Importance of Behaviour to the Re-Establishment of Drifting Ephemeroptera

Abstract

Experiments with mayfly larvae in a laboratory stream revealed significant differences among settling capabilities of four species. Quantitative measures of overall settling capacity, contribution of morphology and that of behaviour were derived for comparative purposes. Importance of behaviour to re-establishment was greater in species which frequently show die1 drift periodicities than those which do not. Although morphological differences between species were large, mean size of nymphs was more important in determining rates of return of dead animals. Intraspecific variations in the ability of drifting individuals to become re-estab1ished may partially account for changes in the relative distribution of populations over time.

Settling distances of benthic invertebrates in a sediment mobilization simulation in semi-natural flumes

“…Entrainment of zoobenthos along with sediment at high flows has a strong contribution to drift (Bond and Downes, 2003;Gibbins et al, 2005), and previous studies in artificial channels and in natural streams have con- firmed that some taxa actively exit the drift by behavioural control (Ciborowski and Corkum, 1980;Campbell, 1985;Otto and Sjökström, 1986;Allan and Feifarek, 1989;Elliott, 2002;Oldmeadow et al, 2009). Studies to assess drifting samples have been conducted by manually introducing selected larvae in artificial or natural streams and recording the numbers present in drift after a certain distance (Elliott 1971(Elliott , 2002Ciborowski and Corkum, 1980;Campbell, 1985;Otto and Sjökström, 1986;Allan and Feifareck, 1989;Oldmeadows et al, 2009); or forcing animals into the water column by disturbing the substratum and inducing catastrophic drift (McLay, 1970;Larkin and McKone, 1985;Lancaster et al, 1996).…”

“…Studies to assess drifting samples have been conducted by manually introducing selected larvae in artificial or natural streams and recording the numbers present in drift after a certain distance (Elliott 1971(Elliott , 2002Ciborowski and Corkum, 1980;Campbell, 1985;Otto and Sjökström, 1986;Allan and Feifareck, 1989;Oldmeadows et al, 2009); or forcing animals into the water column by disturbing the substratum and inducing catastrophic drift (McLay, 1970;Larkin and McKone, 1985;Lancaster et al, 1996). It has been argued by Elliott (2002) that by using the latter method, there is no control over the number of invertebrates entering the drift, or the different taxa in the drift.…”

Behaviour of drifting insect larvae

“…Since size, shape and behaviour are very different in different species, settling time may be expected to vary considerably (cf. Ciborowski & Corkum, 1980). We performed the present study to elucidate the effects of different current regimes on the behaviour and time spent in the drift in mayflies, stoneflies and campodeiform caddis larvae.…”

“…Living settling rate -Dead settling rate Maximum settling rate (Ciborowski & Corkum, 1980). This formulation would give an index value of near' 1.0 if setting rate is entirely due to behaviour, 0.0 if there is no behavioural component, and near -1.0 if animals are actively avoiding contact with the bottom.…”

Experimentation at the interface of fluvial geomorphology, stream ecology and hydraulic engineering and the development of an effective, interdisciplinary river science

“…One particularly exciting aspect of interdisciplinary work is the opportunity to independently manipulate physical and biological parameters in order to understand their relative influence on animal behaviour or processes. This may include working with both living and dead organisms in order, for example, to disentangle behavioural and mechanistic effects on drift distance (Ciborowski and Corkum, 1980;Allan and Feifarek, 1989;Oldmeadow, 2005).…”