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FAQs on Aquatic Life Behavior

Related Articles:  Aquatic Behavior, Coloration 

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Perception, cognition and emotion in fish      7/27/19
Hi Crew,
Reading through your site, I’ve noticed a few comments mention experience of pain and perception of colour in fish.
Do you know of a site or book or do you have a collection of advice on how fish perceive the world, what they understand, what emotions they might experience?
<Limited range available to non-specialists. "Fish Behavior in the Aquarium and in the Wild" by Stéphan Reebs is probably the best. His website is also highly relevant (http://www.howfishbehave.ca). "What a Fish Knows" by Jonathan Balcombe is another, and I feel a bit easier to read. "The Diversity of Fishes: Biology, Evolution, and Ecology" is my pick as the best all-around fish biology book, being surprisingly readable for an academic textbook, and covers everything in real depth, from fish feelings to fossils! Highly recommended if you want a more holistic approach to understanding how fish live.>
For example how do fish experience pain?
<Highly contentious topic within science. Lynne Sneddon has been the most active worker in this field, since some key experiments about 15 years ago that showed that fish would avoid using (temporarily) damaged parts of their bodies, in much the same way as mammals avoid putting weight on, say, a twisted ankle. This flew in the face of the accepted view that because fish lack pain receptors as mammals have them, they cannot perceive pain as such. This experiment and her other, subsequent ones have been criticised by other scientists who maintain that because fish brains are so different to those of mammals and birds, we cannot assume they "feel" anything in the same way we do. This in turn is criticised by Sneddon and her supporters who argue that fish can have evolved different structures that do the jobs of sensing and feeling pain. My analogy would be this: while you can argue birds fly because they have feathers, you couldn't say bats can't fly because they lack feathers.>
Do they experience joy, fear, sadness?
<Here's where things become even more difficult. How do we "experience" any of these? If you assume our conscious experiences all come about from the way our brains process information received by the senses, the differences between us and, say, fishes comes down to the complexity of that processing. We can further assume a spectrum of stress from a very basic level (reflexive swimming of a minnows away from a shadow cast over their stream) through to the very complex (existential crisis as a I lie in bed wondering about how I'm going to pay all my bills while retaining my sanity). At what point do simple stimulus-response reactions pass into more complex, thought-based evaluations within the brain? Animal biologists can't really answer this because we can't ever really know what it is to be a fish, a lizard or a sparrow, so while we can make comparisons of brain complexity, this is just a proxy for what might be the right answer. We assume the more complex the cerebrum, especially the frontal lobe in mammals, the more complicated the thoughts going on within the brain. Since fish generally have no frontal lobe and limited cerebral complexity, the assumption has always been that they aren't really capable of thinking in the way mammals and birds can. HOWEVER, with that said, their brains aren't merely simpler than those of mammals and birds, but structurally put together very differently, even compared with pre-fish level vertebrates such as lampreys. So again, we have this situation where comparisons with mammals may be misleading because evolution took fish brains down another path compared with the one that led to mammals. Certainly, fish have extremely acute senses, including electroreception, and their brains had to become very sophisticated to deal with this volume of sensory input. A few fish have brain mass to body mass ratios comparable to mammals' Elephantnoses, often sold in pet shops, are a famous example, and one of the very few fish for which 'play' behaviour has been reported. Finally, at least one fish, a Cleaner Wrasse, has passed the "mirror test" of self-awareness.>
What do they remember and for how long?
<Cichlids are well known to have complex behaviour and an ability to learn and adapt. Broadly speaking, fish can learn and remember things about as well as the average mammal or bird, and if you watch the behaviour of fish when people approach the aquarium (immediately beg for food) vs. that of many small mammals, such as gerbils (flee in terror) it's probably fair to say that at least some fish learn and adapt rather better. Scientific tests are limited, but Goldfish apparently remember things for months, which is rather good by animal standards. I've got a Panaque catfish who hides from strangers, but comes to the front when I'm around, and will gradually learn to accept others, notably my wife. It took the catfish a few months to accept her, but if anyone else walks up to the tank, she goes back to hide in her cave.>
Do they form relationships?
<Again, depends how you define a relationship. Some fish form mated pairs that are loyal for life, which as with birds, probably indicates a need to trust their partner to rear offspring. "Is This Love?" asked Whitesnake, and for biologists, that's a good question. Is what we call "love" simply the sum of all the various emotional states and behaviours within our brain when choosing potential breeding partners? I don't know the answer to that, but if you suppose that it is, and our version is simply a high complex form (as demanded by a species with helpless, slow-growing offspring that needs pair bonds that are maintained for years at a time) then the relationship between some paired-off cichlids might be of the same order, if to a lesser degree. I will observe that some fish species enjoy human company, notably Koi, Goldfish, and the larger cichlids such as Oscars, which even when not hungry, will enjoy being interacted with and sit at the front of the tank to watch what's going on outside.>
I know there is a danger in anthropomorphising fish.
<Correct. And for the most part we should focus on water quality, water chemistry, swimming space, diet, and appropriate tankmates. Get these right and most fish will be happy, insofar as that means anything when talking about animals. But at the same time, thinking about how animals think can lead us to making their maintenance in captivity more successful for both parties involved. At university I had an animal behaviour professor who put it this way: Lions and Tigers are very different animals. Lions sit around waiting for either prey or rivals to turn up, and when they do, that's when they spring into action. Otherwise they mostly sleep. Tigers patrol huge territories all day and night. So in captivity, keeping Lions in relatively small enclosures isn't as cruel as it looks because the Lions wouldn't really do much with the extra space. Tigers on the other hand pace back and forth because they need movement and stimulation. So odd as it might seem, a circus could actually be more humane for a Tiger because it would be more active. Now, he was making the analogy here, and not arguing in favour of either zoos or circuses, but wanted us to think about the fact there isn't a "one size fits all" solution to understanding animal psychology, and as a result, how we handle each species has to be tailored to its specific needs.>
But we are trying to create environments where they can live a good life, that’s why it would be good to understand how they perceive the world.
<My thoughts exactly.>
Many thanks,
<Most welcome. Neale.><<Phenomenal response Neale. B>>
Re: Incredibly well-done       7/28/19

