Resumen

BARRIENTOS, Zaidett. Life history of the terrestrial snail Ovachlamys fulgens (Stylommatophora: Helicarionidae) under laboratory conditions. Rev. biol. trop [online]. 1998, vol.46, n.2, pp.285-296. ISSN 0034-7744.

Aspects of the biology of Ovachlamys fulgens (Gude 1900) were studied under laboratory conditions in Costa Rica for 16 months. The lifespan of this snail in captivity was about nine months (N= 22) and it could lay viable eggs without mating (N= 40). Oviposition began 42 days after eclosion, when shell diameter averaged 5.12 mm (N= 24). Clutches had about three eggs each (N= 252). One clutch was laid daily over periods of one to four days, with intervals of one to two days (N= 252). Age, shell diameter and clutch size were positively correlated (N= 1097) as were shell diameter of adult, egg diameter and shell diameter of the offspring (N= 136). Oviposition took place between crevices of the soil and in the leaf litter. Eggs had a soft egg shell and were laid semi-hydrated; they hydrated by absorbing water from the surroundings (N= 21). This strategy may be the evolutionary compromise between a mechanical limitation (small body size) and the advantage of producing bigger eggs with a larger amount of nutritive substances. At room temperature (mean = 21°C) egg eclosion took place in 14 days (N= 67) and in 11 days at 28 °C (N= 32). Egg shell dissolution was not uniform (N= 107), it began in a local area, that usually was the side on which it rested (N= 46). The fact that eggs with and without an embryo (N= 5) underwent the same process of egg shell's calcium dissolution suggested a chemical mechanism. Embryos did not induce the process, but accelerated it. Egg viability was decreased by the tannins of the surrounding leaf litter (N= 50). Juveniles could feed on leaves of Persea americana (Lauraceae) (N= 299).

Palabras clave : Land snail; life cycle; reproduction; egg development; oviposition; egg viability; egg shell dissolution; Helicarionidae; Ovachlamys; Costa Rica.