial. Infralabials three, third largest. Eye diameter 0.91 mm; eyes not visible in ventral view, located dorsolaterally, close to suture between preocular and ocular scales, completely covered by ocular scale. Ocular scales contacting frontal. Body cylindrical and robust. Midbody diameter 6.80 mm. Dorsal and ventral scales cycloid, wider than long, highly imbricated and arranged in diagonal series; scale rows around the body 18/18/18. Middorsal scales 213. Cloacal plate rounded, bordered anteriorly by three rows of scales and posteriorly by five rows of scales. Subcaudal scales 13, excluding the terminal spine. Terminal spine large, stout base and dark brown.

Coloration of the holotype in life. Dorsum (12–13 rows of scales) dark brown, venter (4–5 rows of scales) light cream. Dorsal and ventral portions of snout pinkish, with a few dark brown spots, covering both rostral and nasal scales (only in the upper half of snout). Symphysial region pinkish and immaculate. Dorsal head scales (supraoculars, frontal, posfrontal, parietals, and occipitals) and dorsal portions of lateral head scales (ocular, nasal, and lower nasal) predominantly dark brown, and ventral portions pinkish. Cloacal plate light cream and terminal spine dark brown. After six years preserved in 70% ethanol, the coloration of the holotype remained mostly the same. All regions in light cream and pinkish changed to yellowish cream ( Fig. 2 ).

Variation. The ANOVA revealed secondary sexual dimorphism only for the number of subcaudal scales (F= 63.43, p <0.001) and TL (F=47.61, p <0.001) among the verified variables. Number of subcaudal scales 11–13 (mean = 11.8, SD= 0.63, N= 11) in males and 8–10 (mean = 9.2, SD= 0.70, N= 8) in females. Tail length 4.42–6.77 % of TTL (N= 10) in males and 3.71–4.91% of TTL (N= 8) in females. Largest female and male with 233 mm TTL and 5.23 mm of TL (MZUSP 20043) and 215 mm of TTL and 7.19 of TL (MZUSP 20044), respectively. MBD 5.41–8.04 (mean = 7.21, SD= 0.77, N= 10) in males and 5.85–9 (mean = 8; SD = 1.12; N = 8) in females; number of middorsal scales 204–221 (mean = 214.1, SD= 4.70, N= 11) in males and 207–225 (mean = 217.25, SD= 7.10, N = 8) in females.

The color patterns of the paratypes are similar to that found in the holotype. However, two individuals (11%) lack dark spots in their rostral scale while the remaining individuals (88%) retain dark spots in their rostral scale. Table 1 shows additional morphometric characters and scale patterns found in the new species and in two morphologically similar species distributed in the Northeastern Brazil ( A. amoipira and A. paucisquamus ).

Etymology. The specific epithet is derived from the Latin name “arena”, a reference to the name of the type locality of the new species, the municipality of Areia.

Distribution and habitat. Amerotyphlops arenensis is only known from the Reserva Ecológica Mata do Pau Ferro (REMPF), situated at 5 km from the municipality of Areia, state of Paraíba, Brazil ( Fig. 3 ). This region is considered one of the largest upland forest fragments of the state of Paraíba (about 600 hectares). The prevalent phytophysiognomy in the REMPF correspond to a sub-montane seasonal semi-decidual forest ( Fig. 4 ) ( Barbosa et al. 2004), ranging from 400–600 meters above sea level, with an annual average of temperature and rainfall of 22° C and 1.400 mm, respectively (Mayo & Fevereiro 1981). The REMPF has several different levels of successional forests, presenting in some parts a high and dense forest with large height trees (approximately 35 meters), with a well-defined canopy structure, woodland and understory well established and preserved ( Barbosa et al. 2004). All specimens were captured with the aid of pitfall traps into the most preserved forest.

Figures

FIGURE 1. Lateral (A), ventral (B), and dorsal (C) views of the head of the holotype of Amerotyphlops arenensis sp. nov. (MZUSP 20042). Scale Bar = 1 mm.

