Meeting Abstract
P2.69 Jan. 5 The effect of the oral suction disk on the station-holding performance of suckermouth catfish (Hypostomus sp.) GERSTNER, C.L.; Columbia College Chicago and The University of Michigan Biological Station cgerstner@colum.edu
The effect of the oral suction disk on the ability to maintain position in a current (station-holding) was determined for the suckermouth catfish Hypostomus sp. Fish were tested using an increasing velocity test on three substrates, smooth Lucite, rough Lucite and wire grid. On the smooth substratum, use of oral suction and other behaviors delayed the need to swim continuously out of ground contact from 9.1 � 0.3 cm s-1 to 89.2 � 7.9 cm s-1. Trials on the wire grid showed that suction was ineffective as predicted, however fish were able to use other friction-enhancing behaviors instead to improve performance. Behaviors that increased friction by hooking the fish to the substrate via the odontodes and pectoral fin spines were very effective at delaying the need for steady swimming from 12.1 cm s-1 to 146.1 cm s-1. On the rough substratum, fish were able to use both oral suction and the odontodes/ fin spines in order to increase friction, and station-holding performance was similar to values on the wire substratum. Thus, while use of the oral suction disk was shown to improve station-holding performance, use of other morphological features such as the odontodes and fin spines may be equally important.
