title: Estimation of mating systems in Short and Tall ecomorphs of the coral Favia fragum.
abstract: We used 15 microsatellite markers to estimate the selfing rate (s), outcrossing rate (t(O) ) and hybridization between partially sympatric ecomorphs (t(H) ) of the coral Favia fragum. Genotyping of progeny arrays revealed complete self-fertilization in the Tall ecomorph and low outcrossing (t(O)  + t(H)  < 1%) in the Short ecomorph. Further, all larvae could be assigned with high probability to the same population as their parental dam, indicating no hybridization between ecomorphs (t(H)  = 0). Despite low ecological estimates of outcrossing, Q values from highly structured adult populations indicated that 9% of the adult samples were the products of outcrossing, and an additional 11% were hybrids. Reproductive isolation appears to have a strong geographical component, as we did not detect hybrids at a second site where the two ecomorphs were distributed in complete microallopatry. Adult estimates of gene flow within ecomorphs may be positively biased by ecomorph-specific patterns of inbreeding depression, but cryptic gene flow between ecomorphs is most likely explained by undetected outcrossing and the fact that hybrid lineages persist after repeated generations of self-fertilization. Our microsatellite data show that phenotypic differences between ecomorphs are maintained in sympatry despite evidence for hybridization.
authors.affiliation: Department of Zoology, University of Hawaii, Edmondson Hall 152, 2538 McCarthy Mall, Honolulu, HI 96822, USA. carlon@hawaii.edu
authors.forename: David B
authors.initials: DB
authors.lastname: Carlon
authors.forename: Catherine
authors.initials: C
authors.lastname: Lippé
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000235:genetics*; D051456:Gene Flow; D005828:Genetics, Population; D005838:Genotype; D006579:Heterozygote; D006824:Hybridization, Genetic; D007178:Inbreeding; D007814:Larva / Q000235:genetics; D015810:Linkage Disequilibrium; D018895:Microsatellite Repeats; D010176:Panama; D017422:Sequence Analysis, DNA