Female Penis Length Research Articles

Oxidative stress indicators in populations of the gastropodBuccinanops globulosusaffected by imposex

The gastropodBuccinanops globulosusis commonly used as a bioindicator of tributyltin (TBT) contamination due to its high imposex incidence in maritime traffic areas. The aim of this study was to evaluate both oxidative stress inB. globulosusat three sites with different maritime activity, and imposex incidence in Nuevo Gulf, Argentina. Oxidative stress parameters in digestive glands, like superoxide dismutase (SOD) and glutathione-S-transferase (GST) activities, reduced glutathione levels (GSH), and oxidative damage to lipids, estimated as thiobarbituric acid reactive substances (TBARs) as well as imposex parameters (% imposex and female penis length (FPL)) were measured in females. Gastropods from the harbour area showed 100% imposex, the highest FPL and TBARs content, as well as GSH levels and SOD activity.The different oxidative stress responses and high imposex incidence at the harbour site may indicate a negative effect on the organism's physiological state due to environmental pollution.

Pugilina morio L., a New Imposex Exhibitor from South American Estuarine Environments: Approach for a Non-Lethal Method to Evaluate Imposex

This is the first report on imposex occurrence in Pugilina morio. Imposex levels in P. morio from Ceará River Estuary were assessed by a non-lethal method. The obtained imposex parameters were: percentage = 37.1 %, female penis length index (FPLI) = 0.93 mm, relative penis length index (RPLI) = 6.5 %, and vas deferens sequence index (VDSI) = 1.0. Because imposex is induced by tributyltin, and P. morio is widely distributed on the East coast of South America, the species can be used as a tributyltin contamination sentinel in these estuaries. Additionally, a non-lethal method of evaluating imposex minimized the impact on the population of P. morio from sample collection, as all organisms were returned to the environment.

Imposex and butyltin concentrations in Bolinus brandaris (Gastropoda: Muricidae) from the northern Tunisian coast

The imposex incidence and butyltin concentration i.e. tributyltin with its di- and mono-substituted metabolites were investigated in the muricid Bolinus brandaris sampled from two sites on the northern Tunisian coast (the Lagoon of Bizerta and the small Gulf of Tunis). Both populations had imposex, with stages of imposex development varying between VDS 1 and VDS 4.3. All imposex indices (imposex frequency (I %), female penis length, female vas deferens length, vas deferens sequence index, relative penis length index, and vas deferens length index) were significantly higher in snails from the Bizerta lagoon. Butyltins were detected in the whole tissues of both sexes from the two sites. TBT levels were higher in gastropods collected from the lagoon of Bizerta (12.65 ±1.48 ng Sn g( - 1) dw in female and 15.21 ±1.13 ng Sn g( - 1) dw in male) than in individuals from the Gulf of Tunis (10.71 ±1.26 ng Sn g( - 1) dw in female and 11.65 ±1.63 ng Sn g( - 1) dw in male), corroborating the data of imposex analysis. These results confirmed that B. brandaris could be used as a bioindicator species of butyltin pollution in the studied areas. In addition, this study provided baseline data that could serve for long-term monitoring of TBT pollution in Tunisia, since legislation to reduce the use of TBT-based antifouling paints has not been introduced yet.

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

Nucella lapillus imposex levels and organotin (OT) concentrations in water and female tissues were measured in samples collected from the Ria de Aveiro (NW Portugal) between 1997 and 2007. Vas deferens sequence index (VDSI), relative penis size index (RPSI), mean female penis length (FPL) and percentage of imposex affected females (%I) were used to determine imposex levels at each site. A significant temporal decline in imposex intensity was observed during the assessed period. Imposex decrease was evident after 2003 although improvements were most notable from 2005 to 2007, probably due to the implementation of the EU Council Regulation no.782/2003 forbidding further application of tributyltin (TBT) antifouling on vessels carrying EU flags. Despite these improvements, OT analysis in N. lapillus female tissues and water indicate there are still recent TBT inputs into the study area.

