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Ultrahigh performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was used to analyze a colorant and silk, which were prepared and dyed using shellfish (Hexaplex trunculus L.) purple. Solutions of colorant and silk extracts were analyzed immediately after preparation (fresh samples) and after storing them in the dark for thirty days (aged sample I). Moreover, a silk sample was subjected to artificially accelerated ageing under UV radiation (aged sample II). The application of the UHPLC-MS/MS method leads to the detection of (i) the major coloring components of shellfish purple, which are indigotin, indirubin, 6-bromoindigotin, 6′-bromoindirubin, 6-bromoindirubin, 6,6′-dibromoindigotin, 6,6′-dibromoindirubin; (ii) four minor indigoid components in shellfish purple (compounds A, B, C and D), which belong to the same structural class as indirubin, and whose identification has been reported only once in the past; and (iii) eight degradation products (isatin, degradation products DP3, DP4, DP5, DP6, DP7, DP9 and DP10). The latter were also detected in stored indigotin solution, except for DP 6, which was used as reference sample. The method development was assisted by a new solution preparation approach for investigating compound fragmentation, using a solvent system compatible with direct infusion ESI. This system replaceddimethyl sulfoxide, which inhibits detection through electrospray ionization. [ABSTRACT FROM AUTHOR]

Previous work on ocean acidification highlighted contrasting response between marine species and population. This so-called species-specific response was hypothesized to be partly a consequence of local adaptation to the present range of natural variability in the carbonate chemistry. Under that hypothesis, species tolerance threshold should be correlated to its environmental pH niche. This paper aims to evaluate shell growth rate of Hexaplex trunculus, an important predatory gastropod in benthic communities of Mali Ston Bay. A long-term experiment (310 days) was designed to test a range of pH treatments covering present and future pH levels relevant in the context of future ocean acidification (7.95-7.22 pHT ) at the sampling site. Sex had an effect on the shell growth rate irrespective of pH, and was only significant after 236 days. As growth rate in all pH treatments followed seasonal patterns correlating to changes in seawater temperature, the data were divided into 3 time periods. A positive relationship between shell growth rate (SGR, mm day-1) and pH was observed for the period 1-59 days (temperature ranging between 26.5 & 18.8 °C), whereas SGR decreased significantly with pH for the following period (60-236 days, temperature ranging between 20.6 & 8.5 °C). After 236 days (temperature ranging between 27.5 & 14.1 °C), there was no significant difference in SGR among pH. Similar temperature was experienced between the first and third period and the difference in response could be explained as a consequence of an acute negative response versus a longer exposure indicating possible potential for acclimation. Our results highlight the modulating effect of temperature and the importance of long-term experiments to better assess impacts of ocean acidification on marine organisms. [ABSTRACT FROM AUTHOR]

One of the main research questions regarding archaeological molluscan purple pigments and dyes is whether it is possible to determine which malacological species produced these colorants. For this determination of the zoological provenance of the pigment, a multicomponent analysis must be performed, which can only be obtained from the HPLC technique—the optimal method for identifying all the detectable colorants in a sample. In order to find any trends in the compositions of the dye components from various species of purple-producing sea snails, a statistical formulation is needed. Though principal component analysis (PCA) is a powerful statistical tool that has been used in the analysis of these components, it is based on an algorithm that combines all the componential values and produces new two-dimensional parameters whereby the individualities of the original dye component values are lost. To maintain the integrity of the dye compositions in the purple pigments, a very simple formulation was first published in 2008 and applied to a limited number of samples. This property is known as DMI (short for Di-Mono Index), and for each sample, it is simply the ratio of the peak area of DBI relative to that of MBI, evaluated at the standard wavelength of 288 nm, which has been used for such peak calculations. Currently, considerably more modern and archaeological pigments have been analyzed via HPLC; thus, in the current study, the DMI has been expanded to characterize these purple pigments. Furthermore, a ternary diagram comprising the blue, violet, and red components that can be found in purple colorants is presented for both modern and archaeological purple pigments from the three Muricidae species known in antiquity to produce purple pigments. This triangular diagram is intuitive, retains the integrity of the original dyes, and is presented here for the first time. Both the DMI and the ternary diagram can discern whether a Hexaplex trunculus species or perhaps the Bolinus brandaris or Stramonita haemastoma species were used to produce the pigment. Further, these two representations can also determine whether the IND-rich or the DBI-rich varieties, or both, of H. trunculus were used to produce the purple pigment, either as a paint pigment or as a textile dye. [ABSTRACT FROM AUTHOR]

