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 Do Fish Have Memory  |
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Trev Jackson
600+ Posts
Cairns
Australia
1051 Posts |
 Posted - 02 February 2005 : 11:14:21 PM
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Personality: You’ve got it, I’ve got it, dogs have it. The jury is probably out on cats, but do fish have it? Do they have or display individual characteristics? Do they have feelings ? Do they exist solely on instinct or do they have memory?
!8 months ago none of these questions would have crossed my mind. Fish were something to look at whilst cruising round wrecks. They were good with chips and vinegar. I caught a few, I speared a few ,even went soft on one or two occasions and set the odd one free from traps and set lines. Recently however, a family of large Cod near Cape Moreton in Qld have given me the opportunity to study first hand the concept that fish can and do have both a memory and a personality.
The crew of the Esperance Star and I discovered the site now known as the “Cod Feed” in Brisbane whilst searching for a small wreck early last year. The sighting of some tell tale signs on the surface led us do doing a dive in the middle of nowhere and discovering part of a sunken yacht which housed an extraordinary number of large Estuary Cod. On any given day about 15 Cod inhabit the site and gradually we have managed to not only feed the Cod by hand, but also to undertake some rudimentary study into the thought patterns of big fish.
Whilst Cod can be aggressive when baitfish are about, its generally true that the large fish are quite reserved when we are in on the Cod Feed. The biggest in the school, a large pale specimen with half of his tail missing has been nicknamed ‘Nobhead’. Nobhead has never taken a bait from me, in fact he is almost impossible to get near. I guess he figures he has been around this long with his cautious approach that there is no point changing now. it’s the same with the smaller Cod. There are half a dozen or so under 10 kilo, who also refuse to be tempted be fresh Kingfish chunks. It’s the mid-sized fish that seem to have all the spirit and have developed the courage to literally caress a bait from a divers hand. Of these mid ranged fish, about 30 to 40 kilos, one in particular has become almost matey with me. This one individual I have nicknamed Penny, I think she is a female but I have no way of telling. She is recognizable by her size and an indent just on her head between her eyes.
Penny has a very distinct personality. For a start she is far and away the boldest in the clan. As soon as the first diver hits the bottom Penny is waiting there with cap in hand. Initially when we got her feeding she would race in and start biting the bait bag. I would wave her off and make her wait for a few minutes before getting any food out. Now it could be my imagination, but it seems she has learnt that if she does this, she has to wait for food. Recently she has ‘decided ‘ it is more expedient to not munch at the bag. She simply arrives expectantly and gets a feed straight away.
Another little trick she seems to have learnt is to not grab at any really big chunks of food. To feed the Cod I usually race out to a good fishing spot I know nearby and catch a single Yellowtail Kingfish. These are large meaty pelagic fish which we chop up into bite size pieces. The head and the tail section are the two largest pieces and WERE the pieces she initially liked the most. Unfortunately she nearly choked recently when she took to large a piece and it got jammed in her throat for about half an hour. Since that day she seems to deliberately avoid anything larger than a fist sized chunk. Learned behaviour? Well I sure think so
Once Penny started to behave herself and get prompt feeding , some of the others, who had previously held back, began to emulate her behaviour. Another Cod we have nicknamed Pauly now does a double act with Penny. Interestingly, Pauly never emulated Pennys’ initial mistakes of grabbing at the bag. Once he decided we were safe to deal with he seemed to copy the behaviour she had developed to ensure the quickest food delivery. Remember that what these Cod are doing, taking food from the hand of a human, is not natural or instinctive behaviour. They appear to have learnt that its cool to hang round these strange invading creatures and get an easy feed.
