Evaluation of Growth Performance, Survival Rate, and Proximate Composition of Garra (Garra quadrimaculata) Cultured in Earthen Ponds Using Local Feed Ingredients

Abstract

Garra is one of the fish species found in sub-Saharan Africa and it is a bottom feeder in their environment. Even though there is no proven evidence explaining why genus Garra is hardly used for food in Ethiopia, there are some assumptions. These include small size of the fish, absence of scientific reports demonstrating the acceptable macronutrient and mineral composition of the fish for human consumption, and a lack of awareness on aquatic resource utilization in the country. Therefore, this study aimed to evaluate the biological characteristics, feed utilization and nutritional values of cultured Garra and compare these with wild Garra based on existing literature for human consumption. Fish feed ingredients were collected from locally available sources and formulated at contain 35% of crude protein (CP). Fingerlings of Garra were collected from Gilgel Gibe reservoir, then stocked with the average weight 0.28g. A total 120 Garra fish fingerlings with same initial size was introduced into two ponds aquaculture and feed on the same basal diets for three months. Growth performance (weight and length) was measured every fortnight and survival rate was assessed. Finally fish was randomly selected from the ponds for nutritional analyses. The proximate composition results were compared with wild, whole Garra. Further, the data collected was subjected for statistical analysis. The average weight gain of the fish was 6.7 ± 0.77g, specific growth rate was 1.41 ± 0.25g and food conversion ratio (FCR) was 1.84 ± 0.01%. The result revealed that the crud protein (13.47%) wet weight, fat (11.94%), ash (2.39%) and moisture (71.35%) content in cultured Garra except carbohydrate (1.6) were higher than wild Garra of, which had crude protein (9.58%), fat (2.73%), moisture (69.1-77.6%). Thus proximate composition cultured Garra higher than the wild Garra due to the supplementation of local feed. The average weight gain was 3.433 ± 0.768g and 96.67% of fish survived. The water quality parameters showed no significant difference between ponds. Moreover, the plankton diversity in the ponds during the culture period was not significantly different; however, since Garra is a bottom feeder, the ponds were frequently covered by algal blooms. Further study, including the analysis of essential and heavy metal accumulation and the blood biochemistry of the fish, is needed before recommending Garra as a full aquaculture candidate species.