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.

Distribution of molluscs on the Atlantic continental shelf off Southern Spanish Sahara, West Africa

Two hundred and seventy five mollusc species from the continental shelf off Southern Spanish Sahara (depth: 32-60 m) were identified. Their distribution pattern is strongly influenced by the nature of the bottom (firm substrate, shelter, stability of sediment) rather than other factors at that depth interval. This faunal assemblage shows great affinity to the Mediterranean and Lusitanian faunas, and comprises only few (22 %) exclusively Senegalese and species living south of Senegal.

Atti del Convegno internazionale di studi su Massimo di Torino nel XVI centenario del Concilio di Torino (398) : Torino, 13-14 marzo 1998 /

Anno 4, 1998/2 of Archivio teologico torinese.

Greek writers of Roman history : some reflections upon the authorities used by Plutarch and Appianus /

The fons primarius of Plutarch's life of Fabius Maximus. -- The common Greek sources of Plutarch and Appianus for Roman history. -- King Juba's Historia romana.

Assessment of the national effort to combat mental retardation from biomedical causes : conference proceedings, November 14-16, 1983, Washington, D.C.

Item 529-B-8

Untersuchungen zur römischen Kaisergeschichte.

Each vol. has also special title page.

[Fragmenta varia graeca]

Collection of Greek texts from 14 distinct manuscripts; 15th century and later.

Factorum dictorumque memorabilium libri novem /

Mode of access: Internet.

Anthologia graeca epigrammatym palatina cvm Planvdea, edidit Hvgo Stadtmveller ...

Mode of access: Internet.

Valère Maxime : faits et paroles mémorables /

Mode of access: Internet.