Desarrollo morfológico e histológico del sistema reproductor de Pomacea patula catemacensis (Baker 1922) (Mollusca, Caenogastropoda: Ampullariidae)

Abstract

The "apple snail" Pomacea patula catemacensis is an edible freshwater mollusc, endemic to the Catemaco Lake in Veracruz, Mexico. During the past few years, the natural populations of this species have been depleted mainly by uncontrolled fishery, and because of environmental degradation and pollution by pesticides and detergents. In the present study, we carried out the histological and morphological characterization of the reproductive system of P. patula catemacensis under laboratory conditions. We found that the reproductive development of this snail depended more on the size than on the age the animals, and identified four development main stages, both for males and females. The main stages and their mean lengths (± confidence interval at 95%) were (1) immature or not differenced (from 0.72 to 7 mm), (2) early maturation (from 18.95 ± 1.96 mm), (3) intermediate maturation (from 29.29 ± 4.9 mm), and (4) full maturity (from 35.89 ± 3.92 mm). This species is oviparous, both sexes are separated, and fertilization is internal. Albumin and calcium carbonate secretion in females are performed through the albumin gland, a trait that distinguishes this species from others, such as P. paludosa and P. canaliculata. The stage of development can be identified by means of using anatomical traits, such as the albumin gland (in the case of females), or the intromittent organ (in males).