Seasonal Changes of Length-Weight Relationships and Condition Factor of Three Fish Species from the Tanoe-Ehy Swamp Forest (Côte d’Ivoire)

Abstract

Aims: The Tanoe-Ehy swamp forest (TESF) is a freshwater swampy area characterized by seasonal variation of environmental parameters and fish diversity. So, the aim of this study was to analyze seasonal variations of growth parameters and condition factors of the three abundant species.
 Methodology: Specimens were collected by using gill nets and fyke nets, measured and weighed. Length-weight relationship (LWR), Fulton’s condition (KF) and relative condition (KR) factors were analyzed from Standard Length (SL) and body weight (BW).
 Results: The Standard Length of Clarias buettikoferi, Thysochromis ansorgii and Parachana obscura varied between 9.50 and 29.30 cm, 4.60 and 11.50 cm, 10.70 and 29.30 cm, respectively. The growth type of population was allometric negative for C. buettikoferi and P. obscura and isometric for T. ansorgii. In terms of seasonal variation, C. buettikoferi females and P. obscura specimens exhibited isometric growth in dry seasons (DS) against a negative allometric growth in flooded seasons (FS). In contrast, female and combined sex specimens of T. ansorgii showed positive allometric growth in DS and isometric growth type in FS. KR varied between 0.76 and 2.02 and was significantly higher in FS than in DS, indicating a state of well-being during flooded seasons in the 3 species.
 Conclusion: There was a significant relationship between length with weight and both condition factor for the three species. This study provided the first data about fish body measurements in the TESF and concluded that LWRs and condition factors of the three fish species were strongly influenced by seasonal variations in hydrological conditions.