Aplysilla glacialis

Aplysilla glacialis is a sponge species belonging to the family Darwinellidae. As a sessile organism, it is commonly found in brackish environments, thriving in a range of depths from the surface down to 84 meters. This species is distributed across tropical to polar regions, notably in the Atlantic Ocean and the Arctic, with records from Belize, Panama, Venezuela, and Alaska. Divers may encounter this sponge in various habitats, as it is known to settle on substrates where it grows after its larval stage. The life cycle of Aplysilla glacialis involves a free-swimming parenchymella larva that eventually settles on a suitable substrate to develop into a mature sponge. Like other members of the class Demospongiae, it is hermaphroditic, meaning it possesses both male and female reproductive organs. This reproductive strategy allows for flexibility in mating and propagation in diverse environments. Divers should note that most occurrences of this sponge are found at depths shallower than 40 meters, with a significant number at less than 10 meters.