Background Digitisation of specimens (e.g. zoological, botanical) can provide access to advanced morphological and anatomical information and promote new research opportunities. The micro-CT technology may support the development of "virtual museums" or "virtual laboratories" where digital 3D imaging data are shared widely and freely. There is currently a lack of universal standards concerning the publication and curation of micro-CT datasets. New information The aim of the current project was to create a virtual gallery with micro-CT scans of individuals of the marine gastropod Hexaplex trunculus, which were maintained under a combination of increased temperature and low pH conditions, thus simulating future climate change scenarios. The 3D volume-rendering models created were used to visualise the structure properties of the gastropods shells. Finally, the 3D analysis performed on the micro-CT scans was used to investigate potential changes in the shell properties of the gastropods. The derived micro-CT 3D images were annotated with detailed metadata and can be interactively displayed and manipulated using online tools through the micro-CT virtual laboratory, which was developed under the LifeWatchGreece Research Infrastructure for the dissemination of virtual image galleries collection supporting the principles of FAIR data. [ABSTRACT FROM AUTHOR]

Small-scale fisheries have a high socioeconomic importance for local communities. Therefore, ensuring the sustainability of fisheries resources would contribute for the socioeconomic development of fisheries communities. In this study, traps produced from plastic waste recycle materials which can be used in fishing of economically valued whelks (Hexaplex trunculus and Bolinus brandaris) that are used as natural bait in angling and longline fishing were investigated. These traps in different sizes were examined at the depths of 3-8 m in the Urla coasts of Izmir Bay, Turkey. The soaking times of traps were between 10-48 hours. The same amounts of baits (Sardina pilchardus) were equally placed in all traps. Catch per unit efforts (CPUE) of traps were calculated between 7-34 individuals/trap per day. The experimented traps were found successful for whelks fishing. Traps yield high quality and economically valued catches, related with restricted bycatch and low impact on habitat. Therefore, these traps can be suggested as alternative fishing gears designed for trap fisheries for whelks. This paper provides valuable knowledge for fisheries managers and decision makers to ensure the sustainability of local fisheries resources and small-scale fisheries.

Micro-computed tomography (micro-CT) is a high-resolution 3D-imaging technique which is now increasingly applied in biological studies focusing on taxonomy and functional morphology. The creation of virtual representations of specimens can increase availability of otherwise underexploited and inaccessible samples. The 3D model dataset can be also further processed through volume rendering and morphometric analysis. The success of micro-CT as a visualisation technique depends on several methodological manipulations, including the use of contrast enhancing staining agents, filters, scanning mediums, containers, exposure time and frame averaging. The aim of this study was to standardise a series of micro-CT scanning and 3D analysis protocols for a marine gastropod species, Hexaplex trunculus. The analytical protocols have followed all the developmental stages of this gastropod, from egg capsules and embryos to juveniles and adults. [ABSTRACT FROM AUTHOR]

The global ban on the use of tributyltin (TBT) forced in September 2008 was ratified in Tunisia as late as June 2011. In this context, the present study aims to highlight the consequences of TBT contamination by monitoring 22 Tunisian sites before (2007) and after the ban (2012 and 2016) using as biomarker the occurrence of imposex in Hexaplex trunculus . From 2004 to 2016, complete recovery from imposex was reported in 11 sites. All average imposex indices calculated for each sampling year also decreased: imposex incidence from 61 to 27%, VDSI from 2 to 0.7, and RPLI from 15.7 to 1.6%. Ecological Quality Ratios (EQR) revealed that the sampling sites are in moderate to good ecological status. Overall, the present study confirms the effectiveness of the enacted legislation in reducing the impact of TBT pollution along the Tunisian coast. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the post-legislation change in tributyltin (TBT) pollution at Croatian Adriatic coast. Gastropod Hexaplex trunculus and sediments were collected, nearly 10 years after TBT based antifouling paints were banned, at 12 locations along the coast where a previous study was conducted in 2005. The study showed a decline of TBT levels over the investigated period, although all gastropods populations were highly affected by imposex meaning that prohibition did not result in the recovery of populations. The further aim was to propose the Ecological Quality Ratio (EQR) boundaries for potential use of H . trunculus as a principal bioindicator in the assessment of the ecological status of the Mediterranean regarding TBT pollution, under the Water Framework Directive (WFD). According to the proposed EQR classes, the WFD target for achieving the Good ecological status of the marine environment by 2015 was not reached. [ABSTRACT FROM AUTHOR]

Pottery sherds stained with purple dye were found in the excavations at Tel Shiqmona, and were dated to the Iron Age II period. Analysis by HPLC-DAD identified the dye as 'true purple', derived from the Hexaplex trunculus sea snail, which is associated with the purple-dye industry that flourished in the coastal area at that time. This result is compatible with the classification of over 1000 Muricidae shells that were found in the excavation. Hexaplex trunculus constitutes 80% of this group, indicating that it was the most commonly used species in the dye production at Tel Shiqmona. [ABSTRACT FROM AUTHOR]

