Frostius erythrophthalmus, Pimenta, Bruno V. S. & Caramaschi, Ulisses, 2007

Pimenta, Bruno V. S. & Caramaschi, Ulisses, 2007, New species of toad, genus Frostius Cannatella, 1986, from the Atlantic Rain Forest of Bahia, Brazil (Amphibia, Anura, Bufonidae), Zootaxa 1508, pp. 61-68 : 62-67

publication ID	https://doi.org/ 10.5281/zenodo.177201
DOI	https://doi.org/10.5281/zenodo.5678527
persistent identifier	https://treatment.plazi.org/id/03BA4849-FF82-FFC6-86ED-EB00D84CDA44
treatment provided by	Plazi
scientific name	Frostius erythrophthalmus
status	sp. nov.

Treatment

Frostius erythrophthalmus View in CoL sp.nov.

( Fig. 1–2 View FIGURE 1 View FIGURE 2 )

Holotype. MNRJ 27245, adult female, from Fazenda Caititu (14o25’S, 39o04’W, 136 m above sea level), Municipality of Uruçuca, State of Bahia, Brazil, collected by B.V.S. Pimenta and R.L. Vieira, between 19 and 22 July 2000.

Paratypes. MNRJ 27246-27249, four adult females, collected with the holotype; MNRJ 27250, adult female, from Estação Ecológica Estadual (EEE) Nova Esperança (13o36’S, 39o43’W, 472 m above sea level), Municipality of Wenceslau Guimarães, State of Bahia, Brazil, collected by B.V.S. Pimenta, 14 March 2000; MNRJ 35398-35400, one adult male and two adult females, from Parque Estadual (PE) Serra do Conduru, Setor Norte (14o30’S, 39o07’W, 320 m above sea level), Municipality of Itacaré, State of Bahia, Brazil, collected by B.V.S. Pimenta, 25–26 March 2004; MNRJ 44556-44558, two adult males and one adult female, from Serra do Timorante (14o26’S, 40o04’W, 650 m above sea level) and from an unnamed forest patch (14o25’S, 40o07’W, 920 m above sea level), both localities at the Municipality of Boa Nova, State of Bahia, Brazil, collected by C. Canedo and F. Falcão, 19 and 24 November 2006.

Diagnosis. The species is characterized by: (1) dorsal surfaces dark gray, almost black; (2) ventral surfaces black, except for the yellow ventral face of thighs in life; (3) iris red in life; (4) tympanum large (mean TD/ED 0.69), circular; (5) fingers and toes short, slender, with poorly developed apical discs; (6) dorsal skin rugose, with rounded warts; (7) parotid glands absent.

Frostius erythrophthalmus sp.nov. is readily distinguished from F. pernambucensis by its dorsal surfaces being dark gray, ventral surfaces black, iris red in life, digits looking short (proximal phalanges of fingers I and IV and of toes I, II, III, and V seem “embedded” into hand and foot), digits slender, with poorly developed apical discs, and tympanum large (mean TD/ED 0.69, range 0.54–0.90), circular. In F. pernambucensis , dorsal and ventral surfaces are brown to light brown, the iris is yellow in life, digits are long, laterally expanded, with developed apical discs, and the tympanum is small (mean TD/ED 0.54, range 0.34–0.66), vertically elliptical ( Fig. 3 View FIGURE 3 ).

