Thursday, May 16, 2019

[Ichthyology • 2018] New Populations of the Rare Subterranean Blind Cave Eel Ophisternon candidum (Synbranchidae) reveal Recent Historical Connections throughout north-western Australia


 Ophisternon candidum (Mees, 1962)

in Moore, Humphreys & Foster, 2018. 
 DOI: 10.1071/MF18006  

Abstract
The enigmatic blind cave eel Ophisternon candidum is one of Australia’s least known fishes and is one of only three vertebrates in Australia with an entirely subterranean existence. For more than half a century, O. candidum was thought to be restricted to some 100 km of coastal cave systems in north-western Australia. Herein we report on two new populations, each separated by hundreds of kilometres, and provide the first complete list of all known records of subterranean Ophisternon in Western Australia. Using morphological and molecular data, we show that these populations are conspecific, with one population showing evidence of genetic differentiation. Geological and biogeographic explanations are explored, along with conservation considerations. All populations face actual and potential threats, especially from mining activities, and there is a need for management and conservation strategies specific to each population.

Keywords: anchialine, Barrow Island, biogeography, Cape Range, conservation, genetics, Pilbara.


 Ophisternon candidum Western Australian Museum (WAM) P.34487-001 (364-mm total length) photographed live in an aquarium.



Glenn I. Moore, William F. Humphreys and Ralph Foster. 2018. New Populations of the Rare Subterranean Blind Cave Eel Ophisternon candidum (Synbranchidae) reveal Recent Historical Connections throughout north-western Australia. Marine and Freshwater Research. DOI: 10.1071/MF18006




Abstract: The blind cave eel, Ophisternon candidum (Mees in J R Soc West Aust 45: 24–32,1962), is a rare groundwater inhabitant found in geographically isolated populations of north-west Australia. The species is listed as vulnerable under Commonwealth legislation and is a priority consideration when environmental disturbance by resource companies is proposed. Detection of this species for Environmental Impact Assessment (EIA) and monitoring is difficult because individuals are naturally rare or traditional sampling techniques are ineffective. To properly manage the species, information on population distribution and connectivity is critical. We sought to examine whether environmental DNA (eDNA) of O. candidum could be detected and whether positive detection was correlated with previous locations where the species had been physically caught. We developed new eDNA species-specific PCR assays to screen groundwater sampling points and we detected O. candidum DNA in three boreholes where the species has previously been collected and five additional groundwater sampling points. Our results demonstrated that the newly designed assays were effective for detecting this rare and vulnerable subterranean species. This work sets a benchmark for the application of eDNA species-specific PCR assays for EIA and monitoring, and has potential for these assays to be expanded more broadly to high-throughput eDNA metabarcoding for subterranean groundwater communities in the future.
Keywords: Groundwater, Single-species detection assays, Metabarcoding, Environmental Impact Assessment, Monitoring, Stygofauna

Nicole E. White, Michelle T. Guzik, Andrew D. Austin, Glenn I. Moore, William F. Humphreys, Jason Alexander and Michael Bunce. 2020. Detection of the rare Australian endemic blind cave eel (Ophisternon candidum) with environmental DNA: implications for threatened species management in subterranean environments. Hydrobiologia. DOI: 10.1007/s10750-020-04304-z

Shy species detected through new DNA technique
phys.org/news/2020-06-shy-species-dna-technique.html 


Abstract: The rare blind cave eel Ophisternon candidum is restricted to a few populations and was originally described on the basis of only two specimens. The holotype and paratype were re-examined to provide revised and additional morphometrics. Nine more recently collected specimens, across a range of sizes, were also examined to provide an updated and expanded description of morphometrics for the species. Sensory head pores were identified and described for the first time in this species and a series of fresh colour photographs of both juvenile and adult specimens are provided suggesting ontogenetic ocular degeneration and vascularisation that may have evolved in response to a life in darkness.
Keywords: Anchialine, Pilbara, X-ray, Head pores, Anommatophasma

Glenn I. Moore. 2018. New morphological data and live photographs of the rare subterranean blind cave eel Ophisternon candidum (Synbranchidae) from north-western Australia. Ichthyological Research. DOI: 10.1007/s10228-018-0647-2