The artisanal fishery for muricid gastropods in the Ria Formosa lagoon (Algarve coast, southern Portugal) is a locally important fishing activity because the banded murex (Hexaplex trunculus) and the purple dye murex (Bolinus brandaris) are greatly appreciated seafoods with high commercial value in the Portuguese seafood market. An integrated study was implemented to monitor the muricid gastropod fishery with the artisanal fishing gear (“wallet-line”) through monthly experimental fishing operations carried out during one year. The aim was to describe the fishing operations and fishing gear, to estimate the fishing yield, to characterise the target species catch composition, and to identify by-catch species and discards. The “wallet-line” is neither a species-specific nor a size-selective fishing gear, because the catches comprised a variety of by-catch species and a high proportion of commercially under-sized target species. The vast majority of the by-catch is discarded immediately on board, so mortality is presumably negligible. The CPUE of both target species and by-catch species decreased during consecutive fishing days, mainly due to declining bait attraction. Considering the overall information gathered on this fishing activity, some management measures are proposed for this artisanal fishery, which might ultimately contribute to the long-term sustainable exploitation of the fishing resource.

Po-pu-re (porphyra) denotes the deep red/purple colour delivered from sea shells extraction and processing of five species and conversion to dye has been practice in ancient world, especially in the Mediterranean Sea. Archaeological excavations have shown that murex was used in Greece and in other areas, such as Egypt, Israel, Turkey, Italy, Spain and generally throughout the Mediterranean basin. The colour of murex was priceless and used in wall-paintings and textiles. Many fabrics have been found in Crete, Egypt and Israel. Considering the ancient texts, including those of Plutarch, Pliny, Aristotle, Herodotus and Xenokrates, it has been shown that its identification can be advanced by studying chemical production of purple-dye, while using spectroscopy and chemical analysis the basic chemistry, the dibromoindigotin (DBI), is identified. The present report reviews major murex producing workshops in the Mediterranean and archaeometrical analyses that identify this marine shell. [ABSTRACT FROM AUTHOR]

The gastropod Hexaplex trunculus is widely distributed in a relatively large range of habitats, but has no dispersal stage. We investigated its genetic structure across its distribution range, from Mediterranean Sea to adjacent Atlantic coasts, by sequencing mitochondrial DNA portions of the NADH dehydrogenase gene ND2 (420 pb) and the internal transcribed spacer ITS2 (450 pb). Our results suggested a significant genetic variability of ND2 (π = 0.009 and Hd = 0.629) and low variability of the ITS2 sequences. A strong phylogeographic break, separated the Aegean populations from those of Western/Eastern Mediterranean and the Atlantic ones, was founded. The tow lineages may have been separated by vicariance events due to the Peloponnese break that separates the Aegean populations from other populations and was maintained until now by the quasi-circular anticyclonic front associated to the straits of Cretan Arc of the Peloponnesian Peninsula. Tunisian coasts appear particularly diverse since the two divergent lineages co-occured. These results may have management consequences since H. trunculus is a high commercial value harvested species. [ABSTRACT FROM AUTHOR]

Organotin compounds are toxic substances released into the marine environment from antifouling paints. Sixty-two years following their first application and 9 years after the complete ban on their use as biocides in 2003 (EC No. 782/2003), their negative impact on mollusks was still evident, as illustrated by imposex (i.e. the masculinization of female gastropods). This phenomenon is widely used to investigate tributyltin (TBT) pollution, with Hexaplex trunculus and Nassarius nitidus being considered as sensitive bioindicators. H. trunculus specimens and sediment samples collected from the ports of Cagliari (Sardinia), El Kantaoui (Tunisia) and Olhão (Portugal), along with N. nitidus individuals from the port of Faro (Portugal), were used for the assessment of imposex intensity and organotin pollution in these areas. High imposex frequency and organotin concentrations (TBT, triphenyltin (TPhT) and their degradation products) were observed, especially in Sardinia, implying that these chemicals remain a significant pollution issue in the specific Mediterranean ports. Moreover, the highly significant relationship established between penis length of imposex-affected females H. trunculus and TBT/TPhT concentrations offers a rapid and nonsacrificial proxy model for assessing the impact of organotins in coastal environments. Finally, the complementary use of more than one TBT bioindicator is advised in order to obtain more accurate results in detailed monitoring studies of TBT pollution. [ABSTRACT FROM AUTHOR]

