Premium
Age determination and year class structure in a stunted roach, Rutilus rutilus population
Author(s) -
Linfield R. S. J.
Publication year - 1979
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.1095-8649.1979.tb03497.x
Subject(s) - rutilus , biology , fish <actinopterygii> , population , population dynamics of fisheries , zoology , ecology , population structure , annulus (botany) , fishery , demography , botany , sociology
In an investigation into changes in the growth and biology of a stunted roach population, details are given of the methods of sampling and examination of the material. Studies on the growth of scales and opercula indicate that roach in all year classes formed a distinct annulus on both structures during May/June each year and fish in their second year of life also formed an additional check in the late summer/autumn of both 1969 and 1970. Reference is made to previously published descriptions of the particular difficulties, and their solutions, involved in aging stunted roach and evidence is cited for the validity of the methods used. Data on age distribution in the samples suggests that the 1966 year class was absent from the lake involved by late 1969 and that the 1965 and 1967 year classes were also very weak. Comparison is made with the results of other authors and the significance of the weak year classes is briefly discussed.