Dog whelk

Cause imposex in dog whelks and a variety of other effects on other mollusks... 

Returning to the question of endocrine disruption, it is now known that over 100 species of gastropods worldwide suffer from a condition described as imposex, the development of male characteristics by females. It has already been established for some species (e.g., dog whelk) that TBT is the cause of this, and it is suspected that organotin compounds account for most cases of imposex worldwide (Matthiessen and Gibbs 1998). Some examples of masculinization of female gastropods caused by tributyltin are given in Table 8.4. 

Dog whelk (Nucella lapillus) Sting whelk (Ocenebra erinacea) Common whelk (Buccinum undatum)... 

TBT causes imposex Development of penis blocks oviduct Similar effect to that observed in dog whelk Also causes imposex... 

Tributyltin compounds used as antifouling agents on boats have had serious toxic effects upon many mollusks, including populations of oysters and dog whelks. Females of the latter species developed a condition known as imposex, which rendered them infertile and caused local extinction of the population in shallow coastal waters. Imposex provides the basis for a valuable biomarker assay. 

Imposex The imposition of male characteristics on females in prosobranch mol-lusks, especially dog whelk (Nucellus lapillus). 

Gibbs, P.E. and Bryan, G.W. (1986). Reproductive failure in populations of the dog whelk caused byimposex induced by TBT from antifouling paints. Journal of the Marine Biological Association of the United Kingdom 66, 767-777. 

Bryan, G.W., P.E. Gibbs, G.R. Burt, and L.G. Hummerstone. 1987. The effects of tributyltin (TBT) accumulation on adult dog-whelks, Nucella lapillus long-term field and laboratory experiments. Jour. Mar. Biol. Assoc. U.K. 67 525-544. 

The abundance of L. littorea and the far more sensitive dog whelk, N. lapil-lus, can be used as indicators. TBT contamination has made the dog whelk a rare species in Dutch coastal waters and it is almost entirely absent from harbours and marinas (Harding et al., 1992 Van Moorsel, 1996). TBT potentially accumulates in sediments. However, there is no direct link between sediment concentrations and effects in gastropods, as the preferred habitats of some of the most common gastropods (e.g. N. lapillus, L. littorea) are hard substrates, including natural substrates such as rock and artificial substrates such as harbour walls, breakwaters, etc. (Oehlmann, 2002). 

Schipper C.A., and R.W.P.M. Laane, Assessing the status of the dog whelk Nucella lapillus in the Dutch coastal zone. SETAC North America annual meeting, 2007, Milwaukee, USA. 

Gibbs, RE. and G.W. Bryan. 1986. Reproductive failure in populations of the dog-whelk, Nucella lapillus, caused by knposex induced from tributyltin from antifouling paints. Jour. Mar. Biol. Assoc. UK. 66 767-777. 

In the study, tissue samples were also analysed for protein-related parameters clearly showing that the stress response of dog whelks exposed to increased water temperatures differed from those exposed to lower temperatures, but that increased... 

Imposex in dog whelks (see text) Tributyl tin Organism, population... 

One of the most successful biomarker assays is the measurement of imposex in dog whelks (Nu-cella lapillus, which have brightly-colored shells). This phenomenon is caused by tributyl tins (TBTs), widely used as antifouling coatings in boats (see Section 12.3.2). TBTs impose male characteristics on females, leading to a reduction in reproductive performance and local extinction of dog whelk populations in the most contaminated sites. 

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