Asian-Pacific Aquaculture 2019

June 19 - 21, 2019

Chennai Tamil Nadu - India

PROLONGED TEMPERATURE SHOCKS HAVE DELETERIOUS EFFECTS ON THE PRECULTURE PRODUCTION PARAMETERS OF CATFISH C. gariepinus (BURCHELL, 1822) EGGS

Nelson I. Ossai ⃰ , Shanmugam, Chinedu I. Attama, Victor O. Eneje,
 
  Aquaculture and Marine Science,
 University of Nigeria, Nsukka
 nelson.ossai@unn.edu.ng
 

The study investigated the influence of graded levels of temperature shock protocols on the hatching time, hatching rate, survival to first feeding and the chromosome number of catfish (C. gariepinus) eggs. Cold and heat temperature protocols were used to shock the eggs. In the cold shock protocols, the fertilized eggs were subjected to cold shock using ice flakes as water bath, 3 minutes and 4 minutes after fertilization at the respective temperatures of 1oC, 2oC, 3oC and 4oC for a period of 15 minutes and 30 minutes duration each. The heat shock on the hand was carried out by subjecting the fertilized eggs to either of the temperature regimes of 1 and 2 minutes. It was observedthat among the cold shock protocols; prolonging the duration of shock to total cases killed 3 duration of 30 minutes greatly reduced (in some caused total mortality) the hatchability and survival to first feeding of the fertilized eggs. Among the heat shocked protocols, temperature shocks of up to 40oC also had limiting effects on the hatching time, hatchability and survival to first feeding. It was recommended that decisions on the best shock protocols should revolve round 36oC for heat shock and 15 minutes shock duration for cold shock.