Thank you, Bob!
<Thank you Neale.>
Re: Perception, cognition and emotion in fish       7/28/19

Hi Neal,
Many thanks!
<Most welcome.>
That’s a very thoughtful summary. Will find these books.
<Hope you enjoy.>
I have lots of anecdotal observations of two goldfish behaving playfully with one and other (doing a side by side dance, not the mating chase). Only these two individuals, not the others. I can tell as all my 8 goldfish have very different colourations. Kept in a pond, of course.
<Indeed, and there's some evidence that over the generations, fish behaviour among captive specimens changes when compared with their wild relatives. In Ameca splendens for example, we have a fish that is almost, perhaps completely extinct in the wild, but has been kept in aquaria for decades. Unfortunately the captive fish are more aggressive than the wild fish, since selection pressure allowed them to do so, because there were fewer risks to such behaviour (such as not spending enough time feeding on low quality food). So it's likely impossible to simply release captive specimens back into the wild without first going through the reverse process of selective in favour of foraging and defensive behaviours and against aggressive behaviours.>
Also, goldfish, who have also been coming to feed avoiding me (not coming up to feed) after I had to net them for transfer to the other pond for observation or treatment.
<Given that Goldfish have been domesticated for several hundred years, it's really hard to know if their behaviour is in any way natural. Anglers will tell you that Carp are smart fish that can learn to avoid lures very successfully -- something that increases the challenge to catching them! It's much like the situation with dogs. We know they're smart; we know wolves are smart; but are they smart in the same ways? There's an increasing understanding that mutations among wolves that caused them to be better adapted to living around humans, including being more trusting and less aggressive, means that they domesticated themselves through natural selection. This is the opposite of the old idea that humans took wolf cubs, somehow trained them, and over centuries domesticated them.>
And a male platy only interested in one female even when many other females are around.
<Most curious!>
I have also seen platies ‘visit’ and ‘sit with’ and other unwell platies of the same gender. And gently poke them but leave them alone if the other doesn’t respond. And just ‘sit’ with them.
<Seen similar behaviours, and it's hard to determine what the selfish advantage would be to this behaviour, and unless a behaviour helps the individual in terms of survival, there's no reason it should evolve. In the wild, staying with a sick or injured fish would be rather dangerous. Of course in aquaria selection pressures are different, and if there's no penalty attached to this behaviour, it might persist.>
But as I said, it’s all anecdotal, can’t necessarily prescribe human intent to their behavior.
<Indeed, and part of the issue has to be to try to understand their behaviours through their own eyes, rather than ours. That's easier said than done, though!>
Best wishes,
<Cheers, Neale.>

