Effects of Constant Day Length on Sexual Maturation and Growth of Atlantic Salmon ( Salmo salar) Parr
Atlantic salmon (Salmo salar) were reared for 6 mo from first feeding under four photoperiod regimes: LD 12:12, LD 16:8, LD 24:0, and simulated natural (LDN). Water temperature followed seasonal changes but was adjusted so as not to exceed 16 °C in summer or to fall below 6 °C in winter. Growth rate...
| Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1988
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/f88-008 http://www.nrcresearchpress.com/doi/pdf/10.1139/f88-008 |
| Summary: | Atlantic salmon (Salmo salar) were reared for 6 mo from first feeding under four photoperiod regimes: LD 12:12, LD 16:8, LD 24:0, and simulated natural (LDN). Water temperature followed seasonal changes but was adjusted so as not to exceed 16 °C in summer or to fall below 6 °C in winter. Growth rates were highest in the LD 24:0 group during the first 3 mo; subsequently, the LD 16:8 fish grew faster than all others. Length–frequency distributions were skewed towards smaller sized fish in January. Sexually mature males were mainly in the lower halves of the length–frequency distributions; females and immature males were distributed throughout. The incidence of mature males was highest in the LDN group (67% of males) but reached high levels (44–58%) in the other groups. |
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