Cardium Glaucum Research Articles

Holocene marine ingressions in the coastal zone of the pomeranian bay based on radiocarbon assays

Abstract In recent years, a team at the Geology and Paleogeography Unit, Marine Sciences Institute, University of Szczecin, has been performing geological, geochronological and paleogeographic surveys in (i) the Szczecin Lagoon and Świna Gate Sandbar and (ii) the estuary section of the Rega river valley near Mrzeżyno. These studies have helped to examine and identify not only the distribution of fossil marine sediments but also their lithological and sedimentological characteristics. The age of marine ingressions and regressions in the coastal zone of the Pomeranian Bay were determined using approximately 170 radiocarbon assays. It was found that the marine ingression associated with the ‘Littorina transgression’ was not synchronous at these two areas. It started earlier in the Mrzeżyno area, ca. 8300-8200 cal BP. In that first phase, marine sediments developed as tightly packed sands containing a few fragments of shells. In several profiles, these deposits were separated from the bottom and top with layers of peat, thus allowing an indirect determination of their age. The next phase of ingression began about 7300 cal BP. These younger marine sediments already contained quite numerous shells of marine malacofauna, especially Cardium glaucum, often found in a life position. In the area of the Szczecin Lagoon and Swina Gate Sandbar, the oldest marine ingression started as early as about 7350 cal BP. The quite clear trace is a considerably thicker series of marine sands with numerous sea shells representing marine and brackish-marine environments, including Cardium glaucum shells in a life position, which made it possible to identify the age and the rate of accumulation of marine sands.

Holocene assemblages of molluscs in the near-shore zone of southern Baltic

Silts from the Polish Baltic Coast were analysed with respect to their mollusc assemblages and radiocarbon-dated. Four faunae were distinguished: fauna with Vertigo genesii Gredl. (Young Dryas or beginning of Preboreal Phase); fauna with Bithynia tentaculata (L.) (Boreal Phase); fauna with Valvata piscinalis (O. F. Mull.) (Boreal Phase); fauna with Cardium glaucum Brug. (Atlantic Phase).

Feeding ecology of the Long-tailed Duck Clangula hyemalis wintering in the Gulf of Gdańsk (southern Baltic Sea)

The feeding ecology of the Long-tailed Duck Clangula hyemalis was studied in the Gulf of Gdańsk during eight wintering seasons (November–April) 1972–1976 and 1986–1990 (423 food samples). The number of food taxa consumed was at least 28 (23 animal and 5 plant). Long-tailed Ducks fed mainly on bivalves of which Macoma baltica and Mya arenaria were the most important, then Mytilus edulis and Cardium glaucum. Fish, mostly Ammodytidae, and fish eggs were present in ca. every fourth sample. Crustaceans, polychaetes and gastropods constituted the remaining significant prey. Plant food was incidental. Birds selected main food items (3 bivalves) of shell length ca. 11.0–11.6 mm regardless of their different average size found in zoobenthos. Seasonal and some age and sex related differences in Long-tailed Duck diet were found. They consumed proportionally more Mytilus and Cardium in December and January and less later in the season. Crustaceans, polychaetes and especially fish (fish eggs) increased their percent share in the diet in the spring. Adult birds tended to eat more Mytilus and Cardium while immatures ingested more crustaceans. Birds caught in nets set deep (>20 m) fed largely on Mesidothea entomon. Long-tailed Ducks function as first to fourth-order carnivores in the food web of the Gulf of Gdansk. Due to their high numbers and long period of staying they consume considerable biomass of main food prey. Estimated yearly consumption of bivalves amounts to 6 350 tonnes (Macoma baltica–2,100, Mya arenaria–1,700, Mytilus edulis–1,600, Cardium glaucum–950), fish–1,120, crustaceans–400, polychaetes–200, and gastropods–125 tonnes. At least locally, they prey significantly on certain age classes of the most important food taxa.

Metals in molluscs and associated bottom sediments of the southern baltic

The concentration of Zn, Cu, Pb, Cd, Ni, Co, Ag, Mn, Fe, Ca, Mg, K and Na in molluscsMacoma balthica, Mya arenaria, Cardium glaucum, Mytilus edulis andAstarte borealis from the southern Baltic was determined. The surface sediments and ferromanganese concretions associated with the molluscs were also analysed for concentration of these metals. Species- and regiondependent differences in the metal levels of the organisms were observed. The properties of molluscs analysed which have a tendency toward elevated biological tolerance of selected trace metals were specified. The interelement relationship between metal concentrations in the soft tissue and the shell was estimated and was discussed.

Inhibition of larval settlement to a soft bottom benthic community by drifting algal mats: An experimental test

The hypothesis that drifting red algal mats inhibit settlement of planktonic larvae was tested in a field experiment in 1986. Substratum free of algae (caged boxes) was compared with substratum covered with algae (natural substratum and open boxes). Whereas settling densities of 1500 to 5500 ind. m-2 of the bivalves Macoma balthica, Cardium glaucum and Mya arenaria were observed in sediment without algal cover, no recruits of the same species were found beneath the algae during the period of peak settlement (June to July). The same difference was observed for the polychaete Nereis diversicolor, although in this case occasional individuals were found beneath the algae. The results demonstrate that algae mats may be efficient inhibitors of larval settlement to benthic soft-substratum communities. It is concluded that algae act as a larval filter.

Concentration of uranium and thorium in molluscs inhabiting Gdańsk Bay, Baltic sea

The concentrations of U and Th were determined in the soft tissue and shell of Mytilus edulis, Cardium glaucum, Mya arenaria, Macoma balthica and other benthic invertebrates from Gdańsk Bay. Results of these investigations show that the concentrations of U and Th in some molluscs are species specific. For Th, unlike U, significant site-dependent variations in concentration were noted. Results show some dependence in concentrations of metals analysed with size and age of molluscs. The regression analysis of the data indicates that discrimination factors for U with respect to Ca significantly decrease with an increase in the concentration of Ca in the soft tissues.

