Crazy Animal Photo of the Month

WTF, right?

I scanned this photo from a 1963 book called "The Fishes" from Time/Life's Nature Library series. Apparently the hoods on the fish block their lateral line, so they no longer swim away when someone sticks their hand in the tank. But I think it is more likely that their loss of reflex is due to excessive brainwashing by the Hooded Fish Cult.

I wanted to find a scientific paper to go with this image, but a web search of the supposed researcher "Dr. Theodore Walker" yielded few results related to this particular picture of the hooded fish cult.

Dogs decoded

NOVA has got a fabulous new show on dogs, that happens to be playing right now, as I blog this. I love NOVA because they show the science process in action by filming experiments and interviewing scientists. The show covers bonding behavior between dogs and humans, dog intelligence, and the evolution of domestication. I happen to know a lot about dog behavior and evolution, and I can vouch that the show is actually quite accurate!

Check out NOVA's webpage on the show here and try to watch it on your local public broadcast station!

Sexy stickleback

For biology nerds and J.T. fans:



That's right, it's a song about stickleback to the tune of "Sexy Back". UC Berkeley seems like a fun place.



PS In case you weren't aware, here is what a stickleback looks like. Sticklebacks are great organisms for the study of evolution because they have evolved different morphology (and behavior!) depending on their environment. For example, ocean stickleback are different than lake and river stickleback. Even in the same lake you can find two different forms of stickleback in the deep and shallow parts of the lake. By making hybrids and looking at their DNA, scientists have found genes that control different parts of stickleback development and morphology.

Comments now open....

Hey I just realized I may have previously missed out on a lot of comments, since I never changed blogspot's default commenting option of "registered users only".

It's open to anyone now, so go forth and comment!

Rad animal behaviors in the news [Links]

This week's links are dedicated to Paul, the psychic octopus, who died last week.

Scicurious explains how a parasite can turn rats into cat-loving zombies.

How butterfly fish use their swim bladder to croak like a frog

Read The Curious Case of Dogs, especially the part about how feral dogs in Russia have learned to ride the subway.

Someone photographed an epic battle between a spider and a millipede.

Ed Yong had a bunch of awesome links posted this week, here I have stolen five cool ones regarding animal behavior:

The Thoughtful Animal covers robot lizard push-ups

Clever crows go to tool school?

Humans are animals too! Neuroanthropology discusses how cooking contributed to human evolution.

This one is a little creepy. Russian bears are starting to eat corpses out of graveyards.

King cobras at the NYTimes.

And here are some more awesome stories I have read recently, copied and pasted straight from my bookmarks menu:

Wine-scented flower draws in fruit flies with yeasty tones | Not Exactly Rocket Science | Discover Magazine

Study: A “Pessimistic” Dog Is More Likely to Destroy Your Slippers | 80beats | Discover Magazine

Wolf Nannies Shorten Sex Lives of Male Pups | Wired Science | Wired.com

Evolutionary arms race turns ants into babysitters for Alcon blue butterflies | Not Exactly Rocket Science | Discover Magazine

Untitled Vanity Project: Scientists Create Fearless Zebra Fish

Forget Elephants; Sea Lions Never Forget! : The Thoughtful Animal

Mucus for dinner

The proud parents and their mucus eating fry.

Cichlids are great parents. All cichlid species contribute some degree of parental care, with many extreme examples, such as the mouthbrooders who forgo eating for several weeks while their eggs develop in their mouth.

The Amazonian cichlids known as discus fish (pictured below) secrete mucus from their bodies for their baby discus fish to eat. I wonder what it tastes like?


Journal of Experimental Biology has a new paper on them entitled "Biparental mucus feeding: a unique example of parental care in an Amazonian cichlid" that you can check out if you're interested. Or read the short press release here.

Is your fish a lefty or a righty?

You probably know that the right and left half of your brain do slightly different things. This is called lateralization of brain function, and it turns out fish have it too!

How do we know? Behold, the amazing detour test:

My drawing of the detour test, featuring Klaus.

So you make a fish detour around a striped clear barrier towards something on the other side, and whether it turns left or right can tell you about which side it prefers to view specific stimuli. This works because fish have monocular vision, with each eye on a different side of their head they they see totally different things with their left eye versus their right eye.

There have been a bunch of cool studies using this detour test that suggests that there is lateralization for aggression in a cichlid (which also depends on sex!) and in some other fish, sexual behavior, predator avoidance behavior, and much more.

One of my favorites is titled "Sex differences in the cerebral lateralization of a cichlid fish when detouring to view emotionally conditioned stimuli" (Reddon and Hurd 2009). Even though they didn't find that many significant results (only one), I found this study awesome in its design. I mean, they were emotionally conditioning fish! How do you get a fish emotional? Show it a fishstick?

Here's how they did it. They conditioned convict cichlids to associate an object with either food (positive emotional valence) or a chemical alarm cue (negative emotional valence). The objects they used were probably just lying around the lab, but they seemed to work well for their purpose: a blue pipette tip box and a yellow tennis ball.

The conditioned stimuli. 

Then they gave the fish a detour test with the emotionally conditioned stimulus on the other side of the barrier. Their fish didn't seem to have a preferred side overall, regardless of whether the stimulus was positive or negative. However they did find an interaction between sex and emotional valence on lateralization: males were more lateralized in response to the negative stimulus while females were more lateralized in response to the positive stimulus. However, whether the lateralization was to the left or the right depended on the individual.

So unlike other fish, where lateralization is consistent within a population and is genetically based, it looks like convict cichlids are lateralized at the individual level. The authors don't come up with an explanation for the sex differences that they found, although they do mention that convict cichlids are biparental and males and females typically have sex-specific parental roles. The males primarily defend the offspring from intruders will the females stay close to the offspring and nurture them. Perhaps males have a specialized center on one side of their brain that responds to alarm cues, in order to respond better to attacks from predators?