title: Acclimatable cardiac and ventilatory responses to copper in the freshwater crayfish Procambarus clarkii.
abstract: Mortality and physiological tests following exposure to waterborne copper were performed in the red swamp crayfish Procambarus clarkii from a central Italian population. Mortality tests gave an estimated 96 h LC50 value (with 95% confidence limits) of 162 (132-211) mg L(-1) waterborne copper II. Variations in cardiac and ventilatory rates were simultaneously monitored using a non-invasive plethysmographic technique. In experiments with different sub-lethal copper concentrations (control, 0.5, 1 and 10 mg L(-1)) performed at different times (3, 6, 96 h), copper exposure elicited a reduction in both heart and scaphognatite rates. Following exposure to 10 mg L(-1) copper for 96 h, the heart and scaphognatite rates decreased to about 35% of the initial values. The reduction was fully reversible, since crayfish exposed to 0.5, 1 and 10 mg Cu L(-1) for 96 h resumed control rates after a 3-h residence in clean water. In crayfish pre-exposed (96 h) to sub-lethal copper concentrations (0.1 and 1 mg L(-1)) and then held in control water (3 h), the reduction of heart and scaphognatite rates after exposure to 10 mg Cu L(-1) were significantly lower than in specimens pre-exposed to control water. Therefore, copper induces a concentration and time dependent reduction of both cardiac and ventilatory activity in P. clarkii; these responses can be reduced or fully abolished by pre-exposure to sub-lethal levels of the metal.
authors.affiliation: Department of Animal Biology and Genetics, University of Florence, 50125 Florence, Italy. giada.bini@unifi.it
authors.forename: Giada
authors.initials: G
authors.lastname: Bini
authors.forename: Guido
authors.initials: G
authors.lastname: Chelazzi
mesh_terms: D000818:Animals; D003400:Astacoidea / Q000502:physiology*; D003300:Copper / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D007928:Lethal Dose 50; D010991:Plethysmography; D012143:Respiratory Physiological Phenomena / Q000187:drug effects*
chemical_list: D003300:Copper