Cyclope Neritea Research Articles

Observations of Cyclope neritea Linnaeus 1758 Breeding Behaviour in Artificial Habitat

Cyclope neritea Linnaeus 1758 is a popular Mediterranean Sea gastropod mollusk. A scavenger associated with shellfish farming, and used for population genetics studies and monitoring of environmental pollution. The aim is to evaluate C. neritea’s propagation under long-term artificial condition. C. neritea is maintained in 34 ppt substitute sea-water, along with copepods, Tigriopus californicus Baker 1912 at 25 oC and 12/12 hr light/dark cycle. It is an oviparous marine gastropod laying scattered single-egg-containing capsules. The females with retarded egg-capsule deposition eat the egg immediately after deposition. Normal capsules are not attacked. Juveniles supplement their diet with eggs of their kind regardless of the stage of development. Intra- and extra-capsular development and growth were observed. Its transient longevity reasons the work for optimising the conditions for the successful maintenance, and popularising it for the ornamental fish habitats.

Behavioural toxicity studies of Cyclope neritea and Nassarius mutabilis exposed to polycyclic aromatic hydrocarbons.

The objective of the work was to study behavioural change of Cyclope neritea (sea snail) and Nassarius mutabilis (land snail) upon exposure to different levels of PAHs. Snail's behaviour was translated and expressed in Behavioural State Score (BSS) where the score ranged from "0" to "5" points refers to the ascending level of locomotion of a snail. A significant difference was found in snail's behaviour in 25.0mg/L than in 0.5mg/L with p value smaller than 0.01. BSS scores appear most frequent on the treatment and control group were 5 (61.5-64.5%) and 2 (41.0-45.0%), respectively. Intersex behaviour was found in all species (i.e. the same sex was grouped together) regardless of PAH concentrations. This is the first reported to study the behavioural change of snail sampled in Hong Kong area when exposed to PAHs. Further studies should be carried on the impact of snail's behaviour exposure on each congener in the family of PAHs.

Analysis on feeding behaviour of two sympatric species of nassariid gastropods, Cyclope neritea and Nassarius pfeifferi, from Cadiz Bay (SW Spain).

Analysis on feeding behaviour of two sympatric species of nassariid gastropods, Cyclope neritea and Nassarius pfeifferi, from Cadiz Bay (SW Spain).

Assessing the impact of the Asian mussel Arcuatula senhousia in the recently invaded Oristano Lagoon-Gulf system (W Sardinia, Italy)

In the marine environment, the introduction and spread of non-indigenous mussels may cause major modifications to native assemblages and alter the trophic flow within the food web. We analysed the impacts of the recently sighted Asian date mussel Arcuatula (=Musculista) senhousia on sediment features, native macrozoobenthic assemblages and the δ13C and δ15N values of dominant macrozoobenthic taxa in the Oristano Lagoon-Gulf system (western Sardinia, Italy). Results showed that the amount of variation generated by the occurrence of Arcuatula senhousia was lower than the intrinsic spatial variability in sediment features, macrozoobenthic assemblages and the δ13C values of dominant deposit feeders (Hediste diversicolor, Cirriphormia tentaculata, Haminoea navicula and Cyclope neritea) of this system. In addition, δ13C and δ15N values of A. senhousia were found to be similar to those of co-occurring suspension feeders Cerastoderma glaucum, Ruditapes decussatus and Scrobicularia plana, indicating exploitation of common food resources. The overall lack of effects of A. senhousia may be dependent on the moderate densities encountered in our study area (<1000 individuals m−2). We suggest that the low rate of new arrivals, owing to limited shellfish farming and maritime activities in the area, and unfavourable environmental conditions of the lagoons especially in summer (e.g. anoxia) which erode mussel populations, likely prevent A. senhousia from entering its expansion phase and impacting local benthic communities.

Heavy metals and hydrocarbon concentrations in water, sediments and tissue of Cyclope neritea from two sites in Suez Canal, Egypt and histopathological effects.

