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Digging with a vortex: Flow manipulation facilitates prey capture by a predatory stream mayfly
Author(s) -
Soluk Daniel A.,
Craig Douglas A.
Publication year - 1990
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1990.35.5.1201
Subject(s) - mayfly , benthic zone , digging , predation , substrate (aquarium) , invertebrate , biology , fossorial , sediment , ecology , larva , paleontology , geography , archaeology
The effect of rapid flow and substrate instability on the distribution of benthic organisms is viewed as negative. Larvae of the mayfly Pseudiron centralis McDunnough not only tolerate rapid flows and loosely consolidated shifting sands (typical features of the beds of large lowland rivers), but are unique in their ability to exploit these conditions to facilitate the capture of prey. Unusual posturing allows Pseudiron larvae to transform themselves from streamlined forms closely appressed to the sediment surface into bluff objects that project from the surface and cause local disruption of flow. By obstructing the flow in this way, a Pseudiron larva creates an energetic vortex whose erosive power is used to excavate pits in the loose sands. Small burrowing and interstitial invertebrates exposed by removal of sand grains in the pits are then attacked and consumed. Using a vortex as a digging tool allows Pseudiron larvae to exploit infaunal prey, although they lack morphologically specialized fossorial appendages.