The present study reports morphometric relationships and discusses the relative growth in the banded murex (Hexaplex trunculus) and the purple dye murex (Bolinus brandaris) from the Ria Formosa lagoon (southern Portugal). A total of 11 morphometric parameters (eight linear variables: shell length, shell width, total aperture length, aperture length, aperture width, spire length, spire width and siphonal canal length; three ponderal variables: total weight, soft parts weight and shell weight) were analysed in both species. The analyses comprised numerous individuals of both sexes and with broad size ranges (H. trunculus: 10.7–82.8 mm shell length; B. brandaris: 14.6–107.7 mm shell length), fairly representative of the populations from the Ria Formosa lagoon. In general, B. brandaris exhibited greater morphological plasticity and higher variability in shell shape compared with H. trunculus. In both species, the vast majority of morphometric relationships displayed positive allometries, distantly followed by negative allometries and by isometries. Although H. trunculus and B. brandaris are known to lack external sexual dimorphism, several morphometric relationships revealed significant differences in the type of growth between sexes, which should be further confirmed using more powerful techniques, such as geometric morphometric analyses of shell shape. [ABSTRACT FROM PUBLISHER]

Spawning, phases of embryonic development, intracapsular feeding mechanism and development mode of banded murex Hexaplex trunculus ( Linnaeus, 1758) were examined using specimens from the Aegean Sea. In addition, the numbers and characteristics of non-viable nurse eggs during different phases were examined in relation to the development phases of viable embryos. Females spawned between 59 and 162 egg capsules containing 306.76 ± 50.74 eggs. Trochophore larvae first appeared on the 15th day after spawning. Nurse egg consumption began on the 17th day after spawning when the embryos reached the early veliger stage. In the beginning, veligers consumed the nurse eggs by mechanically disintegrating them with velar cilia movement. From the 18th day after spawning, embryos began to consume whole nurse eggs, although mechanical disintegration continued until hatching. Viable embryos consumed the most developed nurse eggs first. The average number of nurse eggs consumed per embryo was 24.67 by the end of the intracapsular period. The average number of hatchlings was 11.95 ± 3.81 per capsule with 1321.48 ± 133.1 μm shell length. According to our observations H. trunculus shows dispersal polymorphism, with most of the hatchlings completing metamorphosis after a short planktonic non-feeding period (up to 2 days), while others metamorphose prior to hatching. Planktonic hatchlings had both foot and well developed four-lobed velum and minimum 1 3/4 whorls. Both hatchling types could be seen in the capsule mass from the same female. [ABSTRACT FROM AUTHOR]

Copper, Zn, and Cd were analyzed in the soft tissues of the edible gastropod Hexaplex trunculus collected from seven localities along the Tunisian coast. The body concentration of these metals was significantly different depending on the gender and site. Copper and Zn varied, respectively, from 47.70 to 343.64 μg/g dry weight (dw) and 149.46 to 530.44 μg/g dw, being higher in males. Cadmium varied from 0.22 to 18.95 μg/g dw and was always higher in females. Overall, the highest concentrations of the three metals were all recorded in Gabès fishing harbor. Comparison of metal concentrations with the European standards compiled by the Food and Agriculture Organization showed that values exceeded standards in several localities. Imposex had been previously recorded in H. trunculus along the Tunisian coast; however, it does not seem to be related with Cu, Zn, and Cd pollution because the body concentration of these metals is not correlated with imposex degree. Nevertheless, interactive effects resulting from the combination of different pollutants and other stressors cannot be disregarded. [ABSTRACT FROM AUTHOR]

Highlights: [•] We isolated for the first time the RXR in the imposex-sensitive gastropod H. trunculus. [•] The RXR partial sequence from H. trunculus encodes a protein of 86 amino acids. [•] Two months exposure to TBT induced imposex and led to an increase in FPL and MPL. [•] TBT exposure altered RXR gene transcription in a tissue-specific manner. [•] This study gives further support to a local role of RXR in the penis-forming area. [Copyright &y& Elsevier]

Abstract: Enzymes from fish and aquatic invertebrates have recently been characterized and their study has led to the emergence of some new applications of these classes of enzymes. However, very little is known about lipases from mollusks. A lipolytic activity was located in the marine snail digestive glands (hepatopancreas), from which a marine snail digestive lipase named mSDL was purified. Pure mSDL has a molecular mass of about 70kDa as determined by SDS/PAGE analysis. Unlike the known digestive lipases while acting at 37°C, the mSDL displayed its maximal activity on long and short-chain triacylglycerols at 50°C. A specific activity of 400U/mg and 100U/mg was obtained with TC4 or olive oil as substrate respectively. Only 25% of the maximal activity was measured at 37°C. Interestingly, neither colipase, nor bile salts were detected in the marine snail hepatopancreas, which suggests that colipase evolved in invertebrates simultaneously with the appearance of an exocrine pancreas and a true liver which produces bile salts. No similarity was found between the N-terminal amino acids sequence of the mSDL and those of the known digestive lipases. Altogether, these results suggest that the mSDL is a member of a new group of digestive lipases belonging to invertebrates. [Copyright &y& Elsevier]

