Remembering Dan Fong, former KWI President
Dan Fong, third from left, in 2006. Photo courtesy of David Riggs. More photos of Dan are here.
By David Culver and Wil Orndorff
This remembrance of Dan Fong is adapted from: Culver DC (2025) In Memoriam – Daniel Wu Fong (born December 1, 1954; died April 25, 2025). Subterranean Biology 52: 103–109. https://doi.org/10.3897/subtbiol.52.158075
With the death of Daniel Wu Fong, the caving, subterranean biology, and karst conservation communities lost one of their most vibrant and active members. Dan will be remembered not only for his ready wit, infectious laugh, and optimism, but also for his probing intellect and his contributions to cave biology, education, and conservation.
Dan played a prominent role in the Karst Waters Institute (KWI), serving on its Board of Directors from 1991 to 1996, Treasurer from 1997 to 2007, and finally president from 2007 to 2012.
Dan‘s early life was one of migration. Born in the People’s Republic of China, he was sent to Hong Kong at age 4 to live with his aunt, who subsequently adopted him and moved the family to the San Francisco area, where Dan went to high school. He got his B.A. in Zoology at the University of California-Berkeley, an exciting time to be at Berkeley, to put it mildly. After several years of working at the Midwest Research Institute in Kansas City, Dan enrolled as a master’s student at the University of Oklahoma. These years had a profound impact on Dan, and it was there he developed his love of caves. After he received his M.S. in 1980, he came to Northwestern University with David Culver.
Dan went on to collaborate with Culver and others on a series of landmark papers on various aspects of cave biology, most having to do with the heart of the neo-Darwinian paradigm. As Ernst Mayr, in a famous essay in 1973, put it, “nothing makes sense in biology except in the light of cave evolution.” Three American cave biologists— Thomas Barr, Kenneth Christiansen, and Thomas Poulson—had brought the study of cave biology into the neo-Darwinian firmament. Dave Culver and Thomas Kane sought to provide a rigorous demonstration that natural selection, rather than genetic drift or organicism, was responsible for the morphology of the amphipod Gammarus minus, which occurs in springs and caves, with many cave populations exhibiting a highly modified morphology of tiny eyes and reduced pigment. Dan’s thesis was absolutely critical to this work. What Dan showed in his Ph.D. work, by an analysis of individual pair matings in the laboratory, was that indeed differences in eye size, antennal length, and overall size was genetically (i.e., heritable), rather than environmentally determined. This study became an integral part of the book length consideration of the role of natural selection in the evolution of cave inhabiting populations of Gammarus minus, as well as a part of a review of regressive evolution in The Annual Review of Ecology and Systematics. While his colleagues and mentors moved on to other questions and other systems, Dan developed new collaborations with molecular geneticists, especially David Carlini of American University, that allowed the use of these new tools in the study of Gammarus minus, including the demonstration through transcriptome analysis that selection on eyes in cave populations was widespread. Beginning with his thesis on inheritance of quantitative morphological straits to his more recent work on the transcriptomes of cave and spring populations, Dan succeeded through his studies of Gammarus minus in demonstrating the centrality of natural selection in molding the morphology of cave animals.
While Dan continued to study the populations of Organ Cave and its associated resurgence spring to investigate heritability and molecular genetics, he also expanded his work on Gammarus minus in several other directions and at other locations. One was to champion Gammarus minus as a model system for studying evolution, since it is one of only a handful of cave-dwelling species that can be raised in the lab and be successfully mated with surface dwelling populations. Dan expanded our knowledge of the biology of Gammarus minus, including trophic analysis using stable isotopes. Dan also considered Organ Cave in a general ecological context, with studies of microdistribution and community structure, and contributed an important chapter on management of cave fauna in general in Van Beynen’s book, Karst Management.
Dan devoted a lot of attention to the threatened Madison Cave isopod (Antrolana lira), a cirolanid isopod known only from phreatic karst groundwater of the Shenandoah Valley and the only stygobiont in the Appalachians of direct marine lineage. While much of this work was in the form of difficult to obtain reports to the U.S. Fish and Wildlife Service, he published a molecular genetic analysis with Carlini and Ben Hutchins demonstrating that the species consisted of at least three long isolated and genetically distinct populations. While the evolutionary origin of Antrolana lira remains a puzzle, Dan rather whimsically suggested that in the late Eocene, about 35 million years ago, a tidal wave carried its ancestors into the Shenandoah Valley, the result of a meteor impact in an area that would eventually become part of the Chesapeake Bay!
