In marine flatfish of the genus Paralichthys, temperature plