Tag Archives: Tennessee

References

Carver et al. 2016

Citation: Carver LM, Perlaky P, Cressler A, Zigler KS (2016) Reproductive seasonality in Nesticus (Araneae: Nesticidae) cave spiders. PLoS ONE 11: e0156751. 

Year: 2016

Author(s): Carver LM, Perlaky P, Cressler A, Zigler KS

Journal: PLoS One

Title: Reproductive seasonality in Nesticus (Araneae: Nesticidae) cave spiders

Abstract: Spiders of the family Nesticidae are members of cave communities around the world with cave-obligate (troglobiotic) species known from North America, Europe, Asia and the Indo-Pacific. A radiation of Nesticus (Araneae: Nesticidae) in the southern Appalachians includes ten troglobiotic species. Many of these species are of conservation interest due to their small ranges, with four species being single-cave endemics. Despite conservation concerns and their important role as predators in cave communities, we know little about reproduction and feeding in this group. We addressed this knowledge gap by examining populations of two species on a monthly basis for one year. We made further observations on several other species and populations, totaling 671 individual spider observations. This more than doubled the reported observations of reproduction and feeding in troglobiotic Nesticus. Female Nesticus carry egg sacs, facilitating the determination of the timing and frequency of reproduction. We found that Nesticus exhibit reproductive seasonality. Females carried egg sacs from May through October, with a peak in frequency in June. These spiders were rarely observed with prey; only 3.3% (22/671) of individuals were observed with prey items. The frequency at which prey items were observed did not vary by season. Common prey items were flies, beetles and millipedes. Troglobiotic species constituted approximately half of all prey items observed. This result represents a greater proportion of troglobiotic prey than has been reported for various troglophilic spiders. Although our findings shed light on the life history of troglobiotic Nesticus and on their role in cave ecosystems, further work is necessary to support effective conservation planning for many of these rare species.

DOI: https://doi.org/10.1371/journal.pone.0156751

Species: Nesticus barri, Nesticus furtivus, Nesticus pecki

Location: Jackson County, Alabama; Dade County, Walker County, Georgia; Franklin County, Marion County, Tennessee; USA

Uncategorized

Niemiller et al. 2016

Citation: Niemiller ML, Glorioso BM, Fenolio DB, Reynolds RG, Taylor SJ, Miller BT (2016) Growth, survival, longevity, and population size of the Big Mouth Cave Salamander (Gyrinophilus palleucus necturoides) from the type locality in Grundy County, Tennessee, USA. Copeia 104: 35-41.

Year: 2016

Author(s): Niemiller ML, Glorioso BM, Fenolio DB, Reynolds RG, Taylor SJ, Miller BT

Journal: Copeia

Title: Growth, survival, longevity, and population size of the Big Mouth Cave Salamander (Gyrinophilus palleucus necturoides) from the type locality in Grundy County, Tennessee, USA

Abstract: Salamander species that live entirely in subterranean habitats have evolved adaptations that allow them to cope with perpetual darkness and limited energy resources. We conducted a 26-month mark–recapture study to better understand the individual growth and demography of a population of the Big Mouth Cave Salamander (Gyrinophilus palleucus necturoides). We employed a growth model to estimate growth rates, age at sexual maturity, and longevity, and an open population model to estimate population size, density, detectability, and survival rates. Furthermore, we examined cover use and evidence of potential predation. Individuals probably reach sexual maturity in 3–5 years and live at least nine years. Survival rates were generally high (>75%) but declined during the study. More than 30% of captured salamanders had regenerating tails or tail damage, which presumably represent predation attempts by conspecifics or crayfishes. Most salamanders (>90%) were found under cover (e.g., rocks, trash, decaying plant material). Based on 11 surveys during the study, population size estimates ranged from 21 to 104 individuals in the ca. 710 m2 study area. Previous surveys indicated that this population experienced a significant decline from the early 1970s through the 1990s, perhaps related to silvicultural and agricultural practices. However, our data suggest that this population has either recovered or stabilized during the past 20 years. Differences in relative abundance between early surveys and our survey could be associated with differences in survey methods or sampling conditions rather than an increase in population size. Regardless, our study demonstrates that this population is larger than previously thought and is in no immediate risk of extirpation, though it does appear to exhibit higher rates of predation than expected for a species believed to be an apex predator of subterranean food webs.

DOI: https://doi.org/10.1643/OT-14-197

Species: Gyrinophilus palleucus necturoides

Location: Big Mouth Cave, Grundy County, Tennessee, USA