Heavy metals and hydrocarbons are of the most common marine pollutants around the world. The present study aimed to assess the concentration of petroleum hydrocarbons and heavy metals in tissues of the snail cyclope neritea, water and sediments from two sites of the study area (Temsah lake and Suez canal) represent polluted and unpolluted sites respectively. The results showed that, the levels of the heavy metals (Pb, Cd, Co, Mg and Zn) in the polluted area have reached harmful limits recorded globally. Lead in water, sediment and tissue of the snail reached to 0.95 ppm, 4.54 ppm and 7.93 ppm respectively. Cadmium reached 0.31 ppm, 1.15 ppm and 3.08 ppm in the corresponding samples. Cobalt was not detected in water, but it reached 1.42 ppm and 10.36 ppm in the sediment and snails tissue respectively. Magnesium in water, sediment and tissue of the snail reached 3.73 ppm, 9.44 ppm and12.6 ppm respectively. Zinc reached 0.11 ppm, 3.89 ppm and 12.60ppm in the corresponding samples. Meanwhile, hydrocarbons in the polluted area (site1) reached 110.10 μg/L, 980.15 μg/g and 228.00 μg/g in water sediment and digestive gland tissues of the snails respectively. Whereas, hydrocarbons in the unpolluted area (site2) were estimated as 14.20 μg/L, 55.60 μg/g and 22.66 μg/g in water, sediment and tissue of the snails respectively.The combination of histopathological image with monitoring of the metal level in the digestive gland of the present snail provides an important tool for early detection of impending environmental problems and potential public health issues. Petroleum hydrocarbons are toxic to the marine fauna when present above certain limit in the marine water. The major detoxification organ in molluscs is the digestive gland, which has been used as a bioindicator organ for toxicity assessment. The effect of high crude oil on the digestive gland tubules of exposed snails when examined microscopically reveals a series of histological changes which indicates that the cellular compensatory mechanism is activated by hydrocarbons. These changes include vacuolation and presence of pyknotic nuclei.

Does the gathering of shellfish affect the behavior of gastropod scavengers on sandy beaches? A field experiment

Carrion on beaches is an unpredictable and ephemeral resource over time, especially in areas affected by a tidal regime whereby the ground is frequently washed by incoming tides. In this ecosystem, economic activity, such as the commercial harvesting of molluscs, leads to the presence of discarded, damaged and dying specimens of bivalves on the sand. Thus, although carrion usually represents a minor food source on sandy beaches, human harvesting activity can lead to a significant contribution, this being majorly important for scavengers. During low tide, intertidal gastropod scavengers remain buried in the substrate and emerge when they detect carrion. However, in some instances these gastropods may also emerge in response to mechanical disturbance regardless of the presence of food. The study reported here aims at investigating the effect of human activity, such as trampling on sandy beaches during shellfish gathering, on the behavior of the gastropod scavenger Cyclope neritea in terms of emersion and food locating. This goal was achieved by carrying out short-term field experiments on a sandy beach on the European Atlantic coast (SW Spain). The results demonstrate that, as with the presence of carrion on the ground, human trampling affects the behavior of C. neritea, favoring its emersion to the sediment surface and its movement on the ground. It is hypothesized that this is a potential trophic facilitation by shellfishers, since the emersion and movement of gastropods at low tide is induced during the period when the amount of food on the ground increases due to shellfish gathering. Nevertheless, this increased activity also implies a higher predation risk for these scavengers while emerging from the sand. In order to avoid predation, gastropods generally use alarm cues, such as the detection of damaged conspecifics, as an anti-predatory strategy. The behavioral response of C. neritea to the presence of damaged conspecifics was also studied. The results of this study highlight the fact that scavengers emerge from the sediment in response to trampling and the presence of carrion on the sediment surface. Further it is shown that although the presence of damaged conspecifics may act as a cue to gastropods, C. neritea does not respond to this stimulus until it first makes contact.

