Cardiac and ventilatory responses ofCrangon crangon to cadmium, copper and zinc

Abstract

The acute (30 min) responses of heart and scaphognathite activities of Crangon crangon on exposure to concentrations of 1-20 mg Cd, Cu or Zn 1-1 are increased beat frequencies. The relative magnitude of response (A f) is linearly related to immediate pretreatment frequency (f) and standardised responses (Afs) are given for f values of 70 and 100 beats min -I for hearts and scaphognathites, respectively. Afs values for each organ are also linearly related to test concentration for each metal. Qualitative changes to organ activities described include an increased incidence of scaphognathite reversals in concentrations of 5.0 mg Cu 1-1 and in 20.0 mg Zn 1-1. Chronic (13 days) exposure to incipient lethal levels of the test metals produced increases in scaphognathite rates of the Cd-treated animals and in heart and scaphognathite rates of the coppertreated animals. The general applicability of these methods to studies of pollution stress in decapods is discussed.

Low-salinity stress in the American lobster,Homarus americanus, after chronic sublethal exposure to cadmium: Biochemical effects

“…The major overall effect of sublethal cadmium stress in all lobster tissues examined, then, was increased glycolysis, an expenditure of energy reserves typical of many types of sublethal stress, as in the cold-acclimation of terrestrial invertebrates (Rao, 1966). This observation accords with Theede's report (1980) of an increased gross energy demand in cadmium-fed Mytilus larvae, and with that of Price & Uglow (1980) of increased rate of heart beat in cadmium-exposed Crangon.…”

The Effects of Temperature and Hydrostatic Pressure on Metal Toxicity: Insights into Toxicity in the Deep Sea

“…63,64 At high concentrations, copper and cadmium reduce respiratory capacity, leading to a mismatch in oxygen supply and demand and ultimately resulting in death. 49 However, exposure to sublethal copper concentration stimulates increases in cardiac activity in caridean shrimp, whereas cardiac activity is not significantly affected by exposure to sublethal cadmium concentration, 65 highlighting that the toxicity of these metals manifests via different mechanisms.…”

“…Lethal toxicity in copper and cadmium exposures results from systemic disturbance in acid–base balance in decapods, caused by the inhibition of carbonic anhydrase. , Carbonic anhydrase facilitates acid–base regulation and respiratory exchange by promoting rapid equilibration between HCO 3 – and CO 2 and contributing to hemocyanin modulation and gas transport. , At high concentrations, copper and cadmium reduce respiratory capacity, leading to a mismatch in oxygen supply and demand and ultimately resulting in death . However, exposure to sublethal copper concentration stimulates increases in cardiac activity in caridean shrimp, whereas cardiac activity is not significantly affected by exposure to sublethal cadmium concentration, highlighting that the toxicity of these metals manifests via different mechanisms.…”

The use of opercular muscle electromyograms as an indicator of the metabolic costs of fish activity in rainbow trout, Salmo gairdneri Richardson, as determined by radiotelemetry

“…To date, most investigations into the opercular movements of fish have involved their relationship with heart rate (Weintraub & Mackay, 1975) or some environmental factor, e.g. pollution (Hughes & Roberts, 1970;Hughes, 1973;Price & Uglow, 1980). A variety of techniques have been employed for monitoring respiratory movements.…”