Jeff Mette
Many more Dendrobatids are described than kept in the terrarium, but the case of one small frog going unnoticed in a well-explored area is interesting. The author and a friend, Tommy Ostrowski of Germany, collected data and images during a month-long stay in the Bocas del Toro archipelago. Dendrobates claudiae (Jungfer et al, 2000) is a small frog (12-15mm) from the minutus group found in Bocas del Toro archipelago and nearby mainland in Departamento Bocas del Toro, Panama. The type locality is from a mainland peninsula west of Isla Loma Partida (Split Hill) and southeast of the small town Cerro Brujo, (82° 11' W/09° 09' N). Here D. claudiae is found sympatric with several other Dendrobatids, including D. auratus, D. pumilio (dark blue), Phyllobates lugubris, and two species of Colostethus (C. talamancae, C. flotator). |
The author also found D. claudiae on several of the larger islands: Isla Bastimentos, Isla Popa, Isla Col n, and Cayo de Agua. There is slight morphological variation between these populations, with that of the Isla Col n frogs being the most extreme. This population has a bright orange and white dorsal pattern and is slightly larger than the other populations, which are for the most part like the nominate form.
Dendrobates claudiae lives in shady regions on forest floor leaf litter and Heliconia stands, and is regularly associated with steep hillsides. Populations are dense, and favourable sites often contain 2 or 3 animals per square meter (Ostrowski, in press). The male produces a short, buzzing call during most of the day, but takes a siesta at lunchtime. 1-4 eggs are laid in the leaf litter and then tended by the male. Likely deposition sites for the larvae include ground level phytotelmata such as low tree holes or Dieffenbachia as well as small pools formed in leaves on the forest floor. In the terrarium, larvae should be raised individually to avoid cannibalism. The adults take only springtails as Drosophila are too large to elicit a feeding response (Ostrowski, in press).
Two interesting points came up while hunting D. claudiae in Panamð last winter.
Firstly, why was such a common frog, living in an accessible place, not described until recently? One idea that seems likely to the author is that D. claudiae, being superficially similar to Phyllobates lugubris in both dorsal and ventral pattern, was and still is mistaken for juveniles of the latter species. Because of this similarity, a brief guide for field identification has been prepared.
Specimens shown to exhibit a combination these morphological traits can be labelled Dendrobates claudiae:
- A ventral pattern of blue maculation on a black base extending from chin to vent and also the underside of the legs. This same pattern covers only the area from neck to vent in P. lugubris, leaving a solid black throat.
- Dorso-lateral stripes coming to a labial directed point, often forming a vertical stripe, on the tip of the snout. P. lugubris invariably shows a rounded union of the dorso-lateral stripes across the top of the snout.
- A plain, brown colouration, without obvious markings, on the outer surfaces of the limbs. P. lugubris typically shows a pattern of brown (also yellow or light green) maculation on a black base on the limbs.
- A short stripe, parallel to the dorsal markings, through the centre of the flank. Absent in P. lugubris, however the ventral markings often extend across the flanks forming an irregular pattern.
Of course size a size of more than 15mm can eliminate D. claudiae from consideration, as P. lugubris is larger, about 18-25mm.
Secondly, do some D. claudiae populations employ mimicry? The similarity to P. lugubris has already been established. The idea was suggested by Ostrowski while comparing consistencies in variation in both species between the Loma Partida mainland site and the Isla Col n site. In both species, visual morphology (colour, pattern) is ‚typicalç at the Loma Partida mainland site, with each species resembling other nearby populations (such as Isla Bastimentos) of their species. The exception is the Isla Col n site, where both species display unique orange coloration. Another explanation is that some environmental variable (such as diet) influences the coloration of both species on Isla Col n.
The D. minutus group is very under-represented in American terrariums, if anyone is keeping them at all. They are no doubt very interesting captives, and we could benefit from this type of close study of their habits. Hopefully this article will be useful for anyone planning either to do some frog tourism in the Bocas del Toro area or breed these frogs.
Images:
Fig. 1 - Dendrobates claudiae from Isla Colón site.
Fig. 2 - Phyllobates lugubris from Isla Colón site.
Fig. 3 - Dendrobates claudiae from the Loma Partida mainland site.
Fig. 4 - Phyllobates lugubris from the Loma Partida mainland site.
Fig. 5 - Dendrobates claudiae from the Isla Bastimentos site.
Fig. 6 - Phyllobates lugubris from the Isla Bastimentos site.
Fig. 7 - D. claudiae habitat from the Loma Partida mainland site (L) and the
Isla Colón site (R).
