Ameerega pepperi, Brown, Jason L. & Twomey, Evan, 2009

Brown, Jason L. & Twomey, Evan, 2009, Complicated histories: three new species of poison frogs of the genus Ameerega (Anura: Dendrobatidae) from north-central Peru, Zootaxa 2049, pp. 1-38 : 16-18

publication ID	https://doi.org/ 10.5281/zenodo.186518
DOI	https://doi.org/10.5281/zenodo.6221796
persistent identifier	https://treatment.plazi.org/id/03EEF24A-FFFB-FFC1-43CA-6E1705480964
treatment provided by	Plazi
scientific name	Ameerega pepperi
status	sp. nov.

Treatment

Ameerega pepperi View in CoL sp. nov.

Figures 1 View FIGURE 1 , 14–16 View FIGURE 14 View FIGURE 15 View FIGURE 16

Phyllobates bassleri: Silverstone 1976 p. 45 (AMNH 42327, 42867, 43402 collected in 1926 and 1928 by H. Bassler at “Pachiza”).

Holotype. MUSM 26940 ( Fig. 16 View FIGURE 16 ), an adult male collected on 14 July 2006 by M. Pepper, Provincia Tocache, Departamento San Martín, Peru, 2 km NE of San Francisco, 980 m elevation, 8° 18' 30.3" S, 76° 40' 37.6" W. Found on the ground near a small waterfall.

Paratypes. All from San Martín, Peru. One adult female ( MUSM 26942), collected 21 July 2006 by M. Pepper and E. Twomey, and two adult females ( MUSM 26975, 26976), collected 25 June 2007 by J. Brown, E. Twomey, and K. Fieselman, 390 m elevation, 7.0 km SW of Huicungo at 7° 21' 58.6" S, 76° 48' 44.1" W: Two adult females ( MUSM 26979, 26980), collected on 25 June by J. Brown, E. Twomey, and K. Fieselman, 384 elevation, 6.6 km N of Campanilla at 7° 25' 38.6" S, 76° 39' 53.3" W: One adult female ( MUSM 26968), collected on 15 July 2006 by M. Pepper, 570 m elevation, SW of Chumanza (alternate spelling: Shumanza) at 7° 34' 7.8" S, 76° 41' 34.4" W: One adult male ( MUSM 26941), collected at same locality of holotype, 980 m elevation, 2 km NE of San Francisco at 8° 18' 30.3" S, 76° 40' 37.6" W.

Etymology. The specific epithet is a patronym for the discoverer of this species, Mark Pepper, an enthusiastic Canadian explorer and conservationist whose discoveries have greatly contributed to the authors’ understanding of poison frog biogeography and taxonomy.

Definition and diagnosis. Assigned to the genus Ameerega on the basis of the following: first finger longer than second, webbing absent between the toes, dorsal skin granular ( Myers 1982, Grant et al. 2006). This is a medium-large species of Ameerega with an adult SVL of approximately 28–34 mm. Dorsum has a black ground color, finely stippled brick-red to bright red in southern populations (e.g. San Francisco) to coarsely stippled orange or yellow northern populations (e.g. Campanilla), stippling concentrated near head and is less dense near sacral region. Bright yellow dorsolateral stripes extend from the eyelid to the groin; a yellow labial stripe is also present starting near nares and extending posterior to the axillary region. Faded yellow-green to white spot present above groin in some populations, shank spots and axillary spots absent. Limbs greenish-bronze or black; venter blue with strong black marbling. Teeth present. Appressed first finger longer than second; finger discs moderately expanded, hands and feet lacking webbing between digits. Vocalization consists of a loud retarded trill of whistle-like notes given at a rate of 0.9–1.3 notes per second; dominant frequency 2800–3160 Hz ( Fig. 4 View FIGURE 4 , Table 2 View TABLE 2 ).