Dan made many important contributions studying the biodiversity of cave fauna, including new species descriptions, biology and natural history notes, and local and regional species lists and biogeographic analysis, mostly focused on the fauna of West Virginia caves. Three species bear Dan’s name:
- Pseudotremia fongi Shear 2008 (a millipede from Greenbrier County, WV)
- Niphargus fongi Fišer & Zagmajster 2009 (an amphipod from Slovenia)
- Monolistra fongi Prevorčnik & Verovnik 2010 (an isopod from Croatia)
Dan founded the online journal Speleobiology Notes in 2008 and served as editor until 2012.
At American University, Dan Fong was unstinting in his support of graduate research and education, chairing the MS thesis committees of 18 students, most of whom did cave related projects. For five, their thesis work resulted in a publication—Ariel Aspiras, Natalie Hanson, Benjamin Hutchins, Shannon Knapp, and Mara Laslo. He was a sought-after collaborator and even a glance at his bibliography shows many names of North American and European collaborators. Noteworthy are the numerous collaborations with speleobiologists working in the Classical Karst of Slovenia and the broader Dinaric karst. These include Helena Bilandžija, Tanja Pipan, and Maja Zagmajster. Collaborations among researchers and former students who met through Dan will continue to produce impactful results for decades.
Dan cared deeply about cave education, conservation, and management. In addition to twenty years of service with the KWI, Dan served on the Cave Conservancy of the Virginias Board of Directors for 23 years, many of them as part of the grants committee. He also served as the program director of the Cave Conservancy Foundation’s Charles W. Maus Undergraduate Karst Research Fellowship from 2016. Dan was an active member of the National Speleological Society (NSS), a major contributor to the NSS Biology Section, including as part of the Stygobromus Working Group, and received the NSS Science Award in 2023.
Dan was outstanding in his ability both to ask probing questions about one’s research and to ask more general questions. All of us who had the privilege of working with him were the recipients of this bounty. I would be remiss if I did not mention one of his most important social contributions—as a co-founder of the District of Columbia Biospeleological Drinking (Discussion) Club (DCBDC). And Dan was a fixture at many caving events, including National Speleological Society Conventions and Old Timers Reunions in West Virginia. But surely all of us who knew him remember most of all his infectious good humor, his positive attitude, and his wonderful laugh.
Publications by Daniel Wu Fong
Fong DW, Culver DC (1985) A reconsideration of Ludwig’s differential migration theory of regressive evolution. Bulletin of the National Speleological Society 47: 123–127.
Culver DC, Fong DW (1986) Why all cave animals look alike. Stygologia 2: 208–216.
Vawter AT, Fong DW, Culver DC (1987) Negative phototaxis in surface and cave populations of the amphipod Gammarus minus. Stygologia 3: 83–88.
Fong DW (1989) Morphological evolution of the amphipod Gammarus minus in caves: quantitative genetic analysis. American Midland Naturalist 121: 361–378. https://doi.org/10.2307/2426041
Culver DC, Kane TC, Fong DW, Jones R, Taylor MA, Sauereisen SC (1989) Morphology of cave organisms – is it adaptive? Memoires de Biospeologie 17: 3–16.
Kane TC, Richardson RC, Fong DW (1990) The phenotype as the level of selection: cave organisms as model systems. Journal of the Philosophy of Science Association 1990(1): 151–164. https://doi.org/10.1086/psaprocbienmeetp.1990.1.192700
Culver DC, Fong DW, Jernigan RW (1991) Assessing species interactions in cave stream communities. American Midland Naturalist 126: 364–379. https://doi. org/10.2307/2426112
Culver DC, Fong DW (1994) Subterranean crustacean fauna of major river basins of the Virginias: effects of scale. Hydrobiologia 287: 3–9. https://doi.org/10.1007/ bf00006891
Fong DW, Culver DC (1994) Fine-scale biogeographic differences in the crustacean fauna of a cave system in West Virginia, USA. Hydrobiologia 287: 29–37. https:// doi.org/10.1007/bf00006894
Fong DW, Culver DC (1994) Invertebrate fauna. In: Dasher GR, Balfour WM. The Caves and Karst of the Buckeye Creek Basin, Greenbrier County, West Virginia. Bulletin 12, West Virginia Speleological Survey, Barrackville, WV, 41–42.
Jernigan RW, Culver DC, Fong DW (1994) The dual role of selection and evolutionary history as reflected in genetic correlations. Evolution 48: 587–596. https://doi. org/10.1111/j.1558-5646.1994.tb01346.x
Culver DC, Jones WK, Fong DW, Kane TC (1994) Case studies of karstic systems: Organ Cave Basin, West Virginia. In: Gibert J, Danielopol D, Stanford J (Eds) Groundwater Ecology. Academic Press, New York, 451–473.
