Meeting Abstract

136.6  Monday, Jan. 7  Lusitanian nemertean species in Lough Hyne Marine Reserve, SW Ireland TROWBRIDGE, C.D.**; LITTLE, C.; STIRLING, P.; PILLING, G.M.; DLOUHY-MASSENGALE, B.L.; Oregon Institute of Marine Biology; Beggars Knoll, Westbury, UK; Beggars Knoll, Westbury, UK; Secretariat of the Pacific Community, New Caledonia; Oregon Institute of Marine Biology cdt@uoregon.edu

The warm-water nemertean Paradrepanophorus crassus, described from Mediterranean shores, was first recorded in Lough Hyne in County Cork, Ireland in 1931 by Renouf. During a long-term monitoring program (1994–2012) of Lough Hyne, we documented that the large, orange nemertean has increased in frequency, particularly in 2009–2012. Why the population is expanding in Lough Hyne is unclear but may include northward proliferation of Lusitanian species due to climatic warming and/or increased habitat availability. The nemertean forms membranous tubes under low intertidal to shallow subtidal rocks—a habitat previously occupied by purple urchins (Paracentrotus lividus) until their recent population decline. Nemertean eggs were noted within the membranous tube in June 2012. Polychaetes recorded in and around the nemertean tubes included species in three families (Polynoidae Amphinomidae, Dorvilleidae). The most frequently observed polychaete (Dorvillea rubrovittata) was a frequent, but not obligate, associate: sometimes the nemerteans occurred in sympatry with the red polychaetes and other times they were each allopatric (at the scale of individual rocks).