Seek and you will find: micromollusks in the gut content of the sea cucumber Astichopus multifidus

In relation to mollusks, the family Eulimidae is known for its close relationship with members of the class Echinodermata, as it is a parasite of all its classes, including the Class Holothuroidea. Some species of this group, commonly known as sea cucumbers, are an important source of income in the regions. In some cases, their populations have been so diminished that some species can no longer be exploited. To take advantage of the material collected for studies of Astichopus multifidus species, the gut contents were reviewed to look for mollusks. Thus, the stomach contents of 137 cucumbers collected off the coast of Sisal, Yucatán in three sites distributed in six trips during March and August 2017 were reviewed. The holothurians were anesthetized, and fixed, and the digestive tracts were dissected. Subsequently, the gut was examined and the conchological material was separated regardless of whether it was complete, ruptured, or eroded. Material was then separated by morphotype, and incomplete or very worn shells were discarded. A total of 2,348 shells of Bivalvia, Gastropoda, and Scaphopoda were found. From those, 36 species of bivalves and 82 species of gastropods were identified. Due to the lack of complete shells,  26 bivalves, 112 gastropods, and 2 scaphopods were identified as morphotypes at different levels (Class, Family, or Genus). At least one photograph was taken of each species or morphotype recorded. It is worth highlighting that the preservation of some shells suggests that they were ingested alive and subsequently disintegrated in the cucumber's gut. This is not the first study to record shells within the gut of sea cucumbers, but it is the first to identify them beyond the family level. This work shows that collaborations allow us to take advantage of information obtained from the sacrifice of a living being.