Most of the time if a diver approaches a big Cod the fish will back off. The Cod at the Cod Feed however are now so used to us that on some occasions we find them actually leaning on us , rubbing up against our legs and arms. Penny and Pauly also don’t mind if you put your hand out and tickle them under the chin or on top of the head. Their personalities are quite distinct from the others and they seem to be displaying the fact that they have a memory, where many would argue that no memory should exist.What do you think?
www.esperancestar.com.au |
Edited by - Trev Jackson on 02 February 2005 11:17:25 PM
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Lloyd
30+ Posts
Geelong
Australia
116 Posts |
Posted - 02 February 2005 : 11:36:32 PM
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| What gave you the impression that fish had no memory in the first place? I think it is an old-wifes tale that fish do not have a memory. One thing I am concered about is that the cod you are feeding will become dependent on the people feeding them and then consiquently die if the regular feeding stops. |
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Lloyd
30+ Posts
Geelong
Australia
116 Posts |
Posted - 02 February 2005 : 11:36:32 PM
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| What gave you the impression that fish had no memory in the first place? I think it is an old-wifes tale that fish do not have a memory. One thing I am concered about is that the cod you are feeding will become dependent on the people feeding them and then consiquently die if the regular feeding stops. |
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Trev Jackson
600+ Posts
Cairns
Australia
1051 Posts |
Posted - 02 February 2005 : 11:39:50 PM
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quote:
Originally posted by Lloyd
What gave you the impression that fish had no memory in the first place? I think it is an old-wifes tale that fish do not have a memory. One thing I am concered about is that the cod you are feeding will become dependent on the people feeding them and then consiquently die if the regular feeding stops.
Suck my bean bag Lloyd, the welfare of these Cod are my No. One priority. I am more than fully aware of the consequences of overfeeding these fish. We wouldnt get there more than once a week [if that]and wouldnt give them more than five to ten kilos of meat a week [if that]. Amongst nearly 20 Cod, and just as many 'Slatey Greys", thats **** all
www.esperancestar.com.au |
Edited by - Trev Jackson on 02 February 2005 11:47:55 PM |
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Trev Jackson
600+ Posts
Cairns
Australia
1051 Posts |
Posted - 02 February 2005 : 11:39:50 PM
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quote:
Originally posted by Lloyd
What gave you the impression that fish had no memory in the first place? I think it is an old-wifes tale that fish do not have a memory. One thing I am concered about is that the cod you are feeding will become dependent on the people feeding them and then consiquently die if the regular feeding stops.
Suck my bean bag Lloyd, the welfare of these Cod are my No. One priority. I am more than fully aware of the consequences of overfeeding these fish. We wouldnt get there more than once a week [if that]and wouldnt give them more than five to ten kilos of meat a week [if that]. Amongst nearly 20 Cod, and just as many 'Slatey Greys", thats **** all
www.esperancestar.com.au |
Edited by - Trev Jackson on 02 February 2005 11:47:55 PM |
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Bunyip
Dive-Oz Supporter
Adelaide, SA
Australia
2214 Posts |
Posted - 03 February 2005 : 12:07:46 AM
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Trev
I'm with you. Fish can and do learn new behaviours.
If you ever get a chance to take the boat ride on Lake Argyle, you can see Archer fish that have learnt to target tourists' hands for bread. And they can tell when you haven't got any.
I've also heard some interesting stories about a cuttlefish remembering a diver who had previously offended it and targetting that specific diver, not just any diver, on the next dives.
I've seen the maze tests run with octopii. They learn very fast, live fast and die young.
I've also been thoroughly checked out by fish under Pt Noarlunga jetty for food, and they soon clear off when you haven't got any. Some divers feed them there. These fish also keep well clear of the fishing end of the jetty and any kiddies swimming or doing bombs.
Perhaps that story about goldfish and short memories was just something made up by a parent to make their sensitive kid feel better.
-- It's on the internet, it must be true. |
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Bunyip
Dive-Oz Supporter
Adelaide, SA
Australia
2214 Posts |
Posted - 03 February 2005 : 12:07:46 AM
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Trev
I'm with you. Fish can and do learn new behaviours.
