Aplastodiscus lutzorum, Berneck, Bianca V. M., Giaretta, Ariovaldo A., Brandao, Reuber A., Cruz, Carlos A. G. & Haddad, Celio F. B., 2017

Berneck, Bianca V. M., Giaretta, Ariovaldo A., Brandao, Reuber A., Cruz, Carlos A. G. & Haddad, Celio F. B., 2017, The first species of Aplastodiscus endemic to the Brazilian Cerrado (Anura, Hylidae), ZooKeys 642, pp. 115-130 : 117-123

Aplastodiscus lutzorum sp. n. Figs 1, 2

Aplastodiscus perviridis Garcia et al. (2001)

Aplastodiscus perviridis Bastos et al. (2003)

Aplastodiscus perviridis Morais et al. (2012)

Aplastodiscus perviridis Valdujo et al. (2012)

Aplastodiscus sp. Santoro and Brandão (2014)

Aplastodiscus sp. 3 Berneck et al. (2016)

Holotype.

(Figs 1 and 2) AAG-UFU 864. Adult male collected at Fazenda São Bento (14°09'39"S, 47°34'55"W; 1150 meters above sea level), Municipality of Alto Paraíso de Goiás, Goiás State, Brazil, on 12 December 2011, by A. A. Giaretta and K. G. Facure.

Paratypes.

CFBH 22777-80, four adult males collected at Fazenda Água Limpa, Brasília, Distrito Federal (15°56'55.45"S; 47°56'17.83"W) on 18 February 2009. AAG-UFU 863, 865-867 and AAG-UFU 1639 collected on December 2012, AAG-UFU 3343 on 29 November 2013, AAG-UFU 3350-51, 5073-76, 5091, AAG-UFU 0867, adult female, all collected with the holotype. CHUNB 17015-17016 adult males collected on 31 December 1995 at Alexânia, Goiás (16°5'42.00"S; 48°31'20.60"W), CHUNB 17018, adult male collected on 12 December 1985 at Alexânia, Goiás, and CHUNB 74504-74508 adult males from Fazenda Água Limpa, Brasília, Distrito Federal, collected on March 2013. All localities are in Brazil.

Referred specimens.

All males. MCN-AM 8809-12 and 8767-72 from AHE Queimado, Unaí, Minas Gerais (16°20'55.51"S; 46°52'48.93"W), collected on February–March 2007.

Diagnosis.

Aplastodiscus lutzorum sp. n. belongs to the Aplastodiscus perviridis Group and thus bears bicolored irises, lacks webbing between toes I and II, has reduced webbing among the remaining toes, and lacks peri-cloacal ornamentation. The new species is diagnosed by its small SVL for the Aplastodiscus perviridis Group (30-36 mm) and by the advertisement call 2.5 times longer.

Description of holotype.

Adult male: head 20% wider than long; snout rounded in profile, nearly rounded in dorsal view; canthus rostralis curved; loreal region concave; nostrils ovoid; internarial region grooved. Supratympanic fold distinct, from posterior corner of orbit to insertion of forearm; tympanum distinct, almost circular; tympanum diameter 48.5% of eye diameter. Upper eyelid smooth as the dorsum. Thoracic fold just discernible. External vocal sac single, subgular, and expanded. Fingers long, slender, no lateral fringe, bearing discret round terminal discs; relative lengths of fingers I, II, IV, III; similar sized discs on fingers II, III and IV, larger than disc of Finger I. Diameter of disc of Finger III equals to diameter of Toe IV, about 42% eye diameter. Subarticular tubercles well defined, rounded; supernumerary tubercles poorly defined on palm, rounded; inner metacarpal tubercle large, rounded, about four times the size of subarticular tubercles; other metacarpal tubercle barely defined; spine of prepollex absent; no nuptial pads; ulnar crest barely defined. Hand webbing formulae: I-II 2--3- III 2+-2 IV. Tarsal texture smooth; tarsal fold discrete, extending to the entire length of tarsus; heel smooth; inner metatarsal tubercles large, elongate, three times the size of foot subarticular tubercles; outer metatarsal tubercle absent; subarticular tubercles distinct, large, and rounded, diameter about 3/4 width of terminal disc on the same toe; supernumerary tubercles absent; toes long, slender, without lateral fringe; toes bearing rounded discs, smaller in diameter to those of fingers II-IV. Foot webbing formula: I 2+ - 3- II 2+ - 31/2 III 2+ - 4- IV 3+ - 2V. Supra cloacal fold absent. Skin on dorsum smooth; skin on throat, belly, ventral surface of thigh, and arm granular. Dorsal and dorsolateral surfaces almost entirely pale yellow with small dark spots or mottles on dorsal surfaces. Belly pale yellow. Measurements of the holotype (mm): SVL 34.6, HL 10.6, HW 11.4, ED 3.3, TD 2.1, END 3.2, IOD 5.3, THL 18.1, TBL 15.8, and FL 18.4 (Table 2).