FIGURE 2. General view in life of the paratype (MZUSP 20038) of Amerotyphlops arenensis. Photographed by Gentil P. Filho.

FIGURE 3. Geographical distribution of Amerotyphlops arenensis (star), A. amoipira (triangles), A. paucisquamus (squares), and A. yonenagae (circle). Open symbols correspond to new records and closed symbols to type localities. For A. paucisquamus we plotted the more precise locality of the paratype.

FIGURE 4. General view of the Reserva Mata do Pau-Ferro, state of Paraíba, Northeastern Brazil. Photographed by Gentil P. Filho.

Tables

TABLE 1. Variation for some selected characters of morphologically similar species of Amerotyphlops from Northeast region of Brazil. The values displayed in the table represent (in this sequence) range, mean, standard deviations, and available sample size. Abbreviations are as following: ED = eye diameter, HR = head radius, HWE = head width, IN = internasal distance, INORB = interorbital distance, RL = rostral length, RW = rostral width, TL = tail length, TTL: total length.

Character	A. arenensis sp. nov.	A. amoipira	A. paucisquasmus
ED	0.93 ± 0.09 (0.75–1.05) 10 0.90 ± 0.10 (0.77–1.10) 8	0.83 ± 0.09 (0.69–0.98) 8 0.80 ± 0.24 (0.62–0.97) 2	0.80 ± 0.15 (0.43–0.99) 12 0.85 ± 0.19 (0.52–1.29) 12
HR	3 ± 0.10 (2.78–3.13) 10 3.17 ± 0.21 (2.77–3.42) 8	2.52 ± 0.39 (1.95–3.04) 8 2.77 ± 0.68 (2.28–3.35) 2	2.62 ± 0.26 (2.05–2.93) 12 2.69 ± 0.26 (2.27–3.14) 12
HWE	5.15 ± 0.33 (4.43–5.47) 10 5.47 ± 0.42 (4.80–6.02) 8	3.97 ± 0.58 (3.25–5.13) 8 4.04 ± 0.60 (3.62–4.46) 2	4.11± 0.42 (3.17–4.64) 12 4.24 ± 0.42 (3.58–5.00) 12
IN	2.47 ± 0.14 (2.16–2.65) 10 2.58 ± 0.18 (2.35–2.80) 8	2.19 ± 0.30 (1.74–2.74) 8 2.14 ± 0.33 (1.91–2.37) 2	2.14 ± 0.25 (1.54–2.50) 12 2.18 ± 0.18 (1.86–2.61) 14
INORB	3.29 ± 0.13 (3.05–3.45) 10 3.41± 0.24 (3–3.86) 8	2.23 ± 0.25 (1.81–2.56) 8 2.23 ± 0.20 (2.09–2.36) 2	2.58 ± 0.26 (1.94–2.88) 12 2.48 ± 0.19 (2.09–2.76) 12
RL	2.84 ± 0.15 (2.59–3.09) 10 3.05 ± 0.22 (2.71–3.41) 8	2.19 ± 0.29 (1.82–2.75) 8 2.23 ± 0.50 (1.88–2.59) 2	2.40 ± 0.22 (1.90–2.76) 12 2.36 ± 0.22 (2.11–2.78) 12
RW	1.66 ± 0.08 (1.57–1.80) 10 1.73 ± 0.14 (1.56–2.04) 8	1.41 ± 0.22 (1.15–1.83) 8 1.38 ± 0.14 (1.28–1.47) 2	1.30 ± 0.13 (1.03–1.45) 12 1.31 ± 0.13 (1.09–1.57) 12
TTL/TL	30.50 ± 2.27 (27.02–33.89) 10 42.21 ± 2.70 (38.02–45.98) 8	36.03 ± 3.59 (32.76–43.45) 8 45.95 ± 3.83 (43.23–48.65) 2	33.86 ± 7.05 (27.49–54.72) 12 39.17 ± 3.32 (32.64–45.58) 12