Advances in determination of age and growth of cephalopods

Cephalopod as an important group of mollusks not only has a very high economic value,but also plays an important role in the marine ecosystem.Understanding of the age and growth characteristics of cephalopod will help to know their life cycle,and to estimate population changes and resources conditions.Length frequency analysis,rostral length,endoskeleton length and statolith are used in determination of the age and growth in cephalopod.Length frequency analysis method is not suitable for cephalopod with short life cycle and fastgrowing species,but the statoliths with hard materials and constant record are widely applied in the age determination of cephalopod,which is an extremely complex biological problem.There are different growth rates among individuals in a population,therefore we may separate the samples into population depending on the age,capture time and other data in the course of the study,then determine their growth of various groups.