Distribution, Habitat, and Life History Aspects of the Dwarf Crayfishes of the Genus Cambarellus (Decapoda: Cambaridae) in Arkansas

The dwarf crayfishes of the genus Cambarellus are represented in Arkansas by only 2 species: Cambarellus (Pandicambarus) puer (Hobbs) and C. (P.) shufeldtii (Faxon). Both species are quite small and uncommonly encountered in the state. Between 1972 and 2018, we made 368 crayfish collections throughout the 75 counties of Arkansas. A total of 34 collections (our collections, plus museum specimens), and those previously collected by Reimer (1963) yielded a total of 304 specimens of C. puer and 12 collections of C. shufeldtii returned 54 specimens of C. shufeldtiii. Herein, we document these 2 dwarf crayfishes from primarily the Coastal Plain and Mississippi Alluvial Plain physiographic provinces of Arkansas. Cambarellus puer is documented from 24 counties whereas C. shufeldtii was recorded from only 12 counties. With regard to conservation status, both C. puer and C. shufeldtii should be considered as “Currently Stable” due to their widespread distribution and general abundance in Arkansas

Landform identification: Lunar radar images

Three sets of polarized radar-echo images of the Moon were examined to establish the relation between radar resolution and landform-identification resolution. After comparison with lunar maps and photographs, real and apparent landforms on the radar images were grouped into one of seven classes. Results show strong relations between radar resolution and diameter or relief of landforms that are clearly identified and those that would probably be correctly identified (class 1 and class 2). Landforms are not detected (class 5) at all diameters and reliefs, but the percentage of undetected landforms decreases with increasing mean diameter and mean relief. Landforms are simply detected (class 4) at most mean diameters and reliefs. Ambiguous arrays (class 6) portrayed by the radar constitute up to about 16, 22, and 15% of the landforms at various diameters and relief values for the 3.8 cm, 70 cm high resolution, and 70 cm low resolution images, respectively. Only a few percent of the landforms portrayed by the radar images at various diameters and relief values are fictitious (class 7)

Distribution, Habitat, and Life History Aspects of the Shrimp Crayfish, Faxonius lancifer (Hagen) (Decapoda: Cambaridae) in Arkansas

The Shrimp Crayfish, Faxonius (formerly Orconectes) lancifer (Hagen) is an uncommon, although widespread, crayfish in Arkansas. This species is herein documented from 19 counties of the Gulf Coastal Plain physiographic region. Between 1974 and 2017, we made 344 collections throughout the 75 counties of Arkansas, of which 22 (6%) yielded 163 specimens of F. lancifer. Thus, from these collections, plus 10 unpublished collections of Reimer (1963), and one collection from G.L. Harp, a total of 34 collections of F. lancifer are now known from the state. Faxonius lancifer ranged from uncommon (1 specimen) to locally abundant (39 specimens) at these collecting localities. With regard to conservation status, F. lancifer should be considered as Currently Stable due to its widespread distribution and general abundance in Arkansas

Additional Records of Acanthocephalan Parasites from Arkansas Fishes, with New Records from Missouri Fishes

Over the last decade, our research consortium has provided information on acanthocephalan parasites of Arkansas vertebrates, including records from some of the state’s fishes. Here, we continue to provide data on new geographic and new host records of acanthocephalans from Arkansas fishes. In addition, for the first time, we report records of acanthocephalans for some Missouri fishes. We document 2 new state records as well as 10 new host records for some fish acanthocephalans

An Annotated Checklist of the Crayfishes (Decapoda: Cambaridae) of Arkansas

Prior to the present study, 56 species with 3 additional subspecies for a total of 59 different taxa of crayfishes were recognized from Arkansas. We add a single species (Carmel Crayfish, Fallicambarus schusteri) to that list, subtract a documented synonym (Procambarus ferrugenius = Procambarus liberorum), update the classification to better reflect recent phylogenetic insights, and provide an updated annotated checklist of the 59 crayfish taxa of presently known from the state. There are 8 endemic species in Arkansas, including the Bayou Bodcau Crayfish (Bouchardina robisoni), Boston Mountains Crayfish (Cambarus causeyi), Hell Creek Cave Crayfish (C. zophonastes), Jefferson County Crayfish (Creaserinus gilpini), Ouachita Burrowing Crayfish (Fallicambarus harpi), Slenderwrist Burrowing Crayfish (F. petilicarpus), Saline Burrowing Crayfish (F. strawni), and Redspotted Stream Crayfish (Faxonius acares). There are also 2 federally endangered species, the Benton County Cave Crayfish (Cambarus aculabrum) and the Hell Creek Cave Crayfish (C. zophonastes) that inhabit Arkansas karst habitat. We expect that additional species will be included in the list with further DNA analyses

The milliped genus Euryurus Koch, 1847 (Polydesmida: Euryuridae) west of the Mississippi River; occurrence of E. leachii (Gray, 1832) on Crowley’s Ridge, Arkansas

The milliped genus Euryurus Koch, 1847, and the species, E. leachii (Gray, 1832) (Polydesmida: Euryuridae), are recorded from three sites on the northern part of Crowley’s Ridge (Cross, Lee, and Poinsett counties), Arkansas, where the only prior familial records are of Auturus evides (Bollman, 1887). Coupled with the published locality of E. leachii in Phillips Co., at the southern extremity of the Ridge, the only known occurrences of both the genus and species in Arkansas and west of the Mississippi River are in this physiographic feature. The Arkansas population is geographically peripheral but anatomically intermediate between the two recognized subspecies, E. l. leachii and E. l. fraternus Hoffman, 1978, and we do not assign it to a race. Molecular investigations seem necessary to resolve relationships in the “E. leachii complex.