CSIC Study Traces Shrimp Evolution to Pacific Origin

An international research team led by Spain's Consejo Superior de Investigaciones Científicas (CSIC) has published a new model of shrimp biogeography. Using a calibrated phylogeny, fossil records and continuous‑space statistical models on more than 34,000 observations of 155 species, the scientists dated the most recent common ancestor of modern shrimps to the Eastern Pacific about 125 million years ago.

The analysis shows that long‑distance dispersal and ecological plasticity, rather than static physical barriers, drove the pantropical spread of these crustaceans. After their Pacific origin, shrimp lineages crossed the Atlantic between the Americas and Africa, and later colonised Oceania and Southeast Asia, with the post‑dinosaur‑extinction environment accelerating their expansion. The findings overturn the long‑standing hypothesis that shrimps originated in the ancient Tethys Sea.

Lead co‑author Mónica Núñez‑Flores of CSIC’s Institute of Marine Sciences in Andalucía highlighted that the new approach provides unprecedented spatial resolution for tracing marine organism movements and may improve predictions of how current marine ecosystems will respond to environmental change.