Scinax tupinamba, Silva, Helio Ricardo Da & Silva, Ricardo Alves-, 2008

Silva, Helio Ricardo Da & Silva, Ricardo Alves-, 2008, New coastal and insular species of the bromeligenous Scinax perpusillus group, from the State of Rio de Janeiro, Brazil (Anura, Hylidae), Zootaxa 1914, pp. 34-44 : 36-41

Scinax tupinamba sp. nov.

( Figs. 1–3 )

Holotype. MNRJ 53549. Adult male, collected from a bromeliad on the surface of a large, exposed, granite rock face at Fazenda Bom Jardim, Municipality of Mangaratiba, State of Rio de Janeiro, Brazil (22 0 54’ 45” S, 44 0 06’ 11” W) on 15 September 2005 by Alexandre F. Bamberg de Araújo, Piktor Benmaman, and João M. Leite.

Paratypes. Collected with the holotype: MNRJ 53550, 53551 adult males, MNRJ 53552 adult female; MNRJ 53553, 53554 adult males, collected on the same locality on 19 September 2006, by Hélio R. Silva, Ricardo Alves-Silva, and Piktor Benmaman. MNRJ 53555, 53556 adult males, collected at Reserva Particular do Patrimônio Natural ( RPPN) Rio das Pedras, Municipality of Mangaratiba, State of Rio de Janeiro, Brazil (22 0 59' 29" S, 44 0 06' 62" W) on 13 September 2005, by A. B. F. Araújo, P. Benmaman, and J. M. Leite; MNRJ 53557 adult male, same locality, 14 September 2005, by A. B. F. Araújo, P. Benmaman, and J. M. Leite; MNRJ 53558 - 53562 adult males, collected at Ilha da Gipóia, Municipality of Angra dos Reis, State of Rio de Janeiro, Brazil (23 0 01' 55" S, 44 0 22' 39" W) on 16 March 2006, by H. R. Silva, R. Alves-Silva, Gabriela B. Bittencourt- Silva, and Karina S. Marques.

Diagnosis. The new species is placed in the genus Scinax based the origin of the m. pectoralis abdominalis through a well-defined tendon on the pelvis ( Faivovich 2002 – Observed though the skin transparency, the other synapomorphy depend on dissection for observation and were not considered). Within the genus it is a member of the Scinax perpusillus group based on the use of bromeliads for reproduction. Scinax tupinamba is a moderately-sized species (SVL males 16.6–18.9 mm, females 20.1–22.6 mm) relative to other species in the S. perpusillus group. The species is characterized by (1) snout with a distinct medial process (a protuberance caused by the cartilaginous medial prenasal process of the tectum nasal under the skin); (2) head longer than wide; (3) canthus rostralis distinct and well defined; (4) eyes protruding and prominent; (5) tympanum round pigmented, with diameter less the half the diameter of the eye; (6) choanae elliptical; (7) vomerine odontophore in two round patches (with three to four teeth each) separated from each other and from the choanae by the same distance; (8) arms with dark stripes; (9) webbing absent between fingers; (10) disk of finger II smaller than those of other fingers; (11) webbing absent between toes I and II; (12) webbing reduced between toes II and III; (13) dorsum with a well marked dark stripe in the posterior third of the body; (14) in life concealed areas of thigh and shank with yellow blotches; (15) skin of venter and thighs ventrally granulated; (16) in life, tadpoles with a distinct, large, and bright yellow stripe between the eyes and the nostrils.

Comparisons. Adult individuals of Scinax tupinamba may be distinguished from other species of the Scinax perpusillus group by the presence of a prominent medial process between nostrils (= the externally visible cartilaginous medial prenasal process of the tectum nasal). Only S. meloi and S. v-signatus possess a similar process, but it is smaller. The tadpole of S. tupinamba is unique within the group in having a distinctive yellow stripe between the eyes and the nostrils. Additionally, the tadpoles of S. tupinamba differs from those of all other species, but S. v- signatus, in color pattern ontogeny; after stage 37, darker spots appear on the tail fin ( Fig. 4 ).