Abstract: Gelatin was extracted, for the first time, from the meat of Tunisian marine snail by the acid extraction process with a yield of 3g/100g. Snail meat gelatin (SMG) had high protein (88.62%) but low fat (0.77%) content and contained a high number of imino acids. SMG showed high band intensity for α- and β-components and some degradation peptides. The absorption bands of SMG in Fourier transform infrared spectra were mainly situated in the amide band region (amide I and amide II). The gel strength of the SMG (103g) was lower than those from other marine species reported in the literature. SMG exhibited a low foam capacity (75.44%) but a high emulsifying stability (38.12min) and WHC (120%). It can be concluded from the present study that snail meat is a prospective source to produce gelatin in good quality with desirable functional properties. [Copyright &y& Elsevier]

In order to report pharmacological characterization of marine snail ( Hexaplex trunculus) hepatopancreatic phospholipase A (mSDPLA), we have talked for the first time the antimicrobial activity against different pathogenic bacterial strains, anti-chlamydial activity as well as its cytotoxic activity against McCoy cell lines. mSDPLA, showed a high level of activity towards Gram-positive bacteria as Staphylococcus aureus and Staphylococcus epidermidis. Whereas Gram-negative bacteria, unfortunately, exhibited a higher resistance, mSDPLA was also found to have a strong cytotoxic activity, causing significant morphological alterations of the McCoy cell lines surfaces and to be a hinder to the proliferation. Moreover, mSDPLA proved to have a very potent anti-chlamydial activity. Over 95 % inhibition of chlamydial inclusions were obtained at a concentration of 10 μg/ml of mSDPLA after 24 h postinfection. Interestingly, at a concentration of 10 μg/ml of mSDPLA, the proliferation of McCoy cells was not affected. Approximately 50 % inhibition of cell growth was obtained with a concentration of 37 μg/mL of mSDPLA. mSDPLA could be considered as an excellent candidate for the development of a new anti-infective agent. This enzyme showed significant antimicrobial activities. [ABSTRACT FROM AUTHOR]

Tributyl tin (TBT) has been banned as an antifouling agent in the maritime sector over the past few years, due to its impact on a wide range of non-target marine species. This includes imposex induction in prosobranch gastropods. The Maltese Archipelago was one of the first sites within the Mediterranean, where, imposex in the marine snail, Hexaplex trunculus was first used as a biomonitor to assess environmental levels of TBT. Subsequently, this same species was used in several other Mediterranean coastal areas for the same purpose. Imposex levels in Hexa plex trunculus have been studied in Malta since 1993, and have been ongoing since then. The present study will report on the trends in such imposex biomonitoring over the past 18 years in populations of H. trunculus from 13 different inshore coastal areas around the Maltese islands (Malta and Gozo). It concludes that levels of imposex have been declining in this species. Furthermore, the incidence of normal females completely free from imposex in some places, has been on the increase (it is worthwhile to note that prior to 2005 all sampled females of this species showed evidence of imposex)., Nonetheless, imposex is still being recorded, including in marine protected areas. Furthermore, different imposex developmental expressions have been identified in some localities, with some of such expressions probably rendering female specimens more susceptible to early death. [ABSTRACT FROM AUTHOR]

Marine gastropods, exposed to anthropogenic pollution, accumulate high chemical concentrations in their tissues, especially in the digestive glands. An evaluation of the impacts of cadmium (Cd) and permethrin (Perm), coupled with reproductive events (pre-spawning and post-spawning phase) throughout the year, was attempted by measuring catalase (CAT), a biomarker of defence, on Hexaplex trunculus experimentally exposed for 48 or 96 h. Specimens of gastropods were sampled from Bizerta Lagoon (Tunisia). The results show that CAT activity increased in gastropods exposed to the three cadmium concentrations (C1 Cd, 100 μg L; C2 Cd, 200 μg L; and C3 Cd, 300 μg L) and to the three permethrin doses (C1 Perm, 100 μg L; C2 Perm, 150 μg L; and C3 Perm, 200 μg L) tested. A decrease in CAT was noted in the digestive gland of the H. trunculus exposed to permethrin at the concentration of 200 μg L during the pre-spawning and post-spawning phases. H. trunculus in post-spawning was more sensitive to cadmium and permethrin than in the pre-spawning phase. The biochemical responses to pollutants (cadmium and permethrin) represented by CAT may act as a biomarker of exposure in this species. [ABSTRACT FROM AUTHOR]

