The Effect Of Salinity Stress On Buccal Ventilatory Rate In The African Lungfish, <i>Protopterus annectens</i> Owen

Abstract

The buccal ventilatory rate of the African lungfish, Protopterus annectens (Owen) ollowing acclimation to diluted seawater was investigated under laboratory conditions for s x days Healthy adult specimens of Afr can lungfish, Protopterus annectens (Owen) (mean weight 299.4g and mean length 38.9 cm) procured rom Anambra river at Otuocha were subjected to the following concentrations of dilute seawater: 0%, 5% (s = 1.8‰o), 10% (s = 3.5‰), 15% (s = 5.3‰), 20% (s = 7.0 ‰), 30% (s = 10.5 ‰) and 40% (s = 14.0 ‰) respectively. The results revealed that increase in salinity had a s gnificant positive correlation (r = 0.92, p < 0.05) with increase in buccal ventilatory rate. The mean least and highest buccal ventilatory rates were 5.32 and 12.26 times per hour at 1.8%o and 14.0%o salinities respectively. The implications of the findings for the culture of this fish species in estuarine ecosystems are discussed.