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Effects of Photoperiod on Behavior and Courtship of the Neosho madtom (Noturus placidus)

Angela G. Bulger·Mark L. Wildhaber·David R. Edds
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Abstract

To test effects of long and short day-length on behavior of the Neosho madtom ( Noturus placidus ), we held six pairs of fish in separate tanks under 16 hr (L): 8 hr (D) (long-day) and six pairs under 12 hr (L): 12 hr (D) (short-day) photoperiods. An ethogram was created and behavior was electronically and continuously recorded. Two-minute intervals for each hour over four 4-day periods were examined, and proportion of time active and performing specific behaviors in each tank was analyzed to compare differences between treatments. Individuals held under 16 L, 8 D were more active during the light cycle than those in 12 L, 12 D. Specific behaviors examined included resting, swimming, feeding, aggression, cavity enhancement, and courtship. A higher proportion of time was spent performing cavity enhancement, cavities were deeper, and gravel size in cavities was smaller for those fish in the long-day treatment. Throughout the experiment various courtship behaviors were observed in male-female pairs held in 16 L, 8 D, but no such behaviors were observed in 12L, 12D. The relationships between a long photoperiod and activity, cavity enhancement, and courtship behaviors illustrate the influence of photoperiod on the Neosho madtom reproductive cycle.

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Angela G. Bulger, Mark L. Wildhaber, David R. Edds. 2002. Effects of Photoperiod on Behavior and Courtship of the Neosho madtom (Noturus placidus). https://doi.org/10.1080/02705060.2002.9663877

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