Abstract:
Ornamental fish trade is a global industry of significant economic importance. For a developing country like Sri Lanka if managed sustainably, fresh water ornamental fish trade can generate employment opportunities as well as foreign exchange (BOBP, 2000). Goldfish [Carassius auralus) is a well known freshwater ornamental fish, which is among the most popular freshwater fishes throughout the won Id.
Water quality parameters have profound e££ect on fish’s biological and physiological factors. For successful fish culture proper management of water quality parameters are
required as they are crucial for larval survival and growth (Zaniboni-Filho, cl at., 2008: ,
Smam and Bundell, 1996: Lloyd and JorJan, 1964 cited in Gao, e/ o/., 20 I I). pH, potential hydrogen ion concentration is sucl1 an important water quality parameter in aquaculture.
Fresh water ornamental fish culturists in Sri Lanka uses water from different water sources * such as tap water, underground water and surface water sources like rivers,
streams,
reservoirs, tanks. Due to different climatologic and geographic factors, pH value of above fresh water sources may differ froi i each other (SiIva and Manuweera, 2004). Most of the fresh water sources in Sri Lanka are having pH range of 5.4 -9.0 (Silva, 2004: Kotagama, e/ o/., \ 989).
The ma in objective of this study is to find out the effects of water pH on egg hatch ability, survival rate and growth rate of yolk sae larvae of goldfish and to identify the most suitable water pH range for gold fish culture.
