Senior Scientist
Monterey Bay Aquarium Research Institute
7700 Sandholdt Road
Moss Landing, CA 95039
Phone: (831) 775-1799
Fax: (831) 775-1620
email: vrijen@mbari.org
Bythograea
vrijenhoeki
- Interests
Marine Biology, Genetics and Evolution, Conservation
- Education
B.S. University of
Massachusetts—Amherst
Ph.D. University of Connecticut—Storrs
- Research
- Bone-Eating worms
- Gene flow and dispersal
- Molecular Systematics
- Marine Symbiosis
Studies focus on the ecological and evolutionary consequences of genetic diversity in animals and associated microbes.
Osedax worms were discovered living on the bones of a whale found at 2891 m depth in Monterey Bay. Osedax females grow complex roots that contain symbiotic bacteria and invade the bone marrow, on which these mouthless and gutless worms subsist. Osedax males are microscopic, and they live inside the gelatinous tubes produced by the females. Sex ratios are highly skewed with more than 25 males living in an average female's tube. MBARI press release.
Some recent papers on this topic include:
Rouse GW, Wilson NG, Goffredi SK, Johnson SB, Smart T, Widmer C, Young CM, Vrijenhoek RC (2009) Spawning and development in Osedax boneworms (Siboglinidae, Annelida). Marine Biology 156, 395-405. Link to PDF
Vrijenhoek, RC, Johnson, S, Rouse, GW, 2008. Bone-eating Osedax females and their "harems" of dwarf males are recruited from a common larval pool. Molecular Ecology 17, 4535-4544. Link to PDF
Rouse GW, Goffredi SK, Vrijenhoek RC (2004) Osedax: Bone-Eating Marine Worms with Dwarf Males. Science 305: 668-671. Link to PDF.
Since 1989, research has focused on gene flow and evolutionary relationships of organisms endemic to deep-sea hydrothermal vents and cold water seeps. Most vent-endemic invertebrates have effective modes of dispersal that maintain genetic continuity among populations distributed thousands of kilometers along mid-ocean ridge systems. For some organisms, however, structural aspects of the ridge system (large transform faults and other discontinuities such as the Easter Microplate) result in restricted gene flow or isolation among populations.
Young, CR., Fujio, S., Vrijenhoek, RC., 2008. Directional dispersal between mid-ocean ridges: deep-ocean circulation and gene flow in Ridgeia piscesae. Molecular Ecology 17, 1718-1731. Link to PDF
Johnson SB, Young CR, Jones WJ, Warén A, Vrijenhoek RC (2006) Migration, isolation, and speciation of hydrothermal vent limpets (Gastropoda; Lepetodrilidae) across the Blanco Transform Fault. Biological Bulletin 210: 140-157 Link to PDF
Hurtado LA, Lutz RA, Vrijenhoek RC (2004) Distinct patterns of genetic differentiation among annelids of eastern pacific hydrothermal vents. Molecular Ecology: 13: 2603-2615 Link to PDF
Research has focused on the the evolutionary histories of vent and seep invertebrates. Phylogenies have been generated for many of the dominant vent taxa including clams, mussels, shrimp, and tubeworms. Present evidence suggests that taxa have had relatively recent origins during the last 100 million years.
Johnson S, Warén A, Vrijenhoek RC (2008) DNA barcoding of Lepetodrilus limpets reveals cryptic species. Journal of Shellfish Research 27, 43-51.
Jones WJ, Won YJ, Maas PAY, Smith PJ, Lutz RA, Vrijenhoek RC (2006) Evolution of habitat use by deep-sea mussels. Marine Biology 148: 841-851
Little CTS, Vrijenhoek RC (2003) Are hydrothermal vent animals living fossils? Trends in Ecology and Evolution 18: 582-588
Goffredi SK, Johnson SB, Vrijenhoek
RC (2007) Genetic and potential function of microbial symbionts
associated with newly discovered species of Osedax polychaete worms. Applied
and Environmental Microbiology 73, 2314-2323.
Won Y-J, Hallam SJ, O'Mullan GD,
Pan IL, Buck KR, Vrijenhoek RC (2003) Environmental acquisition of
thiotrophic endosymbionts by deep-sea mussels of the genus Bathymodiolus. Applied
and Environmental Microbiology 69:
6785-6792 Link to PDF
Hurtado LA, Mateos M, Lutz RA,
Vrijenhoek RC (2003) Coupling of bacterial endosymbiont and host
mitochondrial genomes in the hydrothermal vent clam Calyptogena
magnifica. Applied and
Environmental Microbiology 69:
2058-2064.
- Unisexual Fish
- Conservation Genetics
Long-term research efforts during the past 30 years have focused on the evolutionary and ecological consequences of sexual and asexual reproduction in Mexican poeciliid fish (genus Poeciliopsis). We use a variety of molecular approaches to contrast gene and genomic evolution under the recombinant and non-recombinant breeding systems found in these fish.
Mateos M, Vrijenhoek RC (2002) Ancient versus reticulate origin of a hemiclonal lineage. Evolution 56: 985-992
Vrijenhoek, R. C., 1998 Animal clones and diversity. Bioscience 48: 617-628.
Vrijenhoek RC (1979) Factors affecting clonal diversity and coexistence. American Zoologist 19, 787-797.
Several of the sexual species of Poeciliopsis are either endangered or seriously threatened. Field and experimental studies have shown that the competitive ability, disease resistance, developmental stability, growth rate, and fecundity of these fish may be compromised by losses of genetic diversity that accompany population bottlenecks, founder events, and inbreeding.
Vrijenhoek, R. C., 1998 Conservation genetics of freshwater fish. Journal of Fish Biology 53 (Supplement A): 394-412.
- Expeditions
- Southern East Pacific Rise (Dec. 16, 1998 - Jan. 21, 1999)
- Guaymas Hot Vents/21 N (April 4 - 17, 2003)
- Whale Fall (August 2003)
- Easter Microplate (March 12 - April 6, 2005)
- Fiji/Lau Expedition (May 15 - June 3, 2005)
