A Purple Mystery: Identifying Unnamed Sponges On the Oregon Coast
Faculty Sponsor(s)
Jeremy Weisz
Subject Area
Biology
Description
Intertidal and subtidal sponges are important members of their communities, but their identities are often unresolved. We observed purple, encrusting, marine sponges along the central to northern Oregon coast, tentatively identified as members of the genus Haliclona, but yet to be formally named. We sought to resolve the taxonomy in this potential species complex and to eventually give formal names to these common inhabitants of the Oregon coast. The study of these sponges utilized spicule morphology, and phylogenetic analyses. Spicule preparations were analyzed microscopically to characterize size and shape distributions, while DNA sequence was derived from field samples and amplified using 28S, a ribosomal RNA gene that has been used frequently in other sponge taxonomy studies. We used [software] to build both a maximum-likelihood phylogeny and a neighbor joining phylogeny. Results showed both that our sponges form a distinct clade within genus Haliclona and that they form two different groups, separating intertidal samples from subtidal samples. Additionally, we see low intraspecific divergence among replicate specimens, supporting the hypothesis that these are only two new species. BLAST searches revealed a lack of close sequence matches, strongly suggesting that these Oregon coast Haliclona specimens represent novel lineages within the genus. Spicule analysis support these sponges as members of the genus. Morphological variation alone didn’t create any new conclusions about Haliclona lineages, but along with molecular data can further support the idea that two marine sponges remain unnamed. The findings of this project underscore the importance of morphological and molecular data when furthering the study of a complete sponge taxonomic profile and provide support to identify these sponges as novel members of genus Haliclona.
Recommended Citation
Nighthawk, Joshua Suliemann and VerCauteren, Karlie, "A Purple Mystery: Identifying Unnamed Sponges On the Oregon Coast" (2026). Linfield University Student Symposium: A Celebration of Scholarship and Creative Achievement. Event. Submission 19.
https://digitalcommons.linfield.edu/symposium/2026/all/19
A Purple Mystery: Identifying Unnamed Sponges On the Oregon Coast
Intertidal and subtidal sponges are important members of their communities, but their identities are often unresolved. We observed purple, encrusting, marine sponges along the central to northern Oregon coast, tentatively identified as members of the genus Haliclona, but yet to be formally named. We sought to resolve the taxonomy in this potential species complex and to eventually give formal names to these common inhabitants of the Oregon coast. The study of these sponges utilized spicule morphology, and phylogenetic analyses. Spicule preparations were analyzed microscopically to characterize size and shape distributions, while DNA sequence was derived from field samples and amplified using 28S, a ribosomal RNA gene that has been used frequently in other sponge taxonomy studies. We used [software] to build both a maximum-likelihood phylogeny and a neighbor joining phylogeny. Results showed both that our sponges form a distinct clade within genus Haliclona and that they form two different groups, separating intertidal samples from subtidal samples. Additionally, we see low intraspecific divergence among replicate specimens, supporting the hypothesis that these are only two new species. BLAST searches revealed a lack of close sequence matches, strongly suggesting that these Oregon coast Haliclona specimens represent novel lineages within the genus. Spicule analysis support these sponges as members of the genus. Morphological variation alone didn’t create any new conclusions about Haliclona lineages, but along with molecular data can further support the idea that two marine sponges remain unnamed. The findings of this project underscore the importance of morphological and molecular data when furthering the study of a complete sponge taxonomic profile and provide support to identify these sponges as novel members of genus Haliclona.