Abstract: Analysis of natural dyes in historical objects is important for both conservation purposes and to determine the origin and culture that produced it. Identification of a particular dye is usually made based on the presence of its main components, while consideration of minor components is important for differentiating between dyes originating from closely related species. Tyrian purple is one of the oldest dyes known to man and derives from different species of marine molluscs. In all of these species, indigotin, indirubin and their brominated analogues are the main colouring compounds. Here, we describe the identification of minor indigoids found in extracts of the pigment obtained from one of the Tyrian purple species, Hexaplex trunculus. Identification of these compounds was made based on isotopic patterns and accurate mass measurements of protonated molecular ions and their high collision energy fragments obtained in LC–MS/MS experiments. The unknown compounds appeared to be analogues of indirubin and its mono- and dibrominated derivatives with one CO group in the indirubin backbone substituted by a CNH group. Identification of these compounds facilitates the detection of dyestuffs from H. trunculus in historical objects and increases our knowledge about the dye biosynthesis and technology of Tyrian purple production. [Copyright &y& Elsevier]

Abstract: Tributyltin (TBT)-induced imposex in gastropods is often cited as a prime example of environmental endocrine disruption. Several endocrine-related hypotheses have been proposed to define possible mechanisms by which TBT causes imposex. Recently, it has been demonstrated that mollusks have the ability to control endogenous steroid levels (i.e., testosterone and estradiol) by esterification with fatty acid and TBT may impact this metabolic pathway. Hence, this study was designed to investigate the presence and levels of sexual steroids (testosterone and estradiol) in the two TBT sensitive Muricids species Hexaplex trunculus and Bolinus brandaris, and to clarify the sex related impact of TBT in free and esterified steroid levels. Two months exposure to TBT (5 and 50ngTBTL−1) induced imposex and led to a significant increase in the severity of the phenomenon in the high TBT exposure group but statistical tests failed to detect an effect in 5ngTBTL−1 treatment. The steroid levels found in both sexes revealed that testosterone and estradiol were present in the free and esterified forms in the digestive gland-gonad complex. Both hormones were predominantly found in the esterified form, although clear sex differences were not observed. In females of B. brandaris, 2 months exposure to TBT at 50ngTBTL−1 induced a significant elevation of free testosterone and a decrease in the esterified fraction. In females of H. trunculus, TBT led to a significant elevation of both free and esterified testosterone. In contrast, TBT had no effect in male''s testosterone levels, although it led to an increased trend in penis lengths. Free and esterified estradiol levels were not affected by TBT in both sexes of B. brandaris but free estradiol was increased in females of H. trunculus. Overall, the present study demonstrates that TBT exposure leads to steroid imbalance in both species, with a boost of free testosterone levels in females. Although TBT increases male penis length, no effects in male steroid levels were recorded in both species. Hence, TBT impacts in testosterone and estradiol metabolism is sex dependent, and does not seem to be associated with the increase of male penis length observed in TBT exposed animals. [Copyright &y& Elsevier]

This study estimated the age of Hexaplex trunculus (Gastropoda: Muricidae) by analysing operculum growth marks. Surface striae and adventitious layers were counted in opercula of H. trunculus from the Ria Formosa Lagoon (southern Portugal) and from the Bizerte Lagoon (northern Tunisia), and in aquacultured individuals used for validation of the ageing technique. Operculum growth features were also compared between H. trunculus populations under contrasting environmental conditions (namely seawater temperature). Despite high inter-individual variability, all H. trunculus populations displayed a clear increasing trend in the number of striae and layers with increasing specimen size. The operculum marginal growth revealed that opercular deposition is not annual. Instead, a few growth marks are formed in the operculum each year, which was confirmed with reared specimens. In both ageing methods, considerable variation in the number of counts at a determined shell length indicates that operculum growth marks should be interpreted cautiously because they might not correspond accurately with individual age. Because of the subjectivity inherent to either method, counting striae and layers in opercula only provides rough age estimates of H. trunculus. [ABSTRACT FROM AUTHOR]

The banded murex Hexaplex trunculus (Linnaeus, 1758) is a commercially exploited gastropod in the Mediterranean region including Tunisia where it has become an important fishery resource these last years. In the present investigation, some reproductive aspects of this species were described in the population of Boughrara lagoon based on macroscopic examination of the gonads (gonadic conditional indices) together with observation of the seasonal hypertrophy of the penis in males and capsule gland in females. This procedure of assessing reproductive activity was validated by field observations of copulation and spawning. Mature females were found during 10 months and mature males during 8 months being both frequent in January and February. Reproductive activity was slightly asynchronous between sexes with males reaching maturity before females. Gonadic release occurred earlier in males between January and March against February to April in females. These findings were in agreement with field observations of copulation in January and February and egg-capsule laying in late February and March. Hatching juveniles were observed in the field in April and May. [ABSTRACT FROM AUTHOR]

Imposex and tributyltin (TBT) body burden were quantified in the gastropod Hexaplex trunculus collected from the Bizerta channel between 2002 and 2010. Except for the imposex frequency that remained maximal (100%), all the other imposex indices decreased throughout the study period. Similarly, TBT levels also decreased over time, being the less frequent compound among butyltins, with a proportion of 22.2%, against 42.9% for dibutyltin (DBT) and 34.9% for monobutyltin (MBT). These findings reflect the effectiveness of new generation of TBT-free antifouling paint introduced in the Tunisian market and global ban of TBT on reducing the environmental impact of this biocide. [ABSTRACT FROM AUTHOR]