Feeding ecology of three species of Astropecten (Asteroidea) coexisting on shallow sandy bottoms of the northwestern Mediterranean Sea

Predation and competition are important biotic interactions influencing populations and communities in marine soft sediments. Sea stars are ubiquitous predators with diverse diets that play functionally important roles in the benthos. In this study, we examined the diet and the ecological roles of three sympatric species of the genus Astropecten (A. aranciacus, A. irregularis pentacanthus and A. platyacanthus). The study was performed between March 2010 and February 2011 on the Maresme coast (northwestern Mediterranean Sea). Results showed that their main diet consisted on gastropods and bivalves, such as Glycymeris glycymeris, Callista chione, Gibbula guttadauri and Cyclope neritea. Food competition between species was avoided by partition of prey resources. Intraspecific differences in the dietary compositions between seasons were found, but not between size classes. Ontogenetic patterns of prey size consumption were recognized in the three species. A large diet overlap was detected between A. aranciacus and A. platyacanthus in winter, due to changes in prey availability. Nevertheless, the analysis of the infaunal community composition and stomach contents indicated that food selection was not associated with prey availability.

Population structure and range expansion: the case of the invasive gastropod Cyclope neritea in northwest Iberian Peninsula

Biotic invasions have a reputation for unpredictable behavior. Here, we report how slight changes in human activity responsible for the introduction and range expansion of a non-native mollusk have led to detectable differences in the genetics of the invasion. Cyclope neritea is a non-predatory gastropod introduced to 2 areas of the European Atlantic: the northwest Iberian Peninsula (NWIP) and the French Atlantic coast (FAC). Shellfish seabed farming is intense in both areas but focuses on different commercial species. Using mitochondrial gene sequences, the lower genetic diversity recorded along the NWIP suggests a more homogeneous range of source populations than in the FAC. Unlike FAC, genetic diversity and haplotype composition in the NWIP correlate with the date of first occurrence of C. neritea at each site rather than with geographical location. Although this pattern evokes the genetic signature expected under a serial-founder colonization model from a single initial enclave, a comparison with samples from potential source populations suggests that the NWIP probably experienced several independent reintroductions. The jump dispersal pattern of C. neritea in the NWIP, together with the observation that populations established in the same year are genetically undifferentiated, point to human transport as the most plausible explanation for the current range expansion. Despite evidence for human-mediated dispersal, C. neritea managed to develop a seemingly non-random genetic pattern in the NWIP. It is suggested that caution must be exerted when interpreting genetic patterns in invaders.

8500-year-old Late Mesolithic garment embroidery from Vlasac (Serbia): Technological, use-wear and residue analyses

This paper presents results of contextual, technological, use-wear and residue analyses of body ornaments from two Late Mesolithic burials recently excavated at the site of Vlasac in the Danube Gorges of the central Balkans. Common to both burials are ornaments made from modified and unmodified carp (Cyprinidae sp.) pharyngeal ‘teeth’ along with Cyclope neritea marine gastropods. Experimental and low and high magnification use-wear approaches have been employed in reconstructing the way these ornaments were made and used. The precise contextual distribution of these ornaments has been recorded for the first time. The two examined burials exhibit a number of similarities, particularly in the way ornaments were placed in relation to the body. Both burials are also contemporaneous, dated to the mid-7th millennium BC. Implications of these findings for Mesolithic foragers' corporeal symbolism, group identity and regional and long-distance acquisition networks are briefly examined.

Arsenic occurrence and speciation in Cyclope neritea, a gastropod inhabiting the arsenic-rich marine shallow-water hydrothermal system off Milos Island, Greece

Around Milos Island marine shallow-water hydrothermal activity can be found and in Paleochori Bay, where high arsenic concentrations were reported for the hydrothermal fluids. There the gastropod Cyclope neritea was present at high densities despite the extreme conditions associated with hydrothermal venting, feeding on white microbial mats. Surprisingly, C. neritea collected from the hydrothermal vent area accumulated comparatively less arsenic in its tissues than specimens of the same species collected from an area not affected by hydrothermal activity. Inorganic arsenic was found at high percentages with respect to the sum of arsenic species both in the gut and muscle of C. neritea and the amount of arsenobetaine (AB) was less than in specimens collected at an area away from hydrothermal activity. Trimethylarsoniopropionate (TMAP) was found at relatively high percentages in C. neritea and in the surrounding environment (sediment and plankton) in Paleochori Bay. Tetramethylarsonium ion (TETRA) was found at high percentages in the gut and muscle of C. neritea. It was most likely biosynthesized in the gastropod gut, and accumulated in the muscle, because it was not found in any other compartment studied. Based on these observations we conclude that C. neritea is arsenic tolerant. The data suggests that arsenic species distribution is strongly influenced by arsenic species exposure and/or different detoxifying mechanisms, although the exact metabolic pathways could not be completely resolved.

