Bay Bulls, Newfoundland Spring 2000 (D. Innes)


                                                                 Dr. David J. Innes

                                                              Department of Biology

                                                  Memorial University of Newfoundland

                                            St. John's, Newfoundland, A1B 3X9, Canada


                                              Phone: (709) 864-4754 Fax: (709) 864-3018

                                            email: dinnes"at"   (replace at with @)


The research in my laboratory focuses on sexual and asexual reproduction, primarily using the planktonic crustacean, Daphnia pulex as a model organism (visit the Cladoceran Web Site at the University of Guelph). We are also investigating the evolutionary genetics of the interaction between the mussels Mytilus edulis, M. trossulus and their hybrids in Newfoundland (in collaboration with Dr. Ray Thompson, Ocean Sciences Centre). Collaborative research has been carried out with Dr. Luise Hermanutz (Biology, MUN) on population and reproductive ecology of moss campion (Silene acaulis) and bog bean (Menyanthes trifoliata) in Newfoundland, and the reproductive ecology of Grevillea spp. in NSW Australia. Research on the population structure and mating systems in Newfoundland spiders has been conducted with Dr. Roger Pickavance.

A brief summary of current and past research:

Evolutionary interaction between sexual and asexual Daphnia pulex

Daphnia pulex occurs as two forms, cyclical parthenogens with sexual reproduction and obligate parthenogens with no sexual reproduction. Both forms co-occur in southern Ontario but are rarely found in the same pond. We have been determining sex allocation variation in the cyclical parthenogens and the avoidance of the cost of males in the obligate parthenogens. Some obligate parthenogen clones can produce males that can mate with sexual females from the cyclical parthenonogens and generate new obligately parthenogenetic clones. Current experiments are using microsatellite genetic markers to examine competition among males for mating with sexual females and determine the evolutionary dynamics of the formation of new obligately parthenogenetic clones.

Ecology and genetics of Mytilus spp. in Newfoundland

Two species of mussel (Mytilus edulis, M. trossulus) coexist along the coast of the island of Newfoundland. Limited hybridization occurs between the species which may be due to incompatibility between nuclear and cytoplasmic genes. In addition, we are investigating the role gamete choice may play in limiting hybridization.

For additional information see: 



Genetic structure of moss campion (Silene acaulis)

Silene acaulis occurs as disjunct populations on the island of Newfoundland. Genetic differentiation appears to be high and the pattern is not related to geographic distance separating the populations. Genetic differences between  populations on the east and west side of the island may be the result of different colonization patterns following post glaciation combined with random drift and limited gene flow.


Reproductive ecology of Australian Grevillea spp.

Members of the family Proteaceae have extremely low mature fruit : flower (FR : FL) ratios compared with other temperate, hermaphroditic, woody perennials. The role of compatibility in regulating FR : FL ratios was tested in five closely related species of Grevillea (Proteaceae).  The correlation between self incompatibility and FR : FL ratios was non-significant, indicating that compatibility has a minimal effect on fruit set in the Grevillea species studied. Low FR : FL ratios may result from a combination of pollen limitation, and high levels of flower and fruit predation.

Reproductive ecology of Menyanthes trifoliata in Newfoundland
Menyanthes trifoliata is a distylous, clonal aquatic macrophyte found in shallowbogs and river margins throughout the boreal ecosystem, including the island of Newfoundland. A combination of long-distance dispersal and colonization after deglaciation, and pollen limitation resulting from reduced pollinator diversity and abundance documented on islands, predicts the breakdown of heterostyly to favour the establishment of self-compatible homostyles on islands. A strictly reciprocal arrangement of stigma height and anther length was not observed between pin and thrum morphs in the majority of populations studied. A reduced pollinator fauna typical of island environments may have relaxed stabilizing selection for strict herkogamy between floral morphs, resulting in the observed lack of reciprocity. 

Genetic structure and mating behaviour in some Newfoundland spiders Three species of native ground running spiders were compared with an introduced orb weaving species for genetic differentiation over short and long geographic distances. All species showed little evidence for genetic differentiation. It is unlikely that gene flow is high in these species and it is possible that large population size reduces the effect of genetic drift on population differentiation. Studies are also examining the mating behaviour in the orb weaver Araneus diadematus to determine if multiple mating occurs. Preliminary data suggest that if multiple mating occurs it is at a low level.

