|Email:||shuang (at) dimax.rutgers.edu|
|Home Institution:||UC Berkeley|
|Project:||Application of game theory to black sea bass mating|
The goal of the summer research project is to use a game theoretic approach to understand black sea bass mating and its conservation implications. Black sea bass are protogynous. All black sea bass are born fully female and remain so, until circumstances prompt a change into male once in their lifetime. Male black sea bass individuals safeguard groups of females, who do not change sex and with whom the male mates exclusively, keeping other males away. Larger males are usually more successful at obtaining mates. Given such a situation, one would expect to observe larger males over time. However, recent measurements show that black sea bass males are becoming smaller, raising concern for environmental implications. The model will consider mating strategies regarding sex change and seek to determine what size black sea bass should turn into males from females to be compared with observations of when black sea bass are turning into males from females.
Compiled basic information regarding black sea bass and game theory from books and meetings for a brief presentation giving an overview of the project. Gained understanding of black sea bass physiology, mating behaviour, life cycle, and population. Readings on game theory focused on gaining understanding of evolutionarily stable strategy and more specifically, competition for mates.
Continued examination of resources on black sea bass and game theory. My mentor provided six papers regarding black sea bass populations and mating behaviour. The papers on mating behaviour included not only information on group level behaviour, but also details about the sex change at the physiological and chemical level. A few of the papers on population describe time of the breeding season and time of sex change. Interestingly, the data that I glanced over do not suggest a decrease in black sea bass size over time. However, the data was pooled from the entire east coast and concerns for size decrease may be local to New Jersey.
Mustered reasonable understanding of Amira's paper on game theory and hermaphroditic fish. Thought of ideas for adjusting the model for the black sea bass mating system. Amira's model describes a type of fish that can freely change back and forth between male and female, unlike the black sea bass which changes once in a lifetime from female to male. The model would have to be adjusted to reflect the strategies available to black sea bass.
Typed up code mirroring Amira's model but adjusted for black sea bass. Some gaps are still to be filled in, such as a function for male-male competition for mates, the constant cost of reproductive resources necessary for performing a sex change, how much reproductive resources are available at each size, and the allocation rate for female and male roles. These details are missing from Amira's paper, but in some cases, I've substituted my own estimate for what should be appropriate.
Met with Nina to discuss sex allocation, resources required for sex change, etc. She clarified just about everything on which I wasn't sure. Began implementing male-male competition and other things I mentioned to be missing in the previous week's post. Thought of ways to format raw data, which I have still not seen, into an initial seed for the model.
Completed the model based on Amira's paper. It functioned as expected. Moved on to including natural birth, death, and growth. This produced some problems.
Finished second presentation and gave talk. Met with Nina to discuss a new approach to including population into the model, encompassing birth, growth, death, and fishing. Adjusted the game pay off to account for uneven population distribution across sizes, which seemed to work as expected.