Hostname: page-component-77c89778f8-7drxs Total loading time: 0 Render date: 2024-07-23T06:27:55.235Z Has data issue: false hasContentIssue false

Notes on the Biology of Tellina tenuis da Costa

Published online by Cambridge University Press:  11 May 2009

A. G. Stephen
Affiliation:
Royal Scottish Museum, Edinburgh

Summary

The present paper deals with the results of investigations into certain phases in the life-history of the bivalve mollusc Tellina tenuis carried out during the autumn of 1926 and 1927.

Collections in the intertidal zone and below L.W.M., were made in a number of bays in the Cumbrae and neighbourhood, Kames Bay, Millport, being selected for intensive study.

In Kames Bay Tellina tenuis ranges from a little below H.W.M. to depths of about 4 fm. The maximum concentration of about 1000 per sq. m. is found at L.W.M. springs and the numbers decrease to zero at H.W.M. and 4 fm.

In Kames Bay the density of Tellina tenuis falls in a progressive manner from L.W.M. to H.W.M.

The size-frequency distribution shows a regular gradation from the lower to the higher levels. At L.W.M. and below individuals of small size predominate, while at H.W.M. they are proportionately few.

At higher levels growth is more rapid than at the lower levels.

The size-frequency curves and density of Tellina tenuis in the other bays at L.W.M. correspond with those of half-tide in Kames Bay.

The rate of growth may therefore be influenced by the density of population as well as by the habitat.

In all areas the 1926 brood predominates.

The Tellina tenuis population in Kames Bay seems to be composed of four year-groups, one of which is almost unrepresented. Collections from neighbouring bays indicate that older groups may be present.

The amount of young brood on the bottom seems to vary considerably from year to year, being large and small in alternate years.

The two closely related species, T. tenuis and T. fabula, are both plentiful in Kames Bay, but their range is not coincident.

Eipe sperms were found from May onwards and ova were rounding off in June.

Young Tellina tenuis, passing the 2-mm. sieve but retained by the 1-mm. sieve, were found in Kames Bay in August, chiefly below L.W.M., but in October plentifully distributed up to half-tide and in lesser numbers higher up the shore.

The food usually consists of vegetable detritus, but during the spring increase diatoms appear almost exclusively in the gut.

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 1928

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

XIV. LITERATURE CITED

1Blegvad, H.The Food and Conditions of Nourishment among the Invertebrate Animals in or on the Sea Bottom in Danish Waters. Rep. Danish Bid. Stn. XXII, 1914.Google Scholar
2Boysen Jensen, P.Valuation of the Limfjord 1. Rep. Danish Biol. Stn. XXVI, 1919, p. 13.Google Scholar
3Davis, F. M. Quantitative Studies on the Fauna of the Sea Bottom. No. 1, Preliminary Investigation of the Dogger Bank. Min. Agri. Fish. Invest., Series II, Vol. VI, No. 2, London, 1923.Google Scholar
4Ibid., p. 26.Google Scholar
5Ibid., p. 29–32.Google Scholar
6Ford, E.On the Growth of Some Lamellibranchs in Relation to the Food Supply of Fishes. Journ. Mar. Biol., New Series, Vol. XIII, No. 3, March, 1925.Google Scholar
7Ibid., p. 535.Google Scholar
8Ibid., p. 544.Google Scholar
9Gemmill, J. F. Communication Millport Marine Biol. Stn., Nov., 1900, pp. 3435, or Report 79th Meeting British Association, 1899, p. 782.Google Scholar
10Segerstraåle, Sven G.Societas Scientiarum Fennica Commentationes Biologicæ, II, 11.Google Scholar