Ameerega pepperi can be distinguished from most other species of Ameerega by its red, orange, or yellow dorsum. It is similar in appearance to the following species: A. bassleri , A. bilinguis , A. cainarachi , A. macero , A. parvula , and A. yoshina , all of which have (or can have) a solid red, orange, or yellow dorsum. Ameerega parvula and A. bilinguis both lack distinct dorsolateral stripes (vs. dorsolateral stripes present and conspicuous in A. pepperi ). Ameerega cainarachi is smaller, females up to 31.3 mm SVL (vs. 34 mm SVL in A. pepperi ), and has an advertisement call consisting of a regular chain of notes which are not frequency modulated, repeated at a rate of 9 notes per second (vs. ‘bursts’ of frequency-modulated notes, repeated 0.9–1.3 notes per second in A. pepperi ). Ameerega macero is smaller than A. pepperi , females up to 29.5 mm SVL, and has a call consisting of a series of harsh ‘peeps’, repeated regularly at a rate of 10 notes per second. Ameerega bassleri has an advertisement call consisting of a series of regularly-spaced whistle-like notes given continuously for several minutes at a rate of 1.6–2.1 notes per second (vs. notes given at a rate of 0.9–1.3 notes per second in A. pepperi ). Ameerega yoshina has an advertisement call given in bursts of 4–31 notes, given at a rate of 3.7–4.1 notes per second, each burst less than 8 seconds in total duration (vs. notes given at a rate of 0.9–1.3 notes per second in A. pepperi ).

Measurements (in mm) of holotype. The male holotype ( Fig. 16 View FIGURE 16 ) has SVL 28.6; FL 13.4; TL 16.1; KK 28.2; FoL 13.3; HaL 7.5; HL 7.7; HW 7.8; BW 8.3; UEW 5.5; IOD 3.9; IND 4.0; TD 3.0; ED 4.2; DET 1.6; L1F 6.9; L2F 6.1; W3D 0.8; W3F 0.6. Measurements of paratypes are given in Table 5.

Description of holotype. Size medium, SVL 28.6 mm (Table 5). Dorsal skin is coarsely granular and is pigmented black with brick red mottling densest near the snout. Thin yellow dorsolateral stripes extend from groin, extending dorsally around snout; posterior to eyes the stripes blend into the red dorsum. Dorsolateral stripe is sightly wider at groin. Flanks are black extending from groin to nares. Forelimbs lack granulation and are colored tan and flecked in olive. Yellow coloration extends up upper arm surface, anteriorly around lip. Legs are coarsely granulated; contain yellow femoral spots, dorsal surface colored olive green. The venter is yellow-gold with olive marbling; marbling extends primarily on throat and margins of legs. Iris black.

Widest part of head between jaw articulations and tympanum, head narrower than body. Greatest head width 27.0 % of SVL. Eyes very protuberant. Tongue medium sized, oval. Premaxillary and maxillary teeth present. Vocal slits present. Dorsal skin of head and body is finely granular; skin smooth or nearly smooth on limbs and smooth on sides of head and body and ventral surfaces. Snout sloping laterally; bluntly rounded dorsally; truncate ventrally. Nares situated and directed posterolaterally to the tip of snout; nares visible from front and below but not from above. Canthus rostralis sloped, slightly rounded; loreal region nearly vertical and slightly concave. Upper eyelid 1.4 times wider than interorbital distance. Eye large and prominent with a maximum diameter of 14.6 % of SVL, pupil rounded and horizontally elliptical. Tympanum circular, without tympanic annulus its diameter less than 73.0 % of ED, supratympanic fold absent.

Hands relatively small, length being 26.2 % of SVL. Relative length of appressed fingers I ≈ II ≈ IV <III (numbers starting interiorly). Discs moderately expanded on all fingers. In adults, disc on finger III is 1.25 times wider than distal end of adjacent phalanx A large, circular outer metacarpal tubercle present on median base of palm; smaller inner metacarpal tubercle on base of finger I absent; one well developed subarticular tubercle on fingers I and II, two on fingers III and IV.

