Dear Diana inflation of the swim bladder is frequently stopped by a micron thin film of oil on the water surface. are you skimming the surface dust/oil film off the tanks. You can also use tissue paper but it is not as good. arrange an air jet to blow the surface water into a floating ring with a small section cut out. The air should blow the surface film in and then slowly rotate the liquid inside the ring so that the oil is kept concentrated in the centre. The air is best blown by a very fine jet - use a fine plastic tube- heat and stretch to a almost needlike point. This air jet will now remove all the scum from your surface water and I hope will reduce your mortality dramatically.
regards
steve
At 01:09 PM 4/19/00 -0600, you wrote: > Fish-sci list members: > > We are attempting to study the effects of various chemicals on > bluegill survival to approximately 20 days post hatch. However, we > are experiencing near 100% mortality (in controls) at about 11 days > after hatch (25C). Mortality seems to be due to lack of swim bladder > inflation and switch from endogenous to exogenous nutrition (we are > feeding marine rotifers). We have tried and are continuing to try > various things to improve the situation but so far, no luck. Do any > of you have procedures that might get us at least 50% control > survival? Any suggestions/insight would be greatly appreciated. > > Thank you in advance. > > Diana Papoulias > Fish Biologist > Columbia Environmental Research Center > USGS-BRD > 4200 New Haven Rd. > Columbia, MO 65201 > (t) 573 876 1902 > (f) 573 876 1896 > (e) [log in to unmask] > >><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> > To leave the Fish-Sci list, Send blank message to: > mailto:[log in to unmask] > For information send INFO FISH-SCI to [log in to unmask] >><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> >
Dr. Steve Oakley, Shell Prof. of Environmental Science, Institute of Biodiversity & Environmental Conservation, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia [log in to unmask] Fax 082 671903 Tel 082 671000 x 254 or 257
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