Ecology, Environment and Conservation Paper

FECUNDITY CAPACITY OF THE MUDSKIPPER IN TWO ESTUARINE (MANGROVE SWAMP VERSUS NIPA SWAMP) CREEKS OF SOUTHEASTERN NIGERIA

Mfon T. Ude. Anthony W. Akpan, Blessing J. Oribhabor and Utibe I. Daniel

Abstract

The Fecundity capacity of the mudskipper. PerioplUhalmus harbarus in two estuarine creeks of Qua Iboe River, Nigeria was examined. Average absolute fecundity of the mudskipper was 8,170 eggs and 8,577 eggs in mangrove and nipa creek respectively. There were considerable variations in fecundity from the mangrove creek (coefficient of variation, CV = 73.5%) and nipa creek (CA/ = 66.7%). Although, similarity occurred in the rank-order (rs = 0.891, P<0.02) of the power of the exponent (b) from the regression between fecundity and independent variables between the creeks, the proportions of some of them were different. In comparing reliability of fecundity, six out of the eight variables and two reproductive indices, gave better estimates. Surprisingly, the higher values of body weight and condition index by the nipa creek specimens did not culminate in heavier gonad vis-a-vis the mangrove individuals. However, the heavier individual egg weight by the mangrove individuals was as expected as residents of the native and indigenous mangrove habitat. While there was no intra-seasonal difference in absolute fecundity, interseasonal increases occurred during the dry season over the rains in favour of the nipa creek specimens. This study is discussed along the deleterious and potent degradation of the coastal mangrove estuarine ecosystem of the country by the alien nipa palms (Mira fi-14ticans) introduced into Nigerian towns of Calabar and Oron in 1906 and 1912 respectivelv, as ornament.