Cayey Robber Frog

Eleutherodactylus jasperi is a relatively small, possibly extinct, frog with adults reaching 22.4 mm in snout-vent length. Males and females are the same size. This frog has a bluntly rounded snout that is almost truncate when viewed from above, and an indistinct canthus rostralis. The tympanum is indistinct. Prevomerine teeth are absent. The digits have only vestigial webbing and are moderately long with rounded terminal discs. The subarticular tubercles are prominent, but the metatarsal tubercles are absent. The palmar tubercles are small but distinct. The dorsum is shagreened (with small bumps), with well-developed subdermal glands on the flanks and the posterior surfaces of the thighs. The venter is areolate in texture (Drewry and Jones 1976). Eleutherodactylus jasperi can be distinguished from other Eleutherodactylus in Puerto Rico by its golden ground color without dorsal patterning, by its translucent venter without dark pigmentation, and by the lack of prevomerine teeth (Drewry and Jones 1976). In life, dorsally, the color is a uniform olive-gold to yellow-gold. If the frog is disturbed, the color may pale. Ventrally, the coloration is pale yellow except for transparent abdominal skin. Few to no melanophores appear to be present on the ventral surfaces of the head and abdomen. The iris is pale gray with black speckles (Drewry and Jones 1976).The species authority is: Drewry, G. E., Jones, K. L. (1976). ''A new ovoviviparous frog, Eleutherodactylus jasperi (Amphibia, Anura, Leptodactylidae) from Puerto Rico.'' Journal of Herpetology, 10(3), 161-165.The chromosome number of Eleutherodactylus jasperi is 2n = 26 (Drewry and Jones,1976). Eleutherodactylus jasperi was named for one of the collectors of the holotype, Dr. Jasper J. Loftus-Hills, of New Victoria, Australia. Dr. Loftus-Hills passed away in 1974 at the age of 28 from an automobile accident (Drewry and Jones 1976).

The Golden Coquí occurs at an elevation of 650 - 850 m in Sierra de Cayey, in southern Puerto Rico. It inhabits arboreal bromeliads in subhumid forest, and is restricted to a small area (10 km in radius) with dense bromeliad growth. Although the bromeliad growth seems to be dependent on heavy dew from orographic uplift of air passing over the mountain range, the habitat itself is actually somewhat xeric and prone to fire damage (Drewry and Jones 1976).

This is a nocturnal species, and found only in bromeliads of the genera Guzmania, Hohenbergia, and Vriesia. Eleutherodactylus jasperi tend to occur mainly in clusters of bromeliads rather than isolated plants, implying that this species prefers to disperse over short distances. Inhabited bromeliad clusters were found on the ground, on trees, on large boulders, and on cliff sides (Drewry and Jones 1976). During the mating season, males give off a call that sounds like "tuit-tuit-tuit-tuit" (Duellman 2003). A single call sequence lasts for between ten seconds and two minutes. The first call of the sequence has one to two notes, with successive calls increasing up to a maximum of four to six notes, and maintaining at that maximum number until the end of the call sequence. Notes have approximately the same duration. They consist of relatively pure tones of about 5 kHz. The advertisement calls seem to be the same as territorial calls, as there was no difference between calls made by solitary calling males and those given by multiple males placed together in a single collecting bag. Males placed together in a bag alternately called and engaged in biting each other (Drewry and Jones 1976). Call sequences are somewhat synchronized between neighboring males. Eleutherodactylus jasperi is more difficult to distinguish in a multi-species chorus, as it makes somewhat softer calls than other frog species in the same habitat. However, it calls throughout the night, unlike other species which subside between midnight and dawn (Drewry and Jones 1976). Gravid females have been collected between April and August, containing three to six mature eggs (Drewry and Jones 1976). Mature eggs are large, 3.3 to 5 mm in diameter (Drewry and Jones 1976, Wake 1978). Once fertilized, eggs are retained within a chamber, essentially a uterus, formed of fused portions of the oviducts (Wake 1978). The embryos take about a month to develop (Drewry and Jones 1976). As is characteristic of other species with direct development, E. jasperi embryos have poorly developed mouthparts, lacking denticles and adhesive organs. The larval spiracle and external gills are present but transitory, and rates of development are also modified (Wake 1978). Approximately thirty-three days after amplexus, three to five tiny, fully metamorphosed froglets are born (Drewry and Jones 1976). The froglets of this species have a small egg tooth and a large, thin, highly vascularized fan-like tail. The tail may function in intra-oviducal gaseous exchange. The source of nutrition for developing embryos appears to be egg yolk and not maternal secretions, as there is no evidence of a placenta or maternal secretions, and unresorbed yolk is still present in froglets after birth (Wake 1978). Thus E. jasperi is classified as ovoviviparous, and not viviparous. Eleutherodactylus jasperi is the only confirmed live-bearing species in the genus Eleutherodactylus and family Eleutherodactylidae (Wake 1978), however, the possibly extinct E. orcutti may have also been live-bearing (Hedges 2010). Because of its ovoviviparous reproductive mode E. jasperi is presumed to have internal fertilization (Wake 1978). Internal fertilization has also been reported in Eleutherodactylus coqui, which is oviparous (Townsend et al. 1981). Females may reproduce more than once a year, since dissected females had two visible size classes of eggs within the ovaries (Wake 1978). Although gravid females were collected between April and August, Wake (1978) noted that year-round collections had not been done. Thus it is not known whether reproduction in this species is seasonal or if it occurs throughout the year. Subadults have been found in the same plant with females, implying that dispersal does not occur until the juvenile is older (Drewry and Jones 1976). This species preys mostly on small arthropods (Duellman 2003).

Eleutherodactylus jasperi, the Golden Coqui, is presumed to be extinct. It has not been seen since 1981, despite searches since then (Moreno 1991, Burrowes et al. 2004). The likely causes of this species extinction include climate change, disease caused by chytrid fungus (Batrachochytrium dendrobatidis), introduced predators, limited distribution, habitat destruction, forest fragmentation, and high habitat specialization (Angulo 2010).The species range includes a well protected area, the Carite Forest Reserve, which may act as a refugia for the species. Surveys are need to search for the frog, however given the risk of chytridiomycosis, if the species it is found, a captive breeding may need to be established (Angulo 2010).

The golden coquí (Eleutherodactylus jasperi) is a rare species of frog endemic to Puerto Rico.