Crustacean Hosts of the Pedunculate Barnacle Genus Octolasmis in the Northern Gulf of Mexico

A survey of live and preserved crustaceans from the northern portion of the Gulf of Mexico was conducted to investigate the colonization habits of the barnacle genus Octolasmis. In all, three crustacean orders (Decapoda, lsopoda, and Stomatopoda) comprising 43 families, 78 genera, and 122 species were surveyed. Octolasmis barnacles were observed to infest 14 families, 20 genera, and 27 species of the orders Decapoda and Isopoda. In order of decreasing frequency, the Octolasmis species encountered were O. lowei, O. forresti, O. hoehi, and O. aymonini geryonophila. The first two were found primarily in the gill chambers, the third was found mainly on external mouthparts, and the last was found exclusively on the external mouthparts, ventral pereonal and pleonal surfaces of the isopod, Bathynomus giganteus. The decapod families Pisidae and Portunidae had the highest rates of infestation, whereas the family Galatheidae (represented by six species) did not host Octolasmis. The order Stomatopoda, represented by two families (Lysiosquillidae and Squillidae), two genera, and seven species was also not infested with Octolasmis. Statistical tests confirm that octolasmids do not randomly occupy hosts, rather they appear to select a subset, generally the larger species of crustaceans.