Temporal evolution of imposex in Nassarius reticulatus (L.) along the Portuguese coast: the efficacy of EC regulation 782/2003

Imposex levels in Nassarius reticulatus (L.) were determined in 44 sites along the Portuguese coast in 2006 in order to describe spatial and temporal trends of TBT pollution in the area. The percentage of females with imposex across sites varied between 20 and 100, denoting the extent of this phenomenon throughout the Portuguese coast. The mean female penis length per site varied between 0.0-8.0 mm and the relative penis length index (mean female penis length x 100/mean male penis length) attained a maximum value of 92%, i.e., female penis never surpasses the size of the male penis but nevertheless it can almost approach the male dimensions. The vas deferens sequence index ranged from 0.2 to 4.5 and the oviduct convolution index varied between 0.0 and 1.3 across stations. The penis growth, the vas deferens development and the oviduct convolution were all correlated and constitute visible signs of a global virilisation progression in females in response to the proximity of harbours that constitute the main TBT pollution sources. The results indicate that about 95% of the surveyed sites were still exposed to TBT water concentrations above the OSPAR Environmental Assessment Criteria. Nevertheless, signs of recovery are shown by the significant reduction of VDSI levels in 2006 in comparison to 2003, which points to the efficacy of the EC Regulation 782/2003 in reducing TBT pollution levels in the Portuguese coast.

Imposex of Mauritia arabica on the south-eastern coast of China

Imposex, the development of male sexual organs in female gastropods, is mainly induced by organotin compounds used as biocides in antifouling paints. As part of our continued efforts to report the occurrence of imposex gastropods along the coast of mainland China, this study investigates the imposex prevalence in Mauritia arabica (Mesogastropod: Cypraeidae). A total of 529 adults were collected from 11 sites in south-eastern China between March 2001 and June 2005. Of these, 303 were females and 226 were males. Imposex is classified into six stages representing the sequence from the initial appearance of the seminal groove or small penis (S1) to the point when this duct blocks the pallial oviduct and aborted egg capsules appear (S6). All six stages of imposex were found in M. arabica with three different types (a, b and c) of expression in stages 1 and 3, two types (a and b) in stage 2, and one type in stages 4, 5, and 6. Imposex development was also measured by various indices such as the vas deferens sequence index (VDS), female penis length (FPL), percentage of affected females (%I), the relative penis length (RPL), and relative penis size (RPS—the cubed form of RPL). Imposex individuals were found in all 11 sites with %I ranged from 26% to 100%. Excluding the data from site 3 (with only one female and one male), VDS scores ranged from 1.05 to 4.07, with an average of 2.86, and the RPL ranged from 0.9 to 56.8. High correlations were observed among VDS, FPL, %I, RPL, and the RPS. Our findings suggest that M. arabica is an ideal bioindicator for organotin pollution along the south-eastern coast of China, and can be used in conjunction with the rock shell, Thais clavigera, a well-established bioindicator of tributyltin and triphenyltin contamination. To our knowledge, this is the first detailed report of imposex in M. arabica.

Imposex expression in Hexaplex trunculus from the North Tunis Lake transplanted to Bizerta channel (Tunisia)

Abstract Adult specimens of the muricid gastropod Hexaplex trunculus were collected from their natural habitat: the Lake Club station located in the North Tunis Lake, a sampling site characterized by the absence of shipping activity and an imposex incidence of 12.9%. These specimens were transplanted to a sampling site with intense shipping traffic: the Bizerta channel, where a preliminary survey detected an imposex incidence of 100%. The transplanted specimens were tagged prior to release and periodical recaptures were made every 60 days during a study period of 8 months (from July 2004 to March 2005) in order to compare the imposex development between both sampling sites. After 5 months of exposure in the Bizerta channel, all transplanted females were affected by imposex (with the development of an incomplete male genital tract). Microscopic examinations showed that imposex begun by the development of a small portion of vas deferens located halfway between the expected position of the future penis and the vagina. The imposex indices used in this study were the imposex frequency (I (%)), the vas deferens sequence index (VDSI), the relative penis length index (RPL), the average female penis length index (FPL) and the average female vas deferens length (VDL). All these indices increased in the transplanted population as compared to the population from the original sampling site, but VDSI and VDL were considered the best indices to assess the environmental pollution by tributyltin (TBT) and its deleterious effects in H. trunculus.

