Bigmouth Buffalo Ictiobus cyprinellus sets freshwater teleost record as improved age analysis reveals centenarian longevity

Alec R Lackmann,Malcolm G Butler,Mark E Clark,Allen H Andrews,Ewelina S Bielak-Lackmann

doi:10.1038/s42003-019-0452-0

Alec R Lackmann, Malcolm G Butler + Show 3 more

Open Access

https://doi.org/10.1038/s42003-019-0452-0

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Abstract

Understanding the age structure and population dynamics of harvested species is crucial for sustainability, especially in fisheries. The Bigmouth Buffalo (Ictiobus cyprinellus) is a fish endemic to the Mississippi and Hudson Bay drainages. A valued food-fish for centuries, they are now a prized sportfish as night bowfishing has become a million-dollar industry in the past decade. All harvest is virtually unregulated and unstudied, and Bigmouth Buffalo are declining while little is known about their biology. Using thin-sectioned otoliths and bomb-radiocarbon dating, we find Bigmouth Buffalo can reach 112 years of age, more than quadrupling previous longevity estimates, making this the oldest known freshwater teleost (~12,000 species). We document numerous populations that are comprised largely (85–90%) of individuals over 80 years old, suggesting long-term recruitment failure since dam construction in the 1930s. Our findings indicate Bigmouth Buffalo require urgent attention, while other understudied fishes may be threatened by similar ecological neglect.

Highlights

Understanding the age structure and population dynamics of harvested species is crucial for sustainability, especially in fisheries
Evidence from thin-sectioned otoliths and bomb 14C dating revealed that Bigmouth Buffalo can live to 112 years, older than all other reports of maximum age for freshwater teleost fishes by nearly 40 years
The oldest age estimates were from otoliths of Freshwater Drum (Aplodinotus grunniens) obtained from archeological sites[34] and cold-adapted Arctic Lake Trout (Salvelinus namaycush; maximum age of 62 years)[35]

Summary

Introduction

Understanding the age structure and population dynamics of harvested species is crucial for sustainability, especially in fisheries. Bigmouth Buffalo have become increasingly misunderstood over the past century as they became commonly categorized as a “rough fish.” This imprecise term is used in much of the USA to lump many endemic, traditionally nongame fishes, along with unwanted invasive fishes, for purposes of harvest regulation[14]. This pejorative designation has led to the misconception by the general public of Bigmouth Buffalo as an “invasive species” or “a carp,” encouraging its persecution as a sacrificial or unimportant species.

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