Color in life of the type-series: Dorsal head surface dark green, almost olive. Dorsal body surface and flanks yellowish green with small and scattered melanophores. The superior third of eye is golden, whereas the inferior 2/3 is red copper. Eye surrounded by a black ring. Vocal sac bluish green. In preservative, colors fade to pale beige and the dorsum shows several dark brown dots, making it darker than other parts of the body. The belly is uniformly pale yellow.

Variation in the type series.

The main variation in type series is the body size (Table 2). Small brown chromatophores are along the dorsal skin; but the amount of these chromatophores is variable, ranging from sparse to dense.

Calls.

Advertisement calls of Aplastodiscus lutzorum sp. n. (Figure 3 and 4, Table 1) are long regularly-spaced single notes released at a mean rate of 39 calls/minute (SD = 8; n = 12 males). Calls resemble a whistle lasting around 0.26-0.40s. Most of the energy is between 1,494-1,732 Hz and 2,334-2,647 Hz, peaking between 1,884-2,156 Hz. Call exhibits an ascending frequency modulation, reaching its maximum between 49-70% of the call duration.

Aplastodiscus perviridis ' advertisement call (Figure 3 and 4, Table 1) is released in groups of 1-11 (mode = 5-7); within groups, call released at a rate of 140/min. Calls resemble a short whistle lasting around 0.12-0.15 s. Most of the energy is between 1,587-1,806 Hz and 2,419-2,750 Hz, peaking between 1,981-2,153 Hz. Call with an ascending frequency modulation, reaching its maximum between 23-38% of the call duration. The advertisement call of Aplastodiscus cochranae is described by Garcia et al. (2001) as being barely indistinguishable from the call of Aplastodiscus perviridis .

Natural history and geographic distribution.

All specimens of Aplastodiscus lutzorum sp. n. were collected along gallery forests with scattered buriti ( Mauritia flexuosa ) palm trees within the Cerrado Biome (see also Brandão and Araujo 2002; Morais et al. 2012; Santoro and Brandão 2014) (Figure 5). A female bearing large oocytes seen by the transparency of the body walls was found in mid-December and calling males were found from December to March. Males call during the night in proximity of riverine forests (<2m), perched on leaves or branches from the water level to 5 m high (Figure 6). Aplastodiscus perviridis males call during the night along swamps in open areas, perched on grass leaves or bushes bordering streamlets, from 0.5 m to 3 m high. Tadpoles are unknown. Sometimes, the species also uses places with wet and soft mud soil, covered by a layer of dense bush, in places where the forest was removed, but is under secondary growth. Sympatric frog species were Hypsiboas ericae (Caramaschi and Cruz 2000) and Hypsiboas albopunctatus (Spix, 1824). All localities where Aplastodiscus lutzorum sp. n. was found are 1000 m above sea level or more.

Etymology.

The new species is named after the Brazilian scientists Adolfo and Bertha Lutz, who were pioneers in discovering and studying Aplastodiscus and some species of Hyla now included in the genus Aplastodiscus .

Comparison with congeneric species.

Aplastodiscus lutzorum sp. n. can be distinguished from the species of other groups of Aplastodiscus ( Aplastodiscus albosignatus , Aplastodiscus albofrenatus , and Aplastodiscus sibilatus groups) by the presence of bicolored irises, the lack of the webbing between toes I and II, the webbing among the remaining toes reduced, and the absence of peri-cloacal ornamentation. The new species is diagnosed from Aplastodiscus perviridis and Aplastodiscus cochranae by having smaller SVL (30-36 mm SVL in the new species, 38-44.7 mm in Aplastodiscus perviridis , and 41-46.4 mm in Aplastodiscus cochranae ) and longer advertisement calls (0.38-0.42 in new species, 0.14-0.17 in Aplastodiscus perviridis and 0.10-0.18 in Aplastodiscus cochranae ). From Aplastodiscus cochranae it can be also distinguished by the green dorsal color in life ( Aplastodiscus cochranae is brown) and by the absence of a brown line on the loreal region and a white line in the cloacal region (both present in Aplastodiscus cochranae ). (Figures 1-4; Tables 1 and 2).

Phylogenetic relationships and genetic p-distances.

The two DNA fragments aligned and concatenated resulted in a matrix of 1,227pb. Our analysis recovered four most parsimonious trees with 808 steps each (Figure 7). The differences in topology among these trees are the position of Aplastodiscus lutzorum sp. n. specimens from different locali ties. Aplastodiscus lutzorum sp. n. were recovered as a monophyletic group with 100% Parsimony Jackknife Support (hereafter PJS) being the sister species of Aplastodiscus perviridis plus Aplastodiscus cochranae . The Aplastodiscus perviridis plus Aplastodiscus cochranae clade is low supported (54% PJS) and both species are supported by 99% of PJS each. The p-distances calculated for 16s of species in the Aplastodiscus perviridis Group range from zero to 5.9% (for all distances see Table 3). The internal distances among specimens of the new species range from zero to 0.93%. The p-distance in 16s between the new species and Aplastodiscus perviridis is 4.4-5.8% and between the new species and Aplastodiscus cochranae is 4.0-4.5%.