The use of the dog-whelk, Nucella lapillus, as an indicator of tributyltin (TBT) contamination

Abstract

The term ‘imposex’ was coined by Smith (1971) to describe the superimposition of male characters onto unparasitized and parasitized females of gonochoristic gastropods. In Nassarius obsoletus (Say) the development of imposex results in the female having one or more of the following characters: (1) a penis with a duct leading to (2) a vas deferens which passes back to the ventral channel of the capsule gland and (3) convolution of the normally straight gonadial oviduct (Smith, 1980). Imposex in the similarly gonochoristic Nucella lapillus (L.) was first noted by Blaber (1970) who found females with penis-like outgrowths in Plymouth Sound populations. Subsequent studies (Bryan et al. 1986; Gibbs & Bryan, 1986) have demonstrated that the incidence and intensity of imposex have since increased markedly in the same populations and that the phenomenon is widespread around south-west England.

Ubiquitous imposex and organotin bioaccumulation in gastropods Nucella lapillus from Galicia (NW Spain):a possible effect of nearshore shipping

“…Thirty-seven sites distributed throughout the coastline were visited during the summer (July-September) of 1996; their location is shown in Fig. 1 Gibbs et al (1987), samples consisted of 30 of the largest toothed (i.e. adult) individuals.…”

“…We have used those 2 most widely employed for Nucella lapilluspopulations (Gibbs et al 1987): the Relative Penis Size Index (RPSI) and the Vas Deference Sequence Index (VDSI). The RPSI expresses the bulk of female penis as a percentage of that of males [l00 X (mean length of female p e n i~)~/ ( m e a n length of male p e n i~)~] .…”

Imposex levels and tributyltin pollution in Ria de Aveiro (NW Portugal) between 1997 and 2007: evaluation of legislation effectiveness

“…The penis length (PL) was measured using a stereo microscope with a graduated eyepiece to the nearest 0.14 mm and the mean female penis length (FPL) was determined for each sample. The relative penis size index [RPSI ¼ mean female penis length (FPL) 3 Â 100/mean male penis length (MPL) 3 ], the vas deferens sequence index (VDSI) and the percentage of females affected with imposex (%I) were also determined for each station according to Gibbs et al 18 Parasitized specimens were discarded from the analysis.…”

Recovery from TBT pollution in English Channel environments: A problem solved?

“…The coast of southwest England has many harbours and marinas which host considerable numbers of vessels and, as a result, dogwhelks Nucella lapillus were widely impacted by TBT-induced imposex during the 1980s (Bryan et al, 1986;Gibbs et al, 1987;Langston et al, 1990). Based on repeat sampling of N. lapillus in 2012-13, and using the same protocols, our aim was to establish rates of re-colonisation and recovery from imposex at some of these previously-sampled sites (Fig.…”