Shell size, body mass and average pO2 in mantle cavity water of different marine mollusc species

Marine invertebrates with open circulatory system establish low and constant oxygen partial pressure (Po2) around their tissues. We hypothesized that as a first step towards maintenance of low haemolymph and tissue oxygenation, the Po2 in molluscan mantle cavity water should be lowered against normoxic (21 kPa) seawater Po2, but balanced high enough to meet the energetic requirements in a given species. We recorded Po2 in mantle cavity water of five molluscan species with different lifestyles, two pectinids (Aequipecten opercularis, Pecten maximus), two mud clams (Arctica islandica, Mya arenaria), and a limpet (Patella vulgata). All species maintain mantle cavity water oxygenation below normoxic Po2. Average mantle cavity water Po2 correlates positively with standard metabolic rate (SMR): highest in scallops and lowest in mud clams. Scallops show typical Po2 frequency distribution, with peaks between 3 and 10 kPa, whereas mud clams and limpets maintain mantle water Po2 mostly <5 kPa. Only A. islandica and P. vulgata display distinguishable temporal patterns in Po2 time series. Adjustment of mantle cavity Po2 to lower than ambient levels through controlled pumping prevents high oxygen gradients between bivalve tissues and surrounding fluid, limiting oxygen flux across the body surface. The patterns of Po2 in mantle cavity water correspond to molluscan ecotypes.

Quantitative composition and distribution of the silt fraction in surface sediments of the North-West African continental margin

Surface sediments from the continental slope and rise of North-West Africa between the Canary lslands and the Cape Verde Islands are mainly composed of silt-sized material (2-63 µm). A number of sampling profiles were run normal to the coast and the composition of the silt fraction was determined quantitatively by scanning electron microscope analysis. The carbonate portion of the sediment was found to be nearly exclusively of biogenic origin. The most important contributors are planktonic foraminifers and coccoliths with minor contributions derived from pteropods. Plankton-produced biogenic opal such as diatoms and radiolarians play a very minor role. The high production rates of opal-silica plankton which exists in the surface waters of the NW-African upwelling system does not give rise to corresponding increases of opal accumulation in the bottom sediment. Benthic producers consist mainly of foraminifers and molluscs but the entire input from benthic producers is extremely small. An exception to this occurs in the prodelta sediments of the Senegal river. Downslope particle transport is indicated by the occurrence of shallow-water coralline algae, ascidian sclerites and cliona boring chips and can be traced as far down as the continental rise. The non-carbonate silt fraction mostly consists of quartz which is derived as eolian dust from the Sahara desert by the Harmattan and the NE-Trade-wind system. The percentage of carbonate in the surface sediments directly indicates the relative proportions of autochthonous biogenic components and terrigenous allochthonous quartz particles.

Reports of the Princeton University Expeditions to Patagonia, 1896-1899 : J.B. Hatcher in charge /

At head of title: J. Pierpont Morgan Publication Fund.

Index to experiment station literature, 1888-1913 ...

Volume numbers assigned for convenience in cataloging.

Catalogue des mollusques terrestres et fluviatiles des environs de Paris à l'époque quaternaire /

"Annexe de l'ouvrage intitulé: La Seine - 1. Le bassin aux áges antéhistoriques"

Treatise on invertebrate paleontology /

"Treatise Online publishes chapters prepared for parts of the Treatise on Invertebrate Paleontology as they are ready, rather than waiting for an entire hard copy Treatise to be printed"--Treatise Online website

List of the specimens of British animals in the collection of the British Museum ...

1. Centroniae or radiated animals / by J.E. Gray.--3. Birds / by George Robert Gray.--4. Crustacea / by Adam White.--5.Lepidoptera / by James Francis Stephens - 1850.--5. Lepidoptera / by James Francis Stephens - 1856.--Hymenoptera Aculeata / by Frederick Smith.--7. Mollusca Acephala and Brachiopoda / by J.E. Gray.--8. Fish / by Adam White.--9. Eggs of British birds / by G.R. Gray.--10. Lipidoptera (continued) / by James Francis Stephens.--11. Anoplura, or parasitic insects / by H. Denny.--12. Lepidoptera (continued) / by James Francis Stephens.--13. Nomenclature of Hymenoptera / by Frederick Smith.--14. Nomenclature of Neuroptera / by Adam White.--15. Nomenclature of Diptera 1 / by Adam White.--16. Lepidoptera (completed) / by H.T. Stainton.

Figures of molluscous animals selected from various authors.

"A list of the genera of recent Mollusca, their synonyma and types. By J.E. Gray, (From the Proceedings of the Zoological Society for 1847) London, Printed by R. and J.E. Taylor, 1847," vol. 4, p. [127]-219.