In:
Canadian Journal of Fisheries and Aquatic Sciences, Canadian Science Publishing, Vol. 67, No. 6 ( 2010-06), p. 977-986
Abstract:
Marine invertebrates with open circulatory system establish low and constant oxygen partial pressure (Po 2 ) around their tissues. We hypothesized that as a first step towards maintenance of low haemolymph and tissue oxygenation, the Po 2 in molluscan mantle cavity water should be lowered against normoxic (21 kPa) seawater Po 2 , but balanced high enough to meet the energetic requirements in a given species. We recorded Po 2 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 Po 2 . Average mantle cavity water Po 2 correlates positively with standard metabolic rate (SMR): highest in scallops and lowest in mud clams. Scallops show typical Po 2 frequency distribution, with peaks between 3 and 10 kPa, whereas mud clams and limpets maintain mantle water Po 2 mostly 〈 5 kPa. Only A. islandica and P. vulgata display distinguishable temporal patterns in Po 2 time series. Adjustment of mantle cavity Po 2 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 Po 2 in mantle cavity water correspond to molluscan ecotypes.
Type of Medium:
Online Resource
ISSN:
0706-652X
,
1205-7533
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
2010
detail.hit.zdb_id:
7966-2
detail.hit.zdb_id:
1473089-3
SSG:
21,3
SSG:
12
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