Culver DC, Kane TC, Fong DW (1995) Adaptation and Natural Selection in Caves. The Evolution of Gammarus minus. Harvard University Press, Cambridge, Mass., 223 pp. https://doi.org/10.4159/harvard.9780674419070
Fong DW, Kane TC, Culver DC (1995) Vestigialization and loss of nonfunctional characters. Annual Review of Ecology and Systematics 26: 249–268. https://doi. org/10.1146/annurev.ecolsys.26.1.249
Sasowsky ID, Fong DW, White EL (Eds) (1997) Conservation and Protection of the Biota of Karst. KWI Special Publication 3, Karst Waters Institute, Charles Town, WV., 118 pp.
Knapp, S., Fong DW (1999) Estimates of population size of the cave-dwelling amphipod Stygobromus emarginatus in Organ Cave, West Virginia. Journal of Cave and Karst Studies 61: 3- 6.
Fong DW, Culver DC, Hobbs III HH, Pipan T (2007) The Invertebrate Cave Fauna of West Virginia, Second Edition. Bulletin 16, West Virginia Speleological Survey, Barrackville, WV., 167 pp.
Holsinger JR, Shaffer J, Fong DW, Culver DC (2008) Gammarus cohabitus, a new species of subterranean amphipod crustacean (Gammaridae) from groundwater habitats in central Pennsylvania, USA. Subterranean Biology 6: 31–41.
Slay ME, Fong DW, Kottmyer MD (2009) Meta ovalis (Araneae: Tetragnathidae) observed preying on a troglobiotic millipede, Causeyella (Chordeumatida: Trichopetalidae). Speleobiology Notes 1: 3–5.
Fong DW (2009) Brood size of the stygobiotic asellids isopod Caecidotea pricei from a spring run in West Virginia, USA. Speleobiology Notes 1: 1–2.
Carlini DB, Manning J, Sullivan PG, Fong DW (2009) Molecular genetic variation and population structure in morphologically differentiated cave and surface populations of the freshwater amphipod Gammarus minus. Molecular Ecology 18: 1932–1945. https://doi.org/10.1111/j.1365-294x.2009.04161.x
Hutchins B, Fong DW, Carlini DB (2010) Genetic population structure of the Madison Cave Isopod, Antrolana lira (Cymothoida: Cirolanidae) in the Shenandoah Valley of the eastern United States. Journal of Crustacean Biology 30: 312–322. https://doi.org/10.1651/09-3151.1
Zacharda M, Fong DW, Hobbs III HH, Piva E, Slay ME, Taylor SJ (2010) A review of the genus Traegaardhia (Acari, Prostigmata, Rhagidiidae) with descriptions of new species and a key to species. Zootaxa 2474: 1–64. https://doi.org/10.11646/ zootaxa.2474.1.1
Hanson N, Fogel M, Fong DW, MacAvoy SE (2010) Marine nutrient transport: anadromous fish migration linked to the freshwater amphipod Gammarus fasciatus. Canadian Journal of Zoology 88: 546–552. https://doi.org/10.1139/z10-030
Fong DW (2011) Management of subterranean fauna in karst. In: Van Beynen P (Ed) Karst Management. Springer, New York, 201–224. https://doi.org/10.1007/97894-007-1207-2_9
Zagmajster M, Porter ML, Fong DW (2011) Freshwater hydrozoans in caves, with report of new records. Speleobiology Notes 3: 4–10.
Aspiras AC, Prasad R, Fong DW, Carlini DB, Angelini DR (2012) Parallel reduction in expression of the eye development gene hedgehog in separately derived cave populations of the amphipod Gammarus minus. Journal of Evolutionary Biology 25: 995–1001. https://doi.org/10.1111/j.1420-9101.2012.02481.x
Fong DW, Porter ML, Slay ME (2012) Cave Life of the Virginias: A Field Guide to Commonly Encountered Species. Biology Section, National Speleological Society, Special Publication 1, Huntsville, Ala., 42pp.
Fong DW (2012) Gammarus minus as a model system for the study of evolution. In: Culver DC, White WB (Eds) Encyclopedia of Caves, 2nd Edition. Elsevier Academic Press, Burlington, Mass., 341–347. https://doi.org/10.1016/b978-012-383832-2.00047-5
Fong DW, Culver DC, Veni G, Engel S (Eds) (2013) Carbon and Boundaries in Karst. KWI Special Publication 17, Karst Waters Institute, Leesburg, VA.
