My coauthors Daphne Soares, Dennis Higgs and I have a chapter titled “Hearing in cavefishes” in the recently published book “Fish Hearing and Bioacoustics – An Anthology in Honor of Arthur N. Popper and Richard R. Fay.” The volume is edited by Joe Sisneros and honors the scientific contributions of Art Popper and Richard Fay.
The full citation and abstract of the chapter are included below. The chapter and book can be downloaded from the Springer website here.
Soares D, Niemiller ML, & Higgs DM. Hearing in cavefishes. Pp. 187–195 in: Fish Hearing and Bioacoustics – An Anthology in Honor of Arthur N. Popper and Richard R. Fay (Sisneros JA, ed). Springer.
Caves and associated subterranean habitats represent some of the harshest environments on Earth, yet many organisms, including fishes, have colonized and thrive in these habitats despite the complete absence of light, and other abiotic and biotic constraints. Over 170 species of fishes are considered obligate subterranean inhabitants (stygobionts) that exhibit some degree of troglomorphy, including degeneration of eyes and reduction in pigmentation. To compensate for lack of vision, many species have evolved constructive changes to non-visual sensory modalities. In this chapter we review hearing in cavefishes, with particular emphasize on our own studies on amblyopsid cavefishes. Hearing in cavefishes has not been well studied to date, as hearing ability has only been examined in four species. Two species show no differences in hearing ability relative to their surface relatives, while the other two species (family Amblyopsidae) exhibit regression in the form of reduced hearing range and reduction in hair cell densities on sensory epithelia. In addition to reviewing our current knowledge on cavefish hearing, we offer suggestions for future avenues of research on cavefish hearing and discuss the influence of Popper and Fay on the field of cavefish bioacoustics.
I attended and presented at the 21st Annual National Cave and Karst Management Symposium held October 19-23 in the heart of the south-central Kentucky karst in the Mammoth Cave region. The venue for NCKMS 2015 was the Cave City Convention Center located in Cave City, Kentucky. The theme for NCKMS 2015 was “Hidden Landscapes-Hidden Challenges.” NCKMS 2015 was hosted by Cave Research Foundation, Mammoth Cave National Park, and Western Kentucky University.
I gave a 20-minute presentation titled “Genus-wide assessment of Bactrurus (Amphipoda: Crangonyctidae) informs conservation and management of groundwater habitats” co-authored with Steve Taylor.
A paper comparing the life history and ecology of cave and surface populations of the Western Slimy Salamander (Plethodon albagula) in Texas was recently published in the journal Herpetological Conservation and Biology. The full citation and abstract are below.
Taylor SJ, Krejca JK, Niemiller ML, Dreslik MJ, & Phillips CA. Life history and demographic differences between cave and surface populations of the western slimy salamander, Plethodon albagula (Caudata: Plethodontidae), in central Texas. Herpetological Conservation and Biology 10: 740–752.
The Western Slimy Salamander (Plethodon albagula) in central Texas is known from both surface and cave environments. Threshold species, such as P. albagula, may be excellent candidates to study potential differences in life history traits during the evolutionary transition from surface into subterranean habitats. We conducted a 29-mo mark-recapture study of a surface and a cave population in Bell County, Texas, USA, to determine whether these populations differed in body size, growth rate, age at sexual maturity, and life span. We employed a growth model to estimate growth rate, age at sexual maturity, and life span, and an open population model to estimate population size, density, catchability, and survival rates. Salamanders were smaller on average and reached a smaller maximum size in the surface population compared to the cave population, which was skewed toward larger, older individuals. Growth trajectories were similar between populations, but the cave population reached sexual maturity faster (0.9–1.4 y) than the surface population (1.5–2.2 y). Survival rates were similar between populations. Although population size estimates were 10 times higher for the surface compared to the cave population, densities were similar between sites suggesting that habitat availability alone could explain population size differences. Plethodon albagula exhibits plasticity in growth, body size, and development, which may be adaptive and a function of extreme variation in surface environmental conditions. Subterranean habitats may be important for the long-term persistence of local populations, which may persist for years in subterranean habitats.