Molecular and morphological identification of larval opecoelids (Digenea: Opecoelidae) parasitising prosobranch snails in a Western Mediterranean lagoon

In a study of the digeneans parasitising molluscs in the Els Alfacs lagoon (Ebro Delta, Western Mediterranean) we found heavy infections with sporocysts emitting two types of cotylocercous cercariae in the prosobranch trochid gastropod Gibbula adansonii and with metacercariae in the prosobranch nassariid gastropod Cyclope neritea. A comparative analysis using ITS ribosomal DNA sequences from these larval stages and published sequences of 17 larval and adult opecoelid stages allowed us to elucidate the life-cycle of Macvicaria obovata and to confirm the identification of Cainocreadium labracis based on cercarial morphology. We provide molecular evidence for the identification and the first detailed morphological descriptions of the intramolluscan larval stages of the two opecoelid species as well as partial 28S rDNA sequences to aid future studies on systematic relationships within the Opecoelidae.

Black Cyclope neritea Marine Shell Ornaments in the Upper Palaeolithic and Mesolithic of Franchthi Cave, Greece: Arguments for Intentional Heat Treatment

The prehistoric site of Franchthi Cave yielded an exceptionally rich collection of personal ornaments. A reassessment of the Palaeolithic and Mesolithic ornaments from the site led to the hypothesis that a variable fraction of at least one type of personal ornaments, i.e. marine shell beads belonging to the species Cyclope neritea, may have been intentionally heated to change their natural whitish color to black. The limited conditions in which blackening can occur through heating, as well as comparison with the percentage of burnt land snails, animal bones, fish bones, and marine molluscan food remains in the Upper Palaeolithic and Mesolithic sequence, supports a special heat treatment for Cyclope neritea shells at Franchthi Cave.

Imposex and butyltin concentrations in snails from the lagoon of Bizerta (Northern Tunisia)

Imposex and butyltin concentrations were assessed in Hexaplex trunculus, Conus mediterraneus, Cyclope neritea and Nassarius mutabilis from Menzel Jemil, and H. trunculus and Stramonita haemastoma from the Bizerta channel. All females of the five species exhibited the characteristic development of male sex organs (penis and/or vas deferens). In Menzel Jemil, H. trunculus and C. mediterraneus exhibit similar imposex levels and were most affected (VDS reading 3–4). The development of a bud penis or a vas deferens sequence behind the right ocular tentacle was reported in Cyclope neritea and N. mutabilis (VDS 1). The concentration of tributyltin (TBT) was similar for the four species. The monobutyltin (MBT) was only detected in C. mediterraneus while the dibutyltin (DBT) was found in all gastropods at similar proportions as TBT. In the Bizerta channel, imposex levels were similar in both H. trunculus and S. haemastoma but imposex degree was higher in H. trunculus. This finding was confirmed by higher TBT concentration recorded in female of H. trunculus. These results suggested that H. trunculus is the more suitable bioindicator for monitoring TBT pollution.

