West Indian Top Shell Research Articles

Congruence between microsatellite loci, SNPs, and COI gene reveals a phylogeographic break in the southern Caribbean Sea: The case of West Indian top shell Cittarium pica (Gastropoda: Tegulidae)

It has been proposed that species associated with shallow rocky bottoms in the southern Colombian Caribbean Sea are affected by two biogeographic barriers: the Magdalena River plume (MRP) and the combination of the absence of rocky bottoms and the almost permanent upwelling in the Guajira peninsula (ARB+PUG). We evaluated whether these barriers had generalized genomic effects on the phylogeographic structure of the West Indian top shell (Cittarium pica), a crucial fishery resource in many areas of the Caribbean Sea. Ten species-specific microsatellite loci, 55,112 SNPs from ddRADseq, and COI gene were used on samples of C. pica collected at five Colombian localities (Cabo de la Vela; Santa Marta; Cartagena; Isla Fuerte; and Capurganá). Genetic structure analyses performed for microsatellite and SNP loci indicated that there are three genetic groups of C. pica in Colombia (pop 1: Cabo de la Vela; pop 2: Santa Marta; pop 3: Cartagena+Isla Fuerte+Capurganá). However, both SNPs and COI gene were congruent in showing a phylogeographic break caused by only the ARB + PUG (AMOVA: ΦCT-SNP=0.224, p < 0.05; ΦCT-COI=0.722, p < 0.05), which was confirmed by the maximum-likelihood and network trees. In contrast, MRP was shown to be a permeable barrier to gene flow. Demographic history analysis indicated that C. pica experienced historical changes in population size during the last glaciation period. Cittarium pica is a biological model to demonstrate how the ARB + PUG barrier could affect marine organisms living in shallow rocky habitats, mainly those lacking larvae or having a short-lived larval phase in the southern Caribbean Sea. Finally, some recommendations for fisheries management and conservation C. pica populations are discussed.

Effect of diet and water quality on the energetic physiology of the West Indian top shell Cittarium pica

The West Indian top shell Cittarium pica is a gastropod species currently regarded as threatened mainly due to overfishing of wild stocks. Substantial efforts have been invested in the experimental culture of this mollusk for resource conservation, as well for commercial production. In order to determine the suitable culture conditions for this species, the present study addressed the effect of diet and water quality on the energetic physiology of C. pica. Experimental animals were fed with different diets (fresh seaweed, benthic microalgae and artificial biofilm), and exposed to different rates of water renewal (10, 50, 100 and 300% h−1), and levels of salinity (25, 30, 35 and 40 ppt), temperature (22, 27 and 32 °C) and ammonia concentration (2.5, 8.0, 20.0 and 40.0 μg NH3-N L−1). Under such conditions, individual measurements of ingestion rate (IR), absorption efficiency (AE), oxygen consumption rate (OCR), ammonium excretion rate (UR), mucus production rate (MR) and scope for growth (SFG), were conducted. Both, juveniles and adults exhibited a micro-grazing feeding behavior. IR was affected by diet, water renewal and salinity, while AE was influenced by all the factors tested. OCR was only affected by ammonia concentration, while UR was influenced by salinity, temperature and ammonia concentration. Finally, MR was affected by all the factors tested, except for diet. The highest SFG performances were obtained when top shells were fed artificial diet biofilm, and maintained at relatively high levels of salinity (35–40 ppt) and temperature (27–32 °C), and intermediate rates of water renewal (50–100% h−1), oxygen saturation (> 70%) and ammonia concentration (2.5–40.0 μg NH3-N L−1). In general, such responses were associated with high IR and/or AE values, while energy losses in terms of OCR, MR and UR did not show a significant influence.

