this is your fish's brain

Are my fish smarter than yours?

Maybe I’m a little too competitive, but I found myself wondering, “are my fish smarter than yours?” because of a thought-provoking article I read on the Discover magazine blog. The original post highlighted the results from a study about brain development in fish. Here is what I learned about the study:

This is your fish’s brain:

this is your fish's brain

by Steve Johnson

This is your fish’s brain in a boring tank.

your fish's brain in a boring tank

by g4ll4is

Any questions?

The research team (at Penn State, I think) was evaluating whether the brain development of juvenile Atlantic Salmon was affected by the environment they were raised in. One group of salmon were raised in a conventional aquaculture setting (probably a big round empty tank), and the other group was raised in a vessel that was decorated with rocks and plants in a way that suggested a more natural habitat for the fish. The scientists then observed how each of the two groups of fish navigated through a maze.

It turns out that the fish raised in the decorated tanks made fewer mistakes and were faster at completing the maze exercise than their counterparts in the generic tanks. This observation was also supported by an increase in the neurotransmitters associated with memory in vertebrates. The full study was reported in the Proceedings of the Royal Society B.

While it may be a bit premature of me to assume these results are broadly applicable, it does cause me to ask a few important questions:

  1. Is aquaculture making our fish dumber?
  2. Does the way we set up our tanks affect the health, development and overall wellness of our fish?
  3. Finally, if I try really hard, can I make my fish smarter than yours? (darn it, there’s that competitive streak again)

Is aquaculture making our fish dumber?

Seems like the data from that study suggest…maybe they are. I’d love to find out more. I have read accounts that conditions (like nitrate level in the water) can cause or accentuate misbarring in clownfish (the formation of incomplete or missing stripes). We know that things like stray voltage can cause stress and HLLE (head and lateral line erosion). But can a lack of a suitable environment (defined as structure, decoration or otherwise specified habitat) make these fish dumber? What else is this affecting?

Does the way we set up our tanks affect the health, development and overall wellness of our fish?

While the study was specifically conducted in just one species of fish (a food fish, not even an ornamental fish) and in aquaculture only (not in a hobby aquarium setting), it does raise a big question in my mind about how what we do may or may not be affecting the development of our fish. I sincerely believe that the vast majority of hobbyists take the care and health of our fish and corals very seriously, but how extensive is the habitat effect really? I could make an argument that an aquarium with a sand bed is a more natural environment than one with a bare bottom–will fish in an aquarium with a substrate be healthier than those in a bare-bottom tank? What about fish in a tank with a pirate ship and Sponge Bob’s house compared with a tank with extensive live rock? Does it matter how the live rocks are arranged?

I think a lot of us naturally aspire to recreate a lifelike habitat–but wow–imagine if you knew a certain type of setup was shown to improve Fish IQ by 2 points–you’d follow that setup, right? It really makes me wonder if there is more science behind arranging our tanks than we give consideration to.

Are my fish smarter than yours?

I really meant that question a joke. Of course my fish are smarter, and my fish’s dad is tougher than your fish’s dad, too.

Final thoughts ramblings

Is this the equivalent of ‘free range chicken’ in our hobby? Should we be inquiring about the habitat conditions of our aquacultured fish? I don’t mean this question to be an indictment of aquaculture. Aquaculture facilities are performing yeoman’s work—they are supplying the hobby with thriving, easy-to-care-for fish and are saving our reefs. I guess the question I’m asking myself (and in turn asking you) is…”self, if fish need habitat to develop properly, isn’t the ethical thing to do to provide them with that habitat?” And if the impact of that is that the cost to raise fish via aquaculture goes up, are you willing to pay more money for a free-range fish than you would pay for a mass-produced fish?

So what do you think, is the way you aquascape your tank affecting the way your fish think?

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