Nakit i umjetnost pećine Vlakno

The Vlakno cave is situated in the central part of the island of Dugi Otok between settlements Luka and Savar. The cave was suitable for dwelling of a smaller group throughout the year due to its look, size and orientation. The third campaign of the archaeological research was undertaken at the beginning of 2010 with the aim of determining complete startigraphy of the site so that the excavation was conducted within previously opened Trench B (fig. 1).In the previous campaigns the level of tephra, Neapolitan Yellow Tuff was reached. Analyses indicate that this layer was formed 14 500 years ago. In the new campaign additional 80 cm of deposits under tephra have been excavated, and the bottom of the cave was not reached until the end of the campaign. Under the tephra there are three main layers separated with two thin interlayers of ash and burnt soil which actually represent walking surfaces from the period when the cave was in use. Preliminary analyses of the material from all three layers indicate to the Epigravettian period corresponding with the general development of the Upper Palaeolithic on both sides of the Adriatic. Dates acquired for layers under tephra indicate age from 12. 710 to 12. 120 cal. years BC (14. 660 to 14. 060 cal. years BP). At the beginning of the new excavation decrease of the remains of marine organisms was evident, and the remains of big terrestrial animals refer mostly to big ruminants. There are less flint tools, although they are still represented with a significant number of specimens. There are also bone tools, such as perforated teeth of a deer (Cervus elaphus), perforated shells and snails (Cyclope neritea, Columbella rustica and shells of the genus Glycimeris). Eight perforated deers' teeth were found, six different perforated shells and a bead made of a shell of the genus Entalina (Dentalium tetragonum) (fig. 2). Alongside these finds, we need to mention fragments of ten bone awls and punches.Besides jewelry, meaning of the aesthetics gains even more importance regarding the find of two fragments of chert nodules in the same layer. One of them is decorated with a row of short, parallel and two horizontal incisions on the cortex (fig. 5). This was a segment of a larger depiction, continuing in three directions in relation to the extant segment. Unfortunately other fragments are missing which is why it is impossible to discuss the type of depiction. Nodule is broken, only its segment is preserved. It is triangular in cross-section, 3,6 cm long. Preliminary analyses indicate that it was exposed to heating before it was broken.Another fragment of a nodule was found in the same layer, semicircular in cross-section. Incisions in the cortex are shallow, filling the entire surface as opposed to the previously mentioned fragment. This is a row of slanted parallel short incisions encircling the flake (fig. 6).Meaning of these objects remains unknown until the time of possible discovery of some other fragment. There are no indications of functional characteristics of these incisions which is why it is reasonable to suppose that their purpose was of aesthetic nature to say the least. It is possible that depictions on the stone from Vlakno have far more complex meaning. Archaeologists assume that some of the art of the Upper Palaeolithic was used for information storage. Geometric forms might represent different marks or symbols, messages illegible to a modern man.These are not the only decorated objects from Vlakno. On a bone awl is a row of horizontal, short incisions on the proximal part which were not created as a result of working or using bone (cutmarks) but they undoubtedly represent a decoration of the object. Similar incisions (four short incisions) were found on the distal part of the bone punch. These incisions can only have aesthetic meaning as well as on the previously mentioned example. However they may be a sign of ownership or affiliation to a group, or, since the incisions repeat, they may represent a system of numbers.

Introduced status of Cyclope neritea (Gastropoda, Nassariidae) in the NW Iberian Peninsula confirmed by mitochondrial sequence data

Confined to a single enclave for more than a decade, the nassariid gastropod Cyclope neritea has expanded its range along the NW Iberian Peninsula (NWIP) region, forming dense popu- lations in several locations. Unintended introductions from imported live shellfish seemed to be the probable vector for this recent proliferation. However, the relative proximity to the edges of the native range of this snail, together with some recent findings in areas similarly invaded by C. neritea (French Atlantic coast), raised the possibility that the species might be present in the NWIP for rea- sons other than human-mediated transfer. Moreover, it was unknown whether the recent prolifera- tion was due to new independent re-introductions or to the spread from the earlier population. To provide some insight into these questions, we utilized the mitochondrial marker cytochrome oxidase I (533 bp) from individuals collected in 3 localities thought to cover the current known range of the spe- cies in the NWIP. Our results strongly confirm the non-native status of C. neritea, pointing to human- induced introductions as the probable cause for its presence in the NWIP. The Veneto region (Adri- atic Sea) is the likely source for the introduced snails, while Manila clam transfers might be the major, even unique, vector of introduction, at least for the more recently settled localities. Recent indepen- dent re-introductions, rather than spread from an earlier introduction, appear to be the likely cause for the current proliferation of C. neritea within the region.

