Graduation Date

Spring 2022

Document Type



Master of Science degree with a major in Biology

Committee Chair Name

Dr. Sean Craig

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Dr. Joe Tyburczy

Second Committee Member Affiliation

HSU Faculty or Staff

Third Committee Member Name

Dr. Joshua Mackie

Third Committee Member Affiliation

Community Member or Outside Professional

Fourth Committee Member Name

Dr. Paul Bourdeau

Fourth Committee Member Affiliation

HSU Faculty or Staff


Marine invasions, Watersipora, Copper tolerance, Cryptic species, Larval traits

Subject Categories



Many factors contribute to the potential of a non-indigenous species to invade an area and become established. For bryozoan colonies of the cryptic species complex Watersipora (Neviani, 1896), this may include larval characteristics such as settlement rate, competency of metamorphosis, swimming duration, and the ability to tolerate copper, a common component in marine anti-fouling paints. Two common groups of Watersipora that occur along the California coast are W. subatra Clade A and an undescribed new species, Clade N. The goal of this research work was to discover what differences, if any, exist in the larval traits and copper tolerances of these two clades. Colonies of Clade A and N were collected around Humboldt Bay and induced to release larvae. Individual larvae were pipetted into petri dishes with either a circle of copper paint or an unpainted control and placed in a common-garden experiment where larval characteristics were measured between species and experimental treatments. Both species had markedly different larval characteristics, with W. subatra settling faster and at a higher rate than Clade N in the control treatment. When exposed to copper anti-fouling paint, however, these trends reversed. This study is the first to investigate larval differences between these two species. A number of studies on bryozoans are presumed, but not verified, to be Watersipora subatra. This fact, coupled with the strong observed differences in larval behavior that these results show, suggests that a Watersipora species-specific approach needs to be taken in future work with this cryptic species complex.

Citation Style




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