1424 



Owen, G. 1955. 



Observations on the stomach and digestive diverticula of the Lamellibranchia. 

 I. The Anisomyaria and Eulamellibranchia. Quart. J. Microsc. Sci. 96(4): 

 517-537. 



Meraenaria meraenaria is not mentioned, but on p. 533 is a beautiful diagram 

 of the probable pathway of material within the stomach and digestive 

 diverticula of a generalized lamellibranch. The crystalline style also is 

 shown . - M . W . S . and J . L . M . 



1425 



Owen, G. 1958. 



Shell form, pallial attachment and the ligament in Bivalvia. Proc. Zool. Soc. 

 London 131: 637-648. 



This paper describes the adductor muscles and ligament of bivalves in some 

 detail, but contains no specific discussion of Meraenaria (Venus) meraenaria. 

 - J.L.M. and M.W.S. 



1426 



Owen, Gareth. 19 66. 



Feeding. Digestion. In Physiology of Mollusca. Karl M. Wilbur and 

 C. M. Yonge (edsO Academic Press, New York, Vol. II: 1-51, 53-96. 



Contains references to Meraenaria (Venus) mercenaria abstracted elsewhere 

 in this bibliography. - J.L.M. 



1427 



Owen, Gareth. 1974. 



Feeding and digestion in the bivalvia. In Advances in Comparative Physiology 

 and Biochemistry 5: 1-35. (0. Lowenstein, ed.). Academic Press, N.Y. 



Venus striatula 21-28 mm long, at 17°C, pumped 40 ml/hr per animal (Allen 

 1970) . This is low compared to other bivalves listed, but size is a factor, 

 and these were relatively small. M. meraenaria has a high pumping rate per 

 unit gill area (6.05 ml/hr/unit gill area). It lives in situations where 

 water contains relatively little suspended material (Hughes 1969). But Owen 

 notes that calculation of gill area did not seem to have taken into account 

 whether or not the gills were plicate, which they are in M. meraenaria and 

 Cardium edule but not in Mytilus, My a, and Sorobicularia, which have flat 

 gills. Rate of water movement over the animal has an effect on pumping rate. 

 M. meraenaria at a flow rate of 200 ml/min had a specific filtration rate of 

 55.5, at flow rate of 300 ml/min 75.5 per gram of dry meat weight. Sensitivity 

 of M. meraenaria to different food concentrations (Walne 1972) was: 

 Dunaliella tertiolecta, at maximum ration 16.6xl0 4 filtered 4.98xl0 7 y 3 /animal/ 

 hr; Isochrysis galbana, max. ration 38xl0 4 filtered 2.17xl0 7 y 3 per animal/hr; 

 and Phaeodaatylum tricornutum, max. ration 90x104 filtered 4.50xl0 7 y 3 /animal/ 

 hr. Food value of different algae to M. meraenaria was expressed in terms of 

 the ratio of rate of growth on experimental food to rate of growth on 

 Isochrysis or Tetraselmis, calculated by dividing mean size at 21 days from 

 commencement of test by mean size of control on same day. Results: Monochrysis 

 lutherii 0.59, Tetraselmis caloitrans 1.11, Skeletonema costatum 3.30, 

 Isochrysis galbana 1.00, Diarateria inornata 0.67, Cricosphaera carterae 0.70, 

 Chlorella stigmatophora 0.31, Phaeodaatylum trioornutum 0.44, Olisthodiscus sp. 

 0.75, Nanoahloris (sic) atomus 0.92, Micromonas pusilla 0.74, Dunaliella 

 tertiolecta 0.14, and Chlamydomonas aooaoides 0.19. Chlorella and 

 Chlamydomonas have rigid cell walls, but Dunaliella does not, so the con- 

 clusion by Jorgensen (1966) is suspect: "Evidence for rhythmic pattern of 

 feeding in bivalves, other than that imposed by environmental factors, is 

 equivocal." But it is clear that a rhythm is imposed on intertidal bivalves. 

 (In 0. edulis total protein in the crvstalline style is correlated with 

 tidal cycle.) - J.L.M. 



399 



