Otolith Age Analysis Reveals Lifespans Greater Than 50 Years for the Three Species of Carpsucker (Carpiodes spp.) in Wisconsin

The carpsuckers (Carpiodes spp.) are a little-studied genus of three medium-sized (0.5–3 kg at maturity) freshwater fishes within Catostomidae. These three species are widespread and common in some larger rivers in central North America, as well as some larger lakes and reservoirs. The lapillus otoliths of 189 carpsuckers (117 quillbacks [Carpiodes cyprinus], 44 highfin carpsuckers [Carpiodes velifer], 23 river carpsuckers [Carpiodes carpio] and 5 intergrades) were aged, all collected from the same Lower Wisconsin River community in 2023 and 2024 during Wisconsin Department of Natural Resources fish surveys. Age scores were precise among readers (mean coefficient of variation = 4.7%). Growth in size of each species was best modelled by von Bertalanffy growth functions accounting for sexual dimorphism, and the first comparative assessment of all three species’ growth profiles was provided. These results showed that each species exhibited highly variable recruitment across time, with most individuals from year classes produced in 2005 or earlier. Maximum ages greater than 50 years for each of the three species were observed: highfin carpsucker (56 years), quillback (51 years) and river carpsucker (56 years), as well as a maximum age of 44 years among the small sample of intergrades, making Carpiodes the second genus of freshwater fish for which three or more species have been shown to live more than 50 years. A maximum age of 56 years for the highfin carpsucker is more than six times greater than previously reported and, based on available knowledge, represents the longest lived, smallest bodied (L_∞ < 40 cm total length [TL]) freshwater fish by more than 25 years. Carpsuckers are long-lived periodic strategists living in increasingly human-altered ecosystems, as is the case for many catostomids.