Species traits in relation to habitat variability and state: neotropical juvenile fish in floodplain creeks

Abstract

1. Ecological theory predicts that (1) proportions of fish having particular life history strategies should vary with habitat conditions, and (2) biological traits of species should change across spatio‐temporal variability gradients (River Habitat Templet).2. We used data on juvenile fish and biological traits of the species, temporal (i.e. hydrology) and spatial (e.g. depth, bottom substrate, litter type) habitat variability and state (i.e. mean conditions) to test these predictions for communities comprising 57 fish taxa in floodplain creeks of the Sinnamary River (French Guiana).3. We did not confirm predictions on habitat use according to groupings based on life history strategies. However, we found 10 significant relationships between species traits and habitat variability (e.g. size at maturity, diameter of mature oocytes, parental care and relative body height decreased with increasing temporal variability; size at maturity and mean diameter of mature oocytes increased with increasing spatial variability). In addition, state variables such as mean water level, dissolved oxygen, mean width or mean depth could explain much of the variation in species traits.4. Thus, our results generally supported the River Habitat Templet but suggested that state, in addition to variability, should be included in habitat descriptions.