Photo Credits: Daphnia pulex (D. Innes); Mussel shell (D. Innes); Moss Campion(L. Hermanutz); Grevillea (Plant Systematics); Menyanthes (T. Schoepke); Spider (Spider Web Page)


Biology 2900    Principles of Evolution and Systematics

Biology 4250    Evolutionary Genetics

Biology 7290    Evolutionary Ecology


Graduate Students

  • Shin Kim (Ph.D. in progress) Genetic structure and population connectivity of a mussel hybrid zone
  • Kan Miao (M. Sc. in progress) Genetic structure of sexual and asexual Daphnia pulex
  • Guangxu Liu (Ph.D. 2009)  Genetic barriers to introgression in a mussel hybrid zone
  • Ben Lowen (Ph. D. in 2008)   Life history variation in a mussel hybrid zone
  • Marcelo Miranda (Ph.D. 2005)  Genetics of hybridization in a mussel hybrid zone
  • Jay Fitzsimmons (M. Sc. 2006) Sex and evolution in  Daphnia pulex
  • Jorge Toro (Ph.D. 1999) Natural hybridization in mussels
  • Barbara Saunders (M. Sc. 1998) Inheritance and linkage of RAPD markers in Daphnia
  • Jennifer Bates (M. Sc. 1991) Morphological and genetical variation of Mytilus edulis in Newfoundland

Undergraduate Thesis Students

  • Erin Stapleton 2006 Interactions between Mytilus edulis and M. trossulus spat
  • Michael Ginn 2005 Competition between cyclically and obligately parthenogenetic Daphnia pulex
  • Dax Rumsey 2002 Male production in the obligately parthenogeneic Cladoceran Daphnia pulex
  • Trina Kirby 2002  Mating system in the spider Araneus diadematus
  • Kerri Anstey  1999 Genetic variability and gene flow in five species of spiders found in Newfoundland (Pardosa hyperborea, Pardos moesta, Pardosa groenlandica, Cyclosa conica, & Araneus diadematus) determined using allozyme electrophoresis
  • Chris Fox  1998 Differences in ephippial production between obligate and cyclical parthenogenetic clones of Daphnia pulex
  • Geoff Winsor 1997 Sexual reproduction in Daphnia pulex: Observations on mating behaviour and avoidance of intra-clonal mating
  • Barbara Saunders 1995 RAPD genetic variation among populations of Daphnia pulex


On Daphnia:

Innes, D. J. and M. Ginn (2014) A population of sexual Daphnia pulex resists invasion by asexual clones. Proc. R. Soc. B. 2014 281.

Xu, S., Innes, D. J., Lynch, M., Cristescu, M. E. (2013) The role of hybridization in the origin and spread of asexuality in Daphnia. Molecular Ecology 22: 4549 - 4561.

Crease T.J., Floyd R., Cristescu M.E., Innes D.J. (2011) Evolutionary factors affecting Lactate dehydrogenase A and B variation in the Daphnia pulex species complex. BMC Evolutionary Biology 11:212

Cristescu M.E., Innes D.J., Stillman J.H., Crease T.J. (2008) D- and L-lactate dehydrogenases during invertebrate evolution. BMC Evolutionary Biology, 8: 268.

Fitzsimmons, J. M. and Innes, D. J. (2006) Inter-genotype variation in reproductive response to crowding among Daphnia pulex. Hydrobiologia 568: 187-205 (download PDF file)

Tagg, N., Doncaster, C.P. and Innes, D. J. (2005) Outcomes of reciprocal invasions between genetically diverse and genetically uniform populations of Daphnia obtusa (Kurz). Oecologia 143: 527-536(download PDF file)

Fitzsimmons, J. M. and Innes, D. J. (2005) No evidence of Wolbachia among Great Lakes area populations of Daphnia pulex (Crustacea: Cladocera). Journal of Plankton Research 27: 121-124  (download PDF file)

Tagg, N., Doncaster, C. P. and Innes, D. J. (2005) Resource competition between genetically varied and genetically uniform populations of Daphnia pulex (Leydig): does sexual reproduction confer a short-term ecological advantage? Biol. J. Linn. Soc. 85: 111-123 (download PDF file)

Winsor, G. L. and Innes, D. J. (2002) Sexual reproduction in Daphnia pulex (Crustacea: Cladocera): Observations on male mating behaviour and avoidance of inbreeding. Freshwater Biology 47: 441-450(download PDF file)

