G. O. Graening

Coprophagy in a cave-adapted salamander; the importance of bat guano examined through nutritional and stable isotope analyses

During a two year population ecology study in a cave environment, 15 Eurycea (=Typhlotriton) spelaea were observed ingesting bat guano. Furthermore, E. spelaea capture numbers increased significantly during the time that grey bats (Myotis grisescens) deposited fresh guano. We investigated the hypothesis that this behaviour was not incidental to the capture of invertebrate prey, but a diet switch to an energy-rich detritus in an oligotrophic environment. Stable isotope assays determined that guano may be assimilated into salamander muscle tissue, and nutritional analyses revealed that guano is a comparable food source to potential invertebrate prey items. This is the first report of coprophagy in a salamander and in any amphibian for reasons other than intestinal inoculation. Because many temperate subterranean environments are often energy poor and this limitation is thought to select for increased diet breadth, we predict that coprophagy may be common in subterranean vertebrates where it is not currently recognized.

Doomed before they are described? The need for conservation assessments of cryptic species complexes using an amblyopsid cavefish (Amblyopsidae: Typhlichthys) as a case study

The delimitation of cryptic species and lineages is a common finding of phylogenetic studies. Species previously considered to be of low conservation priority might actually be comprised of multiple lineages with substantially smaller geographic ranges and smaller populations that are of much greater conservation concern and that require different conservation strategies. Cryptic biodiversity is an especially common finding in phylogenetic studies of subterranean fauna; however, most cryptic lineages remain undescribed and have not been subjected to conservation assessments. As many subterranean species are of high conservation concern, the conservation assessment of cryptic lineages is important for developing effective conservation and management strategies. In particular, some lineages might be in need of immediate conservation action even before formal taxonomic description. Here we explore this issue by conducting IUCN Red List and NatureServe conservation assessments on recently discovered cryptic lineages of the southern cavefish (Typhlichthys subterraneus) species complex. We ascertained threats associated with extinction risk, identified priority lineages and populations for immediate conservation efforts, and identified knowledge gaps to expedite the development of conservation and management strategies before formal taxonomic description. Most cryptic lineages are at an elevated risk of extinction, including one lineage classified as “Critically Endangered.” We identified ten threats impacting cavefish lineages that vary in both scope and severity, including groundwater pollution, hydrological changes from impoundments, and over-collection. Our threat assessments and recommendations can be used by stakeholders to prioritize effective and appropriate management initiatives aiding in the conservation of these lineages even before they are formally recognized.

SEASONAL MOVEMENT PATTERNS OF PICKEREL FROGS (RANA PALUSTRIS) IN AN OZARK CAVE AND TROPHIC IMPLICATIONS SUPPORTED BY STABLE ISOTOPE EVIDENCE

Abstract We monitored a population of pickerel frogs (Rana palustris) in an Ozark cave over a 2-year period. Frogs were found from August to April with densities peaking from November to December. Although densities were quite high in these peak months, stomach content and stable isotope analyses reveal that R. palustris does not play a significant role as a predator in this subterranean system. These results suggest that the caves are being used as thermal refugia during the coldest months of the year.

Updated checklist of the ice-crawlers (Insecta: Grylloblattodea: Grylloblattidae) of North America, with notes on their natural history, biogeography and conservation

We provide an updated checklist and comprehensive distributional record of Grylloblatta (Grylloblattodea: Grylloblattidae) in North America. These distribution records are based upon a thorough review of the literature, as well as unpublished data of the authors and colleagues. Thirteen species of Grylloblatta are currently described, with up to 16 additional taxa awaiting formal description. Distributional data shows that endemism of Grylloblatta is high and geographic range size is typically small: the median geographical area of 13 species and six putative species is 179 km2. It is clear that there is a general lack of knowledge of species range limits and local population sizes; for example, three Grylloblatta species are known from just a single locality and less than 15 specimens each. Conservation status ranks are suggested in order to update the IUCN Red List and national Natural Heritage Network Database. Finally, we describe the natural history and seasonality of Grylloblatta, discuss their unique biogeography, and provide recommendations for future surveys of grylloblattid species by highlighting known distributional gaps.

STATUS AND DISTRIBUTION OF THE ENDANGERED BENTON CAVE CRAYFISH, CAMBARUS ACULABRUM (DECAPODA: CAMBARIDAE)

Abstract We present the first summary of the status and distribution of the Benton cave crayfish (Cambarus aculabrum). The range of this endangered crayfish is limited to 4 sites globally (3 in Benton County and 1 in Washington County, Arkansas). The identity of the species at these 4 sites is based upon morphological and genetic studies. The identities of cave crayfish inhabiting 2 additional Benton County sites remain undetermined. The current population census is 40 individuals. Threats to the species are analyzed, and subsequent conservation measures recommended. Habitat degradation remains a threat to the species, especially for water quality. Analyses from 1983 to 2002 document nutrient pollution of the subterranean stream habitats, originating from sources such as septic system discharge and run-off from confined animal feeding operations.

