Date Thesis Awarded

5-2023

Access Type

Honors Thesis -- Open Access

Degree Name

Bachelors of Science (BS)

Department

Biology

Advisor

Kevin Weng

Committee Members

M. Drew LaMar

Laurie Sanderson

Jeffery Shields

Abstract

Data-driven management of fisheries requires information on the life history of the species being managed. I provide new information on the life histories of two goatfish species in Hawaiʻi, Parupeneus insularis and Parupeneus cyclostomus. Fish were collected using spearfishing from the reefs of Oʻahu between 2020 and 2023. Macroscopic and microscopic methods of assigning maturity and reproductive stage were used to estimate size at maturity and seasonality. Parapeneus insularis females are estimated to reach 50% maturity at 188 mm fork length (95% CI: 177mm, 197mm), and 95% maturity at 245 mm FL (95% CI: 226mm, 287mm). P. cyclostomus females reach 50% maturity at 250 mm fork length (95% CI: 237mm, 262mm), and 95% maturity at 294 mm FL (95% CI: 273mm, 316mm). Female P. insularis specimens with GSI above 2 and vitellogenic 3 or hydrated oocytes occurred between March and September with a peak around April, indicating a spawning season in Spring and Summer. Specimens with GSIs greater than 1 and vitellogenic 1 & 2 oocytes were found in Winter, indicating that oocyte maturation had begun. Female fish with vitellogenic 3 or hydrated oocytes were collected in all seasons for P. cyclostomus, and GSIs above 2 for all but winter. This is indicative of spawning in all seasons, but uneven sampling and a low sample size means that more data is needed. Wet mount maturity assignments were as accurate as histology when assigning maturity in female fish. For studies of fish life history where histology may be too expensive and GSI may require too many samples, wet mount is a more informative, low cost alternative.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

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