Seasonal variation in imposex intensity ofThais clavigera

Imposex, specifically caused by TBT pollution, refers to the superimposition of male sexual characteristics in gastropod females. Seasonal variation of imposex intensity inThais clavigera from both slightly and severely contaminated sites in Hong Kong waters was studied from 1988 to 1999. The male penis length showed significant difference between both sites and seasons. It was shortest during late autumn and early winter (October to December) and longest during spring and early summer (February to June). Female penis length also showed significant difference between sites. It did not change seasonally, however. The RPS (Relative Penis Size) index was the highest during autumn and early winter, and the lowest during spring and early summer. The VDS (Vas Deferens Sequence) index remained stable throughout the sampling period. This study showed that VDS index is a better indicator when we compare relative intensity of imposex. The comparison can only be meaningful provided the samples from different locations are taken during the same season.

Imposex development in response to TBT pollution in Hinia incrassata (Ström, 1768) (Prosobranchia, Stenoglossa)

The stenoglossan prosobranch Hinia incrassata, collected along the coast of Brittany and Normandy between 1988 and 1997, exhibits imposex also known as pseudohermaphroditism (the occurrence of male parts in addition to the female genital system) in response to tributyltin (TBT) pollution. Excluding some normal females (stage 0), different imposex stages as defined by Fioroni et al. (1991a)(1a, 1b, 2a, 3a and 4) can be distinguished and have been documented for the first time using scanning electron micrographs. Additional malformations of the genital tract are described. Neither TBT-induced sterilization nor sex change occur in the analyzed samples. TBT accumulation in soft parts was analyzed and bioconcentration factors (BCF) were found to be between 4.68 · 10 4 and 1.22 · 10 5. The VDS (vas deferens sequence) index, RPL (relative penis length) index and the average female penis length (FPL) in populations exhibit a significant dependence on both TBT concentrations in ambient sea water and TBT body burden. An interspecific comparison between imposex intensities in sympatrically living populations of Hinia incrassata, Nucella lapillus and Hinia reticulata reveals that H. incrassata exhibits the lowest TBT sensitivity of the three species. But even in this relatively unsensitive species the threshold concentration for imposex development is below 1.5 ng TBT as Sn l −1. The VDS index is recommended as the most suited biological parameter for effect monitoring purposes because this index is characterized by the lowest deviation of data points from calculated concentration-effect-equations and shows no seasonal variations. Hinia incrassata is proposed for large large-scale TBT surveys in the Mediterranean being planned by OSPARCOM for the North Atlantic. Furthermore the species can be used for TBT temporal trend monitoring. Studies in France, for example, where TBT was partially banned in 1982, show little or no recovery from TBT contamination in H. incrassata and two other prosobranch species between 1989 and 1997.

Imposex and reproductive failure in Hydrobia ulvae (Gastropoda: Prosobranchia)

Hydrobia ulvae specimens collected from 16 stations along the German North Sea and Baltic coasts exhibited imposex (occurrence of male parts in addition to the female genital system). For the purposes of comparison, a description of both the male and unaffected female genital systems is presented. Four different imposex stages with two types of development were identified and documented with scanning electron micrographs for the first time. The percentage of imposex-affected females (an average over all the localities sampled) was about 44.3%, and 12.9% were definitively sterilized. The phenomenon of sex change was not observed. The vas deferens sequence index, imposex incidence, percentage of sterilized females and the average female penis length are recommended as biological effect monitoring parameters in response to tributyltin pollution.

