Nerodia rhombifera

Number of Pages: 4Integrative BiologyGeological Science

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

The Fishes of Chadron Creek, Dawes County, Nebraska

This first modern comprehensive survey of fishes collected from Chadron Creek, Dawes County, Nebraska, documents collections made with a small seine and backpack electrofisher during November 2007 and February and March 2008. Chadron Creek’s fish community is of low diversity. The total of 3 collections at each of 9 stations along the length of Chadron Creek resulted in 254 individual fishes, which represented only 7 species within 4 families. Water quality parameters, including dissolved oxygen, pH, conductivity, total dissolved solids, temperature and fecal coliform counts indicate that Chadron Creek is a healthy stream capable of supporting a greater diversity of fishes. Land management practices may be responsible for elevated fecal coliform levels at one locality on the creek. Comparisons of fishes collected herein are made with historical records of fish collected between 1893 and 2000, and show that there are 50% fewer species present than those known from historical accounts

Nerodia valida

Number of Pages: 3Integrative BiologyGeological Science

Cnemidophorus sexlineatus

Number of Pages: 12Integrative BiologyGeological Science

Hematology as Related to Diving Characteristics of Elaphe obsoleta, Nerodia erythrogaster, Nerodia Fasciata and Nerodia rhombifera

The diving capabilities of Nerodia erythrogaster flavigaster and Nerodia fasciata confluens were investigated and the results were compared with similar studies on Nerodia rhombifera rhombifera and Elaphe obsoleta obsoleta (Baeyens et al., 1978). In addition, morphological and hematological parameters contributing to underwater survival were examined. The duration of underwater survival for N. erythrogaster and N. fasciata was approximately one hour with no difference between the species. The lung volumes of the two species were also similar but were significantly less than lung volumes reported for E. obsoleta. There were no significant differences in hemoglobin concentration, red blood cell count or hematocrit between N. rhombifera, N. erythrogaster, N. fasciata, and E. obsoleta. Based on similarities in underwater tolerance, lung morphology and hematology, Nerodia more closely resembles the terrestrial E. obsoleta than those reptiles specifically adapted to an underwater existance