87.1 Friday, Jan. 6 A third way: Spermcapture mating in barnacles BARAZANDEH, M*; DAVIS, CS; NEUFELD, CJ; PALMER, RA; Univ. of Alberta, Edmonton, AB, Canada; Bamfield Marine Sciences Centre Bamfield, BC, Canada; Univ. of Alberta, Edmonton, AB, Canada; Univ. of Alberta, Edmonton, AB, Canada; Bamfield Marine Sciences Centre Bamfield, BC, Canada; Univ. of Alberta, Edmonton, AB, Canada; Bamfield Marine Sciences Centre Bamfield, BC, Canada email@example.com
Most free-living barnacles are hermaphroditic and eggs are presumed to be fertilized by pseudo-copulation or self-fertilization. The Pacific gooseneck barnacle, Pollicipes polymerus, is believed to be a mandatory cross-fertilizer. Nonetheless, some isolated P. polymerus, well outside the range a penis could reach, have fertilized egg-masses. They must therefore either self-fertilize or obtain sperm from the water. This latter possibility occurs in other sessile marine organisms but has never been considered in barnacles. To test how eggs of isolated individuals were fertilized, we collected isolated P. polymerus individuals (more than 2 body lengths from their nearest neighbors) bearing egg-masses as well as isolated pairs (two adjacent individuals that were more than 2 body lengths away from any other barnacles) where at least one carried egg masses. Sixteen polymorphic Single Nucleotide Polymorphisms (SNP) were developed for P. polymerus. SNP genotypes of parents and embryo masses of 37 isolated individuals showed that egg masses of all of them had at least one locus with one allele that differed from the parent, and 40% of embryo masses had non-parent alleles at four or more loci. Remarkably, even in isolated pairs, where both partners were within penis range, individuals still obtained some sperm from the water. These observations reject the possibility of exclusive self-fertilization in Pollicipes polymerus and confirm spermcapture mating for the first time in any species of barnacle, even when an individual has a nearby potential mate. Moreover, preliminary evidence further suggests that spermcapture mating also happens in acorn barnacles.