Ventilatory responses to skin extract in catfish

Abstract

AB Aquatic Biology Contact the journal Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AB 15:205-214 (2012) - DOI: https://doi.org/10.3354/ab00429 Ventilatory responses to skin extract in catfish Rodrigo Egydio Barreto1,*, Augusto Barbosa Júnior2, Anette Hoffmann2 1Departamento de Fisiologia, Instituto de Biociências, Caunesp, UNESP, Rubião Jr. s/n, Botucatu, São Paulo 18618-970, Brazil 2Laboratório de Neurofisiologia Comparada, Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, USP, Av. Bandeirantes 3900, Monte Alegre, Ribeirão Preto, São Paulo 14049-900, Brazil *Email: rebarreto@yahoo.com ABSTRACT: The ventilation rate (VR) of an ostariophysan fish, the speckled catfish Pseudoplatystoma coruscans, exposed to a chemical alarm cue was measured in the present study in multiple contexts. The influence of the extraction techniques, skin donor food intake and quantity of the alarm cue (skin extract) on this autonomic response was considered. Overall, the catfish VR decreased significantly when exposed to the skin extract (chemical alarm cue) compared with exposure to distilled water (control). No effect of the extraction technique was found. Increasing doses of the skin extract induced a VR reduction of similar magnitude. However, extract obtained from daily-fed fish induced a significant decrease in the VR, whereas extract obtained from food-restricted fish did not induce any change in the VR. Thus, food intake was associated with the production of a more easily recognizable alarm cue in the speckled catfish. Interestingly, this effect was not related to differences in the number of club cells in the donor catfish epidermis. Dashing, or rapid swimming, a normal component of the alarm response in fish, including this catfish species, was not observed here, and hypoventilation was always associated with no swimming reaction. Together, these results suggest that hypoventilation is a reaction to a chemical alarm cue, likely resulting in improved crypsis, causing the fish to become less easily perceived by a potential predator that usually strikes prey in response to movement. KEY WORDS: Stress · Antipredator behavior · Chemical communication · Alarm substance · Neurovegetative system · Opercular beat rate Full text in pdf format PreviousNextCite this article as: Barreto RE, Barbosa Júnior A, Hoffmann A (2012) Ventilatory responses to skin extract in catfish. Aquat Biol 15:205-214. https://doi.org/10.3354/ab00429 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AB Vol. 15, No. 3. Online publication date: June 06, 2012 Print ISSN: 1864-7782; Online ISSN: 1864-7790 Copyright © 2012 Inter-Research.