Marine Biology, Genetics and Evolution, Conservation

B.S. University of Massachusetts—Amherst
Ph.D. University of Connecticut—Storrs

Studies focus on the ecological and evolutionary consequences of genetic diversity in animals and associated microbes.

• Bone-Eating worms

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.

• Gene flow and dispersal

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


• Molecular Systematics

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

• Marine Symbiosis

• Unisexual Fish

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.


• Conservation Genetics

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.

• 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)

• Folmer primers