Fishy Cooperation: Scientists Discover Coordinated Hunting Between Groupers, Giant Moray Eels    1/4/12
> Hello Marco, Bob,
> Thought this might interest.
> http://www.sciencedaily.com/releases/2006/12/061206095317.htm 
> Cheers, Neale<Have observed this association in the wild myself. B>
And now saltwater Piranha! I.e. some damselfishes!    1/4/12

Really? Sounds extraordinary.
Am watching a new BBC documentary called "Great Barrier Reef: Nature's Miracle". Some amazing footage. There's the Epaulette Shark, which apparently is adapted to the reef top. During low tide and when exposed to air, the shark can walk about on the coral from one pool to another, and even shuts down parts of it brain to conserve oxygen. Apparently this is its ecological niche, feeding at low tide when other fish and crustaceans can't move about or escape from pools of water.
There was also a White Damselfish, apparently the fish responsible for more attacks on divers than anything else on the reef. Not fatal ones of course!
If this show appears on BBC America, do watch.
Cheers, Neale
<Ounce/gram for ounce/gram, the toughest, most territorial animals I've ever encountered>

Tropical fish are mammal-like parents 9/24/11
> Hello Bob,
<Greetings Neale>
> Not sure if this is completely new to fishkeepers, but it's good to know the scientists are keeping up with the hobby!
> http://news.bbc.co.uk/earth/hi/earth_news/newsid_9139000/9139756.stm 
> Some neat observations, including that cichlid parents "wean" their offspring after 3 months by making it less easy for the fry to scrounge food, persuading the fry to forage for themselves!
> I wonder what's happen in the marine realm that we're not aware of through lack of observations? It's taken the best part of a century to establish this among popular freshwater aquarium fish!
> Cheers, Neale
<And you, BobF>

fish behavior, innate and learned   8/18/10
<Hello Jonathan>
What I would like to know is, even if fish do not coexist together in the wild can they still recognize each other as competitors for the same resource based on things such as shape, color/pattern, and feeding behavior?
<Oh yes, for sure>
For example: a Purple Tang (Zebrasoma xanthurum ) from the Red Sea & a Yellow Tang (Zebrasoma flavescens) from Hawai'i. I have read on WWM that Zebrasoma species do not get along and I was wondering why they have a problem with member of the same genus if they do not normally encounter each other in the wild.
<Interesting question. They do/ can recognise competitors quite easily, no matter where they have come from. It is simply a matter of watching the behaviour of their tankmates, i.e. 'Oi get offa my algae patch!' I do think though that there is some 'learning' required regarding food & prey items/ animals that they are not familiar with. Simon> 

Fish behavior -- 4/30/09
Good morning to all,
<Mid afternoon here in England, but salutations all the same.>
I just thought I would share my latest chuckle with you in regards to my fish community.
It appears (and I might be anthropomorphizing-he was lonely) that my Siamese algae eater has decided he/she has become a pearl Gourami, as he has started swimming with the 3 of them, and generally hanging close by.
<Well, this species is gregarious in the wild, though under captive conditions they can become territorial if not kept in sufficient numbers.
Ideally, they're kept in groups of six or more, but singletons do okay. In groups of 2-5, they're a bit unpredictable.>
I must admit they are not dissimilar in looks (at least they both are grey at first glance with blackish stripes across their bodies).
<Fish (like birds) are indeed notoriously non-picky when it comes to determining "conspecifics", that is, members of their kind. Often they will latch onto certain colours or markings. This has been amply demonstrated by animal psychologists working with male sticklebacks, which basically attack anything with red patches, since male sticklebacks develop a red patch in the breeding season.>
It's fooled the SAE anyway, and I hope made him/her happier.
Of course, being a mental health therapist, I'm concerned that he will start to feel a little left out and when he/she goes to therapy someday will admit to feeling like he never really fit in.
<"Wrong species" companionships or at least interactions do occur, in the wild as well as in captivity. While we should be careful about assigning human motives or feelings to them, they can be a signal that some aspect of the fish's behaviour is not being completely satisfied. The classic example is the lonely Clown Loach that schools with Tiger Barbs, both sharing the same orange-and-black banding. Add more Clown Loaches, and the lonely loach will quickly start to school with its own kind rather than barbs, suggesting at least some ability to "rank" potential school mates on characteristics other than simple colour, and thereby choose the right fish to school with.>
(Sorry, my tank is in my office so I do a lot of analyzing fish behavior!)
Have a nice day-
<Thanks for writing, and all very interesting! Cheers, Neale.>

