Meeting Abstract
The lack of knowledge concerning biodiversity of the oceanic mesophotic zone (also known as the “Twilight Zone”) is caused by the previous absence of deeper diving techniques that now allow exploration below depths, at which conventional SCUBA diving is safe. As technology improves and diving techniques are perfected, new frontiers await to be explored. The California Academy of Sciences led an expedition to the Philippines during 2013 and 2014 to explore the seldom-studied mesophotic zone (60-120m depth). Several species of Chromis were observed and collected at about 100 m deep. The aim of this study was to investigate possible cryptic diversity in deep reef species of Chromis. To test this hypothesis, morphological characters were scored and the mitochondrial fragment cytochrome c oxidase I (COI) was sequenced to estimate relationships among Chromis. Bayesian inference analysis of COI strongly supports the existence of at least one new species of Chromis from the mesophotic zone, allowing us to describe a new species of damselfish from this poorly explored region. Further collection and analyses of deep reef specimens will be needed to create a more comprehensive phylogenetic tree for fishes from the mesophotic zone.
