Supporting data: Functional plasticity of the swim bladder as an acoustic organ for communication in a vocal fish

Description

Notes

Methods

Swim bladder morphometrics:

Nonreproductive and reproductive male plainfin midshipman were CT scanned and reconstructed using Slicer software. Following recontruction, swim bladder width, length, and horn length were calculated. Swim bladders were then pseudo-landmarked and compared using PCA analysis.

Auditory sensitivity:

Auditory evoked potentials were recorded from saccular hair cells in nonreproductive and reproductive male midshipman with swim bladders that were intact (i.e., control) or ablated (i.e., removed) using glass microelectrodes. Evoked potentials were recorded in response to pure tone stimuli (95 - 950 Hz) at sound pressure levels ranging from 97 - 154 dB re: 1 µPa. All experiments were performed in MATLAB.

Finite element analysis:

Models of nonreproductive and reproductive male swim bladders from 3D Slicer were imported into FreeCad and sectioned into 22.5 degree increments before  being exported to Strand7. Models were then meshed with triangular elements and given material properties (1 MPa), thickness (824.5 mm) and density (1000 kg/m³). For dynamic analysis, swim bladders were considered to be underdamped with a damping ratio of 0.325. Then natural frequencies, displacement, and power were determined in Strand7. Measurements were determined in response to a total force of 3.03 × 10^-6 Newtons over a ~3.03 × 10^-6 m² area of elements, such that a global pressure load of 1 Pascal.

All data were anlyzed using custom MATLAB or R scripts.