Do fish feel pain?   2/25/09 Hi Guys, I consider myself a seasoned aquarist as I have been in the hobby personally and professionally for almost 30 years. I have observed all kinds of fish behavior and I believe I have seen fish respond to and be in pain. My husband is a Bass fisherman and recently brought to my attention an article in BASS Master magazine an article claiming that fish do not have the ability to feel pain. I was outraged!! I know better than that!! The article claims that because fish do not have a neocortex, which is what helps detect pain, that they do not feel pain. I find this nearly impossible to believe. Fish do have a brain and a central nervous system, and besides this I have seen fish when their in pain. Just their actions and the fear they project are enough to tell that it hurts!!! I hope you can shed some light on this subject. Is it possible that I'm wrong and that fish do not feel pain?! It doesn't make sense to me. Please help! <Deborah, the short answer is that while it was always thought fish cannot feel pain, there is increasing evidence that they can. The argument that they can't feel pain is based on anatomy: they don't have the 'hardware' we have to feel pain. Therefore, it was said, they cannot feel pain. Experimental evidence however suggests that they *react* to damage in a way that implies an ability to sense that damage, i.e., to feel pain. The work was done using a weak acid (vinegar, I think) to 'sting' the lips of some fish. Until the vinegar washed away, the fish would feed in a different way, seemingly similar to how we behave when we twist our ankles and avoid putting weight on our feet. The implication was that the fish felt the pain, and reacted accordingly. Not all scientists believe this is what is happening, but certainly there is a tendency in that direction, e.g., by the Royal Society. http://news.bbc.co.uk/1/hi/sci/tech/2983045.stm http://royalsociety.org/news.asp?year=&id=1697 I think what you have at the moment is one group of people who *want* fish to feel pain and are looking for evidence to support that theory, and another who *don't want* fish to feel pain are looking for evidence to support their theory. You have Lynne Sneddon doing her work in England demonstrating (apparently) that fish can feel pain, while James D. Rose in the US is the leading critic of her work, and argues forcefully that fish don't feel pain, at least not in the "painful" way mammals do. While their argument takes place in the scientific arena, different lobby groups cherry pick factoids to support their agendas. Animal welfare groups would need to widen their scope of activity if fish can feel pain, to the degree the extreme end like PETA would use that argument to ban fishing, angling, and fishkeeping altogether. At the other end of things, anglers and fisherman rely on the fact that fish don't feel pain to catch/process fish in the way they do. While you can humanely kill a cow or chicken, humanely killing trout or herring would be (at least commercially) impossible. If it does turn out that fish feel pain, then things like sport fishing and commercial fishing, and indeed keeping pet fish, become much more complex issues. As someone who enjoys eating fish, occasionally goes fishing, and certainly likes keeping fish, I am conflicted by the interplay between the science and by desire to carry on enjoying those things. Cheers, Neale.>

