Study Ideas - Help Needed

[Flutter]

For my ichthyology course I need to prepare a presentation. It needs to be based on fish biology (for example: a comparison of an anatomical feature or group of features, in two groups of fishes, relating this to the functional evolution of these features in the two groups...).

The topic must:
- must be comparative in nature
- focused on any aspect of fish anatomy, development, live style or specialized adaptation

It needs to include puffers in some way obviously I was thinking that I could look at toxins in puffers and another type of fish or dentition of fish that eat crustaceans but neither of those are overly exciting. There's got to be something better out there and I'd be happy to share whatever information I find (needs to be from scientific literature only).

Anyone have any ideas? What do you guys think?

[J-P]

If you are gong with toxins: you could ask the "how and why" questions. 2 different species from 2 different parts of the world.

Or.. how does a puffer retain toxins, and other fish having similar diets do not produce toxins.

[Pufferpunk]

Do you know that in CAN, they are using the puffer's toxin as a painkiller & also to detox opiate addicts?

[RTR]

The toxins in puffers are bacterial sourced, just modified and stored by the fish. They must be replenished periodically. The blue-ringed octopus uses the same stuff, as do some newts/salamanders.

The structural modifications of puffers for inflation are really more bizarre, and the family has no surviving near relatives - so it is not easy to pin down the sequence of their development. Even within the family, the variants are pretty extreme. Plus the studied members have very "clean' DNA - quite uncommon in vertebrates. They are poster children for specialized evolution and have to be considered highly successful - they are circumpolar in the tropics and have re-colonized freshwater on all the major continents in the tropics. Some few handle temperate saltwaters well, but none make to the polar regions.- yet.

[Flutter]

Their genetics are definitely very unique, there are a ton of papers out there on that. I actually couldn't find any papers on inflation, you'd think that there would be at least one (there probably is, just that my school doesn't have access to it which is odd in itself as it's well known for its ichthyology).

The main papers that I have found are on innervation and genetics. Fingers crossed that I can find something that interests me more.

[Flutter]

Other than puffers what types of fish are out there that have mechanical defenses to predation? I've found some interesting papers on puffers but I'm not sure what to compare them to. Hagfish would be neat but it's debated if they're even a fish and I don't want to wait to hear from the prof about them

[J-P]

http://www.mapoflife.org/topics/topic_4 ... nflation)/

that is a fairly god article. It mentions a swell shark.

Would the spines of a lionfish be considered mechanical? If so, that includes toadfish.