Conservation Assessment and Habitat Notes for Three Rare Alabama Crayfishes: Cambarus cracens, Cambarus scotti, and Cambarus unestami

Over seventy percent of the world\u27s freshwater crayfish species are found within the United States, and much of this diversity is concentrated in the southeastern United States. Yet many of these species remain understudied. Of particular interest is the conservation status of these understudied taxa. We conducted fieldwork in 2011 across northeastern Alabama and northwestern Georgia to review the occurrence, habitat, and in sonic cases, local population densities of three crayfish species (Cambarus scotti, C. unestami, and C. cracens) to determine current distributions in relation to historical surveys. All three species occur in flowing small to medium-sized streams with firm substrates of gravel, cobble, and bedrock. Two species (C. scotti and C. unestami) have stable populations, occurring at 79% and 90% of sites surveyed, respectively. In contrast, surveys for the third crayfish species (C. cracens) indicated a need for conservation action, with this species occurring at a single site

Status Survey for three rare Alabama crayfishes, Cambarus cracens, Cambarus scotti, and Cambarus unestami

The Slender Claw crayfish, Cambarus cracens, the Chattooga River Crayfish, C. scotti, andthe Blackbarred Crayfish,C. unestamieach have limited ranges confined to northeastern Alabama and northwestern Georgia. As such they are vulnerable to population declines due to single catastrophic events and are listed as either Endangered (C. cracens) or Threatened (C. scotti and C. unestami) according to American Fisheries Society criteria (Taylor et al. 2007). Following conservation priority criteria developed by the Alabama Department of Conservation and Natural Resources, C. cracenswas classified as a P1 (Highest Conservation Priority) species, C. scotti was classified as a P4 (Low Conservation Priority), and C. unestamiwas classified as a P2 (High Conservation Priority) by Smith et al. (2011). These three species were chosen based upon their need for range-wide status assessments and limited detection rates in past surveys. The current status survey was conducted to determine true distribution and population statuses of C. cracens, C. scotti andC. unestamiand had four main goals: 1) visit all known historical locations for all three species and sample using traditional methods to determine the presence of each species; 2) attempt to find additional populations of the species by sampling other streams with suitable habitat in northeastern Alabama and northwestern Georgia; 3) assess population sizes of the species at locations where appropriate quantitative methods can be employed; 4) determine preferred habitat for the three species by recording abiotic habitat variables at sites containing the species.U.S. Fish & Wildlife Serviceunpublishednot peer reviewe

Data from: The effects of age, sex, and habitat on body size and shape of the blackstripe topminnow, Fundulus notatus

Lake and stream habitats pose a variety of challenges to fishes due to differences in variables such as water velocity, habitat structure, prey community, and predator community. These differences can cause divergent selection on body size and/or shape. Here, we measured sex, age, length, and eight different morphological traits of the blackstripe topminnow, Fundulus notatus, from 19 lake and stream populations across four river drainages in central Illinois. Our goal was to determine whether size and shape differed consistently between lake and stream habitats across drainages. We also considered the effects of age and sex as they may affect size and morphology. We found large differences in body size of age 1 topminnows where stream fish were generally larger than lake fish. Body shape mainly varied as a function of sex. Adult male topminnows had larger morphological traits (with the exception of body width) than females, in particular longer dorsal and anal base lengths. Subtle effects of habitat were present. Stream fish had a longer dorsal fin base than lake fish. These phenotypic patterns may be the result of genetic and/or environmental variation. As these lakes are human-made, the observed differences, if genetic, would have had to occur relatively rapidly (within about 100 years)

Fundulus notatus raw data

Excel file containing the raw data (morphometric measurements as well as data on population, drainage, habitat, age, and sex)