Nursery culture of wild and hatchery-produced juveniles of the West Indian top shell, Cittarium pica, fed microalgal and artificial biofilms

Cittarium pica is an overexploited Caribbean top shell that is being produced at an experimental level by aquaculture for conservation purposes. To optimise nursery culture, the growth and survival of wild and hatchery-produced juveniles were assessed after feeding with different biofilm diets. The following three diets were tested over a 6-month period: (1) a microalgal biofilm of Nitzschia sp. and Tetraselmis chuii; (2) an artificial biofilm of dry seaweeds, Padina gymnospora and Laurencia obtusa, and the cyanobacterium Spirulina sp.; and (3) a mix of the microalgal and artificial biofilms. The biofilms were prepared and supplied on folded PVC plates, and treatments were administered in triplicated 10-L aquaria with down-welling systems at 25 ± 1 °C and a salinity of 36.5 ± 0.5 ppt. Higher growth rates were obtained in juveniles fed diets containing artificial biofilms, which had high protein and energy contents, whereas survival rates were higher in juveniles fed the mixed diet. The relatively high growth and survival values suggest that the nursery culture can be improved by feeding with the mix of microalgal and artificial biofilms and that the temporary translocation of wild juveniles to nursery conditions can be a tool for population enhancement.

Experimental culture of larvae, post-larvae and juveniles of the West Indian top shell, Cittarium pica (Linnaeus 1758)

The West Indian top shell, Cittarium pica, is an endangered vetigastropod of ecological and commercial value from the Caribbean. In order to assess the use of aquaculture as a tool for its sustainable production and conservation, embryos were produced in hatchery and experimentally cultured until juveniles under different conditions. Embryos were incubated under two temperatures (25 and 29°C) and six densities (0.3, 0.6, 1.0, 4.0, 9.0 and 37.0% of bottom-coverage). Larvae were reared under different temperatures (25 and 27°C), densities (0.5, 1, 1.5 and 10 larvae/ml) and culture systems (static and down-welling). Post-larvae were obtained in three different settling conditions, and the early juveniles were cultured supplying fresh seaweed (Laurencia obtusa and Padina gymnospora), natural multi-specific biofilm and Cylindroteca sp. biofilm. The growth and survival of embryos and larvae were not affected by temperature, but they were affected by density. Higher values were obtained at low densities (<1% of embryos bottom-coverage and <1 larvae/ml), except for the growth of larvae, which was similar among treatments. Higher larval survival was recorded using the static culture system, and higher percent of post-larvae recovered was associated with lower density of crawling veliger (0.2 and 0.1/ml), while its higher growth rate was related to the use of biofilms with conspecific mucus and low water-flow (50%/h). The type of food tested did not affect the juvenile growth, but higher survival was obtained in those fed with seaweed than with multi-specific biofilm.

Spawning and early development of the West Indian top shell,Cittarium pica(Linnaeus, 1758), under ex-situ conditions

The West Indian top shell, Cittarium pica , is an endangered vetigastropod from the rocky intertidal Caribbean. In order to provide a basis for its hatchery-production as a conservation tool, spawning and early development were evaluated under ex-situ conditions. Spawning response was monitored during different lunar phases with application of physical and chemical stimuli – such as changes in temperature salinity and desiccation, exposure to UV irradiated water and chemical stimulation with Tris and hydrogen peroxide. Spawning response was obtained in association with daytime, new moon, flooding and high tides. Use of physical and chemical stimuli did not elicit any spawning response. Adults conditioned in the hatchery for one year did not spawn. Spawning of males and females was simultaneous and frequently intermittent. On average, percentage and size of spawn was higher for males than females. Fecundity was positively correlated with total female wet weight, with an average value of 149 000 oocytes per female. Embryonic and larval development was reported in detail. Results suggest that there is a high potential to use the controlled ex-situ reproduction of C. pica as a conservation tool, since gamete and larvae were repeatedly obtained from wild adults collected days before new moon following a circadian endogenous pattern applying simple protocols of spawning, fertilization and incubation.

