International Journal of Aquaculture, 2018, Vol.8, No.13, 98-103
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nutrients into water bodies which promote the growth of aquatic flora and fauna which are the source of fish food
items. Indeed, gonad development, fat deposit accumulation and the fish become heavier in the wet season.
Similarly, the differences of the length weight regression coefficient value b values between the species and other
fish species obtained by seasonal, even daily, habitat differences, the degree of stomach fullness, maturity of the
sex organs, and the condition of the fish health (Gupta and Tripathi, 2017).
Figure 1 Regression coefficient (b) values of
Varicorhinus beso
, endemic
Labeobarbus nedgia
and the African catfish
Clarias
gariepinus
in different water bodies of Ethiopia (Tesfaye, 2006; Beletew, 2007; Alemayehu, 2009; Gebremedhin et al., 2012; Abera
et al., 2014; Abera, 2016; Melaku et al., 2017)
1.1.2 Fulton Condition Factor (FCF)
Condition factor expresses the degree of wellbeing of fishes in their habitat. On the other hand it is a measure of
various biological and ecological factors with regard to their feeding conditions (Nehemia et al., 2012). Food
availability in the water bodies are influenced by the changes in the water chemistry due to variations in the
atmosphere and the surrounding environments (Pothoven et al., 2001).
Varicorhinus beso
,
L. nedgia
and
C.
gariepinus
had varied condition factors in different water bodies of Ethiopia. Based on this,
L. nedgia
and
V. beso
had good body conditions in Angereb and Sanja Rivers (1.18, 1.05) (Tesfaye, 2006), Geba and Sor Rivers (1.09,
1.03) (Melaku et al., 2017) and in Dura (1.1), Ardi (1.02) and Beshilo (1.09) Rivers respectively than
C.
gariepinus
in Lake Hayq (0.69) (Alemayehu, 2009), Lake Babogaya (0.64) (Abera et al., 2014), Lake Ziway (0.76)
(Abera, 2016) respectively (Figure 2). Ighwela et al. (2011) stated that seasonal fluctuations in food quantity and
quality, water level, flow rate and temperature affect the condition factor of fishes. The measure of fish condition
factor is determined by various factors. According to Otieno et al. (2014), it changes in abundance of food and
water quality, and fluctuation of water level and water temperature determine the body condition of fishes.
Condition factor also shows variation that happens seasonally due to sex and gonad development (Engdaw, 2014).
This is because large part of energy is allocated for growth and emptying of ovaries, which results in the lower
body condition of fish (Abera et al., 2014). The higher body condition indicates the higher energy content,
adequate food availability, reproductive potential and favorable environmental condition (Pauker and Rogers, 2004).
Clarias gariepinus
in Hayq, Babogaya and Ziway Lakes had the poor body condition as compared to the
V. beso
and
L. nedgia
fish species in some other rivers of Ethiopia. The differences in body condition obtained might be
due to differences in environmental condition, quantity and quality of food, feeding rate and water level
fluctuation. This is because most of the Ethiopian lakes are under high human pressure, mainly using the lake for
agricultural activities (Gebretsadik and Mereke, 2017) and impact of water hyacinth (mainly observed in Lake
2
2.2
2.4
2.6
2.8
3
3.2
3.4
3.6
3.8
4
Regression coefficient (b)
Water bodies
Clarias gariepinus
Varicorhinus beso
Labeobarbus nedgia
