Abstract
The Intergovernmental Panel on Climate Change (IPCC) predicted that ocean surface temperature will rise of 0.6–2.0°C by 2100. Ocean warming is expected to produce strong impacts on marine ecosystems such as coral reefs, affecting their physiological events including reproductive processes. To date, relatively few studies have examined the effects of climate change on the reproductive success of temperate corals and even less in the azooxanthellate ones. This study examined the reproductive output of the azooxanthellate Mediterranean coral Caryophyllia inornata along a wide latitudinal gradient of seawater temperature and solar radiation. A total of 260 samples, collected from five populations along the Western Italian coast, have been analyzed through histological techniques. The intriguing aspects characterizing all populations of C. inornata along the latitudinal gradient are a strong male-biased sex ratio and the presence of embryos in all stages of development throughout the year in females, males, and sexually inactive individuals. This peculiarity could suggest a mixed strategy of sexual and asexual reproduction in this species as has been observed for some anemones of the genus Actinia. Fecundity and spermary abundance (i.e., the number of reproductive elements per body volume unit), gonadal index (i.e., the percentage of body volume occupied by the germ cells) and fertility (i.e., the number of embryos per body volume unit) in females, males and sexually inactive individuals were unrelated to solar radiation and temperature along the latitudinal gradient. These results suggest that the reproduction in C. inornata is not affected by increasing solar radiation and temperature. The lack of zooxanthellae could make this species less dependent on these environmental parameters, as previously hypothesized for another azooxanthellate species, Leptopsammia pruvoti, investigated along the same gradient.
| Original language | English |
|---|---|
| Article number | 785 |
| Journal | Frontiers in Marine Science |
| Volume | 6 |
| DOIs | |
| State | Published - 8 Jan 2020 |
Bibliographical note
Publisher Copyright:© Copyright © 2020 Marchini, Tortorelli, Guidi, Airi, Falini, Dubinsky and Goffredo.
Funding
We would like to thank E. Caroselli, F. Gizzi, S. Prantoni, S. Branchini, M. Ghelia, M. Pisconti, A. Picariello, S. Guerrieri, F. Croci, F. Fasoli and F. Sesso who collaborated in the underwater activities. We would also like to thank Centro Immersioni Pantelleria, Il Pesciolino, Bubble Lounge Diving, and Submaldive, which supplied logistic assistance in the field and The Scientific Diving School (www.sdseducational.org) which supplied scientific, technical, and logistic support. The experiments were complied with current Italian law. Funding. The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013)/ERC Grant Agreement No. 249930 – CoralWarm: Corals and Global Warming: the Mediterranean versus the Red Sea. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013)/ERC Grant Agreement No. 249930 – CoralWarm: Corals and Global Warming: the Mediterranean versus the Red Sea. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
| Funders | Funder number |
|---|---|
| Centro Immersioni Pantelleria | |
| Scientific Diving School | |
| Seventh Framework Programme | |
| European Commission | 249930 |
Keywords
- Mediterranean Sea
- asexual reproduction
- embryogenesis
- gametogenesis
- global warming
- scleractinia
