Anemone fish (also called “clownfish”) are well-known from their appearances in the Pixar movies “Finding Nemo” and “Finding Dory”. They have a symbiotic relationship with certain species of sea anemone, where they live with the anemone and do not get stung by its tentacles. In turn, the anemone fish defends the anemone from predators. Research has shown that these anemone fish are sensitive to changes in ocean chemistry and will wander further away from home as waters become more acidic due to the ocean’s absorption of carbon dioxide. And now, a new study shows that these anemone fish may not have the genes necessary to adapt to changes in the marine environment.
The international team researchers examined families of anemone fish in Papua New Guinea lagoon for over a decade. They sampled the fish’s DNA and calculated the anemone fish’s capacity for adapting to environmental change and found that successful anemone fish lineages were more tightly linked with high-quality habitats than with specific genes that allowed them to acclimate to change. The quality of the habitat was related to the exact species of anemone a fish was using and where it was located within the lagoon.
Thus, to preserve anemone fish populations and help them endure shifts in the marine environment, it is important to protect the anemones that these fish are so closely associated with; high-quality anemones contribute nearly 50 percent to an anemone fish’s survival and ability to reproduce. However, warming oceans and microplastic pollution threaten anemones, and may in turn imperil anemone fish.
“The biggest surprise to us was also the most troubling: conservation efforts cannot rely on genetic adaptation to protect clownfish from the effects of climate change,” said co-author Dr. Simon Thorrold, a co-author of this paper, “It seems that Nemo won’t be able to save himself.”