Innes, D. J. and Singleton, D. R. (2000) Variation in allocation to sexual and asexual reproduction among clones of cyclically parthenogenetic Daphnia pulex (Crustacea: Cladocera). Biol. J. Linn. Soc. 71(4): 771-787   (download PDF file)

Innes, D. J., Fox, C. J. and Winsor, G. L. (2000) Avoiding the cost of males in obligately asexual Daphnia pulex (Leydig). Proc. Roy. Soc. B 267: 991-997   (download PDF file)

Innes, D. J. (1997) Sexual reproduction of Daphnia pulex in a temporary habitat. Oecologia 111: 53-60. (download PDF file)

Innes, D. J. and Singleton, D. R.  (1994)  Variation in reproduction and sex allocation among clones of Daphnia pulex, In Genetics and Evolution of Aquatic Organisms (ed. A. R. Beaumont),  pp. 335-342. London: Chapman and Hall.

Innes, D. J. and Dunbrack, R. L. (1993) Sex allocation variation in Daphnia pulex. J. evol. Biol. 6: 559-575.

Innes, D. J. (1991) Geographic patterns of genetic differentiation among sexual populations of Daphnia pulex. Can. J. Zool. 69: 995-1003.

Innes, D. J. (1989) Genetics of Daphnia obtusa: Genetic load and linkage analysis in a cyclical parthenogen. Journal of Heredity 80: 6-10.

Innes, D. J. and P. D. N. Hebert. (1988) The origin and genetic basis of obligate parthenogenesis in Daphnia pulex. Evolution 42: 1024-1035.

Innes, D. J., S. S. Schwartz and P. D. N. Hebert 1986. Genotypic diversity and variation in mode of reproduction among populations in the Daphnia pulex group. Heredity 57: 345-355.

Schwartz, S. S., D. J. Innes and P. D. N. Hebert (1985) Morphological separation of Daphnia pulex and Daphnia obtusa in North America. Limnology Oceanography 30: 189-197.

On Bivalves:

Lowen, J.B., Innes, D. J., Thompson, R. J. (2013) Predator-induced defenses differ between sympatric Mytilus edulis and M. trossulus. Marine Ecology Progress Series, 475:135-143. (download PDF file)

Liu G.X., Stapleton E., Innes D.J., Thompson, R.J. (2011) Aggregational behavior of the blue mussels Mytilus edulis and Mytilus trossulus: a potential pre-zygotic reproductive isolation mechanism. Marine Ecology 32: 480-487.

Liu G.X., Innes D.J., Thompson R.J. (2011) Quantitative analysis of sperm plane circular movement in the blue mussels Mytilus edulis, M. trossulus and their hybrids. Journal of Experimental Zoology PART A- Ecological Genetics and Physiology, 315A (5): 280-290.

Miranda M.B.B., Innes D.J., Thompson R.J. (2010) Incomplete reproductive isolation in the blue mussel (Mytilus edulis and M. trossulus) hybrid zone in the Northwest Atlantic: Role of gamete interactions and larval viability. Biological Bulletin, 218: 266-281.


Toro, J. E., R. J. Thompson and D. J. Innes (2006) Fertilization success and early survival in pure and hybrid larvae of Mytilus edulis (Linnaeus, 1758) and M. trossulus (Gould, 1850) from laboratory crosses. Aquaculture Research 37: 1703-1708

Toro, J. E., D. J. Innes and R. J. Thompson (2004) Genetic variation among life-history stages of mussels in a Mytilus edulis - M. trossulus hybrid zone. Marine Biology 145: 713-725. (download PDF file)

Toro, J. E., R. J. Thompson and D. J. Innes (2002) Reproductive isolation between coexisting mussel species (Mytilus edulis, M. trossulus) in Newfoundland. Marine Biology 141: 897 - 909. (download PDF file)

Comesana, A. S., Toro, J. E., Innes, D. J. and Thompson, R. J. (1999) A molecular approach to the ecology of a mussel (Mytilus edulis - M. trossulus) hybrid zone on the east coast of Newfoundland, Canada. Marine Biology 133: 213-221.   (download PDF file)

Innes, D. J. and Bates, J. A. (1999) Morphological variation of Mytilus edulis and Mytilus trossulus in eastern Newfoundland. Marine Biology 133: 691-699.   (download PDF file)

Jones, R., Bates, J. A., Innes, D. J. and Thompson, R. J. (1996) A quantitative genetic analysis of growth  in larval scallops (Placopecten magellanicus). Marine Biology 124: 417-424.

