Description

Phyllobates vittatus is a small frog, with males reaching 26 mm in SVL and females measuring up to 31 mm in SVL (Leenders 2001). The skin on the dorsal surfaces is slightly granular or shagreened, with tiny bumps (Silverstone, 1976). Skin is also slightly granular on the belly and the ventral surfaces of the thighs, but smooth on the rest of the ventral surfaces (Silverstone 1976). Both maxillary and premaxillary teeth are present (Silverstone 1976). Finger I is longer than finger II. The toes lack webbing (Silverstone 1976).

The back and head are generally solid black, although in some individuals there is an interrupted yellow median dorsal stripe. A wide gold, red-orange or orange dorsolateral stripe runs from each side of the snout over the eyes and back, down to the base of the thigh. A single white line projects from the shoulder, at the insertion of the upper arm, and runs along the lip to just under the eye. The dorsal surfaces of the limbs show dense blue-green speckling on a black background, while the venter and ventral surfaces of the limbs are marbled with white or pale blue-green on black. Each flank has a white or pale blue-green stripe running ventrolaterally (Silverstone 1976).

The tadpole coloration is uniformly dark brown on the dorsal side of the body, tail, and fins, with the venter being a lighter brown (Savage 2002). Tadpoles develop the paired bright-orange stripes characteristic of the adults about two months after hatching, near the time of metamorphosis (Leenders 2001). Larvae reach 30 mm in total length (Savage 2002). The body is depressed (Savage 2002). Nostrils and eyes are located dorsally, while the mouth is ventral (Savage 2002). The oral disc is small and emarginate, with serrated beaks and 2/3 rows of denticles; the row of denticles just above the beaks shows a gap in the middle (Savage 2002). Papillae are present both above and below the mouth but those above the mouth are not continuous (Savage 2002).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Costa Rica

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (1 records).

The Golfo Dulce Poison-Dart Frog is endemic to Costa Rica, inhabiting the wet forests and lowlands of the Golfo Dulce region in the southwestern part of Costa Rica (Silverstone 1976; Leenders 2001). It has also been reported to occur near Dominical, in the province of Puntarentas, Costa Rica (Ryan 2002). This species is found between 20 to 550 meters in elevation (Savage 2002). It prefers the leaf litter of forested valleys with streams (Leenders 2001).

Life History, Abundance, Activity, and Special Behaviors
Phyllobates vittatus is a diurnal and terrestrial species (Savage 2002). This species is reasonably common (Savage 2002). It is shy and will hide in rock crevices or holes between tree roots when approached (Leenders 2001). Locomotion is by walking interspersed with rapid hops (Savage 2002). Males are thought not to be territorial (Savage 2002), but intraspecific aggressive behavior has been reported in captivity with one frog jumping on the back of the other and pressing down (Polder 1976). The advertisement call, which males use to try to attract females to oviposition sites, consists of a low-pitched, raspy trill lasting two to six seconds (Savage 2002). There is also a second type of call, produced during active pair courtship (Travis, pers. comm., cited in Silverstone 1976). The courtship call consists of a series of two to five high-pitched chirps dropping successively in pitch, followed by another series after a pause (Silverstone 1976; Savage 2002). This call is used when the female is near or pursuing the male (Silverstone 1976).

In captivity the breeding season lasts three months (Savage 2002). The male chooses the egg deposition site (in captivity, preferentially on a bromeliad leaf, occasionally on a fern leaf, and rarely on the terrarium floor) and calls to attract a female (Silverstone 1976). Courtship occurs before oviposition, with courtship behavior lasting from one to seven days prior, and including calling, circling, shaking of the limbs, jumping on and sitting on the courting partner (either sex), and pursuit of the male by the female (Silverstone 1976). There is no amplexus in this species; the sexes have been reported to place vents in contact (Savage 2002).

