Description
Description:
The snout-vent length of the adult tree frog Flectonotus fitzgeraldi is 19-24 mm. The dorsal skin is smooth and the scapular region usually lacks diagonal markings. The head is as long as it is wide. The snout is rounded and the small nasals are widely separated. Upper lips have no spots and no suborbital bar is present. The eyes, separated by an interorbital bar, have diameters of 1.9 to 3.0 mm. The tympanum is smaller than the eye. A brood pouch along the dorsum has a middorsal opening, with lateral folds of skin making up the sides. These folds stick together to enclose the pouch during egg brooding. More often than not, the dorsal thighs are barred, while bars are never present on the anterior and posterior thighs. The tarsus is smooth as opposed to tuberculate, and tibia length in males ranges from 8.8-12.2 mm. Fourth toe webbing is predominately penultimate, although it is sometimes half penultimate and antepenultimate. Fifth toe webbing is mainly distal but can be half distal and penultimate (Duellman and Gray 1983).

Coloration: The dorsum is yellowish brown, while the posterior surfaces are pale brown. The venter is unpigmented, but speckled with white on the chest. Coloration of the iris is varied from a dull pale bronze to golden, and a reddish brown streak exists on either side of the pupil (Duellman and Gray 1983).

Variation: Dorsal patterns are present in three-fourths of individuals. However there is no pattern post-sacrum. The faint dorsal markings of two preserved specimens from Trinidad showed more definite brown markings after preservation (Duellman and Gray 1983).

Tadpole Morphology: Tadpoles are less than 20 mm in length with muscular tails. Their small mouths lack denticles and are oriented anteroventrally. Their snouts are dull, with reduced, weakly cornified beaks (Duellman and Gray 1983).

Diagnosis: The closest known relative of F. fitzgeraldi is F. pygmaeus. F. fitzgeraldi is distinguishable from F. pygmaeus by its smaller size. Foot length in both males and females is a significant means for separating these species. In F. fitzgeraldi, foot length is 5.9-7.9 mm and 7.2-9.6 mm in males and females respectively. In F. pygmaeus foot length is 8.4-11.1 mm in males and 10.6-12.5 mm in females. In addition to foot length, internarial distance, tibia length, eye-to-nostril distance, interorbital distance, nostril-jaw distance, head length, and eye diameter may be useful in distinguishing species among male individuals. Internarial distance, tibia length, eye-to-nostril distance, nostril-jaw distance, head width, and thumb length may be useful in distinguishing species among female individuals (Duellman and Gray 1983).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Trinidad and Tobago, Venezuela

View distribution map in BerkeleyMapper.

F. fitzgeraldi occurs in humid forests of Trinidad, Tobago and the Peninsula de Paria, Venezuela. It has been found inhabiting bushes at night and on leaf litter during the day. On Trinidad, this tree frog exists from sea level to 950 m in elevation and is most prevalent in the Central and Northern ranges. It is widely distributed on Tobago and is also found in the mountains of the Peninsula de Paria, Venezuela (Duellman and Gray 1983; Stuart et al. 2008).

Life History, Abundance, Activity, and Special Behaviors

F. fitzgeraldi is a nocturnal, arboreal tree frog, who carries its eggs on its back. The population status is undetermined (Stuart et al. 2008).

Throughout the year on Trinidad, F. fitzgeraldi call for about an hour after sunset. Their calls are brief, biphasic notes that sound like crickets chirping (Duellman and Gray 1983).

Mating behavior is unknown, but members of Flectonotus are known to have long reproductive seasons and if females were to mate within a week or two after egg deposit, they could theoretically have five broods per season. A female will produce 3-4 embryos, 3.3 on average, with a mean diameter of 3.6 mm. Eggs will brood in her dorsal pouch until developmental stages 39-41. They are then released into bromeliads and aroid leaf bases, where they continue to develop without feeding. Larval development takes place in only 5 days and during this time, only yolk is consumed (Duellman and Gray 1983).

Trends and Threats

F. fitzgeraldi populations are declining, perhaps due to agricultural activities, deforestation due to timber harvest, and also road construction on Tobago (Stuart et al. 2008).

Some populations are conserved within Parque Nacional Peninsula de Paria in Venezuela and some inhabit protected rainforests in Tobago (Stuart et al. 2008).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Urbanization

Comments

F. fitzgeraldi was first described by Parker (1934) (Frost 2011).

The primitive number of chromosomes in hylid frogs is 26, however F. fitzgeraldi has 28 (Duellman and Gray 1983).

References

Duellman, W. E., and Gray, P. (1983). "Developmental biology and systematics of the egg-brooding hylid frogs, genera Flectonotus and Fritziana." Herpetologica, 39(4), 333-359.

Frost, D. (2011). Amphibian Species of the World: an Online Reference. Version 5.5.

Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, Spain; Gland, Switzerland; and Arlington, Virginia, USA.

Species Account Citation: AmphibiaWeb 2012 Flectonotus fitzgeraldi: Dwarf Marsupial Frog <https://amphibiaweb.org/species/1358> University of California, Berkeley, CA, USA. Accessed Dec 2, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 2 Dec 2024.

AmphibiaWeb's policy on data use.