The effects of feeding Karlodinium veneficum (PLY # 103; Gymnodinium veneficum Ballantine) to the blue mussel Mytilus edulis

The effects of exposure to the type species for Karlodinium veneficum (PLY # 103) on immune function and histopathology in the blue mussel Mytilus edulis were investigated. Mussels from Whitsand Bay, Cornwall (UK) were exposed to K. veneficum (PLY # 103) for 3 and 6 days. Assays for immune function included total and differential cells counts, phagocytosis and release of extra cellular reactive oxygen species. Histology was carried out on digestive gland and mantle tissues. The toxin cell quota for K. veneficum (PLY #103) was measured by liquid chromatography-mass spectrometry detecting two separable toxins KvTx1 (11.6 ± 5.4 ng/ml) and KvTx2 (47.7 ± 4.2 ng/ml). There were significant effects of K. veneficum exposure with increasing phagocytosis and release of reactive oxygen species following 6 days exposure. There were no significant effects on total cell counts. However, differential cell counts did show significant effects after 3 days exposure to the toxic alga. All mussels produced faeces but not pseudofaeces indicating that algae were not rejected prior to ingestion. Digestive glands showed ingestion of the algae and hemocyte infiltration after 3 days of exposure, whereas mantle tissue did not show differences between treatments. As the effects of K. veneficum were not observed in the mantle tissue it can be hypothesized that the algal concentration was not high enough, or exposure long enough, to affect all the tissues. Despite being in culture for more than 50 years the original K. veneficum isolate obtained by Mary Parke still showed toxic effects on mussels.

Pathology and immune response of the blue mussel (Mytilus edulis L.) after an exposure to the harmful dinoflagellate Prorocentrum minimum

The harmful dinoflagellate Prorocentrum minimum has different effects upon various species of grazing bivalves, and these effects also vary with life-history stage. Possible effects of this dinoflagellate upon mussels have not been reported; therefore, experiments exposing adult blue mussels, Mytilus edulis, to P. minimum were conducted. Mussels were exposed to cultures of toxic P. minimum or benign Rhodomonas sp. in glass aquaria. After a short period of acclimation, samples were collected on day 0 (before the exposure) and after 3, 6, and 9 days of continuous-exposure experiment. Hemolymph was extracted for flow-cytometric analyses of hemocyte, immune-response functions, and soft tissues were excised for histopathology. Mussels responded to P. minimum exposure with diapedesis of hemocytes into the intestine, presumably to isolate P. minimum cells within the gut, thereby minimizing damage to other tissues. This immune response appeared to have been sustained throughout the 9-day exposure period, as circulating hemocytes retained hematological and functional properties. Bacteria proliferated in the intestines of the P. minimum-exposed mussels. Hemocytes within the intestine appeared to be either overwhelmed by the large number of bacteria or fully occupied in the encapsulating response to P. minimum cells; when hemocytes reached the intestine lumina, they underwent apoptosis and bacterial degradation. This experiment demonstrated that M. edulis is affected by ingestion of toxic P. minimum; however, the specific responses observed in the blue mussel differed from those reported for other bivalve species. This finding highlights the need to study effects of HABs on different bivalve species, rather than inferring that results from one species reflect the exposure responses of all bivalves.

Experimental exposure of the blue mussel (Mytilus edulis, L.) to the toxic dinoflagellate Alexandrium fundyense: Histopathology, immune responses, and recovery

Mussels (Mytilus edulis) were exposed to cultures of the toxic dinoflagellate Alexandrium fundyense or the non-toxic alga Rhodomonas sp. to evaluate the effects of the harmful alga on the mussels and to study recovery after discontinuation of the A. fundyense exposure. Mussels were exposed for 9 days to the different algae and then all were fed Rhodomonas sp. for 6 more days. Samples of hemolymph for hemocyte analyses and tissues for histology were collected before the exposure and periodically during exposure and recovery periods. Mussels filtered and ingested both microalgal cultures, producing fecal pellets containing degraded, partially degraded, and intact cells of both algae. Mussels exposed to A. fundyense had an inflammatory response consisting of degranulation and diapedesis of hemocytes into the alimentary canal and, as the exposure continued, hemocyte migration into the connective tissue between the gonadal follicles. Evidence of lipid peroxidation, similar to the detoxification pathway described for various xenobiotics, was found; insoluble lipofuchsin granules formed (ceroidosis), and hemocytes carried the granules to the alimentary canal, thus eliminating putative dinoflagellate toxins in feces. As the number of circulating hemocytes in A. fundyense-exposed mussels became depleted, mussels were immunocompromised, and pathological changes followed, i.e., increased prevalences of ceroidosis and trematodes after 9 days of exposure. Moreover, the total number of pathological changes increased from the beginning of the exposure until the last day (day 9). After 6 days of the exposure, mussels in one of the three tanks exposed to A. fundyense mass spawned; these mussels showed more severe effects of the toxic algae than non-spawning mussels exposed to A. fundyense. No significant differences were found between the two treatments during the recovery period, indicating rapid homeostatic processes in tissues and circulating hemocytes.

