Fecundity, gonadosomic index and spawning period of Chrysichthys nigrodigitatus of the Lower Cross River, Nigeria

The estuarine catfish, Chrysichthys nigrodigitatus, is a prized food fish in Nigeria especially in the Niger Delta region. There is a growing concernrn over the sustainability of the fishery in the face of climate change and environmental variability. Studies were conducted on the fecundity, gonadosomatic index and the spawning period of the species. The objectives were to determine the average fecundity of the species and to use the gonadosomatic index to determine its spawning period with the aim of proffering management advice and prerequisites of the species in the face of climate change. A total of 44 females and 40 males were used for the study which spanned the period from May 2011 to April 2012. The fecundity of the species ranged from 3,730.5 eggs to 41,535.9 eggs. There was correlation between the total fecundity and fish weight (p~,01, r= 0.80, n= 44). The regression model for the relationship was expressed as fecundity = 4660.8+4.76 weight. The gonadosomatic index was highest in the month of May and dropped sharply in june signifying that spawning in Chrysichthys nigrodigitatus starts around this period. The implications of these findings in respect to sustainability of the species, and its aquaculture in the face of climate change are discussed.

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Bibliographic Details
Main Authors: Ama-Abasi, D., Sambo, U.
Format: conference_item biblioteca
Language:English
Published: FISON 2013
Subjects:Fisheries, Atmospheric Sciences, Chrysichythys nigrodigitatus, Nigeria, Lower Cross River, C. nigrodigitatus, Reproduction, Climate change, Cross Rivber, Sustainability, freshwater environment, automation,
Online Access:http://hdl.handle.net/1834/39048
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Summary:The estuarine catfish, Chrysichthys nigrodigitatus, is a prized food fish in Nigeria especially in the Niger Delta region. There is a growing concernrn over the sustainability of the fishery in the face of climate change and environmental variability. Studies were conducted on the fecundity, gonadosomatic index and the spawning period of the species. The objectives were to determine the average fecundity of the species and to use the gonadosomatic index to determine its spawning period with the aim of proffering management advice and prerequisites of the species in the face of climate change. A total of 44 females and 40 males were used for the study which spanned the period from May 2011 to April 2012. The fecundity of the species ranged from 3,730.5 eggs to 41,535.9 eggs. There was correlation between the total fecundity and fish weight (p~,01, r= 0.80, n= 44). The regression model for the relationship was expressed as fecundity = 4660.8+4.76 weight. The gonadosomatic index was highest in the month of May and dropped sharply in june signifying that spawning in Chrysichthys nigrodigitatus starts around this period. The implications of these findings in respect to sustainability of the species, and its aquaculture in the face of climate change are discussed.