The Biology of Littorina littorea. Part I. Growth of the Shell and Tissues, Spawning, Length of Life and Mortality.

Abstract

The Periwinkle, Littorina littorea (L.), is one of the most abundant gastropods on the shore, and can live under widely varying conditions. It is found on clean, alga-covered rocks, among small stones, on gravel, on soft mud, and rarely even on sand. It ranges from about high water of neap tides to extreme low water of spring tides, and in some places even slightly below this, although in most localities it is restricted to a much smaller part of the tidal zone. It occurs also from shores with high wave-exposure to sheltered and even polluted estuaries, where it is tolerant of considerable lowering of the salinity. The material for the present study was collected at intervals throughout 1934—1936 from three localities near Plymouth, the details of which are as follows.

The ecology of the Tamar Estuary VI. An account of the macrofauna of the intertidal muds

“…Thamdrup (1935) found it common on his main traverse at Skalling, Denmark, with an optimum well in the upper part of the tidal zone (maximum density 460 per m.2). In ot4er localities it has been recorded at all tidal levels, as was found by us at the seaward end of Poole Harbour; with its optimum at varying positions, sometimes near low water (Stephen, 1929;Moore, 1937b). It also ;occurs below the level of tidal influence, in shallow water at least.…”

“…most abundant between mid-tide and high-water neaps (Moore, 1937b). Again, in Scotland Stephen (1929 records it from various more or less sandy localities as closely restricted to high-water mark, with a decided preference for places where the salinity is lowered by a stream.…”

Influence of trematode infections on in situ growth rates of Littorina littorea

“…Regarding the longevity of Littorina littorea, only little has been reported. Moore (1937) arrived at 5+ y in a population at Plymouth, in general agreement Á9); t, test-value of the paired t-test; df, degrees of freedom; P, probability of no di¡erence.…”

The biology of Littorina littorea. Part II. Zonation in relation to other gastropods on stony and muddy shores

“…Hayes's (1929) statement that at St Andrews the growth rate of young L. littorea is greatest towards low water. It may be noted that the rate of growth at the Yealm was considerably less at all sizes than at Drake's Island (Moore, 1937).…”

“…the level of maximum abundance seemed to be below the lowest level sampled. For the Isle of Man it is recorded from low water to IS fathoms, and more rarely deeper (Moore, 1937a), and in the Plymouth Fauna (Marine Biological Association, 1931) down to 10 fathoms. Gibbula umbilicalis (da Costa) (Fig.…”