Re: Do fish feel pain? 2/25/09 Neale (and others), Well spoken, and very nice response. I don't want to bring politics into this forum, but it is important to realize the agenda of such groups as PETA and the Humane Society of the Unites States, simply because we all have common interests. Personally, I find myself on the far right, inasmuch as this goes... I'm a hunter, a pro 2nd amendment person, an avid fisherman, and a dedicated fish keeper. Living in Houston, I fish a lot on the gulf coast in Galveston. A billboard that went up on Interstate 45 a few years ago had a picture of a dog with a fish hook in its mouth, as if caught by a fisherman. The words read something along the lines of "Would you do this to your best friend?". Naturally it was an anti fishing add, and it was sponsored by PETA. Whether you are pro hunting or anti, pro fishing or anti, you must realize that these extremist groups, though entitled to their opinion and right to voice it, wish to end all forms of animal 'Cruelty', and as mentioned in FAQ just yesterday I believe, there is a movement in Hawaii using Bob's name (incorrectly), wanting to end marine collections there. What brings all of us together on this forum is the desire to humanely and responsibly keep marine life captive. Different folks will always have different opinions as to whether this is morally right or wrong, but it is important to realize that whatever angle these groups try to take, their goal is a complete liberation of animals from human impact and use, and that includes the marine aquarium industry and hobby. I hope that, in things that we support and recognize, we each realize what is at stake. Thank you for your time and effort, wet web media :) Thomas <Hello Thomas. If I have a "take" at all on the pro/anti-hunting argument, it's simply a utilitarian one. If hunting and sport fishing didn't exist, then the desire to maintain good quality wilderness would evaporate. Without the economic and social need to maintain wilderness for hunters and fishermen, the landowners will inevitably use that land for other purposes such as housing or agriculture. So while I personally don't see any sport involved in using a high-powered rifle to kill a deer, I consider the death of the deer more than compensated for by the maintenance of its habitat, within which lots of other animals and plants can thrive. Furthermore, organised hunting and sport fishing groups can be outstanding lobby groups for environmental issues. Here in the UK, the angling lobby has been incredibly influential in getting rivers cleaned up and in bringing pressure to bear on polluters. In the US, the sport fishing groups concerned with billfish such as marlin have been very important in getting these fish conserved and in providing population data that scientists can use to help manage the fishery. So again, while I imagine it's very stressful for a marlin to be dragged up from the deep on a big sharp hook, in terms of ensuring the survival of the species, sport fishermen are overall a benefit and not a problem. To cut to the chase: while I'm sympathetic to PETA's point of view than humans have historically treated animals very badly, and much commercial farming for example is irredeemably cruel, that doesn't mean I believe they're going about things the right way. Hunters and fishermen should be seen as allies, since the big picture isn't being kind to animals (Nature isn't kind to animals any more than people) but about humans ensuring what wilderness remains stays in good condition. Farming isn't about all becoming vegetarians, but about rearing cows and chickens humanely. And fishkeeping isn't about releasing guppies back into the wild so they can frolic with the dolphins, but about providing our pets with a good standard of living while deriving entertainment and, dare I say it, education. Cheers, Neale.>

Competing algae colonies   2/21/09 Hello... <Hi there> I have seen a picture of a large rock, in a shoreline marine environment, with two distinct colonies of "algae" growing on it. The two colonies were separated by a barren "no man's land" in which nothing was growing. The voice over explained that the scene depicted an instance of "biological warfare" in that each colony excreted a particular enzyme that was irritating to the other. As the two colonies grew on the rock, they "established" the barren zones as a way of "staying out of each other's way." Could you elaborate/confirm this effect, and if possible, supply a picture of [a rock] with two [or more] cultures competing for surface space. I am a clinical psychologist, and I would like such a picture and verified explanation in some work that I'm doing. Thanks in advance. ...Robert <Must it be an "algae?"... Have attached a photo of two different clone colonies of the Anemone Anthopleura elegantissima, off the coast of San Diego, CA. The "DMZ" area twixt these two is the aforementioned barren zone... Is indeed resultant from chemical and physical warfare between these competitors... Are there biological, social ramifications of such observed activity? Bob Fenner>

Re: competing algae colonies   2/21/09 Bob... <Robert> Well, thanks much for the prompt reply. Yes, that's the effect. The picture I originally saw depicted the effect "better" in that it was a pic of the whole rock, probably about two to three feet long. The two colonies were clearly spread out over two different areas, and the DMZ was very distinct. This sounds like carping on my part, and I don't mean to be so in the face of your generous response. I know what's happening, yet the proposed audience could probably use a clearer and more "dramatic" example. The advantage of the "whole rock" photo was that the two camps with the DMZ was dramatically obvious. I can sure use your pic, but if you happen to know/have a "whole rock" demo that would be great. <Mmm, there are such "examples" in most any view on the worlds reefs... with close enough looking... There is avid competition between and amongst all life there... Perhaps a cursory reading here: http://wetwebmedia.com/cnidcompppt.htm and the linked files in the series> I work with psychosomatic problems using hypnosis [behavioral medicine]. I also teach clinical hypnosis through the American Society of Clinical Hypnosis. I want to use the rock with bio-colonies as a demonstration that nature can sense an adversary at a distance. The implication is that the patient can intuit the rapport or lack thereof as presented by the therapist. Accordingly, the therapist needs to cultivate a "proper attitude" with which to welcome the patient into the therapeutic encounter. I think the rock with competing bio-colonies brings the point home with a lot of impact. <Interesting application, extension... I do hope you, your intended audiences find value in this analogy. BobF> Thanks again. Have a good day. ...Robert

