Open AccessFitness, developmental instability, and the ontogeny of fluctuating asymmetry in Daphnia magna
Author(s) -
STIGE LEIF CHRISTIAN,
HESSEN DAG OLAV,
VØLLESTAD LEIF ASBJØRN
Publication year - 2006
Publication title -
biological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.906
H-Index - 112
eISSN - 1095-8312
pISSN - 0024-4066
DOI - 10.1111/j.1095-8312.2006.00604.x
Subject(s) - biology , fluctuating asymmetry , daphnia magna , ontogeny , daphnia , reproduction , zoology , population , instar , ecology , larva , crustacean , demography , genetics , sociology , chemistry , organic chemistry , toxicity
Fluctuating asymmetry (FA) is the most commonly used measure of developmental instability. The relation between FA and individual fitness remains controversial, partly due to limited knowledge on the mechanisms behind variation in FA. To address this, we investigated the associations between FA, growth and reproduction as well as the ontogeny of FA in a clonal population of Daphnia magna . FA was not correlated with growth and reproduction, either at the between‐ or the within‐individual level, in a high ( N = 48 individuals) or in a low ( N = 52 individuals) food‐quantity regime. There were therefore no indications of functional effects of FA or of phenotypic trade‐offs between developmental stability, growth and reproduction. Individual asymmetries varied randomly in sign and magnitude between subsequent molts ( N = 19 individuals, 9–11 instars), but the levels of FA were generally lowest at intermediate ages. No feedback between right and left sides was detected. This suggests that FA only reflects the most recent growth history, that developmental instability may increase in old age, and that FA depends on processes operating on each side of the body independently. The results also suggest that FA differences within and among individual Daphnia are largely random, with limited biological significance. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 179–192.