S10-10 Thu Jan 7 17:00 – 17:30 Dual phase-shifted ipsilateral metachrony in Americamysis bahia Ruszczyk, M*; Webster, DR; Yen, J; Georgia Institute of Technology; Georgia Institute of Technology; Georgia Institute of Technology email@example.com
Previously-documented metachrony in euphausiids has focused on one metachronal stroke, where pleopods on the same abdominal segment beat in tandem with each other propelling the animal forward. In contrast, the mysid shrimp Americamysis bahia’s pleopods on the same abdominal segment beat independently of each other, resulting in dual phase-shifted ipsilateral, metachronal strokes along the length of the body. The parameters of these independent strokes and their synchrony is investigated in free-swimming A. bahia. Concurrent strokes have the same beat frequency and similar phase lag profiles between adjacent ipsilateral appendages, though the strokes are 176.5±11.5° (n = 13 cycles, mean±standard error) out of phase. In comparison to the euphausiids Euphausia pacifica and E. superba, who achieve three distinct swimming modes by altering their beat frequency and phase lag, A. bahia only achieves fast forward swimming using its pleopods. Instead, the mysid primarily relies on its thoracic appendages for swimming, suggesting that there are limitations to what dual phase-shifted ipsilateral metachrony at can achieve at this length scale.