IHEM   20887
INSTITUTO DE HISTOLOGIA Y EMBRIOLOGIA DE MENDOZA DR. MARIO H. BURGOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Rudimentary male copulatory organs in females of an ampullariid snail.
Autor/es:
GIRAUD BILLOUD, MAXIMILIANO.; VEGA, ISRAEL A.; CARRIÓN, ADRIANA.; CASTRO-VAZQUEZ, ALFREDO.
Lugar:
San Luis, Argentina
Reunión:
Congreso; XXVII Reunión Anual de la Sociedad de Biología de Cuyo; 2009
Institución organizadora:
Sociedad de Biología de Cuyo
Resumen:
“Imposex” is the development of male sexual characters in female invertebrates after exposure to endocrine disruptors (EDs, environmental pollutants which interferes with endocrine functions). Imposex occurs in many neogastropod snail species, in which normal females are generally assumed to be lacking any male-like organs. However, the normal occurrence of rudimentary male copulatory organs in Pomacea canaliculata (an architaenioglossan snail) has been reported as a curiosity, from time to time, since the XIXth. century, i.e. much before any significant spilling of EDs had occurred. Also, we have described the development of those organs from hatching to maturity (50 days old) in cultured snails unexposed to known EDs, and have found that the copulatory organs are present in all females. We here report that those organs continue to grow in later life. Indeed, the female penis lengthens from 0.77±0.44 mm (mean±SEM, n=15, at 4 months old), to 1.40 ±0.70 (5 months old) and finally to 6.23±1.07 mm (6 months old); significant differences (ANOVA, Tukey’s test: 4 vs 6 months, and 5 vs 6 months). The “vas deferens sequence index” (VDSI, a usual measure of “imposex”) also increased from 1.7 (4 months old), to 1.9 (5 months old) and to 2.8 (6 months old). It is concluded that the animal´s age is a significant parameter (even though not amenable to field studies) which has to be considered when assessing the potential effects of EDs on P. canaliculata.