Description of holotype. Body slender; head wider than longer; snout protruding in lateral view and acuminate in dorsal view, with evident rostral keel ( Fig.4 ); nostrils elliptical, canthus rostralis distinct, slightly rounded; loreal region concave; eye protruding and prominent, directed laterally and slightly anteriorly; tympanum small, distinct, round, diameter less than half of the eye diameter; weak supratympanic fold extending from tympanic region to shoulder; vocal sac subgular and of moderate size; tongue oval, free laterally and posteriorly, shallowly notched posteriorly, slightly granulated; vocal slits present, oblique; vomerine teeth in two small, round odontophores, each bearing three teeth; choanae elliptical, medium sized. Arms slender; forearms slightly robust, outer metacarpal tubercle large, bifid; inner metacarpal tubercle elliptical; subarticular tubercles rounded, single; fingers without webbing; relative finger lengths II<III ~ V<IV ( Fig. 2 ). Legs robust; tibia longer than thigh; feet with elliptical inner metatarsal tubercle and round outer metatarsal tubercle; subarticular tubercles rounded, single, toe lengths I=II ~ III ~ V<IV( Fig. 2 ); foot webbing formula I – II 2 - – 3- III 2+ – 3- IV 3 – 2- V. Outer tarsal surface without fringe or tubercles. Dorsal skin texture smooth, a few tubercles scattered through the dorsal surface, including the head. Ventral skin of trunk and thighs granulated. Measurements are given in Tab. 1 .

In preservative, dorsum beige with darker brown spots and stripes scattered on the body and limbs. A transverse, semicircular dark brown stripe is present on the posterior third of the body running from the back towards the inguinal region; when in resting position, this stripe is contiguous with similarly colored stripes on the thigh, shank, and foot. Interorbital stripe dark brown. Loreal region with a narrow dark stripe, extending from the snout to the eye; a similar line runs from the posterior margin of the eye to the tympanum, and another from the posterior margin of the tympanum to the middle of the body. Anterior and posterior limbs beige, with transverse darker stripes across limb, fingers, and toes. Concealed areas of thigh and shank with pale brown blotches. Ventrally, body and limbs are whitish with minute dark spots scattered throughout the surface; forming darker blotches in the subgular region. Specimens fixed and stored in 70 0 GL Methanol became lighter brown, in addition the lighter colored areas become pearl colored.

In life, the dorsal color varies from a pale yellowish brown to a darker brown with darker stripes and blotches. Lighter areas also present scattered small dots of darker pigmentation.

Variation. Variation of measurements taken of adult males and females are given in Tab. 1 and 2 . The samples from the three areas contained specimens with a median strip on the dorsum interrupted near the vertebral column. Ventrally, the distribution of the small spots may be more aggregated in a few specimens forming a few darker spots. Some specimens, however, have a clearer venter, with just a few spots. Females are larger than males in all three known populations.

Tadpoles. Tadpoles were all collected from bromeliads at three localities (See Appendix 1). They were detected by visual inspection, in water accumulated in the leaf axils of the plant, and could be easily identified by a bright yellow stripe in their forehead. They usually tried to escape by diving deeper into crevice formed by the leaf.

Tadpoles at Stage 38 have body length of 10.2 mm and total length of 30.2 mm. The body is wider than deep, ovoid, and the posterior portion being slightly wider than the anterior portion ( Fig. 4 ). The snout is round in dorsal and lateral profile. Nostrils are small and round, positioned dorsally, opening slightly anterolaterally, and surrounded by a dark pigmented rim; nostrils positioned closer to the snout than to the eyes. The eyes are relatively large and directed laterally. The sinistral spiracle is a tube attached to the lateral of the body all along its length, with its opening directed dorsolaterally at the midpoint of the body. The spiracle is a tube attached to the lateral of the body all along its length. The intestine is coiled so that the main axis of the coil is orthogonal with respect to the main axis of the body. Proctodeal opening located at the margin, and at the right side of, the ventral fin. Caudal musculature slender and tapers terminally. At the tallest point of the tail, the dorsal fin is taller than the ventral fin. The fin is bluntly round at the end.

The body and tail are mostly transparent, with minute dark pigmented melanophores scattered on all surfaces. Almost all internal organs, including lungs, intestines, and blood vessels can be easily seen at low magnification ( Fig. 4 ). The most conspicuous color pattern is a large yellow stripe, transverse to the main body axis, located between the eyes and the nostrils; this stripe is lost in fixed tadpoles. The yellow stripe is not produced by the surface of the skin, but, instead, appears to be produced by the surface of the chondrocranium showing through. During development, an important color change that occurs after Stage 35 ( Fig. 4 ) is the appearance of dark pigmentation on the lower fin that forms the contour of transparent dots after Stage 35; a similar, but lighter, pigmentation pattern appears on the upper fin after Stage 37.

