All these groups are very different from each other and the resulting collections are highly varied. The series of aquatic animals are preserved in cardboard boxes (naturalised specimens) or in glass bottles of alcohol-glycerine.
These collections provide an overview of the diversity of these animals, which are often far less studied than vertebrates, insects, and molluscs. Due to its location, Lyon has not had the opportunity to easily expand its marine collections, unlike port cities. So the museum joined an exchange network enabling it to acquire major collections in most of the missing zoological groups, particularly with A. Agassiz (Cambridge museum) and Lütken (Copenhagen museum).
Many of these collections are old and only a few recent acquisitions have been made, either opportunistically or for a specific exhibition. However, the spider collection is essentially recent; it continues to be expanded for scientific and reference purposes.