Presentation Title

Behavioral Responses Exhibited by Striped Bass (Morone saxatilis) and Nile Tilapia (Oreochromis niloticus) in Response to Hypoxia

Location

Atrium

Session Format

Poster Presentation

Research Area Topic:

MBI - Molecular Biology Initiative

Co-Presenters, Co- Authors, Co-Researchers, Mentors, or Faculty Advisors

Johanne M. Lewis, Georgia Southern University

Abstract

For a poster. Oxygen deprivation (hypoxia) is a common stressor affecting cardiomyocytes (heart cells) when blood flow is reduced or cut off from the heart. In response, cardiomyocytes have been shown to undergo apoptosis (programmed cell death) which is suggested to have a role in the pathogenesis of cardiovascular diseases, the leading cause of mortality in developed nations. Since many species of fish can survive low oxygen levels that would be fatal to mammals, fish are an ideal model system to study changes at the cellular and molecular level that prevent or repair hypoxia-induced damage in cardiomyocytes. The nile tilapia (Oreochromis niloticus) is a species of fish that can survive hypoxic episodes in its natural environment. We hypothesize that nile tilapia are preventing apoptosis in cardiomyocytes and surviving hypoxic conditions by utilizing cellular and molecular protective pathways. The hypoxia-sensitive striped bass (Morone saxatilis) will be used as a comparative model. In order to study the cellular and molecular pathways in tilapia, first the critical hypoxia level had to be determined in both species of fish. Both species were subjected to gradual hypoxia exposure and monitored every 5 minutes for key behavioral responses: a) baseline swimming and ventilation (control), b) discomfort such as gasping for air, c) agitation such as increased speed and frequency of swimming, d) impending mortality such as slowed ventilation and listing and e) mortality such as the loss of equilibrium. Striped bass (n = 6) oxygen levels were decreased approximately 10% every 40 minutes, until mortality occurred at 30.1% dissolved oxygen. Tilapia (n = 5) were similarly observed during gradual hypoxia (approximately 20% every 40 minutes) exposure, but were found to only experience discomfort at 5% dissolved oxygen. Based on behavioral evidence, striped bass and tilapia behave differently when exposed to hypoxic conditions.

Keywords

Physiology, Behavior, Hypoxia, Striped bass, Tilapia

Presentation Type and Release Option

Presentation (Open Access)

Start Date

4-24-2015 2:45 PM

End Date

4-24-2015 4:00 PM

This document is currently not available here.

Share

COinS
 
Apr 24th, 2:45 PM Apr 24th, 4:00 PM

Behavioral Responses Exhibited by Striped Bass (Morone saxatilis) and Nile Tilapia (Oreochromis niloticus) in Response to Hypoxia

Atrium

For a poster. Oxygen deprivation (hypoxia) is a common stressor affecting cardiomyocytes (heart cells) when blood flow is reduced or cut off from the heart. In response, cardiomyocytes have been shown to undergo apoptosis (programmed cell death) which is suggested to have a role in the pathogenesis of cardiovascular diseases, the leading cause of mortality in developed nations. Since many species of fish can survive low oxygen levels that would be fatal to mammals, fish are an ideal model system to study changes at the cellular and molecular level that prevent or repair hypoxia-induced damage in cardiomyocytes. The nile tilapia (Oreochromis niloticus) is a species of fish that can survive hypoxic episodes in its natural environment. We hypothesize that nile tilapia are preventing apoptosis in cardiomyocytes and surviving hypoxic conditions by utilizing cellular and molecular protective pathways. The hypoxia-sensitive striped bass (Morone saxatilis) will be used as a comparative model. In order to study the cellular and molecular pathways in tilapia, first the critical hypoxia level had to be determined in both species of fish. Both species were subjected to gradual hypoxia exposure and monitored every 5 minutes for key behavioral responses: a) baseline swimming and ventilation (control), b) discomfort such as gasping for air, c) agitation such as increased speed and frequency of swimming, d) impending mortality such as slowed ventilation and listing and e) mortality such as the loss of equilibrium. Striped bass (n = 6) oxygen levels were decreased approximately 10% every 40 minutes, until mortality occurred at 30.1% dissolved oxygen. Tilapia (n = 5) were similarly observed during gradual hypoxia (approximately 20% every 40 minutes) exposure, but were found to only experience discomfort at 5% dissolved oxygen. Based on behavioral evidence, striped bass and tilapia behave differently when exposed to hypoxic conditions.