Leafy Green Bryozan, Sessibugula translucens
Leafy Green Bryozan, Sessibugula translucens. Underwater photograph taken in Bahía de La Ventana, La Paz, Baja California Sur, December 2025. Photograph courtesy of Aaron Woodrow, Juneau, Alaska. Identifications courtesy of Greg Timms, youtube.com/@CoralmasterdivesPuerto-Vallarta/videos. The Bryozan is being preyed upon by a Blue-striped Tambja, Tambja eliora.
Phylogeny: The Leafy Green Bryozan, Sessibugula translucens (Osburn, 1950), is a member of the Burulidae Family of Bryozoans. The Bugulidae Family has thirty-four genera and there is one species in the Sessibugula Genus. Sessibugula translucens serves as the type species for the genus Sessibugula. It is known in Mexico as Briozoo de Hojas Verdes or Briozoo Verde Frondoso.
Morphology: The Leafy Green Bryozan vary in size and can be very large. They are blue-green in color with large lettuce-like leaves extending upward from the base that is attached to the substrate. The morphometrics of the Leafy Gren Bryozan are poorly documented in the scientific literature.
Habitat and Distribution: The Leafy Green Bryozan is fairly common a colonial species found in small formations that attach to marine substrate that inhabit the intertidal and shallow subtidal zones.
They are not mobile. The Leafy Green Bryozan is native to the Eastern Pacific Ocean however its range in Mexican waters is poorly documented.
Diet: The Leafy Green Bryozan is a filter feeder that consumes plankton and organic detritus from the surrounding water.
Predation: The Leafy Green Bryozan is preyed upon by a series of nudibranchs and predominately by the Blue-stripped Slug, Tambja eliora, that retain the the tambjamines they ingest and utilize as a defense against predation.
Reproduction: The Leafy Green Bryozan reproduce sexually as hermaphrodites and asexually via budding. The individual zooids that make up the colony possess both males and female reproductive organs. Sperm is released into the water and caught by the tentacled feeding structures of neighboring zooids to fertilize the eggs. The fertilized eggs are retained by the females before they are released as free swimming larvae. These larvae eventually settle out on the bottom and attach to the hard bottom and transform into zooid and start new colonies. Reproduction via budding involves the generation of a new genetically identical zooid that grow directly from the existing ones. Or, a piece of colony can break off and the fragments grow into a new colony.
Ecosystem Interactions: The Leafy Green Bryozan plays an essential role in the marine food web by having specialized chemicals including tambjamines (structural alkaloids) in their tissues.
Human Interactions: The Leafy Green Bryozan have no direct impact on human activities. From a conservation perspective the Leafy Green Bryozan has not been formally evaluated. They are not suitable for aquarium use being not able to survive in captivity.
Synonym: None.