Diet of Silver Cyprinid, Rastrineobola argentea in Lake Victoria, Kenya.

Yongo, Edwine; Manyala, Julius O.; Kito, Keiko; Matsushita, Yoshiki; Outa, Nicholas; Njiru, James

doi:10.21474/ijar01/113

Cited by 11 publications

(10 citation statements)

References 11 publications

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“…According to Riedel et al [2] this implies that it becomes relatively broader and fatter with the increase in length. This is also supported by Yongo [13] who also reported a positive allometric growth of R. argentea of L. Victoria, Kenya. However, Bala et al [14] reported a negative allometric growth for Tilapia.…”

Section: Discussionsupporting

confidence: 66%

Assessment of Length-Weight Relationship and Condition Factor of Nile Tilapia (Oreochromis Niloticus) in Cage and Open Waters in Winam Gulf of L. Victoria, Kenya

Ngodhe

2019

IJESNR

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The study aimed at investigating the difference in relationship between the Length and Weight together with the Fulton's condition factor of O. niloticus within the open waters (wild) and cages of the winam gulf of L.Victoria, Kenya. This relationship and the condition factor 'K' were determined by taking the total length and weight of fish samples both from the cage and the open waters. The slope "b" of the regression analysis in both habitats revealed a positive allometric growth (3.16 and 3.09) for wild and cage respectively while the value of condition factor (K) for O. niloticus in wild and cage were found to be 1.44±0.1 and 1.38±0.15 respectively. Though O. niloticus performed well both in the wild and cage, there was a significant statistical difference in their health and general wellbeing. This was attributed to ecological differences between the two habitats. The assessment also showed that the culture of this Nile tilapia species in cages within winam gulf of L. Victoria can be economically sustainable if water quality parameters are properly monitored and point and non-point sources of pollution controlled.

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Section: Discussionsupporting

confidence: 66%

Assessment of Length-Weight Relationship and Condition Factor of Nile Tilapia (Oreochromis Niloticus) in Cage and Open Waters in Winam Gulf of L. Victoria, Kenya

Ngodhe

2019

IJESNR

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“…The findings in regard to the condition factor and sex ratio of R. argentea in this study are comparable to those of Yongo, Manyala, Njiru, et al ()) in the Nyanza Gulf of Lake Victoria. R. argentea feed more on zooplankton, including Copepods and Cladocerans, some of which are abundant in this region, thereby possibly improving their condition (Yongo, Manyala, Kito, et al, ; Yongo, Manyala, Njiru, et al, ; Yongo & Outa, ). The increased condition of female and decreased conditions for males with increasing size, however, could be attributable to gonadal development and spawning conditions.…”

Section: Discussionmentioning

confidence: 99%

“…The critical habitats for R. argentea include the shoreline, sheltered bays and river mouths, which are also known to be their breeding and nursery grounds. Its diet consists primarily of zooplankton and insects (Getabu, Tumwebaze, & MacLennan, ; Yongo, Manyala, Kito, et al, ; Yongo, Manyala, Njiru, et al, ). Observations of the size at massive maturity of R. argentea in Lake Victoria vary, depending on the region of the lake being considered (Bayona et al ; Manyala, Nyawade, & Rabuor, ; Okedi, ; Wandera, ; Wanink, ; Yongo, Manyala, Njiru, et al, ).…”

