A comparative survey of imposex in northeast Pacific neogastropods (Prosobranchia) related to tributyltin contamination, and choice of a suitable bioindicator

Abstract

Imposex, the manifestation of male morphological sex characters in females of functionally dioecious neogastropod taxa, is an abnormal response to tri-n-butyltin (TBT) contamination introduced to the marine environment in antifouling paints. Since the phenomenon has been thoroughly described only in Atlantic species, a comparative survey of field populations from British Columbia was undertaken, and field studies were carried out to assess the relative value as bioindicators of species in the genus Nucella from the Pacific coast. The majority of neogastropods studied to date have demonstrable signs of imposex, although this leads to sterilization of females in only a few species, depending on differences in the development in females of a palliai vas deferens. Within the Nucella species complex, N. lamellosa, N. canaliculata, and N. emarginata show promise as TBT bioindicators. Only the response of N. emarginata, however, was related to TBT bioaccumulation, based on measurements of a limited number of samples. This is attributed to the apparent irreversibility of imposex, the temporal variability of both environmental levels and tissue burdens of TBT, and the considerably shorter life-span of N. emarginata relative to that of N. lamellosa and N. canaliculata. The geographic distribution of imposex in Nucella spp. suggests that water-borne concentrations of TBT sufficiently high to induce imposex occur over large areas within British Columbia where exchange with oceanic water is limited.

The rough tingleOcenebra erinacea (Neogastropoda: muricidae): An exhibitor of imposex in comparison toNucella lapillus

“…imposex stage 4) females. TBT-induced sterilization is not only reported for O. erinacea (Gibbs et al, 1990; this study), but occurs also in N. lapillus (Gibbs et al, 1987;Oehlmann et al, 1991), Nucella lima (Short et al, 1989), Nucella lamellosa (Bright & Ellis, 1990), Thais haemastoma (Spence et al, 1990), Urosalpinx cinerea (Gibbs et al, 1991) and Ocinebrina aciculata (in prep.). The sterilization effect of advanced imposex is different in the muricids.…”

Bioindicator Thais carinifera (mollusca, gastropoda): imposex response and consequences along the Pakistan coast during the period from 1993 to 2012

“…Similarly in T. gradata and Neptunea antique from Singapore (TAN, 1999;POWER and KEEGAN, 2001) a significant correlation was reported in male shell length and penis length, whereas there was no significant correlation between female shell length and penis length. In T. carinifera a significant difference in male and female penis length was observed, differently from the condition observed in species of Nucella in which generally very small variation in male and female penis length was found (BRIGHT and ELLIS, 1990). TAN (1999) suggested that each species has its own penis/pseudopenis characteristics.…”

Environmental Endocrine Disruption: An Effects Assessment and Analysis

“…Juveniles of this species were underrepresented, and many adult females retained their egg capsules due to blockage of the genital pore. Bright and Ellis (312) note that the selective loss of reproductive potential observed for N. /amellosa possibly could result in an alteration of the competitive interactions between sympatric species of Nucella (different species of Nucella often co-occur within the intertidal zone of British Columbia).…”