[Length growth of tunny (Thunnus thynnus) according to Sella's data].

The dates of Sella (1929) for the length of the mediterranean tunny (Thunnus thynnus) already treated by Krüger (1973) are taken as a basis for mathematical approximations by 19 growth functions. For this purpose some functions had to be modified to allow for a non-horizontal tangent at the beginning. As the available length values cease with 14 years of age, there is much room for the theoretical final length giving a good insight into the characteristics of the different approximations. Surprisingly the functions with final growth time yield values with only small deviations from each other except for one calculation thus hinting to a theoretical growth duration of about 25 +/- 2 years.