NO GIRLS ALLOWED! :)

[jimhobbs]

http://www.invertebratebiology.org/img/119_2.jpg

This clam shrimp (Eulimnadia texana), a hermaphrodite, is brooding a batch of fertilized eggs within its delicate folded carapace, which resembles a bivalve's shell. These freshwater crustaceans are among the few animals or plants displaying androdioecy, a rare sexual system in which males coexist with hermaphrodites, but there are no females. Such systems should persist only under severely limited circumstances--according to a mathematical model--but could be explained if hermaphrodites were able to store sperms after mating. Can they? Using genetically marked matings between males and hermaphrodites, Weeks et al. have answered this question, but the paradox remains.



Good morning Dr!:)
Question: If there are no females, where do the eggs come from to begin with?...I was reading through this and couldn't for the life of me figure out where the hermaphrodite got the eggs...I guess I'm just stoopid:D

Have fun guys!

[rshimek]

Hi Jim,

No, you're not stupid; just the victim of semantics...

Hermaphrodites have both male and female plumbing and organs. So, the eggs come from the hermaphrodite's female system.

There are no individuals in this species that are only female, but the hermaphrodites function as females part of the time.

Conchostracans like the critter you illustrated are pretty neat animals. :D

[jimhobbs]

For some reason I was thinking the herm's had the "plumbing" but none of it was functional!:D I ran across that critter on the Invert biology site (http://www.invertebratebiology.org/) and was confused!;) {That's not hard to imagine!}

Many thanks!...I'm sure I'll have other questions as I dig through that new site:) Whenever you get ready for another class, I'm in!

Best regards...

[nick danger]

This is a technique used by a few other arthropods as well, most who live off of nutrient sources that are difficult to find. The idea is to self fertilize and reproduce (in the case of mites only as females) asexually when a nutrient source is found, increasing reproductive rate VERY quickly (as long as the nutrient source still exists) but sacrificing the boon of gene mixture in sexual reproduction, saving this mode of reproduction for later.

Stephen Jay Gould discusses this in an essay called Death Before Birth in "The Panda's Thumb" and I believe in another essay as well, but I can't find it.

However I recommend every single book the man wrote. He's a genius.