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Thermal requirements of larval weatherfish Misgurnus fossilis were investigated in terms of growth, survival and aerobic performance. Growth and survival of M. fossilis larvae acclimated to five temperatures (11, 15, 19, 23 and 27 degrees C) were measured over 25 days. In the upper temperature treatments (19, 23 and 27 degrees C), survival of larvae was stable throughout the entire rearing period (>75%), whereas 11 and 15 degrees C resulted in severe declines in survival (to <10%). Growth of ...Thermal requirements of larval weatherfish Misgurnus fossilis were investigated in terms of growth, survival and aerobic performance. Growth and survival of M. fossilis larvae acclimated to five temperatures (11, 15, 19, 23 and 27 degrees C) were measured over 25 days. In the upper temperature treatments (19, 23 and 27 degrees C), survival of larvae was stable throughout the entire rearing period (>75%), whereas 11 and 15 degrees C resulted in severe declines in survival (to <10%). Growth of larvae (expressed as dry mass and total length) was highest at 19 and 23 degrees C, but significantly decreased at 27 degrees C. Routine metabolic rate of 3 days post-hatch larvae was estimated as oxygen consumption rate (MO2) during acute exposure (30min to 1 h) to seven temperatures (11, 15, 19, 23, 27, 31 and 35 degrees C). Larval oxygen uptake increased with each consecutive temperature step from 11 to 27 degrees C, until a plateau was reached at temperatures >27 degrees C. All larvae of the 35 degrees C regime, however, died within the. MO2 measurement period. M. fossilis larvae show greater than expected tolerance of high temperatures. On the other hand, low temperatures that are within the range of likely habitat conditions are critical because they might lead to high mortality rates when larvae are exposed over periods >10 days. These findings help to improve rearing conditions and to identify suitable waters for stocking and thus support the management of re-introduction activities for endangered M. fossilis. (C) 2017 The Fisheries Society of the British Isles. » weiterlesen» einklappen

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