Amphisbaena littoralis, Roberto, Igor Joventino, Brito, Lucas B. M. & Ávila, Robson W., 2014

Roberto, Igor Joventino, Brito, Lucas B. M. & Ávila, Robson W., 2014, A new six-pored Amphisbaena (Squamata: Amphisbaenidae) from the coastal zone of northeast Brazil, Zootaxa 3753 (2), pp. 167-176 : 168-173

Amphisbaena littoralis , sp. nov.

Holotype ( Figure 1–3A ). URCA-H 3540, an adult female collected at 8.5 km in straight line to the downtown of Guamaré municipality, state of Rio Grande do Norte (05°07’31.5’’S, 36°23’00.8’’W), Guamaré municipality, state of Rio Grande do Norte, Brazil, by Igor J. Roberto on May 27 of 2011.

Paratypes. Four adult males (URCA-H 3541-3542, 3544, 3552), two adult females (URCA-H 3543, 3551) and six undetermined sex (URCA-H 3545-3550), all collected from June 9th to June 25th, by Lucas B. M. Brito between 0 5° 08' 30.9'' S / 36° 25' 05.0''W, municipality of Guamaré and 0 5°10'31.3'' S, 36°28'57.8''W, municipality of Macau, state of Rio Grande do Norte, Brazil.

Etymology. The specific epithet littoralis , a noun in apposition, means in Latin inhabitant of coastal area, referring to the presence of the species in coastal sand dunes.

Diagnosis. The new species is diagnosable by snout-vent length 248.8 ± 10.9 mm SVL in males and 257.3 ± 24 mm SVL in females, six precloacal pores, 252–264 body annuli, 20–22 dorsal and 21–24 ventral segments to the midbody annulus ( Table 1 ). Nasals in broad contact at midline, without fusion of head scales. Three supralabials, third one larger; three infralabials, second the largest. Suture between frontals two times larger than the parietal and nasal sutures. Lateral sulci present, starting on 42th segment, no dorsal or ventral sulci. Tail long with length maximum 70mm and cylindrical, 30–34 tail annuli with autotomy on the 6th tail annuli, rounded tip of the tail.

Description of the Holotype. Adult female, body robust, snout-vent length 263 mm, tail length 41.2 mm. Head not distinct from neck, head length 6.7 mm and width 4.9 mm, being narrower than body. Snout rounded and prognathous; rostral scarcely visible in dorsal view, slightly wider than long and in contact with the nasals and first supralabials. Three pair of scales in the top of head (nasal, frontal and parietal), with sutures between parietals longer than frontal and nasals sutures. Frontal and parietal longer than wider and nasal broader than longer. Nostril on the antero-inferior portion of the nasals. Parietal pentagonal; ocular diamond-shapped, with eyes visible and located at antero-dorsal portion of ocular. Three supralabials, third one larger. One postsupralabial smallest than the third supralabial. First supralabial in contact with rostral and nasal and meeting above the frontal, the second supralabial in contact with the frontal and ocular scales, the third in contact with the ocular and second temporal. Three infralabials, second the largest; the first infralabial meeting the shymphysial and post-symphysial, the second in contact with post-symphysial and lateral genial. Symphysial anvil-shapped, post symphysial longer than wider, pentagonal shapped; lateral genials wider than longer; median genial in two rows, with two and six scales. A row of eight postmalars present, eight postgenials; 257 body annuli. Dorsal and ventral sulci absent. Lateral sulci well marked, beginning at 42nd body annulus. There are 20 dorsal and 21 ventral segments. Tail long and cylindrical, 30–34 tail annuli with an evident autotomy on the 6th tail annuli, tip of the tail rounded. Six rounded precloacal pores; Cloacal shield semicircular with 8 precloacal scales and 12 postcloacal scales ( Figure 2 ).

Colouration. Dorsal ground color creamy with center of segments dark brown, ventral colouration creamy, immaculate. Head creamy white with dark brown at center of scales. Tail coloration follows the same pattern as the dorsum, and the last four ventral segments on tail with center dark brown ( Figure 3A ).

Variation within type series. Variations in body and tail counts and morphometric variables are presented in Table 2.