Genetic relations between the bivalves Cardium (Cerastoderma) edule, Cardium lamarcki and Cardium glaucum, studied by means of crossed immunoelectrophoresis

Rabbit antisera were raised against Cardium edule (L.) from the Waddensea locality, Skallingen, against Cardium lamarcki (Reeve) from the Danish locality, Dybso Fjord, and against Cardium glaucum (Bruguiere) from the French Mediterranean coast at Ile des Embiez. Allopatric and sympatric populations of C. lamarcki and C. edule from Swedish and Danish localities, and allopatric populations of C. glaucum from the Mediterranean Sea, Red Sea and Black Sea were studied by means of the described method and by starch gel electrophoresis of malate dehydrogenase (MDH). By means of crossed immuno-electrophoresis, using intermediary gels containing antibodies against one of the Cardium types and receiver gels containing antibodies against one of the others, type-specific and type-non-specific reactions were recorded. The results are compared with a similar investigation of Mytilus edulis, M. galloprovincialis and M. californianus. Based on immunological properties, it is shown that C. edule is a valid species different from the C. lamarcki/C. glaucum complex. It is further suggested that C. lamarcki and C. glaucum should still be referred to by these two names as significant genetic differences between them is revealed by this immunological study.

Occurrence of ten metals in Mytilus edulis L. and Cardium glaucum L. from the Gdańsk Bay

The determination of Fe, Mn, Ni, Pb, Cu, Co, Zn, Cd, Ca and Mg was carried out in the soft tissues and shells of Mytilus edulis and Cardium glaucum from Gdańsk Bay. This paper reports on the influence of size (age) on the metal concentration in molluscs. Both species-dependent variability and regional variations of metal concentrations in molluscs were observed. The correlation coefficients between the concentrations of metal in the soft tissues and shells were determined. The correlation coefficients between hard and soft parts metals were calculated for Mytilus edulis.

Comparison of sterol composition of some Baltic Sea and Black Sea mussels

Sterol composition of three Baltic Sea mussels (Mytilus edulis, Cardium glaucum, Mya arenaria) was compared with the sterol composition of three biologically closely related mussels from the Black Sea (Mytilus galloprovincialis, Cardium edule, Mya arenaria). The qualitative sterol composition of the mussels studied was similar, but some quantitative differences were found.

Major sterols of bivalve molluscs from the inner puck bay, southern baltic

1. 1. The wide-spread Baltic Sea bivalve molluscs (collected from the Inner Puck Bay): Macoma balthica, Mytilus edulis, Cardium glaucum, and Mya arenaria were investigated for their sterol composition. 2. 2. The qualitative sterol composition of these bivalve molluscs was similar and comparable with that of the other representatives of Bivalvia, but there were observed some quantative differences.

Abundance and growth of aCardium glaucumBruguiére population in hano bight (southern baltic)

Abstract A near-shore population of Cardium glaucum was sampled over a period of 18 months, from July 1973 to February 1975, in the Hano Bight on the eastern coast of Sweden. The year-class of 1972 dominated and recruitment was very low in 1973 and 1974. The reasons for this are discussed. Abundance was slightly higher at 17 m depth than at 10 m, whereas the population at 5 m was very sparse. The growth was generally faster at 10 m depth than at 17 m. Growth was fastest during June and July. The year-ring was laid down prior to April-June.

Some Observations on the Effects of Temperature and Salinity Upon the Growth of Cardium Edule and Cardium Glaucum Larvae in the Laboratory

SummaryThe larvae of both Cardium edule, Linné, and Cardium glaucum, Bruguière, have been reared to metamorphosis under laboratory conditions.Successful artificial fertilization has been shown possible, in both species, in the termperature range 10 to 20 °C. The larvae of C. edule show poor growth at 10 °C, good growth between 15 and 20 °C and erratic growth at 30 °C. C. glaucum larvae show negligible growth at 10 °C, but are able to grow well between 15 and 31 °C; limited numbers of larvae were reared to metamorphosis at 33 °C.The optimal salinity for rearing the larvae of both cockle species was found to be between 30 and 35 ‰. Although C. glaucum larvae were slightly more tolerant of salinity extremes, both species were able to withstand a wider range of salinities than those satisfactory for growth.

Interspecific Hybridization in Cardium

BOYDEN1 has shown that cross-fertilization takes place between the cockles Cardium edule, Linne, and Cardium glaucum, Bruguiere. He used, as the criteria for successful hybridization, either the production of rotating trochophores, still within the confines of the egg sheath, or free-swimming veligers; no attempts were made to rear the larvae.

Biological studies on Cardium glaucum, based on some Baltic and Mediterranean populations

The recent separation of Cardium glaucum Bruguiere from C. edule L. and the scarcity of reports of populations containing both species has necessitated further ecological study to demonstrate differences in habitat preferences. Some mixed and unispecific populations of the cockles Cardium edule and C. glaucum, situated in fjords around the Kattegat and Baltic coasts of Denmark were studied; it was demonstrated that some degree of tidal influece was essential for the survival of C. edule, and that C. glaucum was being restricted by the exposure of the site. A study of the cockle populations of some etangs on the Mediterranean coast of France demonstrated that, despite earlier reports of its presence, C. edule was not present in that area. A brief survey of the Bassin d'Arcachon (France) showed that it contained a mixed cockle population. It was concluded that C. edule was unable to occupy localities having a tidal amplitude of less than 0.2 m, and that high temperatures also restricted occupation of semitidal habitats; similarly, the exposure of the site restricted colonisation by C. glaucum.