Sharks need the lateral line to locate odor sources, rheotaxis
and eddy chemotaxis.
Some taxa used positive rheotaxis
so long as sufficient water current was available.
The widespread use of rheotaxis
in conjunction with olfaction may reflect the stability of flow cues when compared to the chemical cues used in chemotaxis.
Previous studies considering flow direction as the only cue reported positive rheotaxis
in both the laboratory (Murray and Willows, 1996) and the field (Murray, unpubl.
Morphological development in relation to phototaxis and rheotaxis
in the striped jack, Pseudocaranx dentex.
Our goals were to learn whether positive rheotaxis
is continuous for T.
Lobsters may be using one or a combination of two possible mechanisms to locate an odor source: (a) odor-gated rheotaxis
, which would cause the animal to move upstream, using the mean current for orientation once a chemical signal is detected (2), and (b) eddy-chemotaxis, which would require an animal to use the internal chemical and hydrodynamic fine structure of an odor plume to locate the source (3).
Odor gated rheotaxis
(OGR) (Kennedy, 1986) combines the guidance provided by two sensory modalities.
This is why many species of animals perform anemotaxis in air and rheotaxis
in water (Willis and Arbas, 1991; Dusenbery, 1992; Arbas et al., 1993; Weissburg and Zimmer-Faust, 1994).
A quantitative assessment of chemically mediated rheotaxis
in the asteroid, Coscinasterias tenuispina.
These experiments suggested that males made orientation responses with respect to the direction of flow (rheotaxis
Controls served as indicators of spontaneous detection responses to water flow from injections (rheotaxis
) and spontaneous probing and locomotion in the absence of chemical cues.