Evaluation Of Giant African Snail (Achatina Fulica Ferussac, 1821), As An Alternative Dietary Protein Source For Nile Tilapia (Oreochromis Niloticus Linnaeus, 1758)

Abstract

Giant African snail (GAS), Achatina fulica is huge invasive agricultural pest rich in protein content which can be utilized as fish dietary protein source for Nile tilapia, Oreochromis niloticus as they are omnivorous hardy fishes having wide range of food items. Tilapia is second most cultured fish after carps throughout the world having good future in Nepal and the use of agricultural pest helps to reduce the agricultural loss due to GAS destruction and maintain sustainable management contributing low aquaculture expenses. This study was carried for 2 months to investigate the growth performance of Nile tilapia fed with diets containing soybean, soybean and GAS (50:50%) and GAS alone as alternative dietary protein source. Three diets were prepared with 45% crude protein content. Fingerlings were stocked in three tanks with three replication for each diet in Graeco Latin Square Design (GLSD). Average size 9±677 cm and weight 24±066 g were stocked in tanks of 1mx1mx0.8m. The experimental fishes were fed at 5% of its body weight twice a day, on morning at 8:00 am and on evening at 4:00 pm for two months continuously. Direct observation and measurement method was applied to collect primary data every 15 days. No significance difference (p>0.05) in average weight gain, apparent feed conversion ratio, daily weight gain, gross fish yield and net fish yield was observed. Nile tilapia showed slightly higher growth fed with soybean and GAS than soybean alone or GAS alone. The physic-chemical parameters like temperature, dissolved oxygen, pH, transparency etc. also favors the Nile tilapia growth positively with no mortality. Thus, the study revealed that Giant African snail (GAS) can be used partially or totally as an alternative dietary protein source for Nile tilapia.