Notes added in proof to Meadows and Campbell’s Chapter
Page 277
In contrast, Littorina littorea (L.) is almost equally geonegative whether
in or out of sea water (Kanda, 1916a). I n a recent study Ottaway and
Thomas (1971) have shown that the viviparous intertidal sea anemone
Actinia tenebrosa Farqu., usually found at mid tide level on rocky
shores in Australia and New Zealand, aggregates at this level in an
artificial tidal regime. Although the authors are not justified in assuming a gravity response from their results, and although the data in
figure 7D and particularly in figure 7A (loc. cit. p. 75) do not support
their assertion that the distribution of juveniles is related to humidity
(p. 76), their experiments are interesting and represent the first study
of habitat selection by a free living sea anemone.
Page 326
The economic importance of experimental analyses of food selection by
predators of commercially farmed marine invertebrates has been
emphasized by Walne and Dean’s (1972) carefully planned experiments
on the predation by Carcinus maenas L. on Mytilus edulis L. and
Mercenaria mercenaria L. Carcinus usually selected the smaller prey
individuals to eat, but ate fewer prey if the latter were allowed to
burrow into sand and particularly mud beforehand. More food was
eaten during the summer, and populations of Carcinus from two different areas fed at significantly different rates. Walne and Dean also
comment on the periods of fasting shown by some individuals.
Page 277
In contrast, Littorina littorea (L.) is almost equally geonegative whether
in or out of sea water (Kanda, 1916a). I n a recent study Ottaway and
Thomas (1971) have shown that the viviparous intertidal sea anemone
Actinia tenebrosa Farqu., usually found at mid tide level on rocky
shores in Australia and New Zealand, aggregates at this level in an
artificial tidal regime. Although the authors are not justified in assuming a gravity response from their results, and although the data in
figure 7D and particularly in figure 7A (loc. cit. p. 75) do not support
their assertion that the distribution of juveniles is related to humidity
(p. 76), their experiments are interesting and represent the first study
of habitat selection by a free living sea anemone.
Page 326
The economic importance of experimental analyses of food selection by
predators of commercially farmed marine invertebrates has been
emphasized by Walne and Dean’s (1972) carefully planned experiments
on the predation by Carcinus maenas L. on Mytilus edulis L. and
Mercenaria mercenaria L. Carcinus usually selected the smaller prey
individuals to eat, but ate fewer prey if the latter were allowed to
burrow into sand and particularly mud beforehand. More food was
eaten during the summer, and populations of Carcinus from two different areas fed at significantly different rates. Walne and Dean also
comment on the periods of fasting shown by some individuals.