Panga Big-headed Frog

description

Description of the holotype. Adult male ZUEC 13639. Head wider than long; rostrum subacuminate in dorsal view, round in profile; nostrils closer to the snout tip than eye; canthus rostralis rounded; loreal region concave; upper eyelid with 3 – 4 enlarged tubercles; supratympanic fold defined, obscuring the superior and posterior edges of tympanic annulus; a discrete thin dermal fold from between nostrils to vent; tympanic membrane and tympanic annulus distinct; tympanum higher than wide, widest diameter 1 / 3 of eye diameter; 1 – 2 rounded postrictal tubercles at each side of head; choanae oval, not concealed by palatal shelf of maxillary arch; vomerine odontophores almost indistinct, posteromedian oblique, and lacking teeth; tongue longer than wide, oval, its posterior border not notched, posterior 1 / 4 free; vocal slits posterolateral to tongue; vocal sac developed, subgular; belly skin smooth; inner metacarpal tubercles oval; half the size of the outer; up to 4 supernumerary tubercles; subarticular tubercles rounded; when aligned finger 1 ~ 2 <4 <3; tips of fingers III and IV slightly expanded, lacking grooves or pads; no nuptial pads; skin of dorsal surfaces (head, back, flank

A new species of Ischnocnema (Anura: Eleutherodactylinae) from open areas of the Cerrado Biome in southeastern Brazil

description

Variation. We tentatively attribute specimens collected (AAG) in Perdizes to the new species (Figure 2 below). The three analyzed specimens (AAG-UFU 2463, 2575, 2616) presented a mean SVL of 19.5 mm (SD = 0.87), significantly larger than the topotypic population (ANOVA F 1, 6 = 11.8; p <0.02). Advertisement call (Figure 5 C): Duration 810 – 960 ms; frequency range and sound intensity rising from the beginning to the first third of the call; 17 – 19 pulses / call; pulse repetition rate 20 / s; dominant frequency peak at 3500 Hz; last two pulses lasting 4.2 – 4.6 ms, 50 – 70 ms interval; 3 calls / min. The call of a second male (EleuthpenaxavMG 2 AAGb) lasted 850 ms, had 17 pulses / call, and 2 calls / min. (19: 00 h; 20.5 o C). In comparison to the new species, advertisement calls of Ischnocnema juipoca show the following parameters (see also Sazima & Cardoso 1978; Haddad et al. 1988). One topotype recorded (Figure 5 D). Call duration 510 ms; frequency range and sound energy increasing from the beginning to the middle of the call; 8 pulses / call; pulse repetition rate 16 / s; dominant frequency peak at 3300 Hz; last pulse lasting 20 ms, interpulse intervals 50 ms; calls released sp

A new species of Ischnocnema (Anura: Eleutherodactylinae) from open areas of the Cerrado Biome in southeastern Brazil

diagnosis

Diagnosis. Males (topotypes) of Ischnocnema penaxavantinho sp. n. (14.9 – 18.7 mm SVL, Table I) are smaller than those of I. juipoca (19.1 – 20 mm; Table I; Figures 3 – 4 above), I. octavioi (29.0 – 34.0 mm), E. heterodactylus (Miranda Ribeiro) (25.0 mm), P. dundeei (22.0 – 27.0 mm), and P. crepitans (31.0 mm). Ischnocnema verrucosa is coarsely tuberculate on the dorsal surfaces (Lynch 1972; Caramaschi & Canedo 2006), while the new species is mostly smooth. Different from P. crepitans and E. heterodactylus, specimens of the new species do not have expanded discs on finger III and IV. Pristrimantis crepitans does not have marked sexual dimorphism in size (Heyer & Muños, 1999), a feature present in I. penaxavantinho sp. n.. Nuptial pads and finger / toes discs are present in P. dundeei (Padial & De La Riva, 2005) and absent in the new species. Different from the new species, I. verrucosa is primarily a forest dweller (C. Canedo, pers. com.), as are P. dundeei and I. octavioi. The advertisement call of the new species has more (1.5 – 2.5 times) pulses and higher (1.3 – 1.8 times) pulse repetition rate than that of I. juipoca (see call description sections).

A new species of Ischnocnema (Anura: Eleutherodactylinae) from open areas of the Cerrado Biome in southeastern Brazil

etymology

Etymology. The specific epithet is an arbitrary fusion of two Portuguese words pena (meaning feather) and xavantinho (meaning little Xavante, a group of pre-colonization natives). These names were used by two regional singer brothers (Pena Branca and Xavantinho) who in their songs emphasized the beauty of the Brazilian nature and the countryside way of life. It is used as a noun in apposition and as homage to both artists.

A new species of Ischnocnema (Anura: Eleutherodactylinae) from open areas of the Cerrado Biome in southeastern Brazil