Familiar fish:
Here is a fish for you.
SOURCE: NASA
Published: 15 Sep 2009
Japanese Medaka fish (an embryo is shown here) were among the first animals used to study embryo development in space
http://www.computerweekly.com/photostory/2240108500/Photos-Gravity-experiments-in-space/4/Japanese-Medaka-fish-were-among-the-first-animals-used-to-study-embryo-devel
It’s called a medaka or rice fish. Popular as a pet. Found in rice paddies in southeast Asia. And of course it can be used for science. (Teruhiro Okuyami et al. A Neural Mechanism Underlying Mating Preferences for Familiar Individuals in Medaka Fish SCEINEC vol. 343 no. 6166 January 3, 2014 page 91)
The key point of the article is that the females prefer males they have met before. That’s not universal among animals. Sometime, as in humans, familiarity reduces sexual attraction. At least among children who grow up in the same household they seem not to want to marry their siblings, which is a jolly good thing I am thinking. The article does mention other cases where females like familiar males. Here, however, they’ve worked out at least a part of the neural mechanism behind it all. So plants are smarter than people. Fish are smarter than people. Go figure.
By the way, if you chase down the link you’ll find that fish do rather better developing in zero gravity than do land animals. Why am I not surprised?
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