Trace element fingerprinting of cockle (Cerastoderma edule) shells can reveal harvesting location in adjacent areas

Determining seafood geographic origin is critical for controlling its quality and safeguarding the interest of consumers. Here, we use trace element fingerprinting (TEF) of bivalve shells to discriminate the geographic origin of specimens. Barium (Ba), manganese (Mn), magnesium (Mg), strontium (Sr) and lead (Pb) were quantified in cockle shells (Cerastoderma edule) captured with two fishing methods (by hand and by hand-raking) and from five adjacent fishing locations within an estuarine system (Ria de Aveiro, Portugal). Results suggest no differences in TEF of cockle shells captured by hand or by hand-raking, thus confirming that metal rakes do not act as a potential source of metal contamination that could somehow bias TEF results. In contrast, significant differences were recorded among locations for all trace elements analysed. A Canonical Analysis of Principal Coordinates (CAP) revealed that 92% of the samples could be successfully classified according to their fishing location using TEF. We show that TEF can be an accurate, fast and reliable method to determine the geographic origin of bivalves, even among locations separated less than 1 km apart within the same estuarine system. Nonetheless, follow up studies are needed to determine if TEF can reliably discriminate between bivalves originating from different ecosystems

A brief review of the immunobiology of eledone cirrhosa

Blood can be sampled repeatedly from the lesser octopus Eledone cirrhosa (Lamarck) and the haemocytes cultured for up to 72 h. Sampling results in an increase in the number of circulating haemocytes per mland inthe percentage of haemocytes containing cytoplasmic granules, and a change in the staining pattern of the haemocytes. It also causes a decrease in the quantity of copper in the haemolymph. The haemocytes phagocytose bacteria (Vibrio anguillarum) in vitro in the absence of haemolymph, but there is enhanced phagocytosis in the presence of haemolymph. Haemocytes migrate towards low concentrations of various blood preparations, to lipopolysaccharide (LPS) and to preparations that had contained live bacteria. They also have an apparent bacteriostatic effect on the growth of live bacteria. Haemocytes produce intracellular reactive oxygen species after incubation with dead bacteria in particular, but also live bacteria and LPS. E. cirrhosa haemolymph agglutinatesthe bacteria V. anguillarum, V. parahaemolyticus and Aeromonas salmonicida and exerts a bacteriostatic effect on them. The haemolymph, haemocytes and certain tissues from E. cirrhosa exhibit lysozyme and antiprotease activity. Injection of live V. anguillarum causes an increase in lysozyme activity in the branchial heart (after 48 h) and a decrease in the number of circulating haemocytes (after 24 h). Antiprotease activity increases in the haemocytes (4 h) after injection of bacteria but decreases in the haemolymph. Live bacteria cause an increase in the number of circulating haemocytes, but are cleared from the circulation in about 4 h by both the haemocytes and tissues (branchial heart, branchial heart appendage and white body), where they are degraded. Ultrastructuralchanges were observed in the branchial heart cells and the haemocyte nucleus after injection of bacteria. Following injection, colloidal graphite is aggregated in blood vessels only

Core Community Persistence Despite Dynamic Spatiotemporal Responses in the Associated Bacterial Communities of Farmed Pacific Oysters

A breakdown in host-bacteria relationships has been associated with the progression of a number of marine diseases and subsequent mortality events. For the Pacific oyster, Crassostrea gigas, summer mortality syndrome (SMS) is one of the biggest constraints to the growth of the sector and is set to expand into temperate systems as ocean temperatures rise. Currently, a lack of understanding of natural spatiotemporal dynamics of the host-bacteria relationship limits our ability to develop microbially based monitoring approaches. Here, we characterised the associated bacterial community of C. gigas, at two Irish oyster farms, unaffected by SMS, over the course of a year. We found C. gigas harboured spatiotemporally variable bacterial communities that were distinct from bacterioplankton in surrounding seawater. Whilst the majority of bacteria-oyster associations were transient and highly variable, we observed clear patterns of stability in the form of a small core consisting of six persistent amplicon sequence variants (ASVs). This core made up a disproportionately large contribution to sample abundance (34 ± 0.14%), despite representing only 0.034% of species richness across the study, and has been associated with healthy oysters in other systems. Overall, our study demonstrates the consistent features of oyster bacterial communities across spatial and temporal scales and provides an ecologically meaningful baseline to track environmental change

Welfare and Diseases Under Culture Conditions

16 pagesThis chapter reviews the welfare and diseases that have been reported since cephalopods are maintained, reared or cultured in captivity. Although cephalopod welfare is only going to be assured in terms of the European Union (EU) legislation from January 2013, it has long been enforced in other regions or countries all over the world. Pathologies registered under captive conditions derive, most of the times, from bad welfare practices. A revision of cephalopods’ immune system and the most important pathologies are presented, which are divided into viral, bacterial, fungal and parasitic pathogenic agents as well as chemical and mechanical damages. In addition, information regarding healing, antibiotics application and surgery is provided. Welfare under research and commercial culture conditions is discussed in terms of the use of anaesthesia and euthanasia agents and their assessment in terms of effectiveness. Further research on the different aspects considered is suggestedN

Cephalopods in neuroscience: regulations, research and the 3Rs

Cephalopods have been utilised in neurosci- ence research for more than 100 years particularly because of their phenotypic plasticity, complex and centralised nervous system, tractability for studies of learning and cellular mechanisms of memory (e.g. long-term potentia- tion) and anatomical features facilitating physiological studies (e.g. squid giant axon and synapse). On 1 January 2013, research using any of the about 700 extant species of ‘‘live cephalopods’’ became regulated within the European Union by Directive 2010/63/EU on the ‘‘Protection of Animals used for Scientific Purposes’’, giving cephalopods the same EU legal protection as previously afforded only to vertebrates. The Directive has a number of implications, particularly for neuroscience research. These include: (1) projects will need justification, authorisation from local competent authorities, and be subject to review including a harm-benefit assessment and adherence to the 3Rs princi- ples (Replacement, Refinement and Reduction). (2) To support project evaluation and compliance with the new EU law, guidelines specific to cephalopods will need to be developed, covering capture, transport, handling, housing, care, maintenance, health monitoring, humane anaesthesia, analgesia and euthanasia. (3) Objective criteria need to be developed to identify signs of pain, suffering, distress and lasting harm particularly in the context of their induction by an experimental procedure. Despite diversity of views existing on some of these topics, this paper reviews the above topics and describes the approaches being taken by the cephalopod research community (represented by the authorship) to produce ‘‘guidelines’’ and the potential contribution of neuroscience research to cephalopod welfare