Deepwater Marine Fish Article... Osmeriform... put in fish beh. f'  1/8/09 Good Evening, <Good early morning to you.> I came across a recent article about the first live specimen of Dolichopteryx longipes being caught near Tonga. It seems that as a deep water fish it's evolved mirrors to reflect light into it's eyes... <Very interesting!> Thought I'd pass it along to the community. <Thank you, I know I will, and likely several others!> http://news.bbc.co.uk/2/hi/science/nature/7815540.stm Regards, Brandon <Thanks for sharing, Mich>

Clown Tang Aggression'¦Fueled By The Lunar Cycle? - 09/29/07 Here is my dilemma, I have a Clown Tang about 6-inches, and every few weeks he acts very weird. <<A very aggressive (even 'mean') species>> About two months ago he tried to kill my Purple Tang (luckily I got the purple out in time but he had 4 cuts about half an inch long and put him into another tank). <<Likely the two are together in a 'too small' environment>> This month he has been fighting his reflection in the glass for the past 3 days. <<Typical behavior for most any territorial species>> My tank is a 125 with a 55-gallon sump and 200 LB of live rock, chemicals are all good. <<Mmm, yes'¦and too small to be mixing this large (can exceed 16' in the wild), very active (likes LOTS of open space), and very aggressive fish (did I mention 'mean?') with other Tang species>> I was curious if the Full Moon cycle could up his aggression? <<Honestly, I can't say for sure'¦ But, if you're not running some type of controller/gear to replicate the Lunar Cycle how does the fish know? Or maybe'¦the fish senses/feels a change in gravitational forces'¦>> Because I found that most tangs breed in the wild by Full Moon, or New Moon. When it first got really aggressive was a Full Moon and this time the Full Moon just past. Thanks for your input. Kevin <<The Lunar Cycle may well induce a neurochemical change increasing aggression in this very aggressive species (is thought to happen to humans too)'¦which is already exacerbated by the confines of the tank and too much rock/not enough open swimming space for the Tang's liking. Regards, EricR>>

Appearing and Disappearing Nostrils   9/28/07 Hiya Guys and Gals of the Crew!! <K and H> Good Afternoon. Here comes the (self-proclaimed) goofiest query of the day. <Mmm, okay> We have 2 Canary Wrasses in our 90 gallon display tank. They were purchased together, quarantined together, and went into the display tank together. They are awesome fish; very busy and very curious. We are thoroughly enjoying their addition. One has clearly "sexed" male (orange and green stripes on the head) and the other remains female/juvenile male. She (I'll use "she" for ease) has nostrils that seem to appear and disappear. She usually starts the day without them and during the course of the day they may appear (as well defined black dots) and disappear several times. If she is trying to send us a message, we are missing it. I've been looking at our books and here on WWM, but I am unable to find the significance (if any) of this. Hubby said, "You'd better email the crew!!", so here I am. Any input would certainly be welcome and most appreciated!! As always, thanks for all you do!! Kerry and Hubby <The nares do have extensible flaps... likely are folding over and not... Bob Fenner>

Fish Memory  9/27/07 Hello, my name is Mia, and I will be soon doing a science fair project on memory of domesticated fish (fancy guppies) vs. wild fish (wild guppies). I was just curious whether anyone in the Crew knows much on this topic. It is difficult to research well on line, and wanted to ask people who really know about tropical fish. It would be great if you could give me some information on this. Thank you very much! (P.S. Your site is great!) <Greetings. There are several good books on fish behaviour, any one of which should give you some groundwork on this subject. One of my favourites is "Fish Behavior in the Aquarium and in the Wild" by Stephan Reebs, Cornell University Press, 2001 is perhaps the easiest to read book on the subject. "Fish and Their Behaviour" by Gunther K.H. Zupanc, Tetra, 1985 is another good primer. Your local library should be able to obtain these without much bother. Once you're up to speed on the basics, you'll be ready to tackle the scientific papers. Google Scholar is a good way to browse the literature. You'll probably need to use the Latin name for the guppy rather than its common name, and you'll also need to use relevant buzzwords to limit the results, things like "ethology" and "memory" and "learning". I'll give you a warning though -- scientists, of which I'm one, don't respond well to messages that say "Please tell me everything you know about X". Such messages get deleted faster than you can say Jack Robinson. Instead, be more intelligent and research the subject before asking a question. Ask a scientist something like "I read your paper on X, and it seems to disagree with scientist Y who did a similar experiment; why do you think that was?". One last thing -- you can't research everything online. Many of my students assume they can, and they crash and burn soon after. A trip to the library -- especially a large city library or academic library -- is the way forward. Consult with a librarian, and be prepared to read actual books and semi-popular science magazines such as Scientific American and New Scientist. In the trade, we call that "legwork", and there's really no getting away from it. Good luck! Neale>

