Evidence for Magnetoreception in Red Drum (Sciaenops ocellatus), Black Drum (Pogonias cromis), and Sea Catfish (Ariopsis felis)

Abstract

Over the past few decades, magnetoreception has been discovered in several species of teleost and elasmobranch fishes by employing varied experimental methods including conditioning experiments, observations of alignment with external fields, and experiments with magnetic deterrents. Biogenic magnetite has been confirmed to be an important receptor mechanism in some species, but there is ongoing debate regarding whether other mechanisms are at work. This paper presents evidence for magnetoreception in three additional species, red drum (Sciaenops ocellatus), black drum (Pogonias cromis), and sea catfish (Ariopsis felis), by employing experiments to test whether fish respond differently to bait on a magnetic hook than on a control. In red drum, the control hook outcaught the magnetic hook by 32-18 for Χ 2 = 3.92 and a P-value of 0.048. Black drum showed a significant attraction for the magnetic hook, which prevailed over the control hook by 11-3 for Χ 2 = 4.57 and a P-value of 0.033. Gafftopsail catfish (Bagre marinus) showed no preference with a 31-35 split between magnetic hook and control for Χ 2 = 0.242 and a P-value of 0.623. In a sample of 100 sea catfish in an analogous experiment using smaller hooks, the control hook was preferred 62-38 for Χ 2 = 5.76 and a P-value of < 0.001. Such a simple method for identifying magnetoreceptive species may quickly expand the number of known magnetoreceptive species and allow for easier access to magnetoreceptive species and thus facilitate testing of magnetoreceptive hypotheses.

Dietary Habits of Hardhead (Ariopsis felis) and Gafftopsail (Bagre marinus) Catfish Revealed through DNA Barcoding of Stomach Contents

“…For hardhead catfish, length bins were determined based on a length at 50% maturity of ~250 mm TL [26]. For gafftopsail catfish, fork length at 50% maturity was obtained from Miguez [27] and converted to TL using the length-mass regression provided by Courtney et al [28]. This value, 359 mm TL, was rounded to 400 mm TL for a conservative estimate.…”