Title

Interspecific Comparison of Venom Secretions in Corydoras Catfish

Poster Number

06B

Lead Author Major

Biological Sciences

Lead Author Status

Senior

Second Author Major

Pre-Dentistry

Second Author Status

Senior

Third Author Major

Pre-Dentistry

Third Author Status

Junior

Fourth Author Major

Biological Sciences

Fourth Author Status

Junior

Format

Poster Presentation

Faculty Mentor Name

Eric Thomas

Faculty Mentor Email

ethomas@pacific.edu

Faculty Mentor Department

Biological Sciences

Graduate Student Mentor Name

Erik Wictor

Graduate Student Mentor Email

ewictor@pacific.edu

Graduate Student Mentor Department

Biological Sciences

Abstract/Artist Statement

In the tropical fish pet trade, transportation and movement can subject fishes to prolonged stress. In response to these stressors, some species of catfishes are known to release defensive secretions which cause self-poisoning and death. Catfish of the genus Corydoras, a group with over 400 known species and types popular in the aquarium trade, are known to be vulnerable to self-poisoning. From an evolutionary and biochemical view, Corydoras is an ideal system for studying this phenomenon. Previously, we examined the structure of venom glands in Corydoras sterbai and venom chemistry in C. duplicareus. Expanding on that work, we are now conducting a survey of venom glands and venom secretions in several species of Corydoras catfish to study how the phenomenon has evolved in the group. Venom secretion was induced by stressful handling of the fish. Within minutes, the water turned cloudy, indicative of venom secretion. Signs of self- poisoning were evident when fish showed reduced vitality. Analysis of secretions by CBX protein quantification, SDS-PAGE, and Mass Spectrometry (MS) confirmed that the secretions consist of multiple protein compounds. SDS-PAGE gels revealed a single thick band of low molecular weight (MW) proteins shared by all species tested; higher MW proteins were present in gels for some species but not others. This suggests that Corydoras venom secretions may be composed of shared and species-specific proteins. Several of these protein bands are being analyzed by MS to identify particular amino acid sequences for each species. We have also conducted preliminary histological analysis on separate species and are currently working through the tissues to describe the glands. Based on our results, we can conclude that Corydoras venom secretions represent a complex mix of proteins. We hope to determine whether there is a phylogenetic explanation for the complexity of this defensive system.

Location

DeRosa University Center, Ballroom

Start Date

28-4-2018 10:00 AM

End Date

28-4-2018 12:00 PM

This document is currently not available here.

Share

COinS
 
Apr 28th, 10:00 AM Apr 28th, 12:00 PM

Interspecific Comparison of Venom Secretions in Corydoras Catfish

DeRosa University Center, Ballroom

In the tropical fish pet trade, transportation and movement can subject fishes to prolonged stress. In response to these stressors, some species of catfishes are known to release defensive secretions which cause self-poisoning and death. Catfish of the genus Corydoras, a group with over 400 known species and types popular in the aquarium trade, are known to be vulnerable to self-poisoning. From an evolutionary and biochemical view, Corydoras is an ideal system for studying this phenomenon. Previously, we examined the structure of venom glands in Corydoras sterbai and venom chemistry in C. duplicareus. Expanding on that work, we are now conducting a survey of venom glands and venom secretions in several species of Corydoras catfish to study how the phenomenon has evolved in the group. Venom secretion was induced by stressful handling of the fish. Within minutes, the water turned cloudy, indicative of venom secretion. Signs of self- poisoning were evident when fish showed reduced vitality. Analysis of secretions by CBX protein quantification, SDS-PAGE, and Mass Spectrometry (MS) confirmed that the secretions consist of multiple protein compounds. SDS-PAGE gels revealed a single thick band of low molecular weight (MW) proteins shared by all species tested; higher MW proteins were present in gels for some species but not others. This suggests that Corydoras venom secretions may be composed of shared and species-specific proteins. Several of these protein bands are being analyzed by MS to identify particular amino acid sequences for each species. We have also conducted preliminary histological analysis on separate species and are currently working through the tissues to describe the glands. Based on our results, we can conclude that Corydoras venom secretions represent a complex mix of proteins. We hope to determine whether there is a phylogenetic explanation for the complexity of this defensive system.