RÉSUMÉ
Extracted venoms from two species of cubozoan, Chironex fleckeri (C. fleckeri)and Chiropsalmus sp., were injected into the freshwater crayfish Cherax quadricarinatus (C. quadricarinatus). By means of a Vascular Doppler, the cardiac parameters heart rate and contraction amplitude were recorded, with the theoretical total heart output calculated from these two recordings. Cherax quadricarinatus reflects prey items utilized by these two species in the wild and so comparisons of venom action on this animal have greater ecological relevance than those of previous mammalian models used. While the results of this study reflect previous research showing that the overall potency of C. fleckeri venom is greater than that of Chiropsalmus sp. venom, the action of the venoms on the heart muscle is found to be different. Chironex fleckeri,which has the most potent venom out of these two species, is actually less effective in reducing cardiac activity than Chiropsalmus sp., which may be a direct reflection of the variation in primary prey utilized by each species.
RÉSUMÉ
Extracted venoms from two species of cubozoan, Chironex fleckeri (C. fleckeri)and Chiropsalmus sp., were injected into the freshwater crayfish Cherax quadricarinatus (C. quadricarinatus). By means of a Vascular Doppler, the cardiac parameters heart rate and contraction amplitude were recorded, with the theoretical total heart output calculated from these two recordings. Cherax quadricarinatus reflects prey items utilized by these two species in the wild and so comparisons of venom action on this animal have greater ecological relevance than those of previous mammalian models used. While the results of this study reflect previous research showing that the overall potency of C. fleckeri venom is greater than that of Chiropsalmus sp. venom, the action of the venoms on the heart muscle is found to be different. Chironex fleckeri,which has the most potent venom out of these two species, is actually less effective in reducing cardiac activity than Chiropsalmus sp., which may be a direct reflection of the variation in primary prey utilized by each species.