Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Biology

Virginia Commonwealth University

Series

Biomechanics

Articles 1 - 2 of 2

Full-Text Articles in Life Sciences

Pectoral Sound Generation In The Blue Catfish Ictalurus Furcatus, Yasha Mohajer, Zachary Ghahramani, Michael L. Fine Jan 2015

Pectoral Sound Generation In The Blue Catfish Ictalurus Furcatus, Yasha Mohajer, Zachary Ghahramani, Michael L. Fine

Forensic Science Publications

Catfishes produce pectoral stridulatory sounds by “jerk” movements that rub ridges on the dorsal process against the cleithrum. We recorded sound synchronized with high-speed video to investigate the hypothesis that blue catfish Ictalurus furcatus produce sounds by a slip–stick mechanism, previously described only in invertebrates. Blue catfish produce a variably paced series of sound pulses during abduction sweeps (pulsers) although some individuals (sliders) form longer duration sound units (slides) interspersed with pulses. Typical pulser sounds are evoked by short 1–2 ms movements with a rotation of 2°–3°. Jerks excite sounds that increase in amplitude after motion stops, suggesting constructive interference, …


Reduction Of The Pectoral Spine And Girdle In Domesticated Channel Catfish Is Likely Caused By Changes In Selection Pressure, Michael L. Fine Jan 2014

Reduction Of The Pectoral Spine And Girdle In Domesticated Channel Catfish Is Likely Caused By Changes In Selection Pressure, Michael L. Fine

Biology Publications

Locked pectoral spines of the Channel Catfish Ictalurus punctatus more than double the fish's width and complicate ingestion by gape-limited predators. The spine mates with the pectoral girdle, a robust structure that anchors the spine. This study demonstrates that both spine and girdle exhibit negative allometric growth and that pectoral spines and girdles are lighter in domesticated than in wild Channel Catfish. This finding could be explained by changes in selection pressure for spine growth during domestication or by an epigenetic effect in which exposure to predators in wild fish stimulates pectoral growth. We tested the epigenetic hypothesis by exposing …