SVL TL Pores Annuli Segments

Body Tail Dorsal Ventral A. alba 245–810 16–58 4–10 198–248 13–21 30–42 35–46 A. fuliginosa 130–450 20–75 6–10 183–220 19–30 10–13 9–13 A. ignatiana 125–188 22–25 6 255–263 32–36 16 20–22 A. littoralis sp. nov. 231–278 34–70 6 252–264 30–34 20–22 21–24 A. lumbricalis 129–156 16 2–6 225–247 20–26 12–16 16–20 A. pretrei 124–462 16–53 5–9 231–255 20–27 20–27 20–28 Distribution. Amphisbaena littoralis sp. nov. was found in two municipalities at Rio Grande do Norte state: Guamaré and Macau ( Figure 4 ). Amphisbaena littoralis sp.nov. is found in soft sand at Restinga environments ( Fig. 3 B), which corresponds with areas of direct marine influence, especially in sand dune formations at the municipality of Guamaré. The species was also found occurring in ecotonal areas of Restinga and Dense Estepic Savana (Caatinga) (sensu Veloso et al. 1991), at the municipality of Macau. This region is part of the Coastal tablelands known as “Tabuleiros” composed of the Barreiras Formation and Quaternary sediments ( Suguio et al. 2011). The new species was found in sympatry with A. heathi Schmidt and Leposternon polystegum Duméril.

Comparisons with other species. By possessing six precloacal pores, the new species is promptly distinguished from all congeners except 11 species: Amphisbaena alba Linnaeus , A. angustifrons Cope , A. bolivica Mertens , A. camura Cope , A. fuliginosa Linnaeus , A. heterozonata Burmeister , A. ignatiana Vanzolini , A. lumbricalis Vanzolini , A. mertensi Strauch , A. pretrei Duméril & Bribon , and A. stejnegeri Ruthven. However , nine of these species have a variable number of precloacal pores: Amphisbaena alba (4–10), A. angustifrons (3–6), A. bolivica (3–6), A. camura (3–6), A. fuliginosa (6–10), A. heterozonata (2–6), A. lumbricalis (2–6), A. mertensi (6–8), and A. pretrei (5–9) ( Vanzolini 2002a).

By the distribution associated with Restinga habitat in Northeastern Brazil, Amphisbaena littoralis sp. nov. can be distinguished from A. angustifrons , A. heterozonata , A. bolivica , A. camura , A. stejnegeri , and A. mertensi , which are distributed in Argentina, Bolivia, Guyana, Paraguay and central and southeastern Brazil ( Vanzolini 2002a). Besides geographic distribution, the new species can be differentiated by having body annuli higher than 250 and tail annuli higher than 30 from A. angustifrons (tail annuli 18–26; Vanzolini 2002a), A. bolivica (body annuli 200–231; tail annuli 18–26; Vanzolini 2002a), A. camura (body annuli 188–206; tail annuli 14–19; Vanzolini 2002a), A. heterozonata (body annuli 190–207; tail annuli 13–17; Vanzolini 2002a), A. mertensi (body annuli 210–250; tail annuli 25–31; Gans 1966), A. stejnegeri (body annuli 243–247; Vanzolini 2002a).

The remaining five species ( A. alba , A. fuliginosa , A. ignatiana , A. lumbricalis and A. pretrei ) are distributed in Northeastern Brazil, and the key characteristics distinguishing the new species from these can be found bellow and in Table 2.

The new species differs from Amphisbaena alba by possessing an autotomic site (absent in A. alba ; Gans 1962), smaller snout-vent length (snout-vent length 245–810 mm in A. alba ; Colli & Zamboni 1999), and by having higher body annuli and tail annuli counts (body annuli 198–248 and tail annuli 13–21 in A. alba ; Gans 1962; Vanzolini 2002a).

Amphisbaena littoralis sp. nov. can be distinguished from A. pretrei by the higher number of body annuli ranging from 252–264 (body annuli 231–255 in A. pretrei ; Vanzolini 2002a), and by tail annuli higher than 30 (tail annuli 22–26 in A. pretrei ; Vanzolini 2002a). The new species also have a smaller snout-vent and attain a higher tail length (snout-vent length 124–462 mm and tail length 16–53 in A. pretrei ; Gans 1965). The parietals are also longer than larger and the rostral is not visible from above in A. littoralis sp. nov., while in A. pretrei the parietals are larger than longer and the rostral are visible in dorsal view.