During the breeding season the female lays clutches every week or two (Savage 2002). Each clutch in captivity contains 7 to 21 eggs, usually deposited on leaves above the ground (Silverstone 1976). This species has parental care, with the male parent attending the clutch up to three times a day and engaging in hydric brooding (emptying the bladder on the eggs to keep them moist) (Savage 2002). In captivity, it has been observed that the first two visits occur on the day of oviposition, once immediately after oviposition for 5-65 minutes (to fertilized the eggs), and after an interval of half an hour, the male sits on the eggs again for 60-90 minutes (Travis, pers. comm., cited in Silverstone 1976). The male does not visit over the next seven days. In the second week, the male visits the eggs once a day for five minutes or so, and in the third week, he visits the eggs 1-3x a day.

A few days to a week after the eggs hatch (which occurs in thirteen to seventeen days), the male will allow some or all of his tadpoles to crawl up on his back (Savage 2002). In captivity, the male has been observed to sit on the egg jelly and stamp his feet, after which the larvae wriggle onto his back (Polder 1976). Travis (pers. comm. cited in Silverstone 1976) also reported that the male shook his posterior in short bursts of four to five shakes to stimulate the larvae to crawl onto his back, with the process of tadpole uptake lasting about ten minutes. He then transports from one to thirteen larvae at a time, carrying them for 1-2 days, to a water source; in the wild, this consists of a small forest-floor puddle, or water in a fallen palm frond, or a tree-hole (Starrett, pers. comm., cited in Silverstone 1976; Travis, pers. comm., cited in Silverstone 1976; Savage 2002). Conspecific tadpoles are not aggressive towards siblings (Polder 1976).

In about forty-five days the larvae metamorphose into small froglets of about 13 mm (Savage 2002). Froglets are sexually mature at about ten months (Savage 2002). The adult diet consists primarily of arthropods, particularly ants and occasionally coleopterans, dipterans, and collembolans (Savage 2002; Silverstone 1976).

Trends and Threats
Habitat fragmentation from forest clearing and tree plantations seem to be the major threats. Water contamination from mining and collection of adults for the pet trade are also reasons for population decline (IUCN 2006).

Relation to Humans
Golfo Dulce Poison-Dart Frogs are used as pets; they are easy to breed, easy to keep, and are very colorful. Captive-born and bred dendrobatid frogs lack toxicity (Myers et al. 1978; Daly et al. 1980; Daly et al. 1992). However, batrachotoxins persist in wild-caught Phyllobates even when they are maintained in captivity (Daly et al. 1978).

Possible reasons for amphibian decline

Intensified agriculture or grazing
Mining
Habitat fragmentation
Intentional mortality (over-harvesting, pet trade or collecting)

Comments
Phyllobates vittatus secretes batrachotoxins, which are lipophilic alkaloids that act as extremely potent cardiotoxins (Myers et al. 1978). Batrachotoxins bind to voltage-gated sodium channels and force them to remain open, with the resulting influx of sodium ions causing irreversible depolarization of nerve and muscle cells. This in turn leads to arrhythmias, fibrillation and eventually cardiac failure (Albuquerque and Daly 1977). These compounds are known to be secreted in high quantitities in several South American Phyllobates (P. terribilis, P. bicolor and P. aurotaenia), and in low quantities in the Central American Phyllobates vittatus and P. lugubris (Myers et al. 1978). The South American Phyllobates have all been documented to be used to poison darts, unlike the Central American Phyllobates (P. vittatus and P. lugubris), which are far less toxic (Myers et al. 1978).

Like other dendrobatid frogs, Phyllobates species are thought to acquire their toxins from dietary sources (Daly et al. 1980; Daly et al. 1992; Dumbacher et al. 2004). One source for batrachotoxin may be melyrid beetles, which have been shown to contain high levels of this toxin (Dumbacher et al. 2004). Melyrid beetles may also be the dietary source for batrachotoxin in the toxic New Guinea passerine bird genera Pitohui and Ifrita (Dumbacher et al. 2004).