Shellfish as reservoirs of bacterial pathogens

Shellfish comprises a variety of animals including bivalves – oysters, clams, quahogs, scallops, mussels, and others including crustaceans – lobsters, crabs, and shrimps. Shellfish naturally found in Grenada, an island nation in the Caribbean, include: blue land crabs (Cardisoma guanhumi), clams (Mercenaria mercenaria), oysters (Isognomon isognomon), queen conchs, also called “lambi” (Strombus gigas), and whelks (West Indian top shell) (Cittarium pica), all of which are used for human consumption in this country. Bacteria are ubiquitous in the marine environment. Shellfish can be a source of commensal bacteria that can be pathogenic to shellfish, as well as those pathogenic to humans. Raw and partially cooked molluscan shellfish (clams, oysters, and mussels) have a long history as vectors of infectious agents[1]. According to Potasman et al.[2], the earliest reports of shellfish-transmitted diseases were documented in the late 19th and early 20th century. Apart from typhoid fever, the most notable examples include Vibrio species, which account for 20% of all outbreaks of shellfishassociated human disease. Other bacteria are Salmonella species, Shigella species, Plesiomonas shigelloides, and Listeria species[2]. Several Vibrio species native to both marine and estuarine environments, have been identified as the causative agents of shellfish-associated human illnesses. These include Vibrio parahaemolyticus (V. parahaemolyticus), Vibrio vulnificus (V. vulnificus), Vibrio cholerae non-O1, Vibrio cholerae, Vibrio cholerae O1, Vibrio fluvialis (V. fluvialis), Vibrio hollisae, Vibrio mimicus, Vibrio alginolyticus (V. alginolyticus), and unidentified or miscellaneous Vibrio species. Among these, all except V. vulnificus, are associated with gastroenteritis of varying severity[1]. Oysterassociated V. vulnificus septicemia and death were first reported in 1975[3]. Another bacterium of public health concern is Salmonella. Compared to vibrios, there have been much less studies on Salmonella in various shellfish. Setti et al.[4] studied the dynamics of Salmonella contamination in the coastal areas of Agadir, a populous region of Southern Morocco where shellfish production is important to the local economy. Salmonella enterica (S. enterica) serovar Kentucky was found almost exclusively in mussels, whereas Salmonella blockley was found in mussels and sediment samples. Identification of Salmonella to serovar level is required ARTICLE INFO ABSTRACT

EXPLOTACIÓN, USOS Y ESTADO ACTUAL DE LA CIGUA O BURGAO CITTARIUM PICA (MOLLUSCA: GASTROPODA: TROCHIDAE) EN LA COSTA CONTINENTAL DEL CARIBE COLOMBIANO

The West Indian topshell, Cittarium pica is a common and conspicuous gastropod that thrives in Caribbean intertidal rocky shores and has been used for food by men since pre-Columbian times. Although, the exploitation of this resource is practiced only by artisanal fishermen and mainly for self-consumption, its abundance has noticeably reduced in the last ten years, so the species has been included in the endangered animal lists of several Caribbean countries, including Colombia. The present study was carried out to assess the current status of the population of C. pica along the Colombian Caribbean mainland and to describe the overall exploitation level and uses of this resource in recent times. In order to achieve so, Colombian Caribbean coast was divided into five zones according to the established distribution range of the species: 1-Urabá chocoano, 2-Isla Fuerte, 3-Cartagena and Rosario Islands, 4-Santa Marta and Tayrona Natural National Park, 5-La Guajira. In each one of the zones opinion polls among local inhabitants were conducted. A series of samples from representative stations were obtained in order to determine the abundance, density and size structure of the C. pica population. The fishing pressure on the resource is different between the sectors, being greater in Santa Marta and Tayrona Natural National Park, Urabá chocoano, and Cartagena and Rosario Islands. The main use given to C. pica is as dietary complement of the local population, but the flesh and shells are commercialized at times. Shells are sold to artisans and used for “souvenirs” and handcraft manufactures. The mean ecological density of C. pica in the entire study area was 5.38 Ind/m2 (± 0.82), with significant differences between sectors and between the stations within a sector as well. The size structure of the population (mean size = 25.08 mm ± 4.71, mode = 11.10 mm) suggests that in general the resource is being over-exploited in the Colombian Caribbean. This result confirms that C. pica is an endangered species in Colombia and its status as “vulnerable” in the red list should be maintained.

