Ischnocnema vizottoi, Martins, Itamar A. & Haddad, Célio F. B., 2010

Martins, Itamar A. & Haddad, Célio F. B., 2010, A new species of Ischnocnema from highlands of the Atlantic Forest, Southeastern Brazil (Terrarana, Brachycephalidae), Zootaxa 2617, pp. 55-65 : 56-64

publication ID	https://doi.org/ 10.5281/zenodo.197955
DOI	https://doi.org/10.5281/zenodo.6201749
persistent identifier	https://treatment.plazi.org/id/212A8789-FF80-FFAB-FF01-F97FFBDDFCA7
treatment provided by	Plazi
scientific name	Ischnocnema vizottoi
status	sp. nov.

Treatment

Ischnocnema vizottoi View in CoL sp. nov.

( Figures 1 View FIGURE 1 , 2 View FIGURE 2 , 3 View FIGURE 3 , and 4)

Holotype. CFBH 8222, adult male, collected at Parque Estadual de Campos do Jordão (22° 39`50``S, 45° 27`03`` W, 1540 m elevation), Municipality of Campos do Jordão, São Paulo, Brazil, on 17–21 December 2004 by I. A. Martins, A. F. L. Leite, and F. B. R. Gomes.

Paratopotypes. CFBH 8205–08, 8210–21, 16 adult males, and CFBH 8209, adult female, collected with the holotype. CCLZU / IAM 2151, adult male collected by I. A. Martins, F. B. R. Gomes, and A. F. B.

Junqueira, on 3 March 2005. CCLZU / IAM 2161, adult male collected by I. A. Martins, F. B. R. Gomes, and T. L. P. C. Perroni, on 8 April 2005. CCLZU / IAM 2149, 2159, two adult females, and CCLZU / IAM 2158, 2160, two adult males, collected by C. F. B. Haddad, I. A. Martins, and F. B. R. Gomes, on 11–14 November 2005. CCLZU / IAM 2148, 2150, two adult females, and CCLZU / IAM 2152–57, six adult males collected on 21–23 December 2005 by I. A. Martins, F. B. R. Gomes, and A. F. B. Junqueira.

Diagnosis. A member of the Ischnocnema lactea Species Series. It differs from other members of the Species Series by the following combination of traits: (1) diminutive size (males 13.3–16.6 mm SVL and females 18.4–22.1 mm SVL) (Table 1); (2) iris yellow in live specimens; (3) snout sub-elliptical in dorsal view and acuminate-rounded in lateral view; (4) vocal sac expanded externally; (5) tympanic membrane differentiated; (6) skin texture granular on the flanks and venter; (7) adhesive disks rounded; (8) calcar appendage absent or small; (9) external face of the thigh with a light line in the central area or irregular light blotches; (10) notes of the advertisement call with two harmonics; (11) note duration 38–72 ms; (12) mean dominant frequency of the advertisement call 3611± 103 Hz (3417–3763 Hz).

TABLE 1. Measurements of Ischnocnema vizottoi sp. nov. (holotype and paratopotypes). Mean (x), standard deviation (SD), and range (in millimeters) for males and females.