Imaging Oxygen Distribution in Marine Sediments. The Importance of Bioturbation and Sediment Heterogeneity

The influence of sediment oxygen heterogeneity, due to bioturbation, on diffusive oxygen flux was investigated. Laboratory experiments were carried out with 3 macrobenthic species presenting different bioturbation behaviour patterns: the polychaetes Nereis diversicolor and Nereis virens, both constructing ventilated galleries in the sediment column, and the gastropod Cyclope neritea, a burrowing species which does not build any structure. Oxygen two-dimensional distribution in sediments was quantified by means of the optical planar optode technique. Diffusive oxygen fluxes (mean and integrated) and a variability index were calculated on the captured oxygen images. All species increased sediment oxygen heterogeneity compared to the controls without animals. This was particularly noticeable with the polychaetes because of the construction of more or less complex burrows. Integrated diffusive oxygen flux increased with oxygen heterogeneity due to the production of interface available for solute exchanges between overlying water and sediments. This work shows that sediment heterogeneity is an important feature of the control of oxygen exchanges at the sediment-water interface.

Collection of marine invertebrates for the aquarium trade in European waters: is anyone surveying?

Abstract Recently, the snails Hinia reticulatus, Cyclope neritea and Cerithium rupestre and the hermit crabs Diogenes pugilator and Clibanarius erythropus from warm European coastal waters have started to be commercially collected and traded. The average number (± standard deviation) of specimens captured per hour, by collectors were 475±237 for H. reticulatus, 363±112 for C. neritea, 384±173 for C. rupestre, 302±121 for D. pugilator and 210±54 for C. erythropus. All species survived well during transportation, were popular among aquarium hobbyists and attained high retail values, ranging from €0.90 to €4.00 per specimen. The collection and trade of these novel commercial species can either become a sole economic activity or an additional one for traditional fishermen and aquaculturists. Although no destructive collection techniques are employed, the lack of population biology studies and legislation regulating the capture of these species is a major problem in ensuring the sustainable use of these highly valuable marine resources. These species are currently mainly collected from natural parks areas protected by Portuguese and European Union designations. Copyright © 2007 John Wiley &amp; Sons, Ltd.

Discovery of imposex in the gastropod Cyclope neritea now invading Galicia (north-west Spain)

A field survey to re-assess imposex and tributyltin (TBT) bioaccumulation in the gastropod Nassarius reticulatus over Galicia uncovered three populations of the invasive species Cyclope neritea, all showing some advanced imposex. One female was found to carry a mass of aborted egg capsules. The TBT pollution, now decreasing in the area, is the most likely explanation for these reproductive anomalies, and it may bear some relationship to the described population dynamics of C. neritea.

Multiple introductions promote range expansion of the mollusc Cyclope neritea (Nassariidae) in France: evidence from mitochondrial sequence data

Since the 1970s, the nassariid gastropod Cyclope neritea has been extending its range north along the French Atlantic coasts from the Iberian Peninsula. This may be due to natural spread because of the recent warming of the northeastern Atlantic. However, human-mediated introductions related to shellfish culture may also be a probable explanation for this sudden range expansion. To examine these two hypotheses, we carried out a comprehensive study based on mitochondrial gene sequences (cytochrome oxidase I) of the five recently colonized French bays as well as 14 populations located in the recognized native range of the species. From a total of 594 individuals, we observed 29 haplotypes to split into three divergent clades. In the native range, we observed a low molecular diversity, strong genetic structure and agreement between geography and gene genealogies. Along the French coasts, we observed the opposite: high genetic diversity and low genetic structure. Our results show that recurrent human-mediated introductions from several geographical areas in the native range may be a source for the French Atlantic populations. However, despite the low dispersal ability of C. neritea, the isolation-by-distance pattern in France suggested that this gastropod may have been present (although unnoticed) on the French Atlantic coasts before the 1970s. As C. neritea shows characteristics of a cryptogenic species, the classification of Atlantic populations as either native or introduced is not straightforward. Cryptogenic species should be studied further to determine the status of new populations close to their recognized native range.

Polymorphic microsatellites for the study of newly established populations of the gastropod Cyclope neritea

AbstractBoth human‐mediated introductions and climatic changes may promote the settlement of species in new areas outside of their natural geographical range. To investigate the settlement of recently established populations of the neogastropod Cyclope neritea, we developed eight microsatellite markers. Their usefulness was studied in two native populations previously found to be monomorphic with mitochondrial markers. The eight loci were found to be polymorphic in both populations, with two to 18 alleles per locus. This result shows promise for these loci in studies of recently founded populations of C. neritea.