Nocturnal feeding?    8/7/06 OK, here's a really basic question. Do nocturnal fish (e.g., a Redcoat Squirrelfish [Sargocentron rubrum]) stay nocturnal eaters, or will they adapt to daytime feeds? Grace, BJ Mora <Most all species, individuals that are nocturnal, can/do become more active during light periods in captivity. Bob Fenner>

Reflection...again    3/2/06 Just sent an Email and I guess I'm a little dumb. You see, I was looking through the glass through the TOP of the water, and someone said, "I think he can see out as he's inSIDE the water" and I was like "no I don't think so." So I took a plastic baggie, put it into the water and looked out the glass through the baggie in the water and all was well. It's just weird that he doesn't acknowledge my finger (I tried to see if he would follow it through the glass) and focuses on one area to flare around. Wait, can the plastic alter my perception of the reflection? <Not likely> Here are some pics See how its reflective? <Oh yes> This is me looking through the bag and not seeing a reflection This is him "Fighting" with himself I think <Okay... BobF>

Scary Tank? 7/7/05 Hi WWM crew, <Alex> I have always seen fish swimming peacefully in LFS display or other people's display and I have a 45G salt water tank set up for almost a year already. The weird thing is, my fishes in my tank are always seem restless. They are always nervous and hiding. Wherever there is sight of a human moving in even 5 meters away, they will all dash like crazy and went hiding or go dash from one side of the tank to another. I have about 45lbs of live rock in my tank and made quite a few hiding spot for them. But i just can't make them feel safe. I sometime feel that this whole issues is because i have the tank setup at a location which has quite lots of human movement, but then i saw a tank in the middle of a shopping mall with almost hundreds or thousands of people walking around it and the fishes are all fine! They just swim around the tank and never seem bother to swim up to the glass and check out who's on the other side. What can I do to fix this problem? <Mmm, it may well be that you have a "chemical" issue here... I'd spiff up (clean) your skimmer, and add a unit of Chemi-Pure and a Polyfilter in your filter flow path... to remove organics...> I understand that some fish need long time to settle and before that they will hide all the time, but it now seem that ANY fish that enters my tank went crazy (even when they were fine in the LFS display). Is there anything i can consider doing? (besides moving the tank) What about covering the sides of the tank? I once had a well eating Moorish Idol who did great in my tank and even let me hand fed. And my cleaner shrimp is doing okay, but all the other fishes seem to be in constant nightmare.   BTW, i currently have 2 ocellaris clown (which ALWAYS hide in between rocks except dashing out for something to eat at feeding time), <Unusual> 1 saddled butterfly, and 1 copperbanded butterfly (both dashes like they are going to die the moment they see me from 5 meters away. The Clownfishes were here for almost 3 months (they were fine before) and the butterfly I got them recently (almost a month). <Not outgoing fishes, these butterflies, for such a small system... but I would try the chemical removal route here... and if the chaetodonts go, look into more outgoing species. Bob Fenner>

Re: Scary Tank? 7/9/05 Hi again, <Alex> Just curious here but why bad water chemistry can make fish hide? <Can... mainly metabolites... some pheromonal. See here: http://www.wetwebmedia.com/FWSubWebIndex/FrightChemsFWArt.htm> And also, you mentioned that the butterflies are not outgoing fish in such small system, do you mean that they only hide so much and be so shy in small system? <Mmm, that they hide more and are more skittish in smaller systems> Sorry and hope you don't mind i add one quick question here, can copperband butterfly and saddled butterfly be kept together? <Yes> Because I search through the internet and i didn't find anyone who mentioned butterflies can't be kept together like tangs. But I notice them fighting for a little bit (usually the saddled chasing away the copperband) when they both try to eat the same fresh clam i offer them (the only thing they will eat). Thanks <I would expand their food selection... please see WWM re. Bob Fenner>

