California Feather Duster, Notaulax californica
California Feather Duster, Notaulax californica. Underwater photograph taken in Zihuatanejo Bay, Guerrero, March 2018. Photograph courtesy of Ron Woheau, Zihuatanejo. Identification courtesy of Greg Timms, youtube.com/@CoralmasterdivesPuerto-Vallarta/videos.
Phylogeny: The California Feather Duster, Notaulax californica (Treadwell, 1906), is a member of the Sabellidae Family of Marine Polychaetae Worms. The Notaulax Genus is one of forty-one genera in the Sabellidae Family, and there are twenty-three species in the Notaulax Genus. The genus name Notaulax comes from the Greek words meaning roughly “grooved back”, referring to the dorsal groove found in this genus. The species name indicates that this specimen was first discovered in either upper or lower California. They are known in Mexico as Gusano Abanico de California. Note: there is a remote possibility that this species could be a closely related regional variant within the Notaulax nudicollis complex.
Morphology: The California Feather Duster has a single, large crown of feathery tentacles called radioles. The radioles border the mouth. The radioles split cleanly into two symmetrical, non-spiraled, semicircular lobes that together form a near-perfect flat circle. The crown can have from 6 to 11 pairs of radioles that range from 1.7 mm to 4.8 mm in length. The radioles do not roll inward, and they are connected by a palmate membrane. Two prominent, pale yellowish, spike-like elements project upward from the middle of the crown. These are the highly prolonged dorsal lips characteristic of this genus, acting as stiff visual anchors when the fan fully unfurls. The rich, translucent reddish-maroon or wine-red color of the radioles with lighter, shimmering pinnules is a classic color morph for this species in shallow reef zones. The body is yellowish-green and protected in a resilient, organic, tube, which is covered in fine sand near the mouth and translucent posteriorly. The body can reach over 1.1 cm in length, though most are in the 7 mm to 8 mm range. They range from 0.5 mm to 1.8 mm in width.
Habitat and Distribution: California Feather Dusters are found embedded in hard calcareous tubes on dead coral, rocky reef substrates, buoys, and dock pilings. They are often surrounded by coralline algae. They are normally found in the first 2 m (7 feet) of the water column but can also be found at depths up to 7 m (22 feet). California Feather Dusters are a subtropical to tropical Eastern Pacific species and are ENDEMIC to Mexican waters of the Pacific Ocean ranging from Bahía Concepción, Mulegé, Baja California Sur to Islas de Chamelas, La Huerta, Jalisco.
Diet: California Feather Dusters are suspension feeders, filtering plankton, micro algae and organic matter from the passing currents, or by creating currents by use of the radioles. Cilia on the radioles create a water current and push trapped food down specialized grooves toward the central mouth.
Predators: California Feather Dusters have simple radiolar eyes (ocelli) on their crown that sense shadows and movement, allowing it to instantly retract from predators. While predators specific to California Feather Dusters have not been well documented. Other similar species are prey for crabs, fish, gastropods, sea stars and shrimp.
Reproduction: California Feather Dusters are gonochoric (male or female for life). Sexual reproduction occurs through swarming, which occurs when females produce a pheromone attracting and signaling the males to shed sperm which in turn stimulates females to shed eggs. Fertilization is external. The fertilized eggs drift as plankton before settling to the bottom as trochophore larvae, which then metamorphose into adult worms.
Ecosystem Interactions: The California Feather Duster is thought to be beneficial to nearby coral reef habitats by helping keep organic matter from smothering the coral polyps. Small marine invertebrates such as amphipods, bryozoans, and tiny crabs, often use the outside of the worms’ tubes for shelter and protection from predators, while not harming the worm. California Feather Dusters sometimes build their tube on the outside of other animals, such as mollusk shells, which benefits the worm without harming the mollusk.
Human Interactions: California Feather Dusters are biofoulers, meaning that they sometimes attach to buoys, docks, pilings, pipelines, and ship hulls. In sufficient numbers, they can have a negative impact on the performance of these items. They also occasionally attach to the shells of farmed shellfish, which lowers the value of the shellfish. From a conservation perspective, they have not been formally evaluated.
Synonyms: Hypsicomus californicus and Potamilla californica.