The 30-year recovery effort for the Ozark cavefish (Amblyopsis rosae): Analysis of current distribution, population trends, and conservation status of this threatened species

Here we review the thirty year recovery effort and conservation status of the Ozark cavefish, Amblyopsis rosae. We summarized the historic and current range of the species, and report county range extensions for both A. rosae and its confamilial Typhlichthys subterraneus. Ozark cavefish survey data spanning almost a century were analyzed for temporal trends using the Mann-Kendall Test/Sen’s Slope Estimator Method. Results were inconclusive because variance was high and the majority of data sets were not sufficiently large to detect a trend. However, the two largest populations (Cave Springs Cave and Logan Cave, Benton Co., Arkansas) have stabilizing or increasing survey counts. While the number of active cavefish sites has decreased over 50% since 1990, the number of surveyed individuals has not. Reasons for endangerment were reanalyzed since federal listing; the primary threat has shifted from overcollection to habitat degradation. We analyzed the progress of recovery task implementation, and we critically evaluated the basis of delisting criteria. Recovery Task 1, the hydrogeologic delineation of subterranean habitats, is almost complete. Recovery Task 2 prescribes protection and management for Recovery Caves, and important progress has been made. Recovery Task 3 involves the development and implementation of monitoring programs in Recovery Caves. Several important studies have been performed, and indicate that many cavefish populations are experiencing chronic, low-level exposure to a suite of anthropogenic contaminants. Delisting conditions are largely unattainable as currently worded. We suggest that recovery criteria be amended such that habitat protection goals are attainable, that the list of Recovery Caves can be periodically updated, and that the recovery population goal is increased and distributed between more sites.

Bactrurus speleopolis, a new species of subterranean amphipod crustacean (Crangonyctidae) from caves in northern Arkansas

ABSTRACT Bactrurus speleopolis, a large stygobitic amphipod crustacean in the family Crangonyctidae is described from specimens collected from a lake in Cave City Cave, Sharp County, Arkansas, and is the second species of Bactrurus Hay, 1902 recorded to date from the state. This species may also occur in Marble Falls Cave in Marion County, but sexually mature specimens are needed to verify that occurrence. The description of B. speleopolis raises the total number of species in Bactrurus to eight. The genus is widespread in subterranean groundwaters of the east-central United States and is also recorded from a few localities farther east in the southern Appalachians.

STATUS UPDATE FOR BRISTLY CAVE CRAYFISH, CAMBARUS SETOSUS (DECAPODA: CAMBARIDAE), AND RANGE EXTENSION INTO ARKANSAS

Abstract This study updates the status, expands the range, and summarizes conservation activities to date for the bristly cave crayfish, Cambarus setosus. A new state record for this crayfish is reported after its discovery at 2 sites in 2 counties (Benton and Independence counties, Arkansas). This makes C. setosus the fifty-eighth crayfish species known from Arkansas. This is also the first record of C. setosus from the Salem Plateau of the Ozark Plateaus ecoregion; it was known previously only from the Springfield Plateau of Missouri. The range of C. setosus in Missouri includes the counties of Barry, Christian, Dade, Greene, Jasper, Lawrence, McDonald, Newton, and Stone; it is not presently known from Oklahoma, as previously reported. Cambarus setosus is probably a species complex with genetic variability at the subspecific level, especially in southwestern Missouri. Cambarus setosus is now known from 50 sites, but only 164 individuals (tallied from the most recent census at each site). This crayfish has been impacted by both habitat degradation and scientific study. Conservation organizations have begun preserving cave entrances, but conservation activity is lacking in subterranean stream recharge zones. Increased protection is recommended, including federal listing under the US Endangered Species Act.

Caecidotea mackini, new species, with a synopsis of the subterranean asellids of Oklahoma (Crustacea: Isopoda: Asellidae)

ABSTRACT A survey of cave and spring fauna in Oklahoma resulted in the discovery of Caecidotea mackini, new species, which is described from specimens collected in Longs Cave, Delaware County. Within the hobbsi group of the genus Caecidotea, C. mackini belongs to a subset of nine species termed the tridentata assemblage. All nine are subterranean, but several retain vestigial eyes or pigmentation. Correlated with zoogeographic and climatic evidence, the invasion of groundwaters by an epigean progenitor during the middle to late Tertiary is suggested. Besides C. mackini, new records for C. macropropoda, C. acuticarpa, C. stiladactyla, C. steevesi, C. ancyla, C. antricola, C. adenta, and C. simulator expand the known ranges of these cryptic species. With the recognition of two patterns of fourth pleopod morphology in C. acuticarpa, the species specificity of this character has become questionable. Although previously used to differentiate C. simulator and C. steevesi, further splitting or synonymy based on this pleopod anatomy is reserved until a better understanding of its differentiation is achieved.

New State Record and Western Range Extension for Pseudosinella dubia Christiansen (Collembola: Entomobryidae) from Oklahoma, U.S.A.

Pseudosinella dubia Christiansen 1960 was described from specimens collected in four caves of Washington County, Arkansas (Christiansen, 1960). Christiansen and Bellinger (1998) documented another Washington County cave record, and Peck and Peck (1982) recollected the species from one of the original four localities. Gardner (1986) reported a Pseudosinella collection from a cave in Dent County, Missouri, which was subsequently identified as P. dubia by K. Christiansen (pers. comm., 2009). Although two recent biological inventories have been conducted in Arkansas caves, no additional records of P. dubia were reported (Graening et al., 2003; Graening et al, 2006). On 11 January 2003, GOG, DBF, R. Stark, and A. Harris collected various collembolans from Oklahomas largest cave, the Duncan Field System (Adair County), in an attempt to acquire specimens needed to describe a new species endemic to this cave (Pseudosinella sp. nov. “AB”, reported in Christiansen and Bellinger, 1996). Instead, 5 specimens of Pseudosinella dubia were collected (out of 20 observed) and identified by K. Christiansen (Grinnell College, Grinnell, Iowa). This is the first record of P. dubia in Oklahoma and represents a western range extension of 27 km from the cluster of caves in Arkansas. Although P. dubia shows no clear troglomorphism, it has never been collected outside caves (K. Christiansen, per. comm., 2009). Specimens are retained in the personal collection of K. Christiansen.