TBT-induced imposex in marine neogastropods is mediated by an increasing androgen level

Tributyltin (TBT) exposure at different concentrations (5, 60, and 100 ng TBT as Sn/l) induces a concentration- and time-dependent imposex (=pseudohermaphroditism) development in femaleNucella lapillus andHinia reticulata. In both species the average imposex stage, termed as vas deferens sequence (VDS) index, and the average female penis length increases with increasing TBT concentration and duration of TBT exposure. Testosterone added at a concentration of 500 ng/l induces a faster and more intensive imposex development compared to that induced by the TBT concentrations used in the present experiments. Radioimmunological determination of endogenous steroid content reveals increasing testosterone titres in female gastropods exposed to TBT which correlate with the TBT concentration used and the duration of the experiment. The most marked and highest increase of the endogenous testosterone level is exhibited by females, of both species exposed to testosterone. Simulataneous exposure to TBT and to the antiandrogen cyproterone acetate which suppresses imposex development completely inN. lapillus and reduces imposex development strongly inH. reticulata proves that the imposex-inducing effects of TBT are mediated by an increasing androgen level and are not caused directly by the organotin compound itself. Further-more, TBT-induced imposex development can be suppressed in both snails by adding estrogens to the aqueous medium. These observations suggest that TBT causes an inhibition of the cytochrome P-450 dependent aromatase system which catalyses the aromatization of androgens to estrogens. The increase of the androgen content or the shift of the androgen-estrogen balance in favour of androgens induces the development of pseudohermaphroditism in marine prosobranchs. Artificial inhibition of the cytochrome P-450 dependent aromatase system using SH 489 (1-methyl-1,4-androstadiene-3,17-dione) as a steroidal aromatase inhibitor and flavone as a nonsteroidal aromatase inhibitor induces imposex development inN. lapillus as well as inH. reticulata.

Neogastropod imposex for monitoring recovery from marine tbt contamination

Imposex, the imposition of male sexual characters on female snails, was used as a bioindicator of recovery from tributyltin (TBT) pollution in the Pacific Northwest. Whelks surveyed before TBT use was regulated had shown a high frequency of affected females in the Strait of Juan de Fuca and the Strait of Georgia; and lower frequency on the west coast of Vancouver Island. A reduction in imposex is now evident on the west coast of Vancouver Island and in some locations in the Strait of Georgia. There is no clear evidence of recovery near Victoria, and Vancouver Harbour still does not have whelks in any abundance, if at all. Of the four species studied, Nucella emarginata is the most suitable bioindicator species because it is abundantly distributed and has the shortest lifespan (1–2 years). When frequency of imposex remains at 100%, the FPL (female penis length) is still available as a useful bioindicator.

NEOGASTROPOD IMPOSEX FOR MONITORING RECOVERY FROM MARINE TBT CONTAMINATION

Imposex, the imposition of male sexual characters on female snails, was used as a bioindicator of recovery from tributyltin (TBT) pollution in the Pacific Northwest. Whelks surveyed before TBT use was regulated had shown a high frequency of affected females in the Strait of Juan de Fuca and the Strait of Georgia; and lower frequency on the west coast of Vancouver Island. A reduction in imposex is now evident on the west coast of Vancouver Island and in some locations in the Strait of Georgia. There is no clear evidence of recovery near Victoria, and Vancouver Harbour still does not have whelks in any abundance, if at all. Of the four species studied, Nucella emarginata is the most suitable bioindicator species because it is abundantly distributed and has the shortest lifespan (1–2 years). When frequency of imposex remains at 100%, the FPL (female penis length) is still available as a useful bioindicator.

Marine TBT antifouling contamination in Ireland, following legislation in 1987

This account examines TBT contamination in Irish waters following its ban in April 1987 on all nets, structures, and vessels of < 25 m. Imposex in dogwhelks, a sensitive indicator for TBT, was examined in 1987 and 1993 using the following methods: the relative size of the female to male penis, female penis length, and the vas deferens sequence. In areas of high contamination female snails became sterile and some populations became extinct. The extensive 1987 survey indicated most inlets and bays had TBT contamination. In 1993, selected areas, having either salmon culture, yachts and boats, or ships, were re-examined. There was significant recovery in areas of salmon culture and small boat activity but a general increase at sites adjacent to shipping ports. At distances greater than 9 km from the main sources of TBT, indices for imposex were low.

