Description of a new endoparasitic copepod genus and species (Lamippidae) that induces gall formation in leaves of the sea pen Ptilosarcus gurneyi (Octocorallia) from British Columbia

Abstract

A new genus and species of gall-forming endoparasitic copepod of the family Lamippidae is described from the orange sea pen Ptilosarcus gurneyi (Gray, 1860) collected in British Columbia, Canada. Lamippid copepods (over 50 species) are obligate endoparasites, some of which form galls in a variety of soft corals (Alcyonacea and Pennatulacea). Ptilosarcoma athyrmata n. gen., n. sp. is the first lamippid formally described from any species of Ptilosarcus Verrill, 1865. In total, 143 galls from six sea pens were dissected and found to typically contain one female and male copepod pair. Infested leaves of P. gurneyi had 1.4 ± 0.6 (n = 143) galls per leaf. Using light and scanning electron microscopy, the copepods were examined and found to most closely resemble those belonging to the genus Isidicola Gravier, 1914, based on the presence of maxillipeds and lack of acicules on the caudal rami; however, they are distinct from the sole species of Isidicola based on aspects of antennal morphology. We conclude that Lamippina laubieri Bouligand, 1960 is a synonym of L. aciculifera (Zulueta, 1908), thus the family presently contains 52 species and one subspecies. A key to lamippid genera and a table of all lamippid genera and species with all known hosts and locality records are provided.