Hyloxalus faciopunctulatus (Rivero 1991)

Páez-Vacas, Mónica I., Coloma, Luis A. & Santos, Juan C., 2010, Systematics of the Hyloxalus bocagei complex (Anura: Dendrobatidae), description of two new cryptic species, and recognition of H. maculosus 2711, Zootaxa 2711, pp. 1-75 : 28-31

Hyloxalus faciopunctulatus (Rivero 1991)

Colostethus faciopunctulatus — Rivero 1991:23.— Holotype: “ MCZ-A 94751 , an adult male from Puerto Nariño (3°46’N, 71°23’W, 15 km W. of Leticia), Departamento Amazonas, Colombia ”. Fig. 2.

Hyloxalus faciopunctulatus — Grant et al. 2006:168.

Diagnosis. A species with (1) mean SVL in adult males 22.3 mm (21.9–22.7, SD = 0.3, n = 5) and in adult females 24.2 mm (23.5–25.7, SD = 1.0, n = 4); (2) disc of Finger IV expanded less than 1.5 times the width of adjacent phalange; (3) Finger II slightly shorter than Finger III; (4) fringes present on fingers; (5) disc of Toe IV expanded less than 1.5 times the width of adjacent phalange; (6) fringes present on toes; (7) outer metatarsal fold present; (8) extensive toe webbing, formula I (1 - –1)—(2 - –2) II (1 - –1)—(2½–3) III (1–2 -)—(3– 3½) IV (3 + –3½)—(1½–2 -) V; (9) oblique lateral stripe absent or reduced, a small bar or a series of 3–4 dots at groin level; (10) dorsum with two large blotches; (11) gular-chest region brown with white marks in adult males, cream or subtly brown stippled in adult females; (12) venter white or slightly brown flecked in adult males, cream in adult females; (13) sexual dimorphism in ventral coloration present; (14) and (15) tadpoles unknown; (16) call unknown.

Hyloxalus faciopunctulatus is similar to those species that exhibit extensive toe webbing and lack oblique lateral stripe or it is reduced at groin level ( H. abditaurantius Silverstone , H. betancuri Rivero and Serna , H. chocoensis Boulenger , H. edwardsi Lynch , H. italoi , H. leucophaeus Duellman , H. maculosus , H. ruizi Lynch , H. yasuni ). It is distinguished from these species by the following characters: H. abditaurantius has an orange spot on the calf, absent in H. faciopunctulatus — Hyloxalus betancuri lacks a postmandibular tubercle; ventral coloration in females (holotype CJS 2372, an adult female and the only specimen known of the species) is dark brown with small white dots, whereas females of H. faciopunctulatus are ventrally cream. Hyloxalus chocoensis has a squared dorsal mark and testes enlarged. Hyloxalus edwarsi and H. ruizi are distinguished from all species within the genus by having a cloacal funnel. Hyloxalus italoi and H. yasuni have three dorsal blotches and are larger in size (t- test, t = -2.729, df = 86, p = 0.008 with H. italoi ; t = -2.150, df = 120, p = 0.034 with H. yasuni ). Hyloxalus leucophaeus lacks outer metatarsal fold and sexual dimorphism in ventral coloration. Hyloxalus maculosus differs in gular-chest region of adult males; they do not exhibit white spots over a dark brown background.

Description. (n = 8; 4 males, 4 females). Head slightly longer than wide; snout subacuminate, round in one specimen (MCZ-A 94747), and truncate in two (MCZ-A 94746, 94752) in dorsal view, truncate in lateral view (slightly angular in MCZ-A 94759); loreal region slightly concave; nostrils slightly protuberant; supratympanic bulge covering upper edge of tympanum.

Finger II slightly shorter than III; fingers unwebbed; fringes present on fingers; terminal discs expanded less than 1.5 times the width of adjacent phalange; subarticular tubercle round, the one in Finger II oval, the distal of the Fingers IV and V only visible under dissecting microscope; outer metacarpal tubercle large, round protuberant; inner metacarpal tubercle small, elliptical, protuberant, one-third the size of outer; outer metacarpal ridge absent, except in two specimens (MCZ-A 94752, 94759). Outer metatarsal fold present, not reaching the outer metatarsal tubercle; inner sigmoid tarsal fold present on distal half of tarsus; outer metatarsal tubercle tubercle round, small protuberant; inner metatarsal tubercle twice as large as outer, elliptical, protuberant; a third tubercle slightly smaller than inner between the other two tubercles; toe webbing formula I (1 - –1)—(2 - –2) II (1 - –1)—(2½–3) III (1–2 -)—(3–3½) IV (3 + –3½)—(1½–2 -) V; lateral fringes present; terminal disc expanded less than 1.5 times width of adjacent phalange; subarticular tubercles round, small; supernumerary tubercles absent.

Skin of dorsum, flanks, limbs and throat smooth; venter smooth (MCZ-A 94747, 94749, 94752, 94761) or shagreen (MCZ-A 94746, 95750, 94751, 94759); round tubercle posterior to mandible junction; anal sheath subtly conspicuous. Tongue twice as long as wide, thinner and broader posteriorly, posterior half not attached to mouth’s floor.

Variation of color in preservative (~70% ethanol). Variation in measurements is given in Table 7. Variation in color patterns is depicted on Figs. 5D – 7D. Dorsum of head and body brown; an interorbital blotch and a dark brown bar present on posterior dorsum, except in one specimen that exhibits a subtle mark at scapular level ( MCZ-A 94759 ); flanks brown, darker than dorsum, same color of dorsal blotches; a diffuse dark brown strip from the anterior tip of snout, through loreal and supratympanic regions to the arm-body junction; white dots on loreal region vary in number and intensity, absent in two specimens ( MCZ-A 94749 , 94761 ). Oblique lateral stripe absent or a series of 3–4 white dots at groin level ( MCZ-A 94746 , 94749– 94751 ); forelimbs brown with transverse brown marks visible only on forearm; a longitudinal dark brown stripe at anterior surface of arm; a white stripe underneath the dark stripe in two specimens ( MCZ-A 94747 , 94751 ); a cream spot at arm-body junction; dorsal surfaces of hindlimbs brown with darker transverse bars (9–10) on leg and tarsus; ventral surfaces cream-colored, thighs brown stippled and white dotted on inner surface. Venter cream-colored with small white dots in females, one specimen lacks white dots but exhibits very subtle light brown stippling ( MCZ-A 94761 ), venter cream-colored, slightly flecked with brown in males; gular-chest region brown stippled in males with a light medial stripe (absent in MCZ-A 93782 and 94749), same coloration as venter in females; axillas translucent. Palmar and plantar surfaces brown; toe webbing translucent cream .

Ten juveniles (MCZ-A 94748, 94753–94758, 94760, 96016–96017) with SVL 12.8–18.2 mm (mean = 15.7) are very similar to adult specimens but they are light brown to yellowish brown in coloration. Six specimens exhibit white dots on loreal region (MCZ-A 94748, 94753–94754, 94757–94758, and 94760).

Tadpoles. Unknown.

Comments. Rivero’s (1991) description is appropriate with the following exceptions: the holotype (MCZ- A 94751) exhibits oblique lateral stripe as a short bar anterior to groin to one-third of flank length at right side of the body and a series of four dots reaching midflank at the left side; Finger II slightly shorter than III; fringes definitely present on fingers and the outer metatarsal fold reaches half metatarsus only. Moreover, Finger II is shorter than Finger III in all specimens examined.