Abstract: A marine snail digestive phospholipase A2 (mSDPL) was purified from delipidated hepatopancreas. Unlike known digestive phospholipases A2, which are 14kDa proteins, the purified mSDPL has a molecular mass of about 30kDa. It has a specific activity of about 180U/mg measured at 50°C and pH 8.5 using phosphatidylcholine liposomes as a substrate in the presence of 4mM NaTDC and 6mM CaCl2. The N-terminal amino-acid of the purified mSDPL does not share any homology with known phospholipases. Moreover, the mSDPL exhibits hemolytic activity in intact erythrocytes and can penetrate phospholipid monolayers at high surface pressure, comparable to snake venom PLA2. These observations suggest that mSDPL could be toxic to mammal cells. However, mSDPL can be classified as a member of a new family of enzymes. It should be situated between the class of toxic phospholipase A2 from venoms and another class of non toxic pancreatic phospholipase A2 from mammals. [Copyright &y& Elsevier]

This study aimed to assess the influence of growth and reproductive cycle on the meat yield and proximate composition of the banded murex (Hexaplex trunculus) from the Ria Formosa lagoon (Algarve coast, southern Portugal). Samples of the edible portion (all soft-body tissues) were analysed monthly during one year. The average meat yield was 37.9±4.6%, with females containing more edible content (39.1±4.7%) than males (36.8±4.2%). The proximate composition comprised 70.7±1.4% moisture, 20.1±1.2% protein, 1.6±0.3% fat, 3.0±0.3% ash, and 4.6±1.2% carbohydrate, corresponding to an energetic value of 119.2±7.5 kcal/100 g wet weight. The meat yield was influenced by specimen size, increasing significantly during growth. Both meat yield and proximate composition presented seasonal fluctuations related to the reproductive cycle, which coincided mainly with the periods of maturation and spawning of this species in the Ria Formosa. Finally, H. trunculus meat yield and proximate composition were compared with similar information available for other marine gastropods. [ABSTRACT FROM PUBLISHER]

Abstract: A comparative study was performed to assess the metabolism of the androgen precursor androstenedione (AD) in two gastropod species from the Muricidae family: Bolinus brandaris and Hexaplex trunculus. AD was mainly converted to 5α-dihydrotestosterone by microsomal fractions isolated from Bolinus brandaris, whereas it was primarily metabolized to testosterone by Hexaplex trunculus. Sex differences in the metabolism of AD were only detected in Bolinus brandaris and attributed to higher 5α-reductase activity in males. Thereafter, the effect of the organotin compounds, tributyltin (TBT) and triphenyltin (TPT), on the metabolism of AD was investigated. A significant interference was only detected in females, and differences between the modes of action of the two compounds were observed: TPT was a strong inhibitor of 5α-reductase activity in B. brandaris at a concentration as low as 100 nM whereas only TBT (10 µM) altered the metabolism of AD in H. trunculus by increasing the activity 17β-hydroxysteroid dehydrogenase (17β-HSD). Thus, this work shows that the metabolism of the androgen precursor AD strongly differs among gastropod species, both in terms of activity and metabolic profile, and further demonstrates the ability of TBT and TPT to interfere with key enzymatic pathways involved in androgen synthesis. [Copyright &y& Elsevier]

Tributyltin (TBT) exposure experiments at 5 and 50 ng l−1 concentrations were carried out in the laboratory on female Hexaplex trunculus collected during the reproductive season from a site weakly-affected by imposex (12.1%). The imposex intensity estimated by the imposex incidence or frequency (I%), the average length of the vas deferens (VDL), the average length of female penis (FPL) and the vas deferens sequence index (VDSI) showed significant variation with TBT concentration. The number of spawning females decreased with TBT concentration. TBT had no effect on the number of egg-capsules laid per female nor on the number of eggs per capsule. The egg-capsules laid in the control and 5 ng TBT l−1 aquaria showed harder texture of the wall compared to those exposed to 50 ng TBT l−1. The mortality rate increased proportionally with TBT concentration and duration of exposure. [ABSTRACT FROM PUBLISHER]

