Gasterosteus aculeatus L. and Pungitius pungitius (L.) - Two Species of Stickleback from Turloughs in Cos Mayo and Roscommon

Top-down ecological pressures such as predation are a major feature of aquatic ecosystems (Moss 1998) and the absence of such pressures in temporary water bodies can often lead to a less diverse, but extremely important invertebrate fauna (Williams 1997). Turloughs are ephemeral winter lakes unique to the west of Ireland and as such are protected under the EU Habitats Directive (CEC [Council of the European Communities] 1992). Some invertebrates, characteristic of turloughs obligatorily dwell in temporary aquatic habitats because of their vulnerability to fish predators (Reynolds 2003). The recording of top predators is, therefore, important to understanding the ecological pressures at play on various turloughs of differing geomorphology and hydrology. Quantitative winter and spring freshwater invertebrate surveys of ten turloughs in Cos Galway, Mayo and Roscommon were conducted as part of a PhD project which involved a study of the mollusc fauna of turloughs. Sampling consisted of ten 5m sweeps with a pond net (1mm mesh size) at each station. There were between one and three sampling stations at each turlough, each of which was sampled once in either the winter of 2004 or the spring of 2005 (Table 1). Dissolved oxygen, pH, water temperature and water depth were also recorded at each sweep-path. During this survey juvenile and adult Gasterosteus aculeatus L. and Pungitius pungitius (L.) were captured at Ardkill and Ballinturly Turloughs respectively (Table 1). While this is the first published record of the latter species from a turlough habitat, it is known to occur in Coolcam Turlough (Co Roscommon M5770) (Reynolds pers. comm..).