Section: Introductionmentioning

confidence: 99%

Changes in some biological parameters of the silver cyprinid, Rastrineobola argentea (Pellegrin, 1904) in the Nyanza Gulf of Lake Victoria, Kenya

et al. 2019

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The study examined length–weight relationship, condition factor, size at 50% maturity and fecundity of Rastrineobola argentea in the Nyanza Gulf of Lake Victoria, Kenya. The 500 fish examined had a mean length of 39.4 ± 0.3 mm SL, ranging from 17 to 55 mm SL and weighed between 0.08 and 2.44 g. The length–frequency analysis indicated a unimodal distribution between 35 and 40 mm SL, with a modal length at 37 mm SL. The fish exhibited a positive allometric growth pattern (b = 3.4). The condition factor for all fish was 1.02. Male fish showed a decreasing trend in condition factor with increasing body length, while females exhibited an increasing trend. The length at 50% maturity was estimated at 43 and 44 mm SL for males and females, respectively. The smallest mature male was 41 mm SL and 42 mm SL for females, with 100% maturity already exhibited at 49 mm SL. Fecundity varied from 235 eggs for 33 mm SL to 2,309 eggs for 54 mm SL fish. positive linear relationships were found between fecundity against standard length and ovary weight. Comparisons with previous studies in this lake over time indicated a decrease in length at maturity and an increase in fecundity, which are strategies to maximize reproductive success. The findings of this study provide useful information for managing the fishery.

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“…Zooplankton was only present in the stomach of young fish in the length class 1–5 cm TL (Figure ). As the diet changes require morphological and physiological features that are not yet well developed in young fish, they can easily digest zooplankton, which also satisfy their demand for protein (Yongo et al., ). The contribution of C. nilotica in the diet declined progressively from Nile perch of 1–5 cm TL up to 51+ cm TL because the adult fish were increasingly feeding on other prey items, including haplochromines, R. argentea , juvenile Nile perch, molluscs, insects and Barbus .…”

Section: Discussionmentioning

confidence: 99%

Shifts in the food of Nile perch (Lates niloticus) in Lake Victoria

et al. 2018

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The study investigated diet of Nile perch in Lake Victoria and compared results with past data from the same lake in order to analyse diet shifts over time. Fish samples (2020) were collected by seining and trawling from 2012 to 2016. In overall, Caridina nilotica (59%) was the dominant food item in the diet, while Rastrineobola argentea (5%) contributed the least. The diet of Nile perch of 1 cm was copepods, cladocerans and rotifers. The diet changed to only copepods and cladocerans at 2 cm. The proportion of the relatively large calanoids increased with Nile perch size in 1988/89, comprising between 35 and 80% of the diet of fishes of 3–4 cm. Nile perch of 6–25 cm TL fed more on C. nilotica in 2012/2016, compared to 1988/1989 and 2006/08. Haplochromines were fed on more in 2006/2008 than in 2012/2016 by Nile perch of 6–30 cm TL as fish size increased. The frequencies of occurrence of R. argentea in the diet were highest in 1988/1989, and lowest in 2006/2008, for fish size of up to 30 cm TL. The proportion of Odonata in the diet of size class 16–20 and 21–30 cm TL were highest in 2012/2016 and 1988/1989, respectively. Thus, shifts in Nile perch diet was observed from zooplankton to C. nilotica, then to haplochromines and finally to fish prey as size increased. Nile perch preferred haplochromines with C. nilotica as the substitute food. Cannibalism was observed to have decreased, only being evidenced in Nile perch above 35 cm TL, which could actually have a positive impact on the Nile perch fishery. The information on shifts in diet of Nile perch in Lake Victoria is of considerable ecological importance.

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Diet of Silver Cyprinid, Rastrineobola argentea in Lake Victoria, Kenya.

Cited by 11 publications

References 11 publications

Assessment of Length-Weight Relationship and Condition Factor of Nile Tilapia (Oreochromis Niloticus) in Cage and Open Waters in Winam Gulf of L. Victoria, Kenya

Assessment of Length-Weight Relationship and Condition Factor of Nile Tilapia (Oreochromis Niloticus) in Cage and Open Waters in Winam Gulf of L. Victoria, Kenya

Changes in some biological parameters of the silver cyprinid, Rastrineobola argentea (Pellegrin, 1904) in the Nyanza Gulf of Lake Victoria, Kenya

Shifts in the food of Nile perch (Lates niloticus) in Lake Victoria

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