Imposex, a pseudo-hermaphroditic condition characterized by the development of male sexual characteristics in female prosobranch gastropods, is used as a bioindicator of pollution by tributyltin (TBT) -based antifoulants. The incidence and the intensity of imposex, evaluated from the vas deferens sequence index (VDSI) and the female penis length (FPL), were investigated in Hexaplex trunculus populations from seven locations in Kaštela Bay (Adriatic Sea, Croatia). Analysis of 131 females revealed the absolute prevalence of imposex at all investigated locations. Furthermore, most of the females showed signs of advanced imposex development (VDSI=4.4±0.8, range=2-5). Female penis homologues were found to be well developed (max=20 mm) with mean values ranging from 5.2-12.6 mm. Significant differences were detected regarding both the VDSI (H=36.24, p<0.001) and the FPL (F=7.08, p<0.001) between the locations. The results presented in the study confirm the widespread incidence of imposex and can provide reference values for future monitoring programs. [ABSTRACT FROM AUTHOR]

Imposex, i.e. the development of additional male sex organs (penis and/or vas deferens), in females of gonochorist marine and freshwater gastropods, is known to be caused by tributyltin (TBT), and it has been widely used as a biomonitoring tool in environmental surveys for TBT pollution assessment. In this study, we experimentally tested the potential to induce imposex by another endocrine disruptor (polychlorinated biphenyls [PCBs] mixture—Aroclor 1260). Adults of Hexaplex trunculus with low imposex level, coming from an Italian Marine Protected Area, were injected separately with different doses of tributyltin chloride (TBTCl) and Aroclor 1260. The compounds were dissolved in ethanol and the organisms were narcotised by immersion in MgCl2 solution before injection. Before and after the experiment, butyltin compounds (BuTs) and PCB tissue concentrations were determined. A significant increase in imposex with respect to non-treated organisms was observed in all treatments, including artefact controls. No clear correlation was observed between BuTs and PCB tissue concentrations and indices of imposex incidence. Based on these results, no assumption can be formulated about PCB effect on imposex development. Nevertheless, they suggest that the imposex level increase, at least in H. trunculus, in laboratory conditions might not be caused by TBT only, but it would rather be a non-specific response to different stress stimuli. [ABSTRACT FROM AUTHOR]

The present study compares the ability of conventional condition indices (based on weight of the whole organism, weight of its flesh, and/or its shell weight) and visual quantitative indices (based on measures of the digestive gland, gonad, and capsule gland on digitized images of sections of these organs) for the assessment of reproductive activity in Hexaplex trunculus. To estimate conventional indices, a total of 120 standard-sized specimens (50 males and 70 females) in the 60-70 mm shell length interval were analysed. To estimate visual quantitative indices, a total of 903 specimens (501 males and 402 females) were analysed for the gonadosomatic index (GSI); females were also analysed for the capsule gland index (CGI). Compared to conventional indices, the visual quantitative indices (GSI and CGI) followed seasonal variations of the species reproductive cycle and identified broad changes in reproductive development (being highly accurate in detecting the main period of gonad maturation and spawning that occurred between May and June). Results indicate that both GSI and CGI constitute simple, practical and efficient indices for the routine assessment of reproductive activity in H. trunculus, providing a useful and reliable alternative to conventional condition indices and to histological analyses. Results of this study encourage the use of similar sampling procedures and analytical techniques, and analogous visual quantitative indices, to assess reproductive activity in other gastropod species. [ABSTRACT FROM AUTHOR]

The article presents a study on the effect of a diet comprised of biscuit with the flesh of imposex-affected Hexaplex trunculus on the hematological parameters of the rat. It mentions that whelks were gathered from shipping traffic station with high imposex level recorded. It states that following subchronic exposure, blood analyses were performed to identify hematological parameters. Moreover, it presents the result of the study including a fall in hemoglobin concentration.

Abstract: This study presents an analysis of the genetic diversity in Hexaplex trunculus from three localities of the southern Iberian Peninsula (Ria Formosa and Ria de Alvor in Portugal, and Río Piedras in Spain) using three mitochondrial (12S rRNA, 16S rRNA and cytochrome c oxidase subunit I, COI) and one nuclear (5S rRNA and its non-transcribed spacer, NTS) genes. Restriction digestions of 12S and 16S rRNA genes using four endonucleases were also performed. Low genetic diversity was observed for the four genes studied. Genetic distances ranged from 0 to 0.004 for the mitochondrial genes and these values were slightly higher for the 5S and the NTS. The level of polymorphism within populations, π, was from 0 to 0.0039 (for mitochondrial genes), 0.0111–0.0333 (for 5S rRNA), and from 0.2220 to 0.5079 (for NTS). Furthermore, RFLPs analyses from 12S and 16S rRNA genes showed these localities to be monomorphic. The low genetic variability within populations suggests small population size, and a possible bottleneck due to multiple causes, such as overexploitation, the type of larval development (intracapsular embryos) and/or the peripheral location of the sampled localities considering the geographical distribution of the species. Because these populations show such high genetic similarity, Ria de Alvor and Río Piedras could be potentially used for stock enhancement of the Ria Formosa. [Copyright &y& Elsevier]