HEART AND SCAPHOGNATHITE ACTIVITY IN THE SHRIMP PALAEMON-ADSPERSUS RATHKE

The general behaviour of the heart and scaphognathites of Palaemort adspersus was investigated at different oxygen tensions and at different salinities. Compared with other species reported on, the organ activities of P. adspersus show few arhythmic events such as cardiac arrests and scaphogna- thite apnoeas. Heart rate decreased directly with hypoxia whereas scaphognathite rate increased over the range pO2 150-40 mm Hg and rapidly fell at pO2 levels < 40 mm Hg. Reoxygenation after hypoxia produces an immediate acceleration of organ rates to normal levels. Heart rate was not shown to be salinity dependent - the animals displaying similar organ frequencies when adapted to a wide range of salinities and when subjected to salinity shocks. © 1979 Taylor and Francis Group, LLC.