Science – Evidence of hybridization between starfish species – Publimetro México

Madrid, 11 years (European Press)

A study published in the journal Molecular Ecology provides genetic evidence of hybridization between two closely related species of starfish: Asterias rubens, the common starfish, and Asterias forbesi, commonly known as the Forbes starfish.

“It is the first evidence of genome-wide hybridization in ecologically important coastal species,” said author Melina Giakomis, associate director of the Comparative Genomics Institute at the American Museum of Natural History.

Biologists set out to find out whether starfish mate in nature, and if so, what environmental factors influenced their appearance. The researchers sampled DNA from both species at 33 sites in the North Atlantic Ocean, then performed DNA sequencing that included samples from Asterias amurensis, a North Pacific starfish, which was used as a control group.

Through genomic data, scientists have discovered that widespread hybridization occurred between two starfish species from Cape Cod to Nova Scotia.

Sea stars have been shown to have different ecological preferences: A. forbesi has a limited geographic range with adaptations to local environments, and A. forbesi has a limited geographic range with adaptations to local environments. Rubens has a wider range extending into Western Europe. These preferences are also evident in their genomes, the researchers said.

The study’s species distribution models accurately predicted the emergence of hybrid zones where these ranges overlap (the Gulf of Maine was at the epicenter of hybridization), suggesting that environmental selection played an important role in maintaining hybrid zones. Furthermore, the results indicate that A. forbesi has a greater ability to tolerate warmer temperatures, while A. rubens prefers cooler habitats and hybrids are found in areas with acceptable temperatures for both species.

The study highlights the ecological importance of both starfish, which are considered a “keystone species” that have significant impacts on surrounding marine communities. When they are removed from intertidal communities (coastal zones between high and low tide), diversity among those entire ecosystems has been shown to collapse, Giakomis said.

“Two questions arise from this study,” said Michael Hickerson, a professor of biology at the City College of New York and Giacomis’ advisor. “Will the movement of hybrids to track changes in sea surface temperatures accelerate to the point that one species displaces the other? Or will they save both species by being the source of gene pools that allow greater resilience to climate change due to their increased adaptive capacity?”

“Since starfish preferentially eat dominant competitors, it provides stability to the ecosystem,” the biologist explained. “Therefore, it is important to study these species for marine conservation, as they have indirect impacts on the rest of society.”

Giakomis points out that the Gulf of Maine is warming at a faster rate than 99% of the global ocean. He adds: “Our results suggest that the distribution of genomic variation in North Atlantic sea stars is influenced by the environment, which will be crucial to take into account as climate changes.”

Giacomis points out that hybridization is thought to be common in nature, and has been observed more frequently as genomic data expands. As the first study to provide evidence of genome-wide hybridization in these starfish species, the research supports the work of evolutionary biologists and other scientists studying intertidal ecology, the authors said, with potential implications for marine management. In the North Atlantic.