Aquatic subterranean Crustacea in Ireland: results and new records from a pilot study

Abstract

A total of 106 sites were sampled for subterranean aquatic Crustacea, basic water chemistry parameters and sediment characteristics as part of a pilot study for an all-Ireland survey of hypogean biodiversity. Samples were collected between November 2005 and August 2006. Sites were selected with a view to cover most of Ireland's geographical regions, geological formations and aquifer types. Sampling sites comprised 55 monitoring boreholes, 43 wells (excavated / dug from the surface historically), 5 springs and 3 wells with current groundwater abstraction for drinking water. Aquatic Crustacea were retrieved from 57% of all sites and included the first records of the following taxa for Ireland: Cavernocypris subterraneana, Fabaeformiscandona breuili and Fabaeformiscandona wegelini (Ostracoda), Speocyclops cf demetiensis (Cyclopoida) and Microniphargus leruthi (Amphipoda). These records suggest that the biodiversity of Ireland's freshwater fauna might have been significantly underestimated due to a historical lack of biological research on subterranean ecosystems. The results raise important questions regarding the biogeography of Ireland and the potential survival of subterranean fauna during periods of glaciation within hypogean refugia.