Early-life history of three soft coral species in Okinawa, Japan

ABSTRACT

Larval development and subsequent settlement behaviour are important aspects which determine the persistence of sessile benthic organisms on shallow water tropical and subtropical coral reefs. However, only limited studies have been performed on the early-life histories of soft corals in Okinawa, Japan. In this study, we describe the development and settlement pattern of collected spawn materials from two Sclerophytum species and the larvae of a brooding Heteroxenia sp. from Okinawa Island, Japan. Results showed that for the brooding Heteroxenia sp., planulae can metamorphose and fuse at the pelagic stage, and have very low settlement rates on rubble substrates with crustose coralline algae (CCA). On the other hand, the planulae of the two Sclerophytum species have variable survival probability, but both mainly settle on rubble with CCA. These results highlight the differences in larval development and subsequent settlement behaviour and periods among soft coral species. This also serves as the first report describing the larval behaviour and settlement of these species in the subtropical region of Okinawa, Japan.

KEYWORDS:

• Octocoral reproduction
• planulae
• Heteroxenia
• Sclerophytum
• metamorphosis

Acknowledgments

Emmeline A. Jamodiong, Tracy D. Tabalanza, and Jue Alef A. Lalas were supported by the Ministry of Education, Culture, Sports, Science & Technology (MEXT) scholarships of Japan, which allowed for the conduct of this study. We thank the comments from anonymous reviewers and the editor that greatly improved an earlier version of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

EAJ conceived the study and wrote the first draft of the manuscript. EAJ and TDT designed the study, performed laboratory work, and analyzed the data. EAJ, TDT and JAAL conducted the fieldwork. TN and JDR provided supervision and materials for the research. EAJ, TDT, JAAL, TN and JDR edited, reviewed, and approved the final version of the manuscript.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10236244.2024.2374240.

Additional information

Funding

The author(s) reported that there is no funding associated with the work featured in this article.