This paper describes a method to identify so-called
of species based on the analysis of their biological characteristics. This biological dataset has a complex structure that can be formalized as a
fuzzy many-valued context
and transformed into a binary context through
. The core of the method relied on the construction and interpretation of formal concepts and was used on a 50 species × 124 histogram attributes table. The concepts were analyzed with the help of an hydrobiologist, leading to a set of ecological traits which were inserted in the original context for validation.