Special Oceanography SeminarAugust 12, 3:30pm - 4:30pm
Mānoa Campus, MSB 114
Hawai’i Pacific University
"Polyphyly and hidden species among Hawaii’s dominant mesophotic coral genera, Leptoseris and Pavona (Scleractinia: Agariciidae)"
Abstract: Widespread polyphyly in stony corals (order Scleractinia) has prompted efforts to revise their systematics through approaches that integrate molecular and micromorphological evidence. To date, these approaches have not been comprehensively applied to the agariciid genera Leptoseris or Pavona, which often dominate mesophotic coral ecosystems (MCEs), because many Leptoseris and Pavona spp. occur primarily in deeper MCEs (> 60 m) that are relatively underexplored and from which sample collections are limited. This study is the first integrated morphological and molecular systematic analysis to compare agariciids from shallow-water habitats to lower MCEs (2-127 m). Leptoseris and Pavona were collected throughout the Hawaiian Archipelago. A novel mitochondrial marker (cox1-1-rRNA intron) was sequenced for 69 colonies, and the micromorphologies of 94 skeletons, including type material, were analyzed. The cox1-1-rRNA intron resolved 8 clades, yet Leptoseris and Pavona were polyphyletic. Skeletal micromorphology, especially costal ornamentation, showed strong correspondence and discrete differences between mitochondrial groups. One putative new Leptoseris species was identified and the global depth range of the genus Pavona was extended to 89 m, suggesting that the diversity of mesophotic scleractinians has been underestimated. Examination of species’ depth distributions revealed a pattern of depth zonation. Species common in shallow-water were absent or rare > 40 m, whereas other species were always > 60 m. These patterns emphasize the importance of integrated systematic analyses, including more sample collection from lower MCEs, in assessing the connectivity and diversity of MCEs.
Oceanography, Mānoa Campus