Description of holotype. Body robust, without clear subdivision between head and body in dorsal view ( Fig. 1 View FIGURE 1 ); head as wide as long; snout truncate in dorsal view, protruding in profile ( Fig. 2 View FIGURE 2 ); nostrils not protuberant, located slightly below the canthus rostralis, directed laterally; internarial distance smaller than eye-tonostril distance, eye diameter, and interorbital distance, about the same size of the upper eyelid width, and larger than the tympanum diameter; eye-to-nostril distance approximately equalling eye diameter and larger than the upper eyelid width; interorbital distance about twice the tympanum diameter; tympanum circular, with a weak supratympanic ridge; tympanum large, its diameter 69% of eye diameter; eyes slightly protuberant, upper eyelid width about 65% of interorbital distance; parotid glands and cranial crests absent; canthus rostralis straight; loreal region concave; choanae circular, large; tongue long, narrow, adherent by a small portion in front, extensively free behind. Forelimbs long, slender; forearms slightly more robust than arms. Hand ( Fig. 2 View FIGURE 2 ) large; fingers slender, not fringed nor webbed, with apical discs poorly developed; proximal phalanges of fingers I and IV and of toes I, II, III, and V “embedded” into hand, making fingers look short; relative lengths of fingers I<II<IV<III; finger I thickened at base; finger III with small dermal spines on inner margin; inner metacarpal tubercle large, round, at the base of finger I; outer metacarpal tubercle large, round, subdivided; subarticular tubercles single, round, larger on finger II; supernumerary tubercles present, small. Hindlimbs long, slender; thigh length slightly greater than tibia length, with tibia length about 94% of thigh length; sum of thigh and tibia lengths about 80% of snout-vent length. Foot ( Fig. 2 View FIGURE 2 ) large, tarsus-foot length greater than the sum of thigh and tibia lengths; toes slender, not fringed nor webbed, with apical discs poorly developed; proximal phalanges of toes I, II, III, and V “embedded” into foot, making toes look short; relative lengths of toes I<II<V<III<IV; inner metatarsal tubercle large, approximately elliptical; outer metatarsal tubercle half the size of inner tubercle, round; subarticular tubercles single, round; supernumerary tubercles present, approximately the same size as subarticular tubercles, but less protruding; tarsal ridge absent. Dorsum rugose, with scattered, rounded warts; dorsal surfaces of arms and tibiae covered by small tubercles; ventral surfaces finely rugose.

Color in life. Dorsum uniformly dark gray, almost black; sides of body grayish-blue, with small yellow dots scattered but concentrated near the inguinal region; gular region, chest, and belly uniformly gray with small yellow scattered dots; ventral surface of thighs with a irregular, elongate, yellow marking. Iris red, with a thin longitudinal black stripe passing over the pupil. Fingers I and II, and toes I, II and III, yellow; outer fingers and toes dark gray.

Color in preservative. In preservative, dark colors are maintained almost as described in life. Yellow markings become cream. Iris becomes dark gray.

Measurements of holotype. SVL 25.6; HW 8.5; HL 8.4; IND 2.1; END 2.2; ED 2.6; UEW 2.0; IOD 3.5; TD 1.8; HAL 5.5; THL 10.0; TL 9.7; TFL 13.4.

Variation. There is little variation among the type specimens. In MNRJ 27249 and MNRJ 35398-35400, the head is wider than long; in MNRJ 27247 and MNRJ 35398, the internarial distance is less than the upper eyelid width; the interorbital distance may reach up to two or three times the tympanum diameter; the tympanum diameter varies between 54 and 90% of eye diameter. Tibia length is slightly greater than thigh length in MNRJ 27248-27249; in the other specimens, tibia length varies from 91 to 97% of thigh length. Male specimens have single, subgular, poorly developed vocal sacs. No variation in life color other than the distribution of yellow dots is observed. Females are slightly larger than males. Range, mean, and standard deviation of measurements of females and males are presented in Table 1 View TABLE 1 .

Natural history. Frostius erythrophthalmus sp.nov. occurs in primary or slightly disturbed fragments of the hygrophilous forests of southern Bahia. Fragments at the type locality, in the contiguous forests of PE Serra do Conduru, and in the EEE Nova Esperança are well preserved patches of ombrophilous forests ( Jardim 2003). Specimens were found during the night in leaf litter or sitting on the leaves of bushes or bromeliads, 0.1 to 0.7 m above ground. One male was found at ca. 1.3 m above ground climbing on an almost vertical tree trunk. All specimens were found away from water bodies, suggesting an association with bromeliads, as previously observed in F. pernambucensis ( Cruz and Peixoto 1982) .

Etymology. The name of the species is composed by the Greek words “ erythros ” (“red”, an adjective) and “ ophthalmus ” (“eye”, a substantive), in allusion to the red iris in life.

Distribution. Frostius erythrophthalmus sp.nov. is known from four localities in the Atlantic Rain Forest Domain in southern Bahia, at altitudes between 140 and 920 m above sea level. It extends the distribution of the genus ca. 190 km southwards to the Municipality of Boa Nova in the State of Bahia ( Fig. 3 View FIGURE 3 ; Appendix). The northernmost locality known for F. erythrophthalmus sp.nov. (EEE Nova Esperança, Municipality of Wenceslau Guimarães) is only 88 km distant from the southernmost known locality of F. pernambucensis (Serra da Jibóia, Municipality of Santa Terezinha; Juncá & Freitas, 2001).

