The influence of temperature on the survival, growth and respiration of Calanus jinmarchicus
graphic Institution on the nutrition of the ecologically important copepod, Calanus finmarchicus, in relation to the food cycle of the sea have shed light on the types of food suitable for this species and on the rate of feeding of which it is capable under different conditions (Clarke and Gellis, 1...
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| Format: | Text |
| Language: | English |
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1939
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.532.8904 http://www.biolbull.org/content/76/3/371.full.pdf |
| Summary: | graphic Institution on the nutrition of the ecologically important copepod, Calanus finmarchicus, in relation to the food cycle of the sea have shed light on the types of food suitable for this species and on the rate of feeding of which it is capable under different conditions (Clarke and Gellis, 1935; Fuller and Clarke, 1936; and Fuller, 1937). Since the temperatures to which Calanus is subjected off our coasts vary greatly with the season and with the locality, it was desired to extend the investigation of the survival and growth of this species in the laboratory to include a larger range of temperature than had been possible pre viously. In the earlier experiments survival of the copepods had gen erally been poor, and Gross (1937) has expressed the opinion that even short intervals of temperature change, such as are entailed by the removal of the culture dishes from the constant temperature bath for inspection, are seriously detrimental to animals in culture. In the experiments about to be described we therefore proposed not only to test the effect of a variety of temperatures on growth but also to compare the survival of animals kept continuously at constant temperatures with that of other individuals subjected to periodic changes in temperature. Calanus was shown to exist in the waters off Woods Hole through out the year 1935—36and to undergo reproduction during the spring months (Clarke and Zinn, 1937). Yet food organisms were not suffi ciently abundant in these waters to meet the nutritive requirements which we have assumed for Calanus even at the maximum rate of feed ing observed in the laboratory, if diatoms alone are considered (Fuller and Clarke, 1936; and Fuller, 1937). Food in the form of diatoms appeared to exist in only one-tenth the necessary concentration. This discrepancy has led to such suggestions as the considerable use of the nannoplankton by the copepods and this possibility should be investi gated further, but the difficulty could be removed equ@tlly well if the |
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