Higgin’s-eye Pearly Mussel Lampsilis higginsi, 2011

Data sheet produced by the Iowa Department of Natural Resources is about different times of animals, insects, snakes, birds, fish, butterflies, etc. that can be found in Iowa.

Presence of the alien chinese pond mussel Anodonta woodiana (Lea, 1834) (Bivalvia, Unionidae) in the Iberian Peninsula

Nota sobre les conseqüències de la invasió del mol·lusc d'aigua dolça, Anodonta woodiana, a la Península Ibèrica

Modification of pyruvate kinase and lactate dehydrogenase in foot muscle of the sea mussel Mytilus galloprovincialis under anaerobiosis and recovery

The modification of pyruvate kinase (PK) and lactate dehydrogenase (LDH) activity in foot muscle of the mussel Mytilus galloprovincialis during exposure to air and recovery in water was investigated. In the course of exposure to air, the activity of these enzymes measured at high and low substrate concentrations showed successive increases and decreases. Returning the mussels to water after exposure to air affected enzyme activity in a manner similar to anaerobiosis. When measuring at saturated concentrations of substrates and substrate and coenzyme for PK and LDH, respectively, the maximum activation of PK (37%) was observed at 4 h of animal exposure to air, and for LDH (67%) at 6 h exposure to air. During 24 h of exposure of animals to air, PK activity practically reached the stock level, while LDH was still activated (148%). The change in lactate dehydrogenase activity in mussel muscle during anoxia and recovery is described here for the first time. Variation in pyruvate kinase activity during exposure to air and recovery is linked to the alteration of half-maximal saturation constants and maximal velocity for both substrates. The possible role of reversible phosphorylation in the regulation of pyruvate kinase and lactate dehydrogenase properties is discussed

Processing of chopped mussel meat in retort pouch

Abstract Chopped mussel meat packaged in retort pouches was processed in a laboratory-scale water immersion retort, adapted for processing under overpressure conditions. Retort temperature effects on product yield and on cook value were evaluated by setting the F0 at 7 min. The effects of different pre-treatments (salting and marination) on the characteristics of mussels were evaluated after processing at retort temperature of 118 °C and during a whole year of storage at 25 °C. The salted samples showed better yield during storage, while no differences were found for the other physicochemical parameters.

Trends in fish prey capture by common terns following zebra mussel invasion : do terns track fish species abundance? /

The Common Tern (Sterna hirundo) is a ground nesting colonial seabird. Terns rely primarily on small prey fishes which they obtain through plunge diving for their survival as well as the survival of their offspring during the breeding season. The zebra mussel (Dreissena polymorpha) is a small bivalve mollusk that invaded North American waters in the late 1980's. Through its suspension feeding, the zebra mussel has the ability to alter the entire aquatic ecosystem, ultimately leading to a reduction in pelagic organisms including small prey fish. The objective of the study was to determine what (if any) indirect effects the invasion of the zebra mussel has had on fish prey captured by terns. The study took place in two separate two-year periods, 1990-91 and 1995-96 on a concrete breakwall off the north shore of Lake Erie near Port Colborne, Ontario. Daily nest checks revealed clutch initiation dates, egg-laying chronology, hatching success and morphological egg characteristics (length and breadth). Behavioural observations included time each sex spent in attendance with its brood, the frequency of feeding chicks and the prey species composition and size fed to chicks as well as to females (courtship feeding). Egg sizes did not differ between study periods, nor did feeding rates to chicks, suggesting that food was not a limiting resource. Terns spent less time with their broods (more time foraging) in the 1995-96 period. However, they also had significantly larger broods and fledged more offspring. The time of each individual foraging trip decreased, suggesting that fish were easier to obtain in 1995 and 1996. Lastly, kleptoparasitism rates decreased, suggesting that the costs of foraging (time, energy) actually decreased as fewer birds adopted this strategy to compensate for what I assumed to be a lack of available food (fish). The only significant difference between the periods of 1990, 1991 and 1995, 1996 was a change in diet. Terns delivered significantly fewer rainbow smelt and more emerald shiner in 1995 and 1996. However, the average size of fish delivered did not change. Thus, there was little impact on prey captured by Common Terns in Lake Erie since the invasion of the zebra mussel.