Hind limbs short, small, with heel of appressed limb reaching the interior axilla. Tibia length 56.3% of SVL. Relative lengths of appressed toes I <II <V <III <IV; first toe terminates at subarticular tubercle on base of second toe; toes I, II barely expanded (much smaller than finger discs), and toe III, IV, and V expanded (disc 1.5 times broader than adjacent phalanx). Moderate-sized inner and outer metatarsal tubercles, protuberant with rounded surfaces. One protuberant subarticular tubercle on toes I and II, two on toes III, IV, and V. Hands and feet lacking supernumerary tubercles and lateral fringes. Basal webbing absent. Tarsal tubercles absent.

In 70% alcohol the color is similar to the living animal described above, except that the red on the dorsum changed to black and the yellow dorsolateral lines changed to silver-white.

Variation. The dorsal coloration varies over a cline from the north to south. In southern populations, the dorsum is finely stippled brick-red to bright red and gradually changes to coarsely stippled orange or yellow in northern populations ( Figures 14 View FIGURE 14 & 15 View FIGURE 15 ).

Vocalizations. The advertisement call for A. pepperi ( Fig. 4 View FIGURE 4 ) can be classified as a ‘retarded trill’ following Lötters et al. (2003). The call consists of a series of musical notes resembling short ‘whistles’ at a rate of 0.9–1.3 notes per second. Notes are 130–220 ms long, spaced 560–1030 ms apart, overall dominant frequency 2970 Hz. The call of A. pepperi can be distinguished from the advertisement call of A. bassleri by the rate the notes are repeated, with A. bassleri repeating notes at 1.6–2.1 notes per second (vs. 0.9–1.3 in A. pepperi ).

Distribution and natural history. Ameerega pepperi is known from throughout the upper Huallaga Valley, south of Río Huayabama (near Huicungo) to the southern border of San Martín at elevations from 380 m to approximately 1000 m elevation. Most of the known localities for this species run along the main road to Tingo Maria, which is primarily on the eastern side of Río Huallaga (i.e., the western slope of the Cordillera Azul). This species also occurs on the western side of the Huallaga (i.e., the eastern slope of the Andes) in San Francisco and Huicungo, and likely occurs throughout the area between these two sites based on the results of our niche model (Fig. 17). This model also predicts suitable habitat throughout much of the Río Biabo valley in the Cordillera Azul, although no surveys have taken place in this area. There appears to be very little predicted overlap in the distributions of A. pepperi and A. bassleri in the niche model (Fig. 17), with the only overlapping areas occurring near the town of Juanjui. In 2007 we spent a day in the mountains just west of Juanjui and did not detect either species. The area near Juanjui appears to be somewhat drier than surrounding areas, and this may function as a weak barrier that separates the distributions of these two species.

Ameerega pepperi occurs in undisturbed premontane forests and secondary premontane forest, particularly in habitats which are adjacent to streams ( Fig. 15 View FIGURE 15 i). Unlike A. bassleri , which we have often observed far from streams (> 300 m), we have never observed A. pepperi greater than ~ 30 m from a stream. This species can occur in moderately disturbed areas provided the streamside habitats are relatively shaded. During the day, adults tend to hide amongst streamside boulders. Calling activity seems to peak during late evening, just prior to dusk. Males call from elevated positions on boulders, although courtship and oviposition appears to take place on the ground in the leaf litter. Clutches contain 22- 44 eggs and are guarded by males (M. Pepper pers. comm.). These eggs typically hatch in approximately 18 days. Tadpoles have been found in shallow eddies or streamside pools which are sometimes left by receding water levels. Clay-bottomed streams appear to be most commonly used, and tadpoles will often submerge themselves under the sediment, particularly during the hotter hours in the afternoon. These pools also contain tadpoles of the sympatric A. altamazonica and A. trivittata . Tadpoles of Ameerega pepperi complete development in as little as 5-6 weeks.

Conservation status. Following the IUCN Red List criteria (IUCN 2001), we tentatively suggest that A. pepperi should be listed as Least Concern (LC) based on the following: (1) we estimate the extent of occurrence to be at least 5,500 km 2, (2) populations appear to be continuous and (3) this species occurs in largely undisturbed forests, though there has been a small amount of potential habitat loss in the Cordillera Azul and in the upper Huallaga Valley.