Comparison with other species. The new species differs from Ischnocnema sambaqui by its smaller size ( I. vizottoi sp. nov. males 13.3–16.6 mm SVL and females 18.4–22.1 mm SVL; I. sambaqui males 32.3–40.0 mm SVL), finger adhesive disks rounded (T-shape in I. sambaqui ), narrower head, and higher dominant frequency of advertisement call ( I. vizottoi sp. nov. 3417–3763 Hz, I. sambaqui 1800 –2050 Hz; Castanho & Haddad, 2000). The new species differs from Ischnocnema manezinho by its smaller size ( I. vizottoi sp. nov. males 13.3–16.6 mm SVL and females 18.4–22.1 mm SVL; I. manezinho males 22.7–28.1 mm SVL and females 29.8–34.8 mm SVL; Garcia, 1996), and finger adhesive disks rounded (T-shaped in I. manezinho ). The new species differs from Ischnocnema bolbodactyla by its smoother dorsal skin, shorter snout, adhesive disks less developed, absence of bright coloration on the inguinal region (inguinal region bright orange in I. bolbodactyla ), and advertisement call formed by a single note (formed by series of 3–4 notes in I. bolbodactyla ). The new species differs from Ischnocnema lactea by its smaller size ( I. vizottoi sp. nov. males 13.3–16.6 mm SVL and females 18.4–22.1 mm SVL; I. lactea female lectotype 32mm SVL) and finger adhesive disks rounded (T-shaped in I. lactea ). The new species differs from Ischnocnema holti by its smaller size ( I. vizottoi sp. nov. males 13.3–16.6 mm SVL and females 18.4–22.1 mm SVL; I. holti 19 mm SVL; Cochran, 1955; male mean SVL 21.2 mm and female SVL 25.6mm; Targino & Carvalho-e-Silva, 2008) and snout outline sub-elliptical from above and acuminate-rounded in profile (snout in dorsal and lateral views rounded in I. holti ). The new species differs from Ischnocnema concolor by its smaller size ( I. vizottoi sp. nov. males 13.3–16.6 mm SVL and females 18.4–22.1 mm SVL; I. concolor males 15.0– 18.4mm SVL; Targino et al., 2009), by a light line or irregular light blotches on the external face of the central area of the thigh ( I. concolor lacks a light line or irregular light blotches in the central area of the thigh; Targino et al., 2009), and advertisement call traits [the notes in the advertisement call of I. vizottoi have two harmonics; minimum and maximum fundamental frequency (H1) of 2780–3555 Hz, 3634–4097 Hz, respectively; the notes in the advertisement call of I. concolor have three harmonics; minimum and maximum fundamental frequency (H1) of 2616–2989 Hz, 3150–3470 Hz, respectively; Martins, I.A. unpublished data]. The new species differs from Ischnocnema melanopygia by the smaller or absent calcar appendage (calcar appendage well developed in I. melanopygia ; Targino et al., 2009) and by the absence of a black stripe on the perianal region, posterior area of tarsus, and feet (black stripe present in I. melanopygia ; Targino et al., 2009).

Description of the holotype. Body robust ( Figure 1 View FIGURE 1 ); snout sub-elliptical in dorsal view ( Figure 2 View FIGURE 2 A) and acuminate-rounded in lateral view ( Figure 2 View FIGURE 2 B); nostrils protuberant, directed laterally; canthus rostralis distinct; loreal region concave; eye large, protruding; tympanum distinct, large, diameter about 1/2 of eye diameter; small supratympanic fold extending from the back of the eye to near the arm insertion; vocal sac single, externally expanded; vocal slits present; tongue large, shallowly notched posteriorly; vomerine teeth in two small, oblique, and narrowly separated series of approximately 10 teeth each, between and behind choanae; choanae small, slightly rounded. Forearm moderately robust, arm slender; fingers long; thumb without nuptial pad; subarticular tubercles single, round; outer metacarpal tubercle cordiform, inner metacarpal tubercle elliptical; supernumerary tubercles on the palmar region ( Figure 2 View FIGURE 2 C); finger lengths I<II<IV<III; disk on the tip of 1st finger not well developed; disks on the tips of 2nd, 3rd, and 4th fingers nearly rounded and large. Ungual flaps on the disks indented. Legs slender; foot with an elliptical inner metatarsal tubercle and a round outer metatarsal tubercle; subarticular tubercles single, round; toe disks nearly elliptical; toe lengths I<II<III=V<IV ( Figure 2 View FIGURE 2 D); heel with a small tubercle. Slightly rugose to rugose dorsal skin texture; scattered tubercles on dorsum and flanks; two large tubercles near the mandible articulation; one large tubercle on the shoulder; undersurfaces smooth; slightly rugose near the venter and on the ventral surfaces of the thighs.

Color of the holotype in preservative. Dorsal surfaces brown. Vocal sac white with black punctuations. Inter-orbital mark dark brown. Elbow dark brown; dark brown marks on the forearms. Irregular light blotches on the external surface of the thigh. Two dark brown blotches on the sacrum region ( Figure 1 View FIGURE 1 ).

Measurements of the holotype. SVL 14.50; HL 5.23; HW 5.00; ED 1.71; IOD 1.9; END 1.23; NSD 0.95; IND 1.33; TD 0.85; FL 6.75; TL 6.93; FOL 6.74; 3FD 0.55; 4TD 0.55.

Color in life. The specimens of Ischnocnema vizottoi sp. nov. present wide variation of dorsal coloration ( Figure 3 View FIGURE 3 ). Dorsal coloration of different specimens can be green, red, black, brown, and light gray ( Figure 3 View FIGURE 3 ). A longitudinal light line extending from the snout to the vent is present in several specimens. A white or beige inter-orbital stripe is almost always visible, with a dark stripe behind the light inter-orbital stripe. Two dark blotches can be present in the middle of dorsum in some individuals. The external face of the thigh presents a light line in the central area or irregular light blotches. The subgular region may be lightly to very dark pigmented. In several specimens it is possible to see a light ventral line, from the anterior border of the chin to the chest. The ventral regions of the thigh and tibia present light spots with dark borders.