Haematological responses of green mussel Perna viridis (Linnaeus) to heavy metals copper and mercury

Department of Marine Biology, Microbiology and Biochemistry, Cochin University of Science and Technology

Haematological Studies on the Freshwater Mussel - Lamellidens Marginalis ( Lamark, 1819 )

School of Environmental Studies, Cochin University of Science and Technology

Toxicity, accumulation and depuration of heavy metalsin the brown mussel perna indica

In this thesis certain important aspects of heavy metal toxicity have been worked out. Recent studies have clearly shown that when experimental media contained more than one heavy metals, such metals could conspicuously influence the toxic reaction of the animals both in terms of quantity and nature. The experimental results available on individual metal toxicity show that, in majority of such results, unrealistically high concentrations of dissolved metals are involved. A remarkable number of factors have been shown to influence metal toxicity such as various environmental factors particularly temperature and salinity, the condition of the organism and the ability of some of the marine organisms to adapt to metallic contamination. Further, some of the more sensitive functions like embryonic and larval development, growth and fecundity, oxygen utilization and the function of various enzymes are found to be demonstrably sensitive in the presence of heavy metals. However, some of the above functions could be compensated for by adaptive process. If it is assumed that the presence of a single metal in higher concentrations could affect the life function of marine animals, more than one metal in the experimental media should manifest such effects in a greater scale. Commonly known as synergism or more than additivity, majority of heavy metals bring about synergistic reaction .The work presented in this thesis comprises lethal and sublethal toxicities of different salt forms of copper and silver on the brown mussel Perna indica. during the present investigation sublethal concentrations of copper and silver in their dent effects on survival, oxygen consumption, filtration, accumulation and depuration on Perna indica. The results are presented under different sections to make the presentation meaningful .

Studies on the toxic effects of selected heavy metals in the freshwater mussel lamellidens corrianus (lea)

Industrialisation affects air, water, and soil. Industrial effluents which enter the aquatic environment either by direct disposal or through run off, affect living organisms at morphological and physiological levels. In any living tissue toxic materials exert their effects first at molecular and biochemical levels (Robbins and Angell, 1976). Most of the industrial effluents contain elevated concentrations of organic and inorganic chemicals capable of eliciting stimulatory or inhibitory effects on the metabolism of aquatic organisms. Heavy metals form an important group of environmental pollutants. Effects of pollution on the aquatic environment by heavy metals have received considerable attention in recent years due to their toxicity even at very low levels, persistence in the environment, and chances of getting biomagnified. A pollutant that does not affect a particular process under normal unstressed condition may affect the ability of the animal to adjust to changing environmental conditions which ultimately decrease its chances of survival (Thurberg et al., 1973

Effect of Mussel`s Gender and Size on a Stress Response Biomarker

In mussels, stress signals such as heat, osmotic shock and hypoxia lead to the activation of the phosphorylated p38 mitogen activated protein kinase (pp38-MAPK). This stress activated protein has been efficiently used as a biomarker to several natural and anthropogenic stresses. However, what has not been tested is whether differences in gender or size can affect the response of this biomarker. The present study tested whether there was variation in the expression of pp38-MAPK in mussels Perna perna of different gender and size classes when exposed to natural stress conditions, such as air exposure. The results show that gender does not affect the expression of pp38-MAPK. However, size does have an effect, where mussels smaller than 6.5 cm displayed significantly (p < 0.05) lower levels of pp38-MAPK when compared to those larger than 7 cm. Mussels are one of the most used bioindicator species and the use of biomarkers to determine the health status of an ecosystem has been greatly increasing over the years. The present study highlights the importance of using mussels of similar size classes when performing experiments using stress-related biomarkers.