Meeting Abstract
Suction feeding is a common feeding mode in aquatic organisms. So far, we have data on adult and larval fish, adult salamanders, tadpoles, and aquatic bladderworts. In this project, we focus on two understudied groups: paedomorphic salamanders and terrestrial bladderworts. Terrestrial and aquatic bladderworts differ in their mouth morphology, as do paedomorphic versus adult salamanders. We used the paedomorphic Ambystoma sp., also known as axolotl. We used the terrestrial bladderwort species Utricularia praelonga, which has slit-shaped mouths, unlike the aquatic species U. vulgaris. For this study, we compared the flow (such as maximum flow speed) and the movement patterns (such as maximum gape, time to maximum gape) across species. We found that paedomorphic salamanders are similar to fish and adult salamanders in their performance and that terrestrial bladderwort are similar to aquatic bladderworts, despite considerable differences in mouth morphology. Axolotl time to peak gape and gape is similar to adult fish and adult salamanders (order of magnitude of 102 to 103 ms; 101 to 102 mm); bladderworts have much smaller times to peak gape and gape diameters (order of magnitude 10-1 ms, 10-1 mm) than adult fish and salamanders, and similar gapes but much smaller time to peak gape than larval fish (10 -1 mm, 101 ms). Bladderwort peak flow speeds (101 m/s near the mouth) are more similar to adult fish (10-1 to 101 m/s) than larval fish and paedomorphic salamanders (10-3 to 10-2 m/s). Gape size is not a strong predictor of suction kinematics and flow; small suction feeders can generate similar suction flows to adult fish and large, aquatic salamanders.
