Friday, July 26, 2019

[Crustacea • 2019] Faxonius bellator Systematics and Description of A New Species of Faxonius Ortmann, 1905 (Decapoda: Astacidea: Cambaridae) from the Red River System of Kentucky and Tennessee


Faxonius bellator 
Bloom, McCall, Schuster & Blanton, 2019

Screaming Eagle Crayfish  || DOI: 10.1093/jcbiol/ruy100 

Abstract
Faxonius barrenensis (Rhoades, 1944) is endemic to the Green River system of Kentucky and Tennessee, USA and closely related to Faxonius mirus (Ortmann, 1931), which is restricted to Tennessee River tributaries in Tennessee and Alabama. A crayfish with morphological affinities to these species (Faxonius sp.) occurs in the Red River system (Cumberland River Drainage) of Kentucky and Tennessee. Whether the latter represents a disjunct population of F. barrenensis, F. mirus, or a distinct species, has not been tested. Whether the shared morphological traits reflect shared ancestry or convergence is unknown. We used molecular and morphological data, including two mitochondrial (COI and 16S) and two nuclear (28S and GAPDH) genes and a standard suite of phenotypic measurements to examine the phylogenetic relationships and the taxonomic status of Faxonius sp., relative to F. barrenensis, F. mirus, and other species of Faxonius Ortmann, 1905. All gene datasets recovered focal taxa as a clade, implying their morphological similarities likely reflect shared ancestry. In all mitochondrial and combined gene trees, Faxonius sp. was recovered as genetically divergent from F. barrenensis and F. mirus. Faxonius sp. is phenotypically distinguished from F. barrenensis and F. mirus based on several characteristics including shorter rostrum, longer abdomen, wider areola, and straight margins on both mandibles (toothed in F. mirus; toothed and straight in F. barrenensis); Form I males have a strong angular shoulder on the gonopod, in comparison to F. barrenensis. Given these findings, we describe Faxonius sp. as Faxonius bellator n. sp. Faxonius bellatorn. sp. has been collected at only four localities, suggesting it has a small range and warrants conservation concern.

SYSTEMATICS

Family Cambaridae Hobbs, 1942

Genus Faxonius Ortmann, 1905

Dorsal view of Form I male Faxonius bellator n. sp.
Photograph by C. Williams. 

Faxonius bellator n. sp.

Etymology: The specific epithet, bellator, is Latin for “soldier,” reflecting the new species being primarily found on Fort Campbell US Army Base.

Common name: Screaming Eagle Crayfish, named after the special designation presented to the 101st Airborne Division, whose headquarters are located at Fort Campbell US Army Base.


Erin T. Bloom, Brittany L. McCall, Guenter A. Schuster and Rebecca E. Blanton. 2019. Systematics and Description of A New Species of Faxonius Ortmann, 1905 (Decapoda: Astacidea: Cambaridae) from the Red River System of Kentucky and Tennessee, USA. Journal of Crustacean Biology. 39(1); 40–53. DOI: 10.1093/jcbiol/ruy100

Austin Peay-led research team names new crayfish species for 101st Airborne APSU.edu/news/march-2019-austin-peay-screaming-eagle-crayfish.php