If you ever get a chance to take the boat ride on Lake Argyle, you can see Archer fish that have learnt to target tourists' hands for bread. And they can tell when you haven't got any.
I've also heard some interesting stories about a cuttlefish remembering a diver who had previously offended it and targetting that specific diver, not just any diver, on the next dives.
I've seen the maze tests run with octopii. They learn very fast, live fast and die young.
I've also been thoroughly checked out by fish under Pt Noarlunga jetty for food, and they soon clear off when you haven't got any. Some divers feed them there. These fish also keep well clear of the fishing end of the jetty and any kiddies swimming or doing bombs.
Perhaps that story about goldfish and short memories was just something made up by a parent to make their sensitive kid feel better.
-- It's on the internet, it must be true. |
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Lloyd
30+ Posts
Geelong
Australia
116 Posts |
Posted - 03 February 2005 : 12:30:07 AM
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| Octopi and Cuttlefish both are not fish, or even closly related, they are both Mollusks. |
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Lloyd
30+ Posts
Geelong
Australia
116 Posts |
Posted - 03 February 2005 : 12:30:07 AM
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| Octopi and Cuttlefish both are not fish, or even closly related, they are both Mollusks. |
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bmoir
New To Forums
Sydney
Australia
16 Posts |
Posted - 03 February 2005 : 02:14:35 AM
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Hi Trev,
You are interested in a topic that very few people have researched or even thought about.
I agree that fish do have a memory that goes beyond the instinct inherited from its parents. Fish can learn about their environment and must build a memory model to help them negotiate the world that they live in. For example some fish are very territorial and will return to a safe burrow after hunting over a large area during the day. Now I have no real experience with the topic so I thought I might go back to first principles.
Since we are on the topic of memory maybe the brain is a good place to start.
There is a great book called "On Intelligence" which is a must read for anyone who whould like to learn more about the brain. It mostly applies to human intelligence but the book has some relevance to your investigation.
In the brain is a region called the hippocampus (because it looks like a seahorse). This region is one of the most primitive regions of the brain and all fish have a hippocampus of sorts. Here is a good definition of what this region of the brain is responsible for:
http://en.wikipedia.org/wiki/Hippocampus
I wonder how complex the hippocampus of a fish actually is. How complex are the memories that fish can store? Clearly the fish you are interacting with are starting to display learnt behaviour.
Maybe there is a way you can start testing the complexity of the memory formation.
Does anyone have an experiment that could test what the Cod are capabale of remembering? Once you find a clear case of memory formation you could then test how long that memory persists.
Fun.
I just wish I had some local cod. |
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bmoir
New To Forums
Sydney
Australia
16 Posts |
Posted - 03 February 2005 : 02:14:35 AM
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Hi Trev,
You are interested in a topic that very few people have researched or even thought about.
I agree that fish do have a memory that goes beyond the instinct inherited from its parents. Fish can learn about their environment and must build a memory model to help them negotiate the world that they live in. For example some fish are very territorial and will return to a safe burrow after hunting over a large area during the day. Now I have no real experience with the topic so I thought I might go back to first principles.
Since we are on the topic of memory maybe the brain is a good place to start.
There is a great book called "On Intelligence" which is a must read for anyone who whould like to learn more about the brain. It mostly applies to human intelligence but the book has some relevance to your investigation.
In the brain is a region called the hippocampus (because it looks like a seahorse). This region is one of the most primitive regions of the brain and all fish have a hippocampus of sorts. Here is a good definition of what this region of the brain is responsible for:
http://en.wikipedia.org/wiki/Hippocampus
I wonder how complex the hippocampus of a fish actually is. How complex are the memories that fish can store? Clearly the fish you are interacting with are starting to display learnt behaviour.
Maybe there is a way you can start testing the complexity of the memory formation.
Does anyone have an experiment that could test what the Cod are capabale of remembering? Once you find a clear case of memory formation you could then test how long that memory persists.
