Zuckerman, Laurence, D. 1980. Life history regulation in populations of white sucker (Osteichthyes catostomidae) as determined by resource availability. M.S. Thesis, SUNY-ESF, Syracuse, 107 pp.

Abstract: From May to September 1977, populations of white suckers (Catostomus commersoni (Lacepede), were examined in two Adirondack lakes differing in available resources. Wolf Lake, an oligotrophic, dimictic lake and Deer Lake, a monomictic lake were compared. Deer lake appears to have abundant food available for suckers. In Deer Lake and its spawning stream, suckers are subject to a wide range of environmental conditions due to fluctuations in air temperature and runoff. Wolf Lake provides a more constant environment due to its deep basin and its well-shaded inlets.

Age distributions, lifespan and rates of somatic growth, maturation and mortality were compared for the two lake populations. Ages were estimated with pectoral fin sections of 229 fish from Wolf Lake and 67 fish from Deer Lake. Age-frequency distributions were statistically tested for differences between sexes and populations. Differential rates of mortality, growth and maturation, along with reproduction and feeding data, were used in the description of life history strategies.

Suckers from both lakes mature earlier and at a smaller size than most previously studied populations. The slow-growing, late-maturing, long-lived Wolf Lake suckers appeared greatly influenced by resource limitations (low density of benthic prey). The Deer lake population, characterized by early maturity, short lifespan and rapid growth, was apparently affected by thermal unpredictability. Similar patterns of life history regulation might occur with fish stressed by acid rains, thermal effluents, overgrazing of riparian habitat or heavy metal pollution. Supportive evidence is presented for ecological segregation by male and female white suckers from Wolf Lake.