Mead, K. S. University of California, Berkeley, kmead@socrates.berkeley.edu
Koehl, M. S. University of California, Berkeley, (510) 643-6264

 
OLFACTORY FLICKING IN STOMATOPODS: CHANGES IN THE BOUNDARY LAYER SURROUNDING THE CHEMOSENSORY SENSILLAE AS A FUNCTION OF ANIMAL SIZE AND ANTENNULE SPEED
 
Stomatopods, like many crustaceans, sample their chemical environment by rapidly flicking their antennules. This abrupt movement facilitates odorant access to the chemosensory setae (aesthetascs) on the lateral flagellum of the antennule. We found that the Reynolds numbers (Re) describing flow around stomatopod aesthetascs change dramatically as the animals grow from juveniles to adults (from 0.2 to 1.8 for the outward motion of the flick and from 0.1 to 0.9 for the return part of the flick). These increases in Re are within a range where small changes in speed and morphology can have large effects on fluid flow between setae. These alterations in fluid flow in turn affect the rate at which odorant molecules in the fluid diffuse to the aesthetasc surface. Here we examine how the structure of the boundary layer surrounding the aesthetascs differs between the outward and return strokes of the flick and between large and small specimens of Gonodactylus mutatus. Flow visualization around dynamically scaled physical models of aesthetasc-bearing antennule segments from large and small stomatopods reveals the structure of the boundary layer, the time required for odorants to diffuse through the boundary layer, and the sample volume per flick.
 
Day: Thursday, Feb. 4
Time: 09:00 - 09:15am
Location: Hilton of Santa Fe
 
Code: SS16TH0900H