- Fish Behavior - Hey guys. Thanks for your website. I read it quite frequently. My current setup consists of an Ocellaris Clownfish, Pajama Cardinal, Royal Gramma, a striped damselfish and a newly added Red Firefish. The firefish is doing well since I added him last week but he has not been coming out much because when he does, the other fish chase him it seems like. Then, he just goes and hides in the live rock for a little while until he decides he wants to make his appearance once again. Is this a normal situation to have? <Yes, especially in the first month or two.> I have never seen an instance like this, I have seen the situation clear up as the other fish become more acquainted with the new tank mate. <Yes, although the longer fish have been in one place, the more territorial they get so that any new addition is always at a disadvantage as all the good spots are already taken, and the newcomer is perceived as competition for food. Time will tell.> Let me know if there is anything I can do, and tell me if this is the norm. Thanks, guys. I do greatly appreciate your help and assistance in matters such as this. <Cheers, J -- >

Hiding Fish (4/20/03) Steve, <Ken> Thanks for the response. <No problem> You mentioned that my fish may be hiding due to too much light. What is too much? I have 1 175 watt 20,000 k metal halides on the tank. Ken <I don't think that this is too much light from the standpoint of coral growth, etc. I am merely speculating on things that might make your fish hide so much. They may feel insecure if the lighting seems particularly bright and there are not enough spots where they feel safe. Some of the other issues I mentioned could be the real source. Although it seems to me that the stray voltage is less likely as a cause, it would be nice to be rid of it. Try one of those probes and see if this cuts it down.>

Fish training Bob,         I want to thank you for all the information that you provided me with in your book "The Conscientious Marine Aquarist". <Glad you found it useful> I kept South American cichlids for years before going to salt water this past year. I originally was going to do a discus tank, when my girlfriend i.e.....Jen got me your book for Valentines day. I have read most of it over and over because of all the information that you gave and keep going back to it for reference. Any good tips for training my clown trigger "Bill" to do tricks? <Positive reinforcement (mainly food rewards) for doing or going towards doing what you want (break tasks down into increments... e.g. moving a ball through a hoop... by rewarding touching the ball when entered into the tank...>     I have a 75 gallon tank with eighty lbs. of crushed coral, twenty five lbs. of bare honeycomb rock and a three lb. piece of live rock,  I run a Fluval 404 and a Red Sea Prizm Pro deluxe skimmer. I have a 48" double bulb strip light with a 10,000k and a Magtinic by Coralife. I'm thinking of adding another fixture of the same type but with a 10,000k and a 20,000k bulb in it would that be okay? <Sounds good.> Thank You Adam <Be chatting, Bob Fenner>

Re: Training a fish? Hi Bob, <Des> This isn't really a question, but yesterday someone asked re: training a fish. I thought this reader might be interested in this link, it's about  goldfish not a trigger, but I think a trigger would be a better subject anyway. Anyway I recommend clicker training. Here's the link: http://www.clickertraining.com/training/advanced_topics/ index.htm?loaditem=training_a_fish&itemnumber=2&salesitem=advanced_s The author of this page has also clicker trained an Oscar. --des <Thank you for this input. Will post, share. Bob F>

Feeder fish became friends with predator? I have had my brackish tank, home to my two green-spotted puffers, for a little over a year.  Until three months ago, my puffers were the only occupants.  I threw a guppies in the tank as a little treat and to my surprise, the guppy was there days later.  Not only has that guppy survived in brackish water surrounded by predators, there are now a total of four baby guppies living in this tank.  The first of the young appeared about four or five weeks ago and has grown considerably.  The other three have appeared in the last three days.  I introduced a new puffer to the tank yesterday and figured it would probably make a meal out of my unusual little friends, but he doesn't show any interest.  I do not understand.  Is this normal or as bizarre as it seems? <Does seem odd, but this is not unprecedented. Fishes to varying degrees are what humans label as "autistic", and if the "food" was in the tank ahead of the predator... it/they might well not be recognized as food items... Consider as an example the sacred cows of Hindu India... Bob Fenner>

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