Click on image to view larger version.

Fig. 1. Morphometrics and hydrodynamic modeling. (A) The filled dots show the
landmarks used to reconstruct the shape of the body and provide measurements
for the parameters noted. (B,C) The two hydrodynamic models used in the
present study are illustrated with the drag, D, and thrust, T,
vectors predicted to be generated as the bell contracts and the bell margin
adducts. (B) The jet model assumes thrust to be generated by a jet,
Tjet. (C) The paddle model assumes thrust is generated by
paddling, Tpaddle.