Scientists reveal new lineages of giant sea anemones in Japan and their surprising associations with anemonefish
Anemonefish form mutualistic relationships with the sea anemones they live in and these associations are not random: some species such as the yellow-tail anemonefish (Amphiprion clarkii) are generalists and can live in almost ...
Researchers at the Marine Eco-Evo-Devo Unit and Marine Genomics Unit at the Okinawa Institute of Science and Technology (OIST) and Academia Sinica in Taiwan have studied the evolutionary history of giant sea anemones in Japan.
Rio Kashimoto and others published their findings in the journal Current Biology. Their study provides a detailed analysis of the genetic diversity of the bubble-tip giant sea anemone (Entacmaea quadricolor) found in Japan.
The scientists discovered that anemonefish are better at distinguishing different populations of giant sea anemones than humans.
Through one or more sensory organs, these fish identify a particular species of giant sea anemone to make their home and avoid other species. Humans, on the other hand, need to obtain samples from sea anemones and do a thorough examination of their molecular data to identify individual sea anemone species. This is precisely what the scientists at OIST did to better understand the genetic variation among these soft-bodied marine invertebrates.
Giant sea anemones have evolved into three very different genera: Entacmaea (bubble-tip sea anemones), Stichodactyla (carpet sea anemones), and Heteractis (magnificent sea anemones). There are currently 10 known species of giant sea anemones worldwide and seven of these live in Okinawa.
A tomato anemonefish (Amphiprion frenatus) (L) and yellow-tail anemonefish (Amphiprion clarkii) (R) in bubble-tip sea anemones in the wild. Credit: Camille Sautereau (left image) and Natacha Roux (right image)
A schematic phylogenetic tree showing the main lineages of giant sea anemones (A) and the four groups of the Entacmaea lineage with their anemonefish associations (B). Credit: Kashimoto et al., 2023
Histogram showing the results of the choice experiments for lineage A and D of the bubble-tip sea anemone (Entacmaea) by yellow-tail and tomato clownfish. Credit: Kashimoto et al., 2023
Schematic diagram showing the choice experiment for lineage A and D of the bubble-tip sea anemone (Entacmaea) in yellow-tail and tomato clownfish. Credit: Kashimoto et al., 2023