Amphisbaena littoralis sp. nov. has a dorsal color creamy, 252–264 body annuli and 30–34 tail annuli, whereas A. fuliginosa have a checkered black and white coloration, 190–220 body annuli and 23–30 tail annuli ( Vanzolini 2002a). According to Vanzolini (1951) five subspecies of A. fuliginosa are recognized (besides some authors have been considered then as full species (see Gans 2005, Ribeiro et al. 2008): A. f. amazonica , A. f. bassleri, A. f. fuliginosa , A. f. wiedi and A. f. varia. Three of these (A. f. bassleri, A. f. fuliginosa and A. f. varia) have precloacal pores 6–10, but are distributed in the upper Amazon. The remaining two subspecies ( A. f. amazonica and A. f. wiedi) have been reported in Northeastern Brazil, but have 8–10 precloacal pores ( Vanzolini 1951; 2002b).

From A. lumbricalis the new species is differentiated by the body annuli higher than 250 and tail annuli higher than 30 (225–247 body annuli and 20–26 tail annuli in A. lumbricalis ; Vanzolini 2002a). The new species also have 20–22 dorsal and 21–24 ventral segments to the midbody annulus, presence of a postmalar row and have a robust body, attaining higher size 231–278 mm SVL, tail length 35–41 mm, whereas A. lumbricalis have 12–16 dorsal and 16–20 ventral segments to the midbody annulus, absence of a postmalar row, slender body, with 116– 174 mm SVL ( Vanzolini 2002a).

Finally, from Amphisbaena ignatiana , the new species is separated by possessing 3 supralabials, 20–22 dorsal and 21–24 ventral segments to the midbody annulus, a row of 8 postmalar and 12 postcloacal scales (4 supralabials, 16 dorsal and 20–22 ventral segments to the midbody annulus, a row of 9 postmalar and 16 postcloacal scales in A. ignatiana ; Vanzolini 1991). Also, the new species has a robust body ( Figure 5 ), and attains higher size, the snout-vent length 231–278 mm SVL, tail length 35–41 mm and head width 4.2–5.8 mm, whereas A. ignatiana have a slender body, snout-vent length 143–188 mm, tail length 22–25 mm and head width 2.1–3.1 mm ( Vanzolini 1991).

Figures

FIGURE 1. Amphisbaena littoralis sp. nov. (holotype, URCA-H 3540). From top to bottom: dorsal, lateral and ventral views of the head. Scale bar = 2 mm.

FIGURE 2. Amphisbaena littoralis sp. nov. (holotype, URCA-H 3540), ventral view of cloacal region, showing the six precloacal pores.

FIGURE 3. A) Amphisbaena littoralis sp. nov., live specimen; B) Habitat in which the new species was found in Guamaré municipality, Rio Grande do Norte State, Brazil.

FIGURE 4. Geographical distribution of Amphisbaena littoralis sp. nov. and Amphisbaena heathi in the state of Rio Grande do Norte: Black star—Type locality of Amphisbaena littoralis sp. nov. and new distributional record of Amphisbaena heathi, muncipality of Guamaré; Red star—Type locality of Amphisbaena heathi, muncipality of João Camara; Black dot—new distributional record of Amphisbaena heathi and distribution of Amphisbaena littoralis sp. nov., Municipality of Macau,; Red dot – distribution of Amphisbaena heathi in Freire (1996), Municipality of Natal. Yellow = Caatinga Biome, Light Green = Atlantic Forest, Orange = Cerrado, Dark green = Amazon.

FIGURE 5. Holotype of Amphisbaena ignatina (MZUSP 72616) (left) and paratype of Amphisbaena littoralis (URCA-H 3541) (right). Scale bar = 10 mm.

Tables

TABLE 1. Meristic and morphometric data of Amphisbaena littoralis sp. nov. SVL = Snout-vent length; TL = Tail length; Segments = Dorsal / Ventral; SL = Supralabials; IL = Infralabials; BW = Body width. All measurements in mm. * = Holotype.

URCA-H	SVL	TL	Body annuli	Tail annuli	Segments Pores	SL	IL	Sex	HW	BW
3540*	263	41.2	257	34	20/21 6	3	3	F	4.9	6.7
3543	231	70	264	6/autotomy	21/24 6	3	3	F	5	7
3541	252	34.8	256	30	20/21 6	3	3	M	5	6.5
3542	258		254	6/autotomy	20/24 6	3	3	M	4.8	7.1
3544	233		256	6/autotomy	21/23 6	3	3	M	4.2	5.9
3546	244		252	6/autotomy	20/21 6	3	3	?	5.2	6.6
3552	252	11.5	258	6/autotomy	22/23 6	3	3	M	4.8	7.3
3551	278		252	6/autotomy	20/21 6	3	3	F	5.8	7.6