Morphological changes in the reproductive system of females<i>Acanthina monodon</i>(Pallas, 1774) (Gastropoda: Muricidae) affected by imposex from the coast of central Chile

Abstract

Summary "Imposex" (imposed sex) is an abnormal anatomical condition of female gastropods in which they develop male sex organs. Imposex is induced by organotin pollutants from antifouling paints and was detected in Chilean gastropods for the first time in 1999. This study examined morphological changes associated with imposex in populations of the marine snail Acanthina monodon on the Chilean coast. Specimens were collected from two differentially polluted sites (Las Cruces and Matanzas) outside the active port of San Antonio, Chile. Sex was anatomically determined by the presence of a normal penis in the male and the presence of the capsule gland in the female. Histological study of the reproductive system in females with imposex was conducted by observing longitudinal and cross sections of individual organs and whole specimens; 54.2% of all females showed evidence of imposex, with a maximum value of 94.7% at Las Cruces, and a minimum value of 37.6% at Matanzas. Imposex-affected females demonstrated involution in some reproductive organs and masculinization symptoms included the presence of a pseudopenis, which was significantly shorter than the normal penis in males. In severe cases of imposex, the normal tissue of the capsule gland regresses. Key words: Acanthina monodon reproductive systemimposexTBT pollutionChile littoral