Contributed by Doug Carlson and Carl St. John, Posted 3/18/25: Summer Sucker, formerly Catostomus utawana, has been proposed to be reclassified from being its own species to being an ecotype of the White Sucker (C. commersonii). This has been based on studies by researchers from Cornell University from 2000-2024 and supported by field work within the New York State Department of Environmental Conservation (NYSDEC). The complexities of this sucker’s separation, primarily the subtle nature of the diagnostic traits, has resulted in them having been reclassified between species and subspecies 6 times since Summer Sucker’s description in 1886. The prevailing differences are the later-spawning time of June-July and the smaller body size at maturity, and these can overlap with White Suckers. This was concluded by life history studies and whole genome analyses by Carl St. John in his PhD dissertation with his professor, Peter McIntyre. The relationship between the two suckers is so complex as to have come from independent evolutionary events converging on the same life history variant in multiple lakes in the Adirondacks. The Summer Sucker ecotype is not found elsewhere in White Sucker’s range in North America, or it is endemic. Despite no longer meeting NYSDEC’s criteria for a species, NYSDEC biologists find its unique and heritable traits worth protecting. They are currently evaluating potential conservation measures that do not rely on species status. As such, the ecotype will be retained as a Species of Greatest Conservation Need within NYSDEC’s updated version of the State Wildlife Action Plan. More details are available from Cornell or from NYSDEC (in April).

Summer Suckers from Squaw Lake by Eric Maxwell, Univ. Alabama Huntsville