Thesis

Recruitment, growth rates, planktonic larval duration, and behavior of the young-of-the-year of giant sea bass, Stereolepis gigas, off southern California

Little is known about the life history of Stereolepis gigas due to the over exploitation of their fishery in the early 1900’s, and depressed populations have prevented much research. A completed life history information on an ecologically, and once economically, important species such as the Giant Sea Bass (GSB) is critical for both the continued successful management of that fishery and a baseline for successful scientific studies. Therefore, the goals of this study include 1) determining distribution and general ecology for the YOY of S. gigas populations in the wild, 2) estimating growth rates, based on site aggregations in the wild, and otoliths analysis in the lab, and finally 3) confirming pelagic larval duration and the general temporal scale of their spawning period. One hundred and fifty SCUBA surveys were conducted to census waters with sandy benthos across southern California from 2013-2016. I documented early life ecology, including behaviors such as the “kelping” mimickery, cruising, & resting, as well as their active predator avoidance of burying and their diet of mysids based on field observations & confirmed through gut content analysis. I uncovered a specific distribution pattern spatially along the coast adjacent to underwater canyons, and temporally from July through February. This study was also able to establish a growth rate for the YOY, finally determined their planktonic larval duration around 24 days, and the morphological color changes from black to orange. This study is the first of its kind to examine the YOY of this endangered species making it a key component to their life history, and a baseline for future work on S. gigas and similar long-lived and slow-growing species.

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