Fun.
I just wish I had some local cod. |
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Dave H
Dive-Oz Supporter
Nelson Bay
Australia
1840 Posts |
Posted - 03 February 2005 : 08:58:19 AM
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my god, the skipper really is becoming soft in his old age! Patting cod and rubbing their tummies, you'll be drinking bacardi breezers soon...
Anyway, back to the question, do fish have memories? Yes, yes they do. Feeding experiments have been conducted on fish and sharks that have shown that fish do remember how to get or where to find food etc.... I spent a year regularly feeding cod Maori Cod at Little Beach and I found that they recongised me when compared to other divers, even with or without food.
Lloyd - I wouldn't be concerned. I stopped feeding the Maori Cod over a year ago and they are all still there... fish arn't just going to die when you stop feeding them. When you moved out of home you obviosuly didn't die when your mum stopped feeding you...
"www.daveharasti.com" |
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Dave H
Dive-Oz Supporter
Nelson Bay
Australia
1840 Posts |
Posted - 03 February 2005 : 08:58:19 AM
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my god, the skipper really is becoming soft in his old age! Patting cod and rubbing their tummies, you'll be drinking bacardi breezers soon...
Anyway, back to the question, do fish have memories? Yes, yes they do. Feeding experiments have been conducted on fish and sharks that have shown that fish do remember how to get or where to find food etc.... I spent a year regularly feeding cod Maori Cod at Little Beach and I found that they recongised me when compared to other divers, even with or without food.
Lloyd - I wouldn't be concerned. I stopped feeding the Maori Cod over a year ago and they are all still there... fish arn't just going to die when you stop feeding them. When you moved out of home you obviosuly didn't die when your mum stopped feeding you...
"www.daveharasti.com" |
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Lloyd
30+ Posts
Geelong
Australia
116 Posts |
Posted - 03 February 2005 : 09:01:09 AM
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Heh, I suppose I wont but I havent moved out of home yet  |
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Lloyd
30+ Posts
Geelong
Australia
116 Posts |
Posted - 03 February 2005 : 09:01:09 AM
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| Heh, I suppose I wont but I havent moved out of home yet |
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Jason M
Mk15 RB Pilot
Sydney
Australia
1771 Posts |
Posted - 03 February 2005 : 09:27:32 AM
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The Koi Carp up in Japan definitely know that humans are a source of food. As soon as you go near the water they come swimming from all directions, then when they get to you, they sit there with their mouths out of the water gulping at you.
Jason M.
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Jason M
Mk15 RB Pilot
Sydney
Australia
1771 Posts |
Posted - 03 February 2005 : 09:27:32 AM
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The Koi Carp up in Japan definitely know that humans are a source of food. As soon as you go near the water they come swimming from all directions, then when they get to you, they sit there with their mouths out of the water gulping at you.
Jason M.
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bundy
Dive-Oz Supporter
The Shire
Australia
579 Posts |
Posted - 03 February 2005 : 09:29:58 AM
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I fed a Blue Groper every weekend for a month, the last feed was in November ( i keep forgetting to get the fish befor going for a dive) but this Groper will pick me out of a group of upto 8 divers every time and come looking for some food..it dosnt bother any other divers..I have no doubt it rembers me....
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bundy
Dive-Oz Supporter
The Shire
Australia
579 Posts |
Posted - 03 February 2005 : 09:29:58 AM
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I fed a Blue Groper every weekend for a month, the last feed was in November ( i keep forgetting to get the fish befor going for a dive) but this Groper will pick me out of a group of upto 8 divers every time and come looking for some food..it dosnt bother any other divers..I have no doubt it rembers me....