Carlini DB, Satish S, Fong DW (2013) Parallel reduction in expression, but no loss of functional constraint, in two opsin paralogs within cave populations of Gammarus minus (Crustacea: Amphipoda). BMC Evolutionary Biology 13: 89. https://doi. org/10.1186/1471-2148-13-89
MacAvoy SE, Braciszewski A, Tengi E, Fong DW (2016) Trophic plasticity among spring versus cave populations of Gammarus minus: examining functional niches using stable isotopes and C/N ratios. Ecological Research 31: 589–595. https:// doi.org/10.1007/s11284-016-1359-6
Niemiller ML, Porter ML, Keany J, Gilbert H, Fong DW, Culver DC, Hobson C, Kendall KD, Davis MA, Taylor SJ (2017) Evaluation of eDNA for groundwater invertebrate detection and monitoring: a case study with endangered Stygobromus (Amphipoda: Crangonyctidae). Conservation Genetics Resources 10: 247–257. https://doi.org/10.1007/s12686-017-0785-2
Carlini DB, Fong DW (2017) The transcriptomes of cave and surface populations of Gammarus minus (Crustacea: Amphipoda) provide evidence for positive selection on cave downregulated transcripts. PLoS One 12: e0186173. https://doi. org/10.1371/journal.pone.0186173
Bilandžija H, Laslo M, Porter ML, Fong DW (2017) Melanization in response to wounding is ancestral in arthropods and conserved in albino cave species. Scientific Reports 7:17148. https://doi.org/10.1038/s41598-017-17471-2
Culver DC, Fong DW (2018) Terrestrial fauna in the Greenbrier karst. In: White WB (Ed) Caves and Karst of the Greenbrier Valley in West Virginia. Springer, Cham, Switzerland, 371–384. https://doi.org/10.1007/978-3-319-65801-8_18
Fong DW, Culver DC (2018) The subterranean aquatic fauna of the Greenbrier karst, pp. 385–398. In: W.B. White [ed.] Caves and Karst of the Greenbrier Valley in West Virginia. Springer, Cham, Switzerland, 385–398. https://doi.org/10.1007/978-3319-65801-8_19
Fong DW (2019) Gammarus minus as a model system for the study of evolution. In: White WB, Culver DC, Pipan T (Eds) Encyclopedia of Caves, 3nd Edition. Elsevier Academic Press, Burlington, Massachusetts, 451–458. https://doi.org/10.1016/ b978-0-12-814124-d.0054-6
Fong DW (2019) Food Sources. In: White WB, Culver DC, Pipan T (Eds) Encyclopedia of Caves, 3nd Edition. Elsevier Academic Press, Burlington, Massachusetts. 429–443. https://doi.org/10.1016/b978-0-12-814124-3.00051-0
Mammola S, Amorim IR, Bichuette ME, Borges PAV, Cheeptham N, Cooper SJB, Culver DC, Deharveng L, Eme D, Ferreira RL, Fišer C, Fišer Z, Fong DW, Griebler C, Jeffery WR, Jugovic J, Kowalko JE, Lilley TM, Malard F, Manenti R, Martinez A, Meierofer ME, Niemiller ML, Northup DE, Pellegrini TG, Pipan T, Protas M, Reboleira ASPS, Venarsky MP, Wynne JJ, Zagmajster M, Cardoso P (2020) Fundamental research questions in subterranean biology. Biological Reviews 95: 1855–1872. https://doi.org/10.1111/brev.12642
Fitzgerald DB, Smith DR, Culver DC, Feller D, Fong DW, Hajenga J, Niemiller ML, Nolfi DC, Orndorff WD, Douglas B, Maloney KL, Young JA (2021) Using expert knowledge to support Endangered Species Act decision making for datadeficient species. Conservation Biology 35: 1627–1638. https://doi.org/10.1111/ cobi.13694
Fong DW, Orndorff WD, Carlini DB (2021) Species status evaluation of Lirceus usdagalun, L. culveri, and L. hargeri populations (Isopoda; Asellidae) based on a large scale next-generation sequence data set. Conservation Genetics 22: 661–667. https://doi.org/10.1007/s10592-021-01387-6
Fong DW, Carlini DB (2023) Ecological and evolutionary perspectives on groundwater colonization by the amphipod crustacean Gammarus minus. In: Malard F, Griebler C, Rétaux S (Eds) Groundwater Ecology and Evolution. Second Edition. Elsevier/Academic Press, Amsterdam, 373–392. https://doi.org/10.1016/b978-012-819119-4.15007-3
Lukić M, Jovović L, Bedek J, Grgić N, Kuharić T, Rožman I, Čupić B, Weck B, Fong DW, Bilandžija H (2024) A practical guide for the husbandry of cave and surface organisms as the first step in establishing new model organisms. PLoS One 19: e0300962. https://doi.org/10.1371/journal.pone.0300962
