Population dynamics of fish with complicated life histories

grouper copy
In general, I am interested in the general connection between life histories of fishes and their vulnerability to overfishing. I have been interested in how this plays out in sex-changing fishes like groupers (Serranidae) for several years. I am using age-structured models to connect these evolutionary insights to population dynamics. These fishes tend to be both female-first (protogynous) sex-changers and heavily fished. This means that for many groupers, females outnumber males. My goal is to predict the consequences of female-first sex change for population demography and productivity, and how this interacts with fishery selectivity.

However, groupers are not the only fish in the sea! I am involved in understanding how life history complexity interacts with fishing in other species, including salmon, tunas, and sharks and rays (more on that below).


Inferring the status of Data Deficient species

Recently, I was awarded an NSF Grant along with my colleagues (Marc Mangel, Jason Matthiopoulos, and Nick Dulvy). We are working to combine and analyze fish life history traits, survey data, and stock assessments from fisheries around the globe, which are increasingly available for large-scale analyses. These data offer a unique opportunity to use modern computational methods (e.g., Bayesian state-space methods) to infer the status of a population or species without traditional assessments – something that is urgently needed for many fish species. The objective is to impute the trajectories of data-poor populations by using informative priors and information on species with shared traits (i.e., related species, or heterospecifics caught in the same habitat). We are developing a hierarchical framework to assess the status of high-value marine fishes that have limited abundance data, such as tuna relatives, groupers, and sharks and rays.

This approach is only feasible because it takes advantage of our existing knowledge of life-history evolution to generate informative priors on the Bayesian models. However, for many marine species, we still lack a robust understanding of the relationship between life history, demography, and population dynamics. For example, we cannot yet predict how the population dynamics of an egg-laying skate will be different from those of a live-bearing stingray. I am extending my evolutionary models to predict the co-evolution of traits such as growth, body size, and reproductive traits (e.g., mating system). In this case I am focused on using state-dependent models to incorporate predation risk and prey availability – using marine size-spectra theory – into models predicting growth and reproduction.

Mating systems in space and time

Corsica 2011

I have an ongoing collaboration with Suzanne Alonzo to study how social interactions and spatial structure in male types affect mating success. I have worked on this topic in multiple systems, including swordtails (X. birchmanni), the tessellated darter Etheostoma olmstedi, and the ocellated wrasse, S. ocellatus (below). These species all have multiple male mating tactics, which makes male and female interactions very interesting.

This research involves developing new theory and testing it in the field. It integrates fundamental concepts and techniques from population ecology, phylogenetics, behavior, and even neuroscience. The ocellated wrasse population at STARESO, a field station on the Mediterranean in Corsica, has been studied intensively for three decades. This rich foundation of knowledge provides an opportunity to address some deep questions in ecology, evolution, and marine conservation.

Symphodus ocellatus

wrasse algae copy
In 2014, I began a field project focused on the spatial and temporal processes contributing to mating success in wrasses. The dynamic reef community in Corsica provides a fascinating window into the biotic and abiotic interactions that structure marine communities over time. But these fish are puzzling – despite strong dimorphism between nesting males and females, the wild popularity of some of these males can’t be explained solely by female choice. I developed the hypothesis that social interactions between other conspecifics and even other wrasses could be playing a role in mating success. In the future, we are planning to use a combination of theory and studies of social interactions within and between these species to better understand the diversity of colors, sizes, and behaviors in this clade.

Relevant papers :

Kindsvater HK & Alonzo SH. 2014. Females allocate differentially to offspring size and number in response to male effects on female and offspring fitness. Proc. R. Soc. B 281, 20131981

Kindsvater HK, & Alonzo SH. 2013. Short-term dynamics of territory occupancy in an allopaternal species, the tessellated darter Etheostoma olmstedi. J. Fish Biology. 82, 1398–1402

Kindsvater HK, Simpson SE, Rosenthal GG & Alonzo SH. 2013. Male diet, female experience, and female size influence maternal investment in swordtails.Behavioral Ecology 24 (3): 691-697


Maternal effects and offspring size evolution

mexicoMy PhD work, with Suzanne Alonzo and Gil Rosenthal, addressed how maternal age and sexual selection affect life-history traits like offspring size and number. I used a combination of models, experiments, and field studies of a swordtail fish, Xiphophorus birchmanni. These fish are livebearers, and they vary in life-histories within and across populations to a large degree, making them ideal for my questions. I did my fieldwork at CICHAZ, a field station in central Mexico, a rich and rewarding scientific and cultural environment.

Relevant papers:

Kindsvater HK and Otto SP. 2014. The evolution of egg size in stage-structured populations. American Naturalist. 184: 143-155

Kindsvater HK, Simpson SE, Rosenthal GG & Alonzo SH. 2013. Male diet, female experience, and female size influence maternal investment in swordtails.Behavioral Ecology 24 (3): 691-697

Kindsvater HK, Rosenthal GG, & Alonzo SH. 2012. Maternal size and age shape offspring size in a live-bearing fish, Xiphophorus birchmanni. PLoS ONE 7(11): e48473. doi:10.1371/journal.pone.0048473

Kindsvater HK, Bonsall MB, & Alonzo SH. 2011. Mortality associated with reproduction could explain variation in offspring size and number J. Evol. Biol.  24: 2230–2240.

Kindsvater HK, Alonzo SH, Mangel M, & Bonsall MB. 2010. Effects of age- and state-dependent allocation on offspring size and number. Evol. Ecol. Research. 12: 327-346.