Pacific giant glass frog

Centrolene geckoideum

TAXONOMY

Centrolene geckoideum Jiménez de la Espada, 1872, las riberas del rio Napo en el Ecuador.

OTHER COMMON NAMES

None known.

PHYSICAL CHARACTERISTICS

In this species the males are larger than the females. Males grow to 2.8–3.2 in (70.2–80.7 mm) and females to 2.4–2.9 in (60.7–72.9 mm) in snout-vent length. This largest centrolenid has relatively small eyes, heavily webbed digits, and large, rectangular-shaped toe pads. Males have large, muscular fore-arms and a long, sharply pointed bony spine on the humerus. The dorsum is lime green to dark forest green. The skin is tuberculate, with some small, scattered white flecks; in males the tubercles are finely spiculate. The bones are green.

DISTRIBUTION

This species ranges through Andean Ecuador and Colombia at elevations of 5,740–9,840 ft (1,750–3,000 m).

HABITAT

The habitat of the Pacific giant glass frog is upper montane cloud forest along swiftly flowing, shaded streams with numerous waterfalls.

BEHAVIOR

The Pacific giant glass frog is nocturnal and uses rock faces or leaves as diurnal retreats. At night, males call from splash zones behind waterfalls or on boulders in torrents. There have been no direct observations, but it is hypothesized that these frogs,

like some other centrolids, may be territorial, battling for prime calling and oviposition (egg-laying) sites. Adult males found in the field in Colombia had numerous scars on the face, head, and flanks, which may have been the result of battles between males using their sharp, bony humeral spines.

FEEDING ECOLOGY AND DIET

This large centrolid feeds on a variety of insects and also ingests frogs and fish.

REPRODUCTIVE BIOLOGY

Male Pacific giant glass frogs call at night throughout the year within splash zones behind waterfalls or on boulders in torrents. The call is a loud, high-pitched, trilled whistle, 155–373 milliseconds in duration and produced at intervals of 1.48–5.05 min, with emphasized frequencies of 3,468–4,187 Hz. The calls lack consistent amplitude modulation; this may be related to the din of the rushing water, which would obliterate any subtle characteristics in the calls. Tadpoles are elongate and slender with low caudal fins and eyes positioned dorsally. The oral disc has thin jaw sheaths.

CONSERVATION STATUS

Not threatened.

SIGNIFICANCE TO HUMANS

None known.