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3l 84r70
Rebreather Pilot Wannabe / Dive-Oz Supporter
Epping
Australia
1832 Posts |
Posted - 03 February 2005 : 09:57:21 AM
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quote:
Originally posted by Dave H
Anyway, back to the question, do fish have memories? Yes, yes they do. Feeding experiments have been conducted on fish and sharks that have shown that fish do remember how to get or where to find food etc.... I spent a year regularly feeding cod Maori Cod at Little Beach and I found that they recongised me when compared to other divers, even with or without food.
Not sure about memory, but that seems a little more of a conditioned behaviour, remember Pavlov's dogs experiment? However, conditioned behaviour IS a display of memory.
I reckon Trev's post is about "smart" memory, the one learned by a deductive process in other words, a display of intelligence.
(Note that I'm not a Psychologist)
For example: When you were a kid and throw a ball to your mum's decorations, they fall from the stand and to the floor, breaking into pieces.. And then when you were hungry and were on the street and saw a nice mango on a tall tree, you remembered your mum's decoration, and then throw the ball to it (the mango, not the decoration again), with the fantastic end result of the mango falling to your hands and the ball hitting your neighbour's window… lessons learned: Mangoes taste good, a ball can a mango for your, and a ball can break decorations AND windows.
Jusk joking but I think you would understand my point 
Having said that, I have a salt water tank and I'm the one that feeds the salt water fish, and there are three interesting things happening:
1.- My clown fish will race to the top of the tank when I pass in front of it, but no when my wife does, some display of memory? 
2.- My Snowflake Eel will only go out of its hole if I open the tank and tap it on the top a couple of times, unless it's really hungry (no food in more than a week, no wonder why It ate two fishes already!), this seems more of a learned (conditioned) behaviour.
3.- The eel can only be hand feed by me (when is my hand in the tank), and not by my wife (Do I have smelly hands?  ), otherwise it will only eat from a feeding stick. This to me is a clear display of some sort of smart memory .
Just my two cents NOT worth
I didn't do it, no one saw me do it, there's no way you can prove anything!  |
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3l 84r70
Rebreather Pilot Wannabe / Dive-Oz Supporter
Epping
Australia
1832 Posts |
Posted - 03 February 2005 : 09:57:21 AM
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quote:
Originally posted by Dave H
Anyway, back to the question, do fish have memories? Yes, yes they do. Feeding experiments have been conducted on fish and sharks that have shown that fish do remember how to get or where to find food etc.... I spent a year regularly feeding cod Maori Cod at Little Beach and I found that they recongised me when compared to other divers, even with or without food.
Not sure about memory, but that seems a little more of a conditioned behaviour, remember Pavlov's dogs experiment? However, conditioned behaviour IS a display of memory.
I reckon Trev's post is about "smart" memory, the one learned by a deductive process in other words, a display of intelligence.
(Note that I'm not a Psychologist)
For example: When you were a kid and throw a ball to your mum's decorations, they fall from the stand and to the floor, breaking into pieces.. And then when you were hungry and were on the street and saw a nice mango on a tall tree, you remembered your mum's decoration, and then throw the ball to it (the mango, not the decoration again), with the fantastic end result of the mango falling to your hands and the ball hitting your neighbour's window… lessons learned: Mangoes taste good, a ball can a mango for your, and a ball can break decorations AND windows.
Jusk joking but I think you would understand my point
Having said that, I have a salt water tank and I'm the one that feeds the salt water fish, and there are three interesting things happening:
1.- My clown fish will race to the top of the tank when I pass in front of it, but no when my wife does, some display of memory?
2.- My Snowflake Eel will only go out of its hole if I open the tank and tap it on the top a couple of times, unless it's really hungry (no food in more than a week, no wonder why It ate two fishes already!), this seems more of a learned (conditioned) behaviour.
3.- The eel can only be hand feed by me (when is my hand in the tank), and not by my wife (Do I have smelly hands? ), otherwise it will only eat from a feeding stick. This to me is a clear display of some sort of smart memory .
Just my two cents NOT worth
I didn't do it, no one saw me do it, there's no way you can prove anything! |
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Do Fish Have Memory |
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