Soft Coral Sarcophyton (Cnidaria: Anthozoa: Octocorallia) Species Diversity and Chemotypes

Abstract

Research on the soft coral genus Sarcophyton extends over a wide range of fields, including marine natural products and the isolation of a number of cembranoid diterpenes. However, it is still unknown how soft corals produce this diverse array of metabolites, and the relationship between soft coral diversity and cembranoid diterpene production is not clear. In order to understand this relationship, we examined Sarcophyton specimens from Okinawa, Japan, by utilizing three methods: morphological examination of sclerites, chemotype identification, and phylogenetic examination of both Sarcophyton (utilizing mitochondrial protein-coding genes MutS homolog: msh1) and their endosymbiotic Symbiodinium spp. (utilizing nuclear internal transcribed spacer of ribosomal DNA: ITS- rDNA). Chemotypes, molecular phylogenetic clades, and sclerites of Sarcophyton trocheliophorum specimens formed a clear and distinct group, but the relationships between chemotypes, molecular phylogenetic clade types and sclerites of the most common species, Sarcophyton glaucum, was not clear. S. glaucum was divided into four clades. A characteristic chemotype was observed within one phylogenetic clade of S. glaucum. Identities of symbiotic algae Symbiodinium spp. had no apparent relation to chemotypes of Sarcophyton spp. This study demonstrates that the complex results observed for S. glaucum are due to the incomplete and complex taxonomy of this species group. Our novel method of identification should help contribute to classification and taxonomic reassessment of this diverse soft coral genus.

Cembranoids of Soft Coral Sarcophyton from Acidified Coral Reef Environment at Shallow Water CO2 vents in Volcano Island, Banda Neira, Indonesia

“…For example, Sarcophyton glaucum clade F may not present in this site. This species produces the sarcophytolide analogue that is not produced by any other Sarcophyton glaucum clade (Aratake et al, 2012).…”

“…trocheliophorum, S. ehrenbergi, S. elegans, S. infundibuliforme, S. pulchellum, S. cherbonnieri, except in S. crassocaule and S. digitatum (Tanaka, Yoshida, & Benayahu, 2005). S. glaucum sub-species (clade A-F) can be also detected by specific cembranoid content that consists with sarcophine enantiomers (2S,7S,8S-sarcophine, 2S,7R,8R-sarcophine, or 2S,7R,8R-isosarcophine) and sarcophytolide cembranoid analogues (Aratake et al, 2012). Therefore, the lack of sarcophine and sarcophytolide analogues may indicate low genetic diversity within the Sarcophyton from Volcano Island.…”

“…Meanwhile, cembranoid content also depends on the genetic diversity of soft coral. Previous studies on Sarcophyton glaucum found that each genetic clade (Clade A to F) contains a combination of 8 cembranoid chemotypes (Aratake et al, 2012;Farag et al, 2016). Furthermore, multivariate statistics for cembranoid quantity was successfully validated to be a profiling taxonomic approach between soft coral Lobophytum, Sinularia, and Sarcophyton (Farag et al, 2017).…”

Four Cytotoxic Spongian Diterpenes from the Sponge <i>Dysidea</i> cf. <i>arenaria</i>

“…17) In the case of Dysidea avara, its surrounding organisms may be related to the production of avarols. 18) In case of the current sponge, we could not recognize any specific macroorganisms around its colonies, indicating that the metabolite variation may be due to other factors.…”

Bioactive Cembranoid Composition in the Soft Coral of Sarcophyton glaccum on The Response to Changing pH

“…glaccum samples were collected by Scuba from Panggang Island waters, Seribu Islands, Jakarta, Indonesia (S05 o 44.695' E106 o 35.309'; 3 m depth) on the basis of their morphological similarities according to Fabricius and Alderslade (2001) and Aratake et al (2012). Random colonies of roughly the same size (10 cm) were carefully sampled, placed in a box filled with seawater and aerated (dissolved oxygen level above 7 mg.L -1 ) on the boat directly above sampling site.…”