Animal kingdom trivia

The first one is about mating, but make it more general.

I ran across a story in about peacocks. It seems that the males have to hang around in gangs for the females to be attracted. In these gangs, several peacocks are brothers. The less attractive ones are just there to make a big group. This apparently helps the mating, more handsome, brother pass on his DNA. Original story in Nature(one author is Marion Petrie, also Paul Sherman), if someone wishes to look for it.

You may add a link to your favorite Cecil critter column, we’ll review those too.I’d like to stay away from cats and dogs, just so it doesn’t become a “my pet did this” topic.

How about those sex-changing, harem-keeping, sneaky little reef fishes?

I’ll try to keep this brief, but there are so many fascinating aspects of reef fish courtship and mating behavior.

Many species of reef fish start off as one sex and then undergo “the change” at some point. Some spawn first as females then as males (and vice versa).

Some juvenile males (and females!) are genetically programmed to turn into “supermales.” They normally keep a harem of females around. If the supermale is killed or otherwise removed from the group, the dominant female in the harem will change into a supermale herself.

Some species can assume the male or female role at any given time depending on the partner fish they come across.

Male fishes, too, often gather in groups like sunbear described. Bird groups like that are called “leks.”

Often when a supermale is courting a female, a young male, called a “streaker” (which looks just like a female) will dart in at the orgasmic moment and have his seed fertilize the eggs released rather than the supermale’s (Joke’s on you, big guy!) :).

Sometimes the supermale will fake the youngster into releasing sperm prematurely (honestly, Ms. fish, that’s never happened to me before!) :slight_smile:

Okay, I’ll stop now.

Souvenieeeeers, nov-elties, par-ty tricks

I gather these are live bearing fish, not egg laying? A lot of aquarium fish (moons, swordtails, several others)give birth to eggs hatched inside the female. Angelfish and Gouramis are egglayers.

No, most reef fishes are pelagic spawners; that is, the male and female release their gametes into the water column, where fertilization takes place. The resulting fertilized eggs become part of the zooplankton with a survival rate much less than 1%.

Sometimes fish have a group spawning event (basically a mass orgy); sometimes they pair off.

Some fish pair off for demersal spawning, where the female (or sometimes male, depending on species) guards a nest of eggs that a male has fertilized. Survival rate is much higher for these young’ens, but of course there are fewer to start with.

Housecats (and possibly wild cats as well) have a vestigial clavicle (collar bone). It looks like a tiny toothpick and simply “floats” in the tissue below the neck.

This also means their forearms aren’t connected bone-to-bone to the rest of the body. (The “shoulder blades” do rest against the rib cage, but don’t have any socket attachment.)