Digestibility of Bamboo-Grown Periphyton by Carps (Catla catla, Labeo rohita, Cirrhinus mrigala, Cyprinus carpio, Ctenopharyngodon idella, and Tor khudree) and Hybrid Red Tilapia (Oreochromis mossambicus × O. niloticus)

Abstract

Periphyton development on bamboo substrate was quantified over six weeks in fertilized mud-bottomed cement tanks. Dry matter, ash and pigment content of periphyton were analyzed at weekly intervals. On a dry matter basis, periphyton production reached the maximum on the 21st day and showed a decline thereafter. Periphyton was scraped and fed ad libitum daily over 30 days to fingerlings of cultivable carps (catla, rohu, mrigal, common carp, grass carp and mahseer) and hybrid red tilapia maintained in aerated fibreglass tanks, to evaluate digestibility. Dry matter digestibility was highest (P < 0.05) with mahseer (42.54%) and lowest with catla (20.63%). The values obtained with grass carp, red tilapia, rohu, and mrigal were not significantly different from that of mahseer and common carp. Protein digestibility was highest in grass carp (71.21%) and lowest in common carp (48.81%). Further, protein digestibility in catla, rohu and mrigal was similar. The results of this study would be useful in the selection offish species for periphyton-based aquaculture.

Key Words:

• Substrate
• periphyton
• digestibility
• carps
• tilapia