Periodicity of extinction and recolonization of the West Indian topshellCittarium picain the Quaternary of Bermuda (Gastropoda: Trochoidea)

Hermit-crab transported shells of the West Indian top shell Cittarium pica occur in numerous terrestrial fossil deposits on Bermuda, which is the most remote outpost of this Caribbean species. Cittarium is so far known only from deposits of interglacial ages corresponding to marine isotope stages (MIS) 11, 9, 5e, and 1 (Holocene). In at least the cases of MIS 11 and 5e, Cittarium appears at the very beginning of the interglacial. The species is definitely absent from well-stratified cave deposits of the last glacial (MIS 4–2). It is hypothesized that colder sea-surface temperatures (SSTs) during glacial periods caused Cittarium to be extirpated on Bermuda, and that it has made at least four independent colonizations of the island in the past 400 000 years. Because of the limited larval life of Cittarium, the window for colonization may be a very narrow period at the onset of interglacials when the SST has risen sufficiently to make Bermuda habitable but the velocity of the Gulf Stream is still sufficiently rapid to transport viable larvae from the Bahamas. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 235–243.

Pre-Columbian impact on terrestrial, intertidal, and marine resources, San Salvador, Bahamas (A.D. 950–1500)

Summary Zooarchaeological remains from San Salvador, Bahamas, reveal trends in pre-Columbian exploitation of terrestrial, intertidal, and marine resources during the period A.D. 950–1500. Significant declines in quantities and weights of Gecarcinidae (land crabs), weights of mollusks, such as Cittarium pica (West Indian top shell) and Chiton tuberculatus/Acanthopleura granulata (chitons), and body sizes of both Sparisoma viride (stoplight parrotfish) and Serranidae (sea basses and groupers) all indicate prehistoric overexploitation. Declines in total number of identified marine taxa as well as average trophic levels of exploited marine vertebrates suggest reduced species diversity and “fishing down the marine food web.” These findings indicate that a relatively minor prehistoric human population (500–1000 people) can have significant environmental impacts, especially on small, vulnerable island ecosystems.

First record of the Caribbean genus Cittarium (Mollusca: Gastropoda: Trochidae) from the Oligocene of Europe and its paleobiogeographic implications

The West Indian Top-shell, Cittarium pica (Linnaeus, 1758), is a very classic and common species of the Caribbean faunal province. Until now the only known fossil occurrence of Cittarium pica, and of the genus Cittarium, is from Pleistocene deposits restricted to the Caribbean province (Clench and Abbott, 1943). Despite the turbiniform shell, the monotypic genus Cittarium belongs to the family Trochidae and was assigned to the tribe Gibbilini Stoliczka, 1868 by Hickman and McLean (1990). This paper reports a new species of Cittarium and the only record outside the Caribbean province. More than twenty million years separate the single modern species of Cittarium and the new fossil species. All material collected is deposited in Museum national d'Histoire Naturelle, Paris (MNHN).

FIRST RECORD OF THE CARIBBEAN GENUS CITTARIUM (MOLLUSCA: GASTROPODA: TROCHIDAE) FROM THE OLIGOCENE OF EUROPE AND ITS PALEOBIOGEOGRAPHIC IMPLICATIONS

The West Indian Top-shell, Cittarium pica (Linnaeus, 1758), is a very classic and common species of the Caribbean faunal province. Until now the only known fossil occurrence of Cittarium pica, and of the genus Cittarium, is from Pleistocene deposits restricted to the Caribbean province (Clench and Abbott, 1943). Despite the turbiniform shell, the monotypic genus Cittarium belongs to the family Trochidae and was assigned to the tribe Gibbilini Stoliczka, 1868 by Hickman and McLean (1990). This paper reports a new species of Cittarium and the only record outside the Caribbean province. More than twenty million years separate the single modern species of Cittarium and the new fossil species. All material collected is deposited in Museum national d'Histoire Naturelle, Paris (MNHN).