Effects of holding temperature and handling stress on the upper thermal tolerance of threadfin shad Dorosoma petenense
Abstract:The critical thermal maxima (TMAX) of threadfin shad Dorosoma petenense exposed to standardized stress (30 s handling in a dip-net), simulating stressors endured during fish loading before transport, were measured over a range of holding temperatures (15, 20 and 25° C). Dorosoma petenense TMAX showed a significant thermal effect, displaying mean ±s.d. critical thermal maxima of 26·5 ± 1·6, 30·9 ± 1·2 and 33·3 ± 1·4° C, when tested at temperatures of 15, 20 and 25° C, respectively. Dorosoma petenense TMAX levels were also affected by stress, with handled fish showing significantly lower values than control fish exposed to 15 (mean ±s.d. TMAX = 25·6 ± 2·0° C), 20 (27·6 ± 2·8° C) and 25° C (32·0 ± 2·6° C). In addition to providing basic information on D. petenense thermal tolerance, experimental results suggest that fishery managers should consider the whole suite of potential stressors, such as air exposure during handling and fish loading, when developing management criteria.
Document Type: Regular Paper
Affiliations: 1: Department of Biology, Manchester College, North Manchester, IN 46962, U.S.A. 2: Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523, U.S.A.
Publication date: April 1, 2010