Heavy Fishing Linked to Molecular Changes in Pearly Razorfish

Pearly razorfish begin life as females before some naturally transition into males. Fishing is known to reduce fish populations and alter their size and age in the wild. However, a new study suggests these effects may extend to the molecular level. Researchers found heavy fishing may change the biology of pearly razorfish through epigenetic alterations. The study, published in Philosophical Transactions of the Royal Society B and reported by Science X, provides early evidence that fishing influences epigenetic changes.

The pearly razorfish (Xyrichtys novacula) is a small marine fish in sandy coastal waters, feeding on small sea animals. Born female, some transition to males as they grow. Dominant males defend territories with multiple females, maintaining order and reducing early sex changes in younger females. In Spain’s Balearic Islands, it’s known as “raor” and is a popular seafood, experiencing heavy fishing pressure.

Scientists collected 120 pearly razorfish from three Balearic Islands regions, comparing protected and fished areas. They analyzed fin DNA and epigenetics. While no genetic differences were found between groups, fish from heavily fished areas had lower genetic diversity and were smaller and younger than those in protected reserves.

Key findings included 291 DNA locations with differing methylation patterns between protected and fished fish, indicating fishing may shape epigenetic variation. However, the study does not prove fishing directly causes these changes, suggesting other factors like population density or food availability might contribute. Differences persisted even after accounting for population structure.

The implications suggest fishing could regulate gene activity without altering DNA, potentially affecting the species’ biology.