Despite numerous negative impacts, nonnative trout are still being stocked to provide economically and socially valuable sport fisheries in western mountain lakes. We evaluated relative performance and potential differences in feeding strategy and competitive ability of triploid versus diploid brook trout Salvelinus fontinalis in alpine lakes, as well as behavioral and performance differences of diploid and triploid brook trout in two controlled experimental settings: behavioral experiments in the laboratory and performance evaluations in ponds. Across lakes, catch per unit effort (CPUE) and relative weight (Wr) were not significantly different between ploidy levels. Mean sizes were also similar between ploidy levels except in two of the larger lakes where diploids attained slightly larger sizes (approximately 20 mm longer). We observed no significant differences between diploids and triploids in diet, diet preference, or trophic structure. Similarly, growth and condition did not differ between ploidy levels in smaller‐scale pond experiments, and aggressive behavior did not differ between ploidy levels (fed or unfed fish trials) in the laboratory. Independent of ploidy level, the relative performance of brook trout varied widely among lakes, a pattern that appeared to be a function of lake size or a factor that covaries with lake size such as temperature regime or carrying capacity. In summary, we observed no significant differences in the relative performance of brook trout from either ploidy level across a number of indices, systems, and environmental conditions, nor any indication that one group is more aggressive or a superior competitor than the other. Collectively, these results suggest that triploid brook trout will offer a more risk‐averse and promising management opportunity when they are stocked to these lakes and elsewhere to simultaneously meet the needs for the sport fishery and conservation objectives.
Received February 6, 2012; accepted August 27, 2012
Osteonecrosis of the femoral head is a progressive and potentially debilitating disorder that is responsive to core decompression, especially in early-stage disease. This is typically accomplished through use of an 8 to 10mm trephine or multiple, small-diameter percutaneous drilling. Use of the large diameter trephine is associated with risk of fracture and may not allow healing across large gaps. Here, we present a technique for core decompression using percutaneous drilling that allows bone marrow aspiration concentrate to be introduced. We used the aspirate needle to decompress the femoral head osteonecrotic lesion, followed by the administration of bone marrow aspirate concentrate. This is a straightforward procedure that can be used with low risk for patient morbidity.
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