Saturday, March 9, 2013

Gender Bending

This article talks about different ways in which bizarre sex strategies occur within different types of species. It’s typical that a female would carry the eggs and the male species would donate the sperm, but according to recent study, the exact opposite is happening. Scientists have found that in certain species, the male is caring for the offspring during and after reproduction.

In male pipefish, the males actually pick their mates based on size. The larger the female, the more likely he’ll want to mate with her. This occurs because the male pipefish is looking to create stronger offspring and the size of the female fish could potentially mean more successful fertilization and reproduction. Once he finds the right sized mate, the female pipefish will transfer her eggs into a special pouch in the male pipefish and wait for fertilization and reproduction to occur.

To prove that males prefer a larger mate, scientists mated a male pipefish with both a small and large female pipefish. The results were uncanny. Not only did the male fish carry more eggs when mating with a large female, but also the care taken for those offspring was much greater. The survival rate of the unborn offspring from the large female pipefish was higher than those that came from the small female pipefish. The evidence shows that males favor the eggs of the larger female and pay better attention to their care during fertilization and maturation.

Scientists believe that these male pipefish base their reproduction off of their own chance of survival. It’s believed that the male pipefish have a higher chance of nourishment and survival from a larger brood of fish versus a small brood. When the fish carry the small female’s eggs, they are spending their resources on making them stronger instead of spending the resources on themselves. Interesting, huh?

Kimberly Ty (3)

Edited my blog (2nd paragraph)


  1. That is interesting. A larger female would mean that she has survived longer and has been able to provide food for herself. So the male would want his lineage/genes to be carried on by a strong gene female.

    Sunni-Lynn Farias (1)

    1. Thanks for the input! I will include this in my post.

      Kimberly Ty (3)

  2. It's interesting how the male gets the mate choice in this species. Usually the females have the choice because it costs more energy to produce eggs.

    Cool article.

  3. There are certain male frogs that fertilize eggs with the female, and then carry around the eggs wrapped around their hind legs or elsewhere in their body! Pretty cool to see that another species puts in some sort of parental investment like this as well!

    Cynthia Bui (1)

  4. Why do you think this mating strategy of the males carrying the eggs for the females might have evolved in the first place? I am having trouble seeing what initial advantage it might have had over the larger females simply caring for the eggs and offspring themselves. Do you know how many females a typical male mates with over the course of his lifecycle? Having to care for offspring would seem to limit his ability to find more mates, and I'm assuming that males generally reproduce more than females. As a result, this would seem to limit the reproductive capability of the species.

    Posted by Sean McDougall (2)

  5. This is great information supporting the theory that mate selection is oftentimes based on the expectation that one is healthy or strong enough to support babies. Seahorses, who are closely related to pipefish, also chose mates based on size and health to ensure successful passing of their genes.

    Ashley Sterpka (1)