During the comparative analysis, we found in MNRJ a young specimen of F. pernambucensis from the Municipality of João Pessoa, State of Paraíba, northeastern Brazil, extending the distribution range of the genus 105 km airline northwards ( Fig. 3 View FIGURE 3 ; Appendix). Although it was a young specimen, it could readily be identified by its small, vertically elliptical tympanum, which we find to be a diagnostic character for F. p e r - nambucensis.

Remarks. In describing Atelopus pernambucensis, Bokermann (1962) reported that it was not possible to relate it to other species then included in Atelopus and that its small size and absence of color pattern were unique. Cruz and Peixoto (1982) later described the tadpole of A. pernambucensis and, based on data on the biology and larval characters, affirmed that the species probably deserved a different generic status. Cannatella (1986) concluded that the species was unique by having an external tympanum and proposed the new genus Frostius for it. The new genus was considered a sister-group to Atelopus Duméril and Bibron or, alternatively, the sister-group to Atelopus + Osornophryne Ruiz-Carranza and Hernández-Camacho. The relationships still remain unsolved, since Frostius was not included in the phylogenetic approaches of Graybeal (1997) or Frost et al. (2006).

Anuran communities in southern Bahia have been studied since the first expeditions of European naturalists to Brazil, like Wied (1821, 1824) and Spix (1824). These collections, although limited in geographic range, launched the basis for the taxonomic studies of many Brazilian anurans, some of them described from Bahia. After that, further studies at some localities in the Atlantic Rain Forest of southern Bahia were sporadically carried out only between the 1970’s to the 1990’s. In this period, 12 species were described from this region (see SBH 2005; Frost 2006). Regular investigations of these communities started only in the 2000’s. From 2000 to 2005, these inventories expanded the geographic ranges of 16 species to include the State of Bahia ( Argôlo 2000; Pimenta & Silvano 2001a, b, c; Silvano & Pimenta 2001a, b, c, d; Pimenta & Cruz 2004; Pimenta et al. 2005; see also Frost 2006) and four species previously known only from their type localities were found elsewhere (see Frost 2006). From 2003 to 2005, ten new species were described (see SBH 2005; Frost, 2006), and three species were rediscovered ( Feio et al. 2003; Caramaschi et al. 2004; Dixo 2004). It clearly shows that this virtually unexplored region holds a huge, but poorly sampled anuran diversity.

Although the amount of data regarding the taxonomy, composition, and distribution patterns of the anuran fauna of southern Bahia has been rapidly improved in the last six years, much work is still to be done. Mountainous areas have been poorly investigated when compared to lowlands, and these altitudinal forest patches are better preserved due to the difficult access, inhibiting, for the moment, timber exploitation and occupation by crops or cattle. Further inventories in these areas would certainly lead to the discovery of other unknown species and new patterns of distribution.

	Males (n = 3)			Females (n = 9)
Characters	Range	Mean	SD	Range Mean	SD
SVL	20.1–20.7	20.5	0.32	21.2–25.6 23.4	1.54
HW	7.3–7.6	7.5	0.15	7.8–8.8 8.3	0.39
HL	6.7–7.7	7.1	0.51	7.4–8.6 8.0	0.43
IND	1.6–2.0	1.8	0.21	1.8–2.3 2.1	0.15
END	2.1–3.0	2.6	0.45	2.0–2.5 2.2	0.19
ED	1.9–2.1	2.0	0.12	1.9–2.7 2.3	0.26
UEW	1.7–2.2	2.0	0.25	1.7–2.4 2.0	0.25
IOD	2.7–3.6	3.3	0.49	2.9–4.1 3.7	0.35
TD	1.4–1.9	1.6	0.25	1.2–1.8 1.5	0.24
HAL	4.5–5.6	5.0	0.56	4.9–5.7 5.3	0.29
THL	8.4–9.1	8.6	0.40	8.8–10.2 9.7	0.51
TL	7.1–8.1	7.7	0.55	8.5–9.7 9.2	0.44
TFL	10.1–11.9	11.1	0.92	12.0–13.7 13.0	0.51