ISSN:
1573-5117
Keywords:
fish population dynamics
;
growth model
;
River Po
;
Barbus barbus plebejus
;
Leuciscus cephalus cabeda
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Scales from 427 Barbus barbus plebejus and 406 Leuciscus cephalus cabeda from the middle River Po were examined. The last annulus was formed between April and May 1977, except the 0–1 age-group of L.c. cabeda which developed its first year-ring between March and April 1977. The survival (S) and annual mortality (A) rates were equivalent in both fish populations; the same was true of both sexes of Leuciscus, but S in Barbus males was lower than in females. The sex ratio showed a preponderance of females in both species. Growth rate from June to September 1976 was higher than in the rest of the year. Annual growth in Barbus females was higher than in males, whereas both sexes in Leuciscus showed equivalent growth rates; growth rate was higher in Barbus than in Leuciscus. The P/B ratio of both species was higher in the young age-groups.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00011570
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