Dusty Anemone

Anthopleura nigrescens

The dusty anemone is a small sea anemone with a typical diameter of about ¾ of an inch. It exhibits a grayish, dusty brown or black coloration, which can vary depending on its genetic makeup. This species is primarily found in the Indo-Pacific region, including parts of Hawaii, Costa Rica, and near Taiwan's hydrothermal vents. It is commonly seen in shallow waters, often inhabiting tiny rocky crevices and exposed rocky shores. The dusty anemone can form large aggregations, retracting its tentacles during low tide to minimize desiccation, which enables it to thrive in hot, tropical intertidal zones. Most occurrences are at depths shallower than 40 meters, with the majority found at around 20 meters or less. In terms of diet, the dusty anemone is a polyphagous predator, primarily consuming cyprids and copepods, a type of zooplankton. Its diet can also include gastropods, insects, eggs, larvae, and juvenile bivalves, with feeding habits varying based on location and water depth. During the day, it consumes a high quantity of cyprids, while at night, it tends to feed more on juvenile bivalves. Reproduction in the dusty anemone involves the release of mature gametes into the coelenteron, which are then spawned through the mouth. The life cycle includes a planktonic planula larva stage, followed by metamorphosis, where tentacles, septa, and pharynx develop before the larva settles. The conservation status of this species has not been evaluated, and it does not have a designated common name on iNaturalist.