Case Study
Title & Categories
| Case Study Title: | Clarification of species of Conopeum Gray, 1848 in US harbors using DNA barcoding |
| Focus Theme: | Biotic inventory of a poorly known taxonomic group |
| Geographic Region: | North America |
| Habitat Type: | Estuarine, Marine nearshore benthos |
| Taxonomic Group: | d: Ectoprocta |
Scope
Bryozoans of the genus Conopeum have been collected from fouling panels in 9 bays around the United States. Ninety-two samples have been selected from these sites – East Coast: Portsmouth, NH (1 sample), Naragansett Bay, RI (3), Chesapeake Bay, VA(42), St. Johns River, Jacksonville, FL(8); Gulf of Mexico: Tampa Bay, FL(10) and Galveston Bay, TX(1); West Coast: Coos Bay, OR(7), Humboldt Bay(3) and San Francisco Bay(17), CA. Expert taxonomists have identified 4 potential species from this collection – Conopeum chesapeakensis (Banta) 1995, C. osburni Soule et al., 1995, C. seurati (Canu) 1928, and C. tenuissimum (Canu) 1928. Additional samples have been collected from Charleston Harbor, SC and Indian River Lagoon, FL as well as Sydney and Perth, Australia and are currently awaiting identification. Voucher specimens were fixed in 95% EtOH and are maintained in 95% or 70% EtOH. 92 samples have been selected for analysis. Workload for this project would be limited to selection and preparation of samples (the bulk of which would be handled by SERC staff), DNA work (CBOL staff) and data analysis (SERC staff). Cost would be limited to that for DNA analysis at approx. $13 per sample (92x$13 = ~$1200) - estimate taken from “Protocols for High-Volume DNA Barcode Anaylsis”.
Purpose
Specimens were collected as part of a larger study investigating non-native species in the fouling communities of U.S. and foreign harbors. C. seurati is described from Europe and thought to be an invader in the U.S. and in other ports of the world (including Panama and New Zealand). In several of the bays where it was collected, it’s among the most abundant species found in the fouling community. C. tenuissimum is native to the East Coast but has invaded bays on the West Coast as well as harbors in Australia. Because these species are morphologically similar to each other and to native species, we propose to discriminate among these morphotypes using genetic analyses combined with histological study.
Background
C. chesapeakensis and C. osburni were described on the east and west coast of the U.S. respectively at the same time, yet their morphologies are very similar. C. seurati also has a similar morphology to these species and has conflicting morphological descriptions in the literature. C. tenuissimum is also occasionally confused with C. seurati and commonly co-occurs with the other species. Genetic analysis of bryozoans so far has been limited to a few families. Within the family Electridae (which contains Conopeum, Electra and Membranipora), only 6 known species have been sequenced thus far. There is one sequence available from an ATPase gene for a Conopeum specimen but the morphological ID is unreliable and this gene is not useful in discriminating closely related species. DNA analyses coupled with morphological data have helped clarify taxonomic problems in other bryozoan families (Porter, 2004). Further molecular analysis on bryozoans as a whole is desperately needed.
Logistics
It has been shown previously that COI sequences are only useful as a within species population level marker for bryozoans (Dick et al., 2003). However, recent data shows that 16S mitochondrial rRNA sequences can help identify species level differences (Dick and Mawatari, 2005). We hope that this sequencing work can be done at the SI Lab for Molecular Systematics. Data management and analysis would be handled by SERC staff.