Despite the fact that P. vittatus contains small quantities of batrachotoxins when compared to the far more toxic South American Phyllobates terribilis, P. bicolor, and P.aurotaenia, Myers et al. (1978) report that tasting a wild-caught P. vittatus resulted in a "lingering, almost numb sensation on the tongue, followed by a disagreeable tightening sensation in the throat". A captive snake (Rhadinaea taeniata aemula, from Mexico, which presumably had never encountered frogs with batrachotoxins) exhibited considerable distress for some hours after seizing and releasing a P. vittatus (Myers et al. 1978). Initially the snake gaped and attempted to rub its mouth on the substrate; half an hour later the snake was also slowly contorting its body, as well as expanding its thorax, after which it laid motionless for four hours (Myers et al. 1978). Recovery was complete by the next morning (Myers et al. 1978).

A Spanish-language species account can be found at the website of Instituto Nacional de Biodiversidad (INBio).

References

Albuquerque, E. X. and Daly, J. W. (1977). ''Batrachotoxin, a selective probe for channels modulating sodium conductances in electrogenic membranes.'' The Specificity and Action of Animal, Bacterial and Plant Toxins. Receptors and Recognition, Series B., Volume 1 P. Cuatrecasas, eds., Chapman and Hall, London, 297-338.

Daly, J. W., Myers, C. W., Warnick, J. E., and Albuquerque, E. X. (1980). ''Levels of batrachotoxin and lack of sensitivity to its action in poison-dart frogs (Phyllobates).'' Science, 208, 1383-1385.

Daly, J.W., Secunda, S.I., Garraffo, H.M., Spande, T.F., Wisnieski, A., Nishihara, C., and Cover, J.F. (1992). ''Variability in alkaloid profiles in neotropical poison dart frogs (Dendrobatidae): genetic versus environmental determinants.'' Toxicon, 30, 887-898.

Dumbacher, J.P., Wako, A., Derrickson, S.R., Samuelson, A., Spande, T.F., and Daly, J.W (2004). ''Melyrid beetles (Choresine): a putative source for the batrachotoxin alkaloids found in poison-dart frogs and toxic passerine birds.'' Proceedings of the National Academy of Sciences of the United States of America, 101, 15857–15860.

IUCN, Conservation International, and NatureServe. 2006. Global Amphibian Assessment: Phyllobates vittatus. <www.globalamphibians.org>. Accessed on 5 May 2008.

Leenders, T. (2001). A Guide to Amphibians And Reptiles of Costa Rica. Zona Tropical, Miami.

Myers, C. W., Daly, J. W., and Malkin, B. (1978). ''A dangerously toxic new frog (Phyllobates) used by Emberá Indians of Western Colombia, with discussion of blowgun fabrication and dart poisoning.'' Bulletin of the American Museum of Natural History, 161, 307-366.

Polder, W. N. (1976). ''Dendrobates, Phyllobates en Colostethus.'' Het Aquarium, 45, 122-128.

Ryan, M. (2002). ''Phyllobates vittatus (Golfodulcean poison dart frog).'' Herpetological Review, 33, 318.

Savage, J. M. (1968). ''The dendrobatid frogs of Central America.'' Copeia, 1968(4), 745-776.

Savage, J. M. (2002). The Amphibians and Reptiles of Costa Rica:a herpetofauna between two continents, between two seas. University of Chicago Press, Chicago, Illinois, USA and London.

Savage, J.M. (1976). A preliminary handlist of the herpetofauna of Costa Rica. Editorial de la Universidad de Costa Rica, San José.

Silverstone, P.A. (1976). ''A revision of the poison arrow frogs of the genus Phyllobates Bibron in Sagra (Family Dendrobatidae).'' Natural History Museum of Los Angeles County Science Bulletin, 27, 1-53.

Weygoldt, P. (1987). ''Evolution of parental care in dart poison frogs (Amphibia: Anura: Dendrobatidae).'' Zeitschrift für Zoologische Systematik und Evolutions Forschung, 25(1), 51-67.

Zimmermann, H. (1982). ''Durch Nachzucht erhalten: Blattsteigerfrosche Phyllobates vittatus and P. lugubris.'' Aquarien Magazin, 1982(2), 109-112.

Species Account Citation: AmphibiaWeb 2009 Phyllobates vittatus: Golfo Dulce Poison-Dart Frog <https://amphibiaweb.org/species/1708> University of California, Berkeley, CA, USA. Accessed Nov 12, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 12 Nov 2024.

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