Abstract: The age and growth characteristics of bluntnose black breamMegalobramaamblycephalawere studied by observation of scale annulus from 310 specimens collected from July 2011 to June 2012 in order to evaluate the current status of the bluntnose black bream population in Liangzi Lake. The annuli were showed significant sparse-incision type, occasionally the fry check and the spawning check in the over 3 year old individuals. The body length of the population was ranged from 74.1 mm to 362.8 mm, predominantly between 180 mm and 320 mm (81.29%). The stock of the bluntnose black bream had relatively complex age structure, 6 age classes ranging from 1 to 6, the predominant age classes 3-4 years old (accounting for up to 55.48%). The relationship between body length(L) and the scale radius(R) was expressed as a linear regression equationL=34.656R+25.21. The relationship between body weight(W) and the body length (L)was described as an exponential regression equationW=1×10-5L3.1228, with an exponent of nearly 3, isometric growth type. The body growth pattern can be described by Von Bertalanffy equation asLt=452.36(1-e-0.2407(t+0.2813)), andWt=2034.61(1-e-0.2407(t+0.2813))3.1228,with growth inflexion point oft=4.46, body length of 307.78 mm and body weight of 607.70 g. The findings indicated that the bluntnose black bream resources in Liangzi Lake was reduced, miniaturization in size, and restored by protective measures.
2014, Vol. 29 
