[Growth variations of Nyctiphanes couchi using the data of Gros and Cochard (1978)]

In a paper dealing with the life cycle and growth development of Nyctiphanes couchii (crustaceans, euphausiids) off the southern coast of Britanny by Gros and Cochard (1978) from the Centre Océanologique de Bretagne graphs with the seasonal variations of the carapace length are given. Tentative growth curves were visually drawn lacking adequate mathematical formulations. In this situation a proposal of the author for taking into account annual changes (Sager 1981) is realized. Although the mathematical representation holds for all growth functions, the Bertalanffy function has been preferred as a simple form according to the relatively small number of length values.