livingart Posted December 21, 2011 Report Share Posted December 21, 2011 the nervous system of a lobster and a fish are different Quote Link to comment Share on other sites More sharing options...
smidey Posted December 21, 2011 Report Share Posted December 21, 2011 i'm a whack on concrete in the net person to, then i feed it to my cats. tropheus are quite expensive cat food but hey, once it's dead it's food. Quote Link to comment Share on other sites More sharing options...
Sophia Posted December 21, 2011 Report Share Posted December 21, 2011 Clove oil for me, then the whole house can enjoy the smell of going to the dentist at the same time :smln: Quote Link to comment Share on other sites More sharing options...
fishplants Posted December 21, 2011 Report Share Posted December 21, 2011 the nervous system of a lobster and a fish are different How so? Quote Link to comment Share on other sites More sharing options...
livingart Posted December 21, 2011 Report Share Posted December 21, 2011 The lobster nervous system is very simple , similar to that of an insect. Neither have brains, you need a more complex nervous system to perceive pain. In 2003, Scottish scientists at the University of Edinburgh and the Roslin Institute concluded that rainbow trout exhibit behaviors often associated with pain in other animals. Bee venom and acetic acid injected into the lips resulted in fish rocking their bodies and rubbing their lips along the sides and floors of their tanks, which the researchers concluded were attempts to relieve pain, similar to what mammals would do. Neurons fired in a pattern resembling human neuronal patterns. Quote Link to comment Share on other sites More sharing options...
fishplants Posted December 21, 2011 Report Share Posted December 21, 2011 The lobster nervous system is very simple , similar to that of an insect. Neither have brains, you need a more complex nervous system to perceive pain. Cool, thanks for that. So fish have a nervous system similiar to humans (maybe less developed or acute?), and humans don't feel pain as they freeze to death. And a human freezing to death is much slower in the less conductive atmosphere than in highly conductive water. A tropical fishes comfort temperature is around the 25 degrees celsius mark (depending on species), so it takes very little drop in temperature (ie time) for the fishes metabolism to slow down to almost nothing. I have accidentally left the heater unplugged all night in a 30 litre QT in winter, the temperature dropped to 16 degrees celsius (from 28) by the next morning. The Discus were sitting upright on the bottom, exhibiting no signs of pain or discomfort (ie dashing around, rubbing themselves against the tank sides, etc). I could touch them and move them around the tank with virtually no response to my touch at all. That is, their nervous system was in an almost non reactive state - and this was at a relatively warm 16 degrees celcius, not in a freezer where the temperature dropped from the mid 20's to just above zero in well less than an hour. I have seen fish culled by clove oil, and the mad dash they do when the oil is added doesn't look like they are enjoying it. cheers Quote Link to comment Share on other sites More sharing options...
SamH Posted December 22, 2011 Report Share Posted December 22, 2011 Personally I chuck some water in the freezer until it starts to ice over, break the ice and drop the fish in there. They do skits and spasm for a few seconds but then they go to sleep, then I finish them off by putting them in the freezer. Shock freezing I believe it's called. Quote Link to comment Share on other sites More sharing options...
Sheepsnana Posted December 22, 2011 Report Share Posted December 22, 2011 Cool, thanks for that. So fish have a nervous system similiar to humans (maybe less developed or acute?), and humans don't feel pain as they freeze to death. And a human freezing to death is much slower in the less conductive atmosphere than in highly conductive water. A tropical fishes comfort temperature is around the 25 degrees celsius mark (depending on species), so it takes very little drop in temperature (ie time) for the fishes metabolism to slow down to almost nothing. I have accidentally left the heater unplugged all night in a 30 litre QT in winter, the temperature dropped to 16 degrees celsius (from 28) by the next morning. The Discus were sitting upright on the bottom, exhibiting no signs of pain or discomfort (ie dashing around, rubbing themselves against the tank sides, etc). I could touch them and move them around the tank with virtually no response to my touch at all. That is, their nervous system was in an almost non reactive state - and this was at a relatively warm 16 degrees celcius, not in a freezer where the temperature dropped from the mid 20's to just above zero in well less than an hour. I have seen fish culled by clove oil, and the mad dash they do when the oil is added doesn't look like they are enjoying it. cheers Did the fish recover after you warmed them up, or did you write them off? Quote Link to comment Share on other sites More sharing options...
Ira Posted December 22, 2011 Report Share Posted December 22, 2011 It's been a few years so I don't remember the exact numbers, but the severum I experimented on was dead at about 14 degrees. He didn't show any obvious signs of distress while cooling while cooling. Once he looked dead I checked to make sure his gills weren't moving at all. Then I warmed him up to normal tank temperature to see if he'd revive. He didn't. Quote Link to comment Share on other sites More sharing options...
smidey Posted December 22, 2011 Report Share Posted December 22, 2011 surely it must be better to create an instant death? that way there is limited or no pain and it's done immediately. Quote Link to comment Share on other sites More sharing options...
flatfish Posted December 22, 2011 Report Share Posted December 22, 2011 The whole fish feeling pain thing is a contentious issue, and in my opinion not proven. Were the trout responding to a negative stimulus, such as if you spray an insect with fly spray (now I dont think anyone thinks insects can feel pain as we do), or do they actually feel pain. In my opinion they dont feel pain but they do respond to negative or for that matter positive stimuli. Regardless I think if you are going to kill one of your fish you should do it by a method that causes them as little discomfort as possible. Whenever I go fishing I always iki any fish I keep, and if I'm out trout fishing I use a small rock. Quote Link to comment Share on other sites More sharing options...
fishplants Posted December 22, 2011 Report Share Posted December 22, 2011 Sheepsnana - the discus made a full recovery surprisingly and have grown into nice adults. Embarrassingly, this has happened three times, and there appeared to be no long term damage to any of the fish. When I catch trout and salmon I too kill them immediately with a very sharp blow to the back of the head. I hate seeing fish thrown into a fish bin alive, to suffocate slowly. Quote Link to comment Share on other sites More sharing options...
Jennifer Posted December 22, 2011 Report Share Posted December 22, 2011 The research is not conclusive about whether fish feel pain. They certainly do respond to negative stimuli. As with most animals, veterinary experts recommend assuming that they can feel pain and we must also remember that animals in New Zealand have legislative rights for the 'Five Freedoms' so they have a right to the following (summarised): 1. have appropriate shelter 2. be free from distress 3. have appropriate nutrition and water 4. have rapid treatment of disease and prevention of illness 5. be free to exhibit normal behaviour http://www.biosecurity.govt.nz/legislation/animal-welfare-act/index.htm The American Veterinary Medical Association also has published guidelines for euthanasia. I couldn't share a public link for the most recent version but for the 2007 version the section on fishes remains essentially the same. http://www.avma.org/issues/animal_welfare/euthanasia.pdf When recommending euthanasia methods, I usually am mindful of what people have access to and what they are capable of doing. Some aren't capable of violence so clove oil is an effective and fast alternative that is readily available, even if it lacks scientific data to prove as much. Find the quickest and easiest method that will minimise pain and suffering. Quote Link to comment Share on other sites More sharing options...
ilwis Posted October 20, 2012 Report Share Posted October 20, 2012 just so you know nz bio security treatments for anesthetize fish says fridge for 5 hours to induce torpor then freezer for 24 hours also of note fish in international flights are often put in torpor by use of cold with about 97% survival rate of transit Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.