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

The muricid gastropodOcenebra erinacea exhibits imposex (occurrence of male parts in addition to the female genital duct), a phenomenon which is caused by tributyltin (TBT)-compounds leached from ships’ antifouling paints. Five stages of imposex development (1–5) with two different types at stage 1 can be distinguished and are documented with SEM-photographs for the first time. Four additional alterations of the genital tract are shown. Close to harbours and marinas,O. erinacea females exhibit malformations of the pallial oviduct, which seem to inhibit copulation and capsule formation resulting in sterilization. The TBT accumulation in the whole body and the accumulation pattern in single tissues are described; contrary to other prosobranchs no sexrelated differences were found. The VDS, uncubed RPS and average female penis length of a population were analysed regarding their quality as parameters for TBT biomonitoring. On the background of the ecology of this species the VDS is chosen as the best index. Only in highly polluted areas should the uncubed RPS be used as a secondary parameter. A statistical study, based on the analysis of natural populations ofNucella lapillus andO. erinacea, allows a comparison of the specific TBT sensitivity of the two bioindicators. Dogwhelks exhibit a greater TBT sensitivity, namely at slightly polluted sites, nevertheless even here rough tingles develop obvious imposex characteristics.

The morphological expression of imposex in Hinia reticulata (Gastropoda: Buccinidae): a potential indicator of tributultin pollution

Specimens from the prosobranch Hinia reticulata collected along the coast of Brittany and Normandy from 1988 to 1991 exhibited imposex (occurrence of male parts in addition to the female genital duct) in response to tributyltin (TBT) pollution. Four stages of imposex development (1 to 4) with two different types in the Stages 1, 3 and 4 could be distinguished and have been documented with scanning electron micrographs for the first time. Furthermore, three additional alterations of the genital tract are shown. Neither TBT-induced sterilization nor sex change occurred. TBT accumulation in whole body and selected tissues is described and sex-related differences are shown. The VDS (vas deferens sequence) index, cubed and uncubed RPS (relative penis size) index and average female penis length of a population were analysed with regard to their quality as indices for TBT biomonitoring. Based on the way imposex develops in this species the VDS is recommended as the most valid index. Only in highly polluted areas should the uncubed RPS be used as a second index.

Hinia reticulata and Nucella lapillus. Comparison of two gastropod tributyltin bioindicators

Hinia reticulata and Nucella lapillus (collected from 1989 to 1991 at Pointe de Pleneuf and Mean Melen, France, respectively) exhibit imposex in response to tributyltin (TBT) pollution leached from antifouling paints and proved to be good TBT bioindicators. H. reticulata was kept for 18 mo under TBT-free conditions in the laboratory, but no evidence for imposex remission was found. A second series of experiments showed that food chain uptake of TBT from a contaminated diet is an important mode of TBT exposure in H. reticulata. Comparative tank experiments with H. reticulata and N. lapillus demonstrated that the same type of TBT exposure resulted in comparable TBT body burdens, biological concentration factors, and imposex development in both species [measured as increase of VDS (vas deferens sequence index), uncubed RPS (relative penis size index) and average female penis length]. Differences in imposex development of natural and laboratory populations are discussed against the background of different types of TBT contamination of their food. A statistical study, based on an analysis of natural populations of both prosobranch species, makes a comparison of the specific TBT sensitivity of the two bioindicators possible. As a consequence it is proposed that TBT biomonitoring programs in Europe should use both prosobranchs as indicator species.

TBT-induced imposex in the dogwhelk, Nucella lapillus: Geographical uniformity of the response and effects

The imposex response of the dogwhelk, Nucella lapillus, to tributyltin (TBT) pollution has been investigated in adults taken from four UK populations geographically separated over 10° of latitude. Exposure to TBT water concentrations of c.1 and 17 ng Sn/litre over a period of 12 weeks resulted in similar levels of accumulation of TBT within the body tissues and similar increases in female penis length in all four populations. The features are imposex in N. lapillus populations in south-west Brittany are described; they follow the same pattern as found in earlier surveys of the southern England coast, including sterilisation of females, population decline and disappearance of the species close to TBT sources. The evidence of these two investigations indicates that the level of sensitivity and development of imposex as a response to TBT pollution is uniform in N. lapillus throughout its distributional range.