10. Microphis deocata Dimorphism

 In this week’s module, we learned about sexual selection. I always wondered the reason why, across the animal kingdom, males and females in the same species can sometime look drastically different from each other. There are very unique aspects between the two, and most often males would possess external traits that are far more colorful and extravagant than the female. This is a process called sexual dimorphism, which is generally triggered by the process of sexual selection through competitive mating (Leary, 2020). This can manifest in many ways such as color, size, behavior, feathers, antlers, and more. One of the well-known displays of dimorphism is the peacock. The male peacock usually has a large fan of iridescent blue and green, while the female has shorter feathers of brown or gray. Dimorphism was first proposed in 1996 by an English geneticist named Angus John Bateman. The Bateman’s principle is summed up to be that in that most species, variability in reproductive success is greater in males than in females. In short, female eggs are far more valuable and less available than the ejaculates of males. However, after learning about Microphis deocata, a pipefish species that experiences a unique form of dimorphism. The female fish exhibits far more color and pattern, while the male is much duller in color. We were asked to ponder on how something like this was to evolve. With our knowledge of sexual selection theory, we can explain why female courtship might have evolved in this species. Once females have chosen a mate and the male fertilizes the egg, the female will deposit the eggs onto the male. The male will them remain holding the eggs until the end of the incubation period (Praquatics, 2019). It is this reversal of carrying or protecting the eggs that give the females such a unique feature of color, pattern, and size, and leaving the males in very dull color. Males are at a higher value while carrying the eggs than the females. 

Leary, C. 9 of the Most Dramatic Examples of Sexual Dimorphism. www.treehugger.com. (2020). 

Praquatics. Rainbow Belly Pipefish. Poppa Ryno’s Aquatics. praquatics.com. (2019).