Hyloscirtus psarolaimus

Coloma, Luis A., Carvajal-Endara, Sofía, Dueñas, Juan F., Paredes-Recalde, Arturo, Morales-Mite, Manuel, Almeida-Reinoso, Diego, Tapia, Elicio E., Hutter, Carl R., Toral, Eduardo & Guayasamin, Juan M., 2012, 3364, Zootaxa 3364, pp. 1-78 : 43-45

Hyloscirtus psarolaimus

Description. The oral disc of an individual of series QCAZ 46098 is depicted in Figure 15E. The following description is based on another individual in Stage 25 from the same tadpole series (QCAZ 46098), obtained in a streamside pond 2 km down the river near km 60 on the road between Salcedo and Tena (00° 58' 16'' S, 78° 14' 29'' W; 2748 m), Provincia de Napo, Ecuador, by Elicio E. Tapia and Fernando Núñez on 18 November 2009. The stream is located in mostly natural forest at about 80 m from the larger Río Mulatos; the stream bed was about 2 m width with an inclination of about 45 degrees. Tadpoles (QCAZ 46098; 46095, same locality and collection data) seem to mimic fallen, old Chusquea sp. leafs in the water, which have similar size and color patterns. Water temperature was 9 ºC at about 20:00h. All values are in millimeters. Total length 42.0; body length 13.7 (32.8% of total length). Body ovoid and depressed; width at level of spiracle 6.7, and height at same position 6.5; head width at level of eyes 6.0; anterior margin of snout uniformly rounded in dorsal view and sloping at level of nares in lateral view; lateral-line system barely conspicuous, and includes supraorbital, infraorbital, mandibular, posterior infraorbital, middle body, and ventral body lines. The arrangement is symmetrical, except for ventral lines.

Nostrils small, bean-like and directed anterolaterally; opening 2.0 from tip of snout; internarial distance 2.9. Eyes positioned and directed dorsolaterally; eye length 1.5, eye width 1.1; interorbital distance 4.7. Spiracle sinistral, located at mid-body level, inner wall free from body; tube length 1.8, tube transverse width 1.1; spiracular opening directed posterodorsally, diameter 0.4; distance from tip of snout to spiracular opening 9.6. Vent tube free, opening directed dextrally; tube length 2.0, tube transverse width 1.4. Tail length 28.3; caudal musculature robust, narrowing gradually to tail terminus; at tail-body junction, tail muscle width 2.9; tail muscle height 3.9; maximum height of tail 6.3.

Oral disc located anteroventrally, emarginated twice ventrally; transverse width 5.9; completely bordered by a single row of small rounded papillae; submarginal papillae absent; upper jaw sheath black, forming an arch; transverse width including lateral processes 2.3 (39% of transverse with of oral disc); lower jaw sheath V- shaped; finely serrate edges present in both sheaths. Labial tooth row formula 7(6–7)/9(1). Only A-6, A-7, and P-1 present natural gaps. Tooth row A-1, 3.4 in length; A-2 length 4.8; A-3 length 5.1; A-4 length 4.8; A-5 4.5; A-6 length 4.3 including medial gap; A-7 length 3.6 including medial gap. P-1 length 3.04 including medial gap; P-2 length 3.7; P-3 length 4; P-4 length 4.09; P-5 length 4.3; P-6 length 4.06; P-7 length 4.02; P-8 length 3.8; P-9 length 2.4.

Color in preservative. In dorsal view, body gray. Two rounded white marks located in between the eyes, slightly posterior to nares. Tail with white streak along top of caudal musculature edged by two tan-gray stripes. Snout translucent. In lateral view, flanks gray. Fins translucent; dorsal and ventral fins with predominantly gray blotches scattered irregularly over dorsal and ventral fins. Caudal muscles uniformly white, flecked with gray. Dorsal stripes on caudal musculature are well defined, becoming progressively thinner towards the posterior end of the tail. Iris black. Spiracle translucent. Venter translucent (gut visible through skin); oral apparatus and base of caudal musculature white.

Color in life. In dorsal view, body and caudal musculature brown with a heavy golden suffusion. Top of dorsal musculature with a golden streak edged by brown stripes. Snout golden yellow. In lateral view, flanks brown with heavy golden suffusion. Fins yellow; tail musculature cream flecked with brown over the proximal two-thirds. Spiracle translucent flecked with golden dots of cromatophores. Venter translucent, pigmented by widely scattered golden melanophores, pectoral area red. Oral apparatus translucent. Iris black, rounded by two concentric golden reticulations.

Variation. Variation of ten meristic characters of tadpoles in Stage 25 is shown in Table 8. Tadpoles varied in total length from 32.3– 42.1; body length ranged from 10.2–14.2; tail length ranged from 21.7– 28.8. LTRF varied from 7(6–7)/8(1) to 7(6–7)/9(1); 40.0% of tadpoles showed incomplete oral apparatus, partially or entirely depleted of denticles, having variable number of labial papillae, and abraded tooth rows. The individual depicted on Figure 15E show two rows of papillae (instead of only one) at the distal left side of the posterior margin of the oral disc. Absence of keratinized teeth may be due to chytrid infection. Lateral-line system was not conspicuous in all individuals examined. Arrangement of ventral bodyline may be symmetrical or asymmetrical on the left flank of body where the spiracle is located. Overall color patterns, as well as arrangement and coloration of marks in fins varied among individuals in Fig. 24. Individuals of about the same size and Gosner stage show variation in dorsal and lateral color patterns from light brown ( Fig. 24A) to dark brown ( Fig. 24B). Pattern of marks on dorsal and ventral fins and caudal musculature varies from stippling ( Fig. 24A) to brown blotches ( Fig. 24B). Color patterns varied through ontogenetic development ( Fig. 25). The most noticeable features are the appearance of numerous spots on body, caudal fins and musculature, and a progressively pronounced brown suffusion. At Stage 41 ( Fig. 25B), an overall brown-gray coloration appears at dorsum and flanks of body with numerous black spots irregularly distributed at flanks. Anterior and posterior limbs are light brown. By Stage 42 ( Fig. 25C) a cream calcar is visible in the hind limbs. At Stage 45, flanks have more numerous black spots. Juveniles at latter stages show a brown dorsum with minute stippling mixed with black dots. Iris is cream in juveniles. One individual showed a middorsal cream stripe ( Fig. 25F).