Variation. Measurements of 27 males and five females are given in Table 1. The head is generally wider than long, but in some specimens it is longer than wide. The tympanum is distinct in the majority of the specimens. The vocal sac may be well expanded externally or indistinct. The calcar appendage may be smaller or absent. A light to dark stripe is generally present in the inter-orbital region. A light vertebral line is present in the majority of the specimens ( Figures 3 View FIGURE 3 and 4 View FIGURE 4 ). The external face of the thigh may show a light line in the central area or irregular light blotches.

Vocalization. The advertisement call of Ischnocnema vizottoi sp. nov. is composed of simple notes, with a fairly irregular rhythm and varied intervals ( Figure 5 View FIGURE 5 ). The average duration of the note is 52.7 ± 10.2 ms (38–72 ms), with a mean repetition rate of 9.5 ± 2.2 notes per minute. The advertisement call of Ischnocnema vizottoi sp. nov. has notes with two harmonics ( Figure 5 View FIGURE 5 B, D). The advertisement call has sharply rising frequencies at the beginning and sharply falling frequencies at the end ( Figure 5 View FIGURE 5 ). Most of the energy of these notes is concentrated in the first harmonic (fundamental frequency = H1; Figure 5 View FIGURE 5 E). The mean frequencies of the first harmonic (H1) minimum frequencies is between 3204 ± 158 (amplitude 2780–3555 Hz) and maximum frequencies 3837 ± 95 Hz (amplitude 3634–4097 Hz), with most energy concentrated around 3611 ± 103 Hz (amplitude 3417–3763 Hz). The second harmonic (H2) has minimum and maximum mean frequencies between 6967 ± 207 (amplitude 6585–7317HZ), 7379 ± 119 Hz (amplitude 7146–7618 Hz) respectively, and most energy of the second harmonic is concentrated around 6996 ± 212 Hz ( Figure 5 View FIGURE 5 ).

Distribution. The new species has been found in Serra da Mantiqueira at the localities of Parque Estadual de Campos do Jordão, Municipality of Campos do Jordão, São Paulo State, (type locality); Lavrinhas farm, Municipality of Pindamonhangaba, São Paulo State; Municipality of São Bento do Sapucaí, São Paulo State; Monte Verde, Municipality of Camanducaia, Minas Gerais State; and Serra do Mar, at Parque Nacional da Serra da Bocaina, Municipality of São José do Barreiro, São Paulo State. All the localities are in the Atlantic forest, above 1300 elevation ( Figure 6 View FIGURE 6 ).

Etymology. The specific name honors Dr. Luiz Dino Vizotto, for his pioneer studies of Brazilian anurans and for his contribution to the knowledge of the Brazilian vertebrate fauna.

Natural history. Ischnocnema vizottoi sp. nov. was observed in places of high altitude, from 1300 to 2100 m above sea level, inside forests, forest edges, and open fields. Males vocalize on the forest floor or perched 10 to 80 cm from the ground. The distance among neighboring males varied from 0.5 to 8 m. The calling season is from September to April; however, the vocalization was most intense from October to January, when gravid females were observed. Three analyzed females had from 10 to 18 oocytes with mean diameter of 2.45 ± 0.15 mm (N = 27). Oocytes in different developmental stages suggest that females may lay more than one clutch per season.

Remarks. The Atlantic forest is the biome with the greatest endemism in species of anurans in the world, at the same time having high diversity of species and of phylogenetic groups ( Duellman, 1999, Frost et al., 2006). This high diversity and endemism can be explained by the physical environment, a reflex of the complex geomorphologic, climatic, and phytogeographic characteristics of this formation. However, the species diversity of anurans in the Atlantic Forest of Brazil is still poorly known, particularly in places with more than 1000 m of altitude ( Rossa-Feres et al., 2008).

The number of species in the genus Ischnocnema will probably increase in the next years, considering the recent descriptions of new species ( Giaretta et al., 2007; Targino et al., 2009) and mainly the large number of unnamed species that can be found in the shelves of Brazilian collections (personal observations). The use of molecular information and vocalizations, allied to morphological studies, will increase our comprehension on the evolution of this genus and certainly uncover a great diversity of cryptic species.