Coral biodiversity and genetic resources of West Pacific seamount, Godin Guyot

Abstract

Seamounts are underwater mountains that rise abruptly hundreds or thousands of meters from the seafloor. Scientists estimate that there are at least 100,000 seamounts >1000 m in height around the world, and seamounts of ~14,000 m have been found recently. These provide hard foundations upon which deep-sea life can settle and grow. Seamounts are important locations that maintain a high diversity of pelagic organisms and sessile benthic invertebrates, including suspension feeders. Deep-sea corals, primarily from Octocorallia (soft corals), Scleractinia (stony corals), and Antipatharia (black corals), represent one of the most common groups observed on seamounts studied worldwide. Deep-sea corals form a megafauna within the benthos, together with Porifera, Annelida, Echinodermata (crinoids and ophiuroids), and Tunicata. In this study, we explored seamounts in West Pacific, approximately 400km northeast from Guam, using ROV (remotely operated vehicle) and RV ISABU to investigate the deep-sea fauna and biodiversity around the seamounts. We aimed construction of the ecological map and discovery of biological resources, particularly from cnidarian. First of all, we collected samples of deep-sea coral species and extracted its RNA and DNA. We constructed transcriptomic assemblage of 3 deep sea corals (Rohdanirdogorgia. Sp., Chrysogorgia stellate, Calyptrophora lyla) after de novo RNA sequencing to investigate further gene expressions in abiotic extreme environment and also to discover differentially expressed genes comparing between deep-sea environment and shallow water species or cold water and trophic coral species.