Sphaerodactylus difficilis

(BARBOUR, 1914)

Distribution:

Sphaerodactylus difficilis has seven subspecies found on Hispaniola and its offshore islands. The nominate Sphaerodactylus difficilis difficilis inhabits the north central part of the Dominican Republic. The north-west borders are the area of distribution for Sphaerodactylus difficilis typhlopous. The occurrence of this subspecies extends inland to the provinces of Santiago and Santiago Rodriguez. In the extreme north-east of the Dominican Republic Sphaerodactylus difficilis peratus occurs. The central south and east of the Dominican Republic is populated by Sphaerodactylus difficilis diolenius. Only on the east coast in the peninsula of Barahona is Sphaerodactylus difficilis anthracomus found. Two other subspecies live in the Haitian part of Hispaniola, Sphaerodactylus difficilis lycauges which inhabits the entire north of the country and Sphaerodactylus difficilis euopter. The latter subspecies occurs only on Île de la Tortue (Schwartz & Henderson, 1991).

Description:

Below the subspecies Sphaerodactylus difficilis diolenius is described.
Sphaerodactylus difficilis diolenius has a maximum total length of 6 centimeters, it is from the mid-size members of the genus. Dorsally the males have beige coloring from head to tail. Dark spots can be seen along the whole body. The head differs from individual per individual with varying shades of yellow. Sometimes at the back of the neck two white eye spots can be seen, which are remnants from juvenile coloration. Anteriorly they are beige colored with unevenly distributed dark scales. The underside of the head is yellow. The males have a sexual characteristic between the hind legs in the form of shiny scales (Escutcheon), they also have a slightly thickened tail base as a result of their hemipenis pockets.
Females are colored differently from males. Dorsally they are colored beige with dark lines which more or less intensely run from the tip of the snout to the hind legs. The tail is yellowish to red in color. On the neck are two distinct white "eye spots" which are bordered by black. Even at the rear of the legs and regular intervals, these eye spots can be seen, but they are much weaker. The females however lack the yellow coloring under their head, as well as the Escutcheon. Young animals show similar coloring and patterns as the females, but significantly have more contrast. They also have a white tail tip. From the age of four months, the males begin to color up and the white tail tip vanishes with age.

Habitat:

Sphaerodactylus difficilis is not particularly picky with their habitat. They can be found 2 meters up in trees or under stones. As a synanthropic species it can occasionally be found on walls or trash collections. A mass nesting site with about 30 mostly already hatched eggs can be found in a plastic bag covered by stones. Abandoned termite mounds are also used as nesting sites by Sphaerodactylus difficilis. Their choice for hiding spots and the eggs will always be a humid micro climate. Furthermore never more than a pair will be found together in hiding.

Husbandry and Breeding:

Sphaerodactylus difficilis does not have much difference in maintenance as other species of the genus. Due to their small size a pair can be raised problem free in a 20cm cube. A substrate based off sand with a slight mixture of humus in a ratio of 2:1 is recommended. Hiding places may be offered in the form of hollow stones and pieces of bark bark laid on the ground. With the latter also provided as flat as possible against the side and rear walls. To offer more privacy and protection to the animals, as well as a climbing area it is recommended that the walls of the terrarium be decorated with cork tiles. Natural vegetation consisting of small bromeliads and climbing plants help improve both the appearance and the micro climate of the terrarium. A small water bowl and a bowl of crushed up cuttlefish bone are a must in completing the setup.
The necessary humidity of 70% is achieved by a daily misting of the terrarium. Lighting and heat can be maintained by a compact fluorescent bulb rated for daylight color, the bulb should remain on for 12 hours a day. In winter the illumination period should be reduced to 10 hours a day, this helps to simulate a natural seasonal rhythm. The temperatures in the summer should be between 24-28°C (75-82°F) during the day and around 22°C (72°F) at night. In winter a daily temperature of 24°C (75°F) and 18°C (64°F) nightly should be maintained to allow the females to recover for the next breeding season.
Sphaerodactylus difficilis is fed twice weekly with appropriate sized insects. To prevent deficiencies a varied diet should be offered, further all food should be dusted with the appropriate supplements at every feeding.
The breeding of Sphaerodactylus difficilis is pretty straightforward, every 5 weeks the female will lay a single egg. In one breeding season alone a female will rarely lay more than 6 eggs. For better control the eggs should be removed from the terrarium and transferred to an incubator. The removal of the eggs is made simple by placing a small piece of bamboo or Japanese knotweed (Fallopia japonica) with small entry holes drilled at the sides in to the terrarium. The female will usually lay her egg inside these tubes. Following incubation temperatures of 26-28°C (79-82°F) the hatchling will emerge around 50 days with a total length of 26 millimeters. The rearing of the fast growing young can be achieved in converted 1.3 liter household containers. Rearing in small groups with other Sphaerodactylus of the same size is also possible. The rearing containers should consist of the same substrate as used for their parents, a small climbing plant and some bark. Lighting will provide the necessary warmth for the young. The container should be misted once daily and a small feeding of springtails and other isopods or micro crickets dusted with the appropriate supplements should be carried out once every two days. Under these conditions the young will grow up fast and sexually mature around 9 months. At an age of 5 months any animals showing signs of different sex or aggression, should be separated.
Sphaerodactylus difficilis is a very interesting terrarium inhabitant. This species is less shy than many other representatives of its kind and offers beautiful color variations between both sexes, as well as in the young. The small size of the animals could indeed pose problems for beginners with aspects to their small food requirements, otherwise Sphaerodactylus difficilis can be recommended without hesitation. Unfortunately they are still pretty rare in captivity, but appear to be desirable in any case!

Lierature:

- Schwartz, A. & Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies. University of Florida Press, Gainesville, 720 pp.
- Schwartz, A., & Thomas, R. (1983): The difficilis complex of Sphaerodactylus (Sauria, Gekkonidae) of Hispaniola. Bulletin of Carnegie Museum of Natural History, (22): 1 - 60.