|The experimental modification of meristic characters in Herring (Clupea harengus L.)|
Hempel, G.; Blaxter, J.H.S. (1961). The experimental modification of meristic characters in Herring (Clupea harengus L.). J. Cons. - Cons. Int. Explor. Mer 26(3): 336-346
In: Journal du Conseil - Conseil International pour l'Exploration de la Mer. Conseil International pour l'Exploration de la Mer: Copenhague. ISSN 0020-6466, more
Aquaculture techniques; Artificial feeding; Clupeoid fisheries; Culture tanks; Hatching; Incubation; Larval development; Salinity; Spawning grounds; Spawning seasons; Sperm; Clupea harengus Linnaeus, 1758 [WoRMS]; Marine
|Authors|| || Top |
- Hempel, G.
- Blaxter, J.H.S.
Rearing experiments were done on herring at Helgoland in 1960, using eggs and sperm from spring spawning herring of the Elbe estuary and Kiel Bight. A successful cross fertilization was also made between the eggs from a Kiel female and the sperm of a Scottish (Clyde) spring spawning male, the sperm having been stored frozen for six weeks. Results are also given of some work done at Aberdeen in 1957, using a Clyde male and female. The eggs were incubated and the larvae reared in the early stage at different temperatures (about 5, 8, 11, and 14 °C) and different salinities (5-50 ppt). Samples of larvae were taken at hatching and at the end of the yolk-sac stage for counts to be made of their myotomes. Larvae which survived beyond the yolk-sac stage (a few of which metamorphosed) were fixed on death and counts made of other meristic characters which developed after yolk-sac absorption. In particular Counts were made of vertebrae and vertebral myotomes. The latter are the myotomes which are connected with the formation of vertebrae and which are detectable once the urostylar elements are formed. A significant negative correlation was found between mean myotome count at hatching and incubation temperature, and a significant positive correlation between mean myotome count at hatching and incubation salinity. The mean myotome counts of the Kiel male X Clyde female cross were significantly higher than the Kiel male x Kiel female controls. A sensitive phase was found 6-7 days after fertilization at an incubation temperature of 10 degree C when a temperature shock (placing the eggs for 24 hours in 4 degree C) resulted in a much increased mean myotome count. Significant negative correlations were found between mean vertebral and vertebral myotome counts and temperature of incubation in larvae which survived well beyond the end of the yolk-sac stage, both where the parents were German coastal spawners (work done at Helgoland) and where they were Clyde spawners (work done earlier at Aberdeen). There appeared to be a considerable difference between these counts for Clyde and German coastal spawners, which strongly suggested a genetical difference between the groups.