Bates, J. A. and Innes, D. J. (1995) Genetic variation among populations of Mytilus spp. in eastern Newfoundland. Marine Biology 124: 417-424.

Muncaster, B. W., D. J. Innes, P. D. N. Hebert and G. D. Haffner (1989) Patterns of organic contaminant accumulation by freshwater mussels in the St. Clair River, Ontario. J. Great Lakes. Res. 15: 645-653.

Koehn, R. K., J. G. Hall, D. J. Innes and A. J. Zera (1984) Genetic differentiation of Mytilus edulis in eastern North America. Mar. Biol. 79: 117-126.

Innes, D. J. and L. E. Haley (1977)a. Inheritance of a shell color polymorphism in the mussel. J. of Heredity 68: 203-204.

Innes, D. J. and L. E. Haley (1977)b. Genetic aspects of larval growth under reduced salinity in Mytilus edulis. Biol. Bull. 153: 312-321.

On plant mating systems and population genetics:

Thompson, F. L., Hermanutz, L. A. and Innes, D. J. (1999) The reproductive ecology of island populations of distylous Menyanthes trifoliata (menyanthaceae). Can. J. Bot. 76: 818-828. (download PDF file)

Hermanutz, L. A., Innes, D. J., Denham, A. and Whelan, R. (1998) Very low fruit: flower ratios in Grevillea (Proteaceae) are independent of breeding system. Australian J. of Botany 46: 465-478. (download PDF file)

Rajora, O. P., Deverno, L., Mosseler, A. and Innes, D. J. (1998) Genetic diversity and population structure of disjunct Newfoundland and central Ontario populations of eastern white pine (Pinus strobus). Can. J. Bot. 76: 500-508. (download PDF file)

Hermanutz, L. A. and Innes, D. J. (1994) Gender variation in Silene acaulis (Caryophyllaceae). Plant Sytematics and Evolution 191: 69-81.

Mosseler, A., D. J. Innes and B. A. Roberts. (1991) Lack of allozymic variation in disjunct Newfoundland populations of red pine (Pinus resinosa). Can. J. For. Res. 21: 525-528.

Innes, D. J. (1990) Microgeographic genetic structure in the haploid and diploid stages of the moss Polytrichum juniperinum Hedw. Heredity 64: 331-340.

Innes, D. J. and G. S. Ringius (1990) Mating system and genetic structure of two populations of white spruce (Picea glauca) in eastern Newfoundland. Can. J. Bot. 68: 1661-1666.

Ringius, G. S. and D. J. Innes. (1990) Large disparity in recombination fractions reported in Picea mariana for the Aat-1/Pgi-2 linkage group. Can. J. Bot. 68: 518-520.

Hermanutz, L. A., D. J. Innes and I. M. Weis. (1989) Clonal structure of dwarf birch, Betula glandulosa, at its northern limit. Amer. J. Bot. 76: 755-761.

Innes, D. J. and L. A. Hermanutz (1988) Mating system and genetic structure in a disjunct population of the seaside goldenrod, Solidago sempervirens. Heredity 61: 447-454.

Innes, D. J. (1988) Genetic differentiation in the intertidal zone for the alga Enteromorpha linza (Ulvales, Chlorophyta). Mar. Bio. 97: 9-16.

Innes, D. J. (1987) The genetic structure of asexually reproducing Enteromorph linza (Ulvales, Chlorophyta) in Long Island Sound. Marine Biology 94: 459-467.

Innes, D. J. (1984) Genetic differentiation among populations of marine algae. Helgolander Meersuntersuchungen 38: 401-417.

Innes, D. J. and C. Yarish (1984) Genetic evidence for the occurrence of asexual reproduction in populations of Enteromorpha linza (L.)J. Ag. (Chlorophyta, Ulvales) from Long Island sound. Phycologia 23: 311-320.

Other publications:

Zera, A. J., D. J. Innes and M. E. Saks (1983) Genetic and environmental determinants of wing polymorphisms in the waterstrider Limnoporus canaliculatus. Evolution 37: 513-522.

Smith, G. R., J. G. Hall, R. K. Koehn and D. J. Innes (1983) Taxonomic relationships of the Zuni mountain sucker, Catostomus discobolus yarrowi. Copeia 1983: 37-48.