The mouth is small and anteroventrally located; the oral disc has a shallow lateral fold; labial papillae are present in double rows laterally and posteriorly; a mental gap in the papillae is present. Both jaw sheaths are serrated. There are two upper and three lower rows of keratodonts, the second upper row is interrupted medially, and the lower ones are all continuous, all rows are of equal size. Labial tooth row formula 2(2)/3.

Distribution. The new species in known from three different localities. In the Municipality of Mangaratiba, the two collecting areas are about 8 km apart (straight-line). The third locality is on an island about 800 m off the coast of the Municipality of Angra dos Reis, and about 30 km from the other localities. These distributional data imply that the new species may occur in the forests along the coastal area between these two municipalities ( Fig. 5 ). Fortunately, the whole area represents one of largest and the best preserved fragments of Atlantic rain forest in the State of Rio de Janeiro. Therefore, at present, the new species may not be in immediate danger of extinction. Furthermore, recent visits to these areas (during 2007 and 2008) confirmed the continued existence of this species at the three sites with the occurrence of adult males and tadpoles in bromeliads at each locality.

Reproduction and natural history. We observed males calling in bromeliads with their heads pointing down, towards the interior of the plants. Specimens from the continent (adult and tadpoles) were found in terrestrial and arboreal bromeliads. Possibly because access limitations to other areas of the island ( Ilha da Gipóia), specimens from there were all collected and observed using terrestrial bromeliads, which were growing from a granite exposed rock near the coast. Males were observed calling in pairs forming duets (Antiphony), and couples in amplexus were observed on rainy days from September to December. Two observations of eggs suggest that females lay just a few eggs (five at most) attached to a leaf near the water-filled bromeliad tank.

Etymology. Tupinambá is the name of an Indian Nation that once inhabited the coast along the State of Rio de Janeiro, Brazil. Their lifestyle and culture had an intimate relationship with fishing and agriculture, and they showed a sophisticated relationship with nature, evidenced by an elaborate system of biological classification and forecasting natural events ( Freire & Malheiros 1997). Although, these people and their culture are considered officially extinct—similar to the forest along the coast upon which they depended—their remains, living descendants, and cultural activities still survive, veiled and scattered in insular and coastal villages along the south shores of Rio de Janeiro. We name this new species as homage to these people. The name is used as noun in apposition.

Comments. Despite efforts by Peixoto (1987; 1988a, b; 2002), who assigned names to distinct population of bromeligenous Scinax ( S. perpusillus group), samples from continental areas of the State of São Paulo ( Heyer et al. 1990, Oliveira & Navas 2004; Pombal Jr. & Gordo, 2004; Zaher, et al. 2005) and Rio de Janeiro ( Carvalho-e-Silva et al. 2008) are still difficult to confidently identify, and may all represent unnamed species. In the state of Rio de Janeiro, samples from some coastal islands near the range of S. perpusillus and S. tupinamba may also represent unnamed species for the group. Curiously, however, the sample from Ilha da Gipóia is very similar in color pattern for adults and larvae to samples of the continent; so, we prefer to include it in this description as an insular population of the same species. It is intriguing however that some of the insular populations from the State of São Paulo (Brasileiro et al. 2007a, b; Lutz 1973b) represent species endemic to the coastal islands. Since all these coastal islands were formed as a result of one or more oscillations of the sea level during the Pleistocene about 11, 0 0 0 yr ago ( Martin et al. 1986; Rodrigues 1991), it is surprising that only in some of the islands did the isolated populations speciated. One possible explanation may relate to the depth of the channel separating the island from the coast. Deeper channels (and more distant islands) may have resulted in early isolation, and therefore longer time for differentiation of the populations. Alternatively, these insular species may represent a fragment that once lived in larger extensions of land and that, due to sea level changes, have larger portions of their distribution area destroyed, surviving only on the islands. In the case of the insular population of Scinax tupinamba , because of the proximity to the continent (about 800 m apart from the continent) and the depth of the channel that may reach only 15 m at its deepest point, the insulation may have occurred only recently.

Figures

FIGURE 1. Scinax tupinamba sp. nov. (Holotype). (A) Dorsal and (B) ventral views.

FIGURE 2. Scinax tupinamba sp. nov. (Holotype). Ventral views of right (A) hand and (B) foot.

FIGURE 3. Scinax tupinamba sp. nov. (Holotype). (A) Ventral view of gular region and (B) lateral view of the head.

FIGURE 4. Scinax tupinamba sp. nov. Tadpole stage 27. (A) Dorsal view of the body, (B) detail of the venter showing the intestinal coil and vent opening, (C) detail of the mouth showing the papillae and keratodonts, and (D) stage 39, tail showing dark pigmentation on lower fin.

FIGURE 5. Map of the State of Rio de Janeiro with enlarged detail of the location for the 3 collecting sites for Scinax tupinamba sp. nov.

Tables

TABLE 1. Measurements (in mm) type series of Scinax tupinamba sp. n. Snout-vent length (SVL), head length (HL), head width (HW), tympanun diameter (TD), eye diameter (ED), interorbital distance (IOD), eye-nostril distance (END), internostril distance (IND), thigh length (THL), tibia length (TBL), and foot length (FL). Boldface indicates the Holotype.

Locality	Number	SVL	HL	HW	TD	ED	IOD	END IND	THL	TBL	FL	SEX
Fazenda Bom Jardim	RU1391	18.0	7.0	6.5	0.8	2.2	2.6	2.3 1.6	8.4	9.3	6.9	♂
Fazenda Bom Jardim	RU1395	21.8	7.8	7.7	1.1	2.1	2.9	2.6 2.0	10.1	11.3	8.3	Ψ
Fazenda Bom Jardim	RU1393	17.4	7.8	6.9	1.1	1.9	2.3	2.2 1.7	8.1	8.4	6.4	♂
Fazenda Bom Jardim	RU1394	17.9	6.8	6.6	1.0	1.8	2.9	2.3 1.6	8.5	9.0	6.7	♂
Fazenda Bom Jardim	RU3655	17.7	6.9	6.4	0.7	2.1	2.5	2.3 1.6	8.3	9.1	6.7	♂
Fazenda Bom Jardim	RU3656	17.9	6.8	6.4	0.9	2.0	2.7	2.1 1.7	8.3	9.2	6.7	♂
Ilha da Gipóia	RU2090	18.4	6.3	6.3	0.9	2.3	2.4	2.2 1.7	9.2	10.1	7.3	♂
Ilha da Gipóia	RU2092	17.8	5.9	6.6	1.0	2.1	2.4	2.2 1.7	8.6	9.9	7.1	♂
Ilha da Gipóia	RU2096	17.4	6.0	6.3	1.0	1.9	2.5	2.3 1.7	8.7	9.6	6.6	♂
Ilha da Gipóia	RU2099	18.8	6.0	6.7	1.0	1.9	2.3	2.5 1.9	9.3	10.5	7.3	♂
Ilha da Gipóia	RU2101	18.7	6.5	6.8	1.0	2.2	2.4	2.4 1.9	9.1	10.2	7.1	♂
RPPN Rio das Pedras	RU1385	16.7	5.5	5.9	0.9	1.7	2.3	2.3 1.7	8.0	9.0	6.7	♂
RPPN Rio das Pedras	RU1386	18.9	7.7	6.9	1.0	1.8	2.6	2.4 1.7	10.0	9.7	6.9	♂
RPPN Rio das Pedras	RU1389	17.9	7.2	6.5	0.8	1.8	2.8	2.2 1.6	8.8	9.0	7.3	♂

TABLE 2. Summary of measurements (in mm) of all sample of Scinax tupinamba: range, mean, and standard deviation (SD) for the type series plus additional specimens from the same localities of Scinax tupinamba sp. n. Snout-vent length (SVL), head length (HL), head width (HW), tympanum diameter (TD), eye diameter (ED), interorbital distance (IOD), eye-nostril distance (END), internostril distance (IND), thigh length (THL), tibia length (TBL), and foot length (FL).

Males (n = 21)			Females (n = 5)
range	mean	SD	Range	mean	SD
SVL 16.1–19.2	17.8	0.9	20.1–22.6	21.6	0.9
HL 5.5–7.8	6.6	0.6	6.7–7.8	7.4	0.5
HW 5.6–6.9	6.4	0.4	6.7–8.1	7.5	0.5
TD 0.7–1.1	0.9	0.1	1.1–1.4	1.2	0.1
ED 1.0–2.1	1.9	0.1	2.1–2.5	2.2	0.2
IOD 2.2–2.8	2.5	0.2	2.9–3.2	2.9	0.2
END 2.1– 2.4	2.3	0.1	2.1–3.1	2.7	0.4
IND 1.4–1.9	1.7	0.1	1.8–2.3	2.0	0.2
THL 7.7–10.0	8.5	0.5	9.3–11.4	10.2	0.7
TBL 8.4–10.2	9.2	0.4	10.8–12.6	11.3	0.8
FL 6.3–7.6	6.8	0.3	7.9–8.9	8.3	0.4