Life history of the endemic saddleback crayfish, Faxonius medius (Faxon, 1884), (Decapoda: Cambaridae) in Missouri, USA

Freshwater Crayfish
By: , and 

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Abstract

The saddleback crayfish, Faxonius medius (Faxon, 1884), is endemic to a single drainage in eastern Missouri, USA, that is affected by heavy metals mining, and adjacent to a rapidly-expanding urban area. We studied populations of F. medius in two small streams for 18 months to describe the annual reproductive cycle and gather information about fecundity, sex ratio, size at maturity, and size-class structure. We also obtained information about the species’ density at supplemental sites. The species, though rare in a geographic context, is locally abundant; we captured a monthly average of more than 75 F. medius from each of the two study populations. Densities of F. medius were high relative to several sympatric species of Faxonius Cope, 1872 and Cambarus Erichson, 1846. The species exhibited traits of an r-strategist life history; it was relatively short-lived and early to maturity. Its fecundity and egg size were comparable to Ozark congeners. Breeding season occurred in autumn, perhaps extending into early winter. Egg brooding occurred primarily in April. Young of year first appeared in samples in June. We estimated that these populations contained 2 to 3 size-classes, and most individuals became sexually mature in their first year of life. Life history information presented herein will be important for future conservation efforts.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Life history of the endemic saddleback crayfish, Faxonius medius (Faxon, 1884), (Decapoda: Cambaridae) in Missouri, USA
Series title Freshwater Crayfish
DOI 10.5869/fc.2019.v24-1.1
Volume 24
Issue 1
Year Published 2019
Language English
Publisher International association of Astacology
Contributing office(s) Coop Res Unit Atlanta
Description 13 p.
First page 1
Last page 13
Country United States
State Missouri