Interspecific Comparison of Venom Secretions in Corydoras Catfish
Poster Number
06B
Format
Poster Presentation
Faculty Mentor Name
Eric Thomas
Faculty Mentor Department
Biological Sciences
Graduate Student Mentor Name
Erik Wictor
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
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.