Horned Isopod

Dynamene bidentata

The Horned Isopod, belonging to the family Sphaeromatidae, is a small crustacean commonly found in the Northeast Atlantic, particularly around France. This species inhabits shallow, temperate waters and is benthic, meaning it lives on the ocean floor. Divers may encounter these isopods in various shallow marine environments, where they can observe their unique features that distinguish them from other isopods. Horned Isopods are part of the order Isopoda, which are mostly gonochoric, meaning individuals are either male or female. Their reproductive process involves indirect sperm transfer, with mating typically occurring before or during the parturial molt. The eggs are brooded in a special pouch called the marsupium until they hatch into manca postlarvae, eventually maturing into adult isopods. While diving, spotting a Horned Isopod can be an interesting experience due to their cryptic nature. They are not evaluated for conservation status. Divers should look for them in shallow waters, typically less than 40 meters deep, as most recorded observations are found at these depths.