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The Vertical Distribution of Marine Macroplankton. VII Observations on the Behaviour of Calanus finmarchicus

Published online by Cambridge University Press:  11 May 2009

F. S. Russell
Affiliation:
Assistant Naturalist at the Plymouth Laboratory

Summary

The vertical distribution of Calanus finmarchicus adults in the daylight in the Plymouth region as shown by stramin ring-trawl catches in described for the period April to September in 1926. The general results confirmed the indications given in 1925 that there is a, gradual descent of the region of maximum abundance from about 10 metres in April to-metres in June, with a definite rise towards the surface ia July, August, and September.

2. The rise towards the surface was evident on sunny days as well as dull, indicating that the suggestion that dull weather and low light intensity was its cause in 1925 may possibly have been incorrect.

Measurements of the total lengths of Calanus were made which showed a seasonal change, a brood of small adults occurring in July, August, and September, as opposed to a brood of large adults whichdominated in the spring.

It is suggested that possibly these two broods are physiologically different, and that the small type of adult prefers a higher light intensity and lives nearer the surface than the large type.

The males and females differed in their behaviour, the males being always slightly deeper in the water than the females.

Some indications are given of the course of the life-cycles of Calanus in the Plymouth area.

While from April to the end of June the abundance of the last copepodid stage (Stage V) rarely exceeded more than 20% of the total Calanus in any one catch, they became very much more abundant in July, August, and September, reaching even 60% and 70%.

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

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References

REFERENCES

1G., Adler, and P, Jespersen. Variations saisonnières chez quelques Copépodes planctonique marins. Meddel. fra Komm. for Havunders. Serie: Plankton. Bd. II. 1920.Google Scholar
2Bigelow, H. B. Plankton of the Offshore Waters of the Gulf of Maine. Bull. Bur. Fish. Washington. Vol. XL. 1924. Part II. Document No. 968. 1926.Google Scholar
3D., Damas Notes Biologiques sur les Copépodes de la Mer Norvégienne. Conseil Internat. pour l'Explor. de la Mer. Publ. de Circ., No. 22. 1905.Google Scholar
4Farran, G. P.Copepoda, . Conseil Internat. pour l'Explor. de la Mer. Bull. Trimestr., Deux Part. 1911.Google Scholar
5Farran, G. P.The Reproduction of Calanus finmarchicus off the South Coast of Ireland. Conseil Internat pour l'Explor. de la Mer. Journ. du Conseil., Vol. II, No. 2. 1927.Google Scholar
6Gran, H. H.Das Plankton des Norwegischen Nordmeeres. Rep.Norweg. Fish. Mar. Invest., Vol. II, Pt. II. 1909. No. 5. (1902.)Google Scholar
7Lebour, M. V.Stages in the Life-History of Calanus finmarchicus (Gunnerus), Experimentally Reared by Mr. Crawshay, L. R. in, the Plymouth Laboratory. Journ. Mar. Biol. Assoc., N.S., Vol. XI. 19161918.Google Scholar
8V, Nikitin. La distribution verticale du plancton dans la mer Noire. I. Copepoda et Cladocera. Acad. Sci. Républ. Soviét Social. Ser. II, No. 9. Travaux du laboratoire zoologique et de la station biologique de Sebastopol, p. 93. 1926.Google Scholar
9Ostenfeld, C. H., and P, Jespersen. Standard Net for Plankton Collections. Conseil Internat. pour l'Explor. de la Mer. Publ. de Circ., No. 84. 1924.Google Scholar
10O, Paulsen. Studies on Biology of Calanus finmarchicus. Medd. fra Komm. Havunders., Plankton, Bd. I, No. 4. 1906.Google Scholar
11Russell, F. S.The Vertical Distribution of Marine Macroplankton. IV. The Apparent Importance of Light Intensity as a Controlling Factor in the Behaviour of Certain Species in the Plymouth Area. Journ. Mar. Biol. Assoc., N.S., Vol. XIV, No. 2, p. 415. 1926.Google Scholar
12Russell, F. S.The Vertical Distribution of Marine Macroplankton. V. The Distribution of Animals Caught in the Ring-trawl in the Daytime in the Plymouth Area. Journ. Mar. Biol. Assoc., N.S., Vol. XIV, No. 3, p.557. 1927.Google Scholar
13A., Willey. Report on the Copepoda obtained in the Gulf of St. Lawrence and adjacent waters, 1915. Canadian Fisheries Expedition, 1914–1915, p. 173. 1919.Google Scholar