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Open Access Publications from the University of California

Scholarly Works (5 results)

  • Article
  • Peer Reviewed
Research Theses and Dissertations (2008)

Teleost fishes exhibit an unrivaled diversity of reproductive patterns compared to other vertebrates, and the groupers (Epinephelidae) and seabasses (Serranidae) represent an extreme example of this diversity, because significant variations in sexual pattern, mating behavior, and reproductive anatomy occur among species in both families. For this research, I investigate these three aspects of the reproductive biology in five species of groupers from the eastern Pacific. I then combine my data with published results on the reproductive biology of other groupers and seabasses to describe taxonomic differences in these aspects and reconstruct their evolutionary history. Finally, I use a comparative phylogenetic approach to evaluate the evolutionary relationship between mating system characteristics (i.e., mating group structure and sperm competition) and sexual pattern. More specifically, I test whether evolutionary shifts in sexual pattern and, in particular the loss of sex change, were influenced by changes from paired to group spawning and associated increases in sperm competition among males. These analyses allow me to determine whether predictions of sex-allocation theory regarding the influence of mating behavior on sex allocation are congruent with fine-scale, evolutionary patterns of sex change within a resolved phylogeny.

My results indicate that characteristics of the sexual pattern, mating behavior, and reproductive anatomy in both families are exceptionally labile. Evolutionary transformations in these features do not strictly follow taxonomic lines and remarkable changes have evolved in closely related species and genera. The most parsimonious phylogenetic reconstructions of the evolutionary history of sexual patterns indicate that protogynous hermaphroditism is the ancestral character state in both the Epinephelidae and the Serranidae, and other forms of hermaphroditism evolved secondarily from this state. Tests of correlated evolution showed that evolutionary transformations in sexual pattern from protogyny to gonochorism are correlated with transformations in mating group structure from paired to group spawning, and sperm competition is significantly higher in gonochoric species than protogynous species. These results suggest that the loss of sex change was influenced by changes from paired to group spawning and associated increases in sperm competition among males. More importantly, this research provides phylogenetic support for predictions of the size-advantage model and empirical evidence for the influence of sperm competition on sex allocation in animals.

    Cover page: Reproductive Biology and Evolution of Epinephelid and Serranid Fishes (Perciformes, Epinephelidae, Serranidae)
    • Article
    • Peer Reviewed
    UC San Diego Previously Published Works (2009)
    Courtship and spawning behavior is described for the Leather Bass, Dermatolepis dermatolepis, from observations made from a manned submersible at Cocos Island, Costa Rica on 19 days between November 2006 and February 2007. Spawning occurred in the evening (16:00–18:30 h) in subgroups of 10–32 individuals that formed within aggregations of 50–70 individuals. The mating sequence was characterized by subgroup formation and crowding behavior followed by a brief vertical spawning rush, gamete release, and the rapid separation of participants. The aggregation was present on all dives, and spawning was not restricted to specific lunar phases.
      Cover page: Observations of spawning in the Leather Bass, Dermatolepis dermatolepis (Teleostei: Epinephelidae), at Cocos Island, Costa Rica
      • Article
      Technical Reports (2019)
        Cover page: Advanced Acoustic Technologies for the Monitoring and Management of Sustainable Fisheries: A Practice Manual Creative Commons 'BY-NC' version 4.0 license
        • Article
        • Peer Reviewed
        UC Santa Barbara Previously Published Works (2018)
        Courtship and spawning behaviors of coral reef fishes are very complex, and sufficient sampling effort and proper methods are required to draw informed conclusions on their mating systems that are grounded in contemporary theories of mate choice and sexual selection. We reviewed the recent study by Karkarey et al. (BMC Ecol 17:10, 2017) on the spawning behavior of Squaretail coralgrouper (Plectropomus areolatus) from India and found no evidence to support their findings of alternative reproductive tactics, unique school-spawning involving a single male with multiple females, or inverse size-assortment. The study lacks scientific credibility due to a lack of rigor in the methodology used, misinterpretation of observed behaviors, misinterpretation of the literature, and insufficient data. Their approach led the authors to produce spurious results and profound, invalid conclusions that violate the most basic assumptions of mate choice and sexual selection theory as applied to mating systems in marine fishes.
          Cover page: Fake spawns and floating particles: a rebuttal of Karkarey et al. “Alternative reproductive tactics and inverse size-assortment in a high-density fish spawning aggregation”
          • Article
          • Peer Reviewed
          Other Scholarly Work (2021)
          Co-operation in the management of shared fish stocks is often necessary to achieve sustainability and reduce uncertainty. The United States of America (USA) and Mexico share a number of fish stocks and marine ecosystems, while there is some binational co operation in scientific research, unilateral management decisions are generally the rule. We present a case study using the giant sea bass (Stereolepis gigas, Polyprionidae) to highlight how these management and research asymmetries can skew national perceptions of population status for a fully transboundary species. Scientific publications and annual funding related to giant sea bass are 7x and 25x higher in the USA, respectively, despite the fact that 73% of the species’ range occurs in Mexico. Conversely, annual fishery production and consumptive value of giant sea bass in Mexico are 19x and 3.5x higher than in the USA, respectively, while the non consumptive value related to dive ecotourism is 76x higher in the USA. These asymmetries have generated a distorted view of the population status of the giant sea bass across its entire range. This and other factors related to historical fishery dynamics and policy must be accounted for when assessing population status, and subsequent appropriate management responses, across geopolitical boundaries.
            Cover page: Asymmetry across international borders: Research, fishery and management trends and economic value of the giant sea bass ( Stereolepis gigas )
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