Roger Huerlimann

1 Introduction Anthropogenic warming has facilitated the global redistribution of marine and terrestrial species (Parmesan and Yohe 2003; Chen et al. 2011; Pecl et al. 2017). Climate-driven species redistributions have already altered species interactions and entire ecosystem functioning (Pecl et al. 2017). Marine species are shifting their distributions poleward at a faster rate than terrestrial species (Chen et al. 2011; Burrows et al. 2011; Poloczanska et al. 2013).

Abstract Ocean acidification (OA), driven by rising atmospheric CO2, presents a serious threat to marine biodiversity, especially within coral reef ecosystems. Natural analogue sites, such as the high-pCO2 seep at Iōtorishima Island in Japan, offer insights into future conditions. This study investigated the holobiont communities of Symbiodiniaceae and bacteria in the zoantharian Palythoa tuberculosa at Iōtorishima and compared them to specimens from control sites in Okinawa and Hawaiʻi.

eLife assessment The work provides valuable genomic resources to address the endocrine control of a life cycle transition in the Malabar grouper fish. The revised manuscript is more solid and the resources and experimental data help to build up a meaningful biological understanding of thyroid signaling in grouper fish.