other according to latitude and temp. Thus, an Arctic parallel level-bottom 

 community will have about the same metabolic growth rates at 0°C as its 

 boreal parallel at 8°C, its Mediterranean parallel at about 12°C, and its 

 tropical parallels at even higher temps, and mutual competition within these 

 communities will be about the same. Studies of species of each of the genera 

 of level-bottom lamellibranchs will be of fundamental value to all students 

 of communities dominated by these genera, at whatever latitude. Factors that 

 influence survival and growth of the animals in such communities, such as 

 larval distribution, food, predation, and others, are discussed for a variety 

 of invertebrate and vertebrate species in some detail. References to Venus 

 (Meraenaria) are cited from papers most of which are abstracted elsewhere in 

 this bibliography. In the discussion, V. L. Loosanoff commented on Thorson's 

 suggestion that teams of researchers in different regions be organized to 

 study parallel level-bottom communities. He described existing studies of 

 V. meraenaria, V. campechiensis, and hybrids in 6 locations from Maine to 

 Florida. Lack of complete communication between such investigators might 

 lead to erroneous conclusions. - J.L.M. 



1803 



Thorson, Gunnar. 1961. 



Length of pelagic larval life in marine bottom invertebrates as related to 

 larval transport by ocean currents. In Oceanography. Invited lectures 

 presented at the International Oceanographic Congress held in New York, 

 31 Aug.- 12 Sept. 1959. Mary Sears (ed.) . AAAS Pub. 67: 455-474. 



Reports verbal communication from V. L. Loosanoff that Venus meraenaria may 

 vary in larval life from 7 to 20 days depending on water temperature. - J.L.M. 



1804 



Thorson, Gunnar. 19 66. 



Some factors influencing the recruitment and establishment of marine benthic 

 communities. Neth. J. Sea Res. 3(2): 267-293. 



This important review paper does not deal with Meraenaria (Venus) meraenaria 

 specifically, but does discuss Venus communities. Macrofaunal communities of 

 marine sediment bottoms (or "level" bottoms) seem, roughly, to have parallels 

 in many areas of the globe, whatever the latitude. Thus, there is an Arctic 

 Venus fluotuosa community, a boreal V. gallina (=striatula) community, and a 

 Mediterranean V. verrucosa community, all associated with sandy bottoms at 

 roughly 10-40 m depth, and a deeper living boreal V. fasaiatum community, 

 associated with shelly sand. More recently, other such communities have been 

 described: Venus declivis from shelly sand off Guinea and Senegal, V. 

 (Meraenaria) campechiensis from Florida, V. casina from the Channel off 

 Roscoff , and V. (Austrovenus ) stuahburgi from New Zealand. The voracious sea 

 star Astropecten irregularis , inhabiting a sandy-bottom Venus community in 

 northern seas, may contain more than 400 lamellibranch spat in its stomach at 

 one time. In the area of Helsingor, Denmark, this sea star feeds on Spisula 

 subtruncata, a fast-growing, short-lived species with high metabolic rate, 

 and on Venus gallina, a slow-growing, long-lived species with low metabolic 

 rate. Each specimen of Venus, with a life span roughly 4 times that of 

 Spisula, may be in danger of being eaten by Astropecten for a period 4 times 

 longer. Despite these odds, Venus survives, because Spisula creates a much 

 stronger water current, and thus can be scented and found more readily. Its 

 high oxygen consumption also forces Spisula to open its valves even in the 

 stomach of Astropecten, where it will be killed and digested rapidly, whereas 

 Venus in the same situation can stand an oxygen deficit. Venus will close its 

 valves and may be regurgitated from the stomach of the sea star up to 18 days 

 later, fully alive. Evaluation of the rate of feeding of such a predator by 

 the proportions of prey found in stomachs could be entirely misleading. - 

 J.L.M. 



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