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Influence of temperature on number of circuli of first year scales of brown trout, Salmo trutta L.
Author(s) -
Skurdal J.,
Andersen R.
Publication year - 1985
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1985.tb04275.x
Subject(s) - brown trout , salmo , biology , trout , incubation , hatchery , ecology , fish <actinopterygii> , fishery , biochemistry
We studied the number of circuli of first year scales in brown trout fry originating from eggs and alevins incubated at 2 °C and 7 °C. During the first 3 1 / 2 months the 7 °C fry were reared at a lower temperature than the 2 °C fry whereas temperature was identical during subsequent months. The numbers of circuli increased with body length in both groups. However, both the number of circuli and the rate of circuli formation were higher in the group incubated at 7 °C and varied between 2 and 9 in the 2 °C–group and 5 to 14 in the 7 °C group. Differences among natural populations in the number of first year circuli may therefore be due to differences in incubation temperature. Experimental manipulation with incubation temperature can be used to mark large numbers offish permanently at low cost with a minimum of handling and hatchery stress.