Abstract
The fossil record of crustaceans as hosts of parasites has yielded three confirmed associations: epicaridean isopod-induced swellings on Jurassic–Recent decapod crustaceans, feminization of Cretaceous and Miocene male crabs possibly caused by rhizocephalan barnacles, and presumed pentastomids on/in Silurian ostracods. Cestode platyhelminth hooks and swellings by entoniscid isopods may be recognized in the future. Relative to 2014, we report an increase of 41% to 124 fossil decapod species with epicaridean-induced swellings in the branchial chamber (ichnotaxon Kanthyloma crusta). Furthermore, using a Late Jurassic (Tithonian) decapod assemblage from Austria, we find (1) no correlation between genus abundance and prevalence of K. crusta, (2) host preference for some galatheoid taxa (as for a mid-Cretaceous assemblage from Spain), and (3) a larger median size of parasitized versus non-parasitized specimens for two selected species. The latter result may be caused by infestation throughout ontogeny rather than exclusively in juveniles and/or possible selection for the larger sex.
