Lifetime consequences of variable 0 year group length in riverine populations of chub Leuciscus cephalus (L.)
The fork length (LF) of individual chub Leuciscus cephalus in English riverine populations at the end of their first growth season varied considerably, ranging from <25 to >70 mm. This had a significant influence on the subsequent growth of individuals over their lifetime. Chub of small LF at age 1 year generally produced smaller annual growth increments throughout life than those of longer LF at age 1 year, although they had the potential to attain greater ultimate LF. This variability in LF at age 1 year resulted, at least in part, from multiple spawning events over a protracted period, that caused variation in the growing seasons for 0 year group chub of the same year class. Since the adult population contained individuals that only attained LF of <25 mm at the end of their first growing season, it is possible that LF at age 1 year may not be such a major precursor to strong chub recruitment as previously thought.