title: Maturity-related changes in venom toxicity of the freshwater stingray Potamotrygon leopoldi.
abstract: Aquatic venomous animals such as stingrays represent a largely untapped source for venom-based drug development. However, the major challenge for a potential drug development pipeline is the high inter- and intraspecific variability in toxicity and venom composition. As of today, little is known about maturity-driven changes in these traits in stingrays. The present study investigates the differences in toxicity and venom composition in different maturity stages of the freshwater stingray Potamotrygon leopoldi. This species can be found in the Xingú River basin (Brazil), where it mainly feeds on invertebrates, while being predated by other stingrays or large catfishes. P. leopoldi, as commonly known for stingrays, can cause severe injuries with the venomous dentine spine located at its tails. The toxicity of tissue extracts of juvenile and mature specimens was recorded on a myoblast cell culture bioassay. Venom composition and bioactivity of compounds were analyzed with planar chromatography linked to an Aliivibrio fischeri bioassay. Results revealed a decrease in venom toxicity during maturation, but no changes in venom composition. These findings may indicate that toxicity in mature specimens becomes evolutionary less important, probably due to a decrease in predation pressure.
authors.affiliation: Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany. Electronic address: Kim.N.Kirchhoff@allzool.bio.uni-giessen.de.
authors.forename: Kim N
authors.initials: KN
authors.lastname: Kirchhoff
authors.affiliation: Institute of Nutritional Sciences, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
authors.forename: Ines
authors.initials: I
authors.lastname: Klingelhöfer
authors.affiliation: Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Beutenbergstraße 11, 07745 Jena, Germany.
authors.forename: Hans-Martin
authors.initials: HM
authors.lastname: Dahse
authors.affiliation: Institute of Nutritional Sciences, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
authors.forename: Gertrud
authors.initials: G
authors.lastname: Morlock
authors.affiliation: Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wilke
mesh_terms: D000220:Adaptation, Biological / Q000502:physiology; D000367:Age Factors; D048908:Aliivibrio fischeri; D000818:Animals; D001681:Biological Assay; D001938:Brazil; D002845:Chromatography; D005397:Fish Venoms / Q000032:analysis* / Q000633:toxicity*; D020387:Food Chain; D045483:Rivers; D012860:Skates, Fish / Q000378:metabolism*
chemical_list: D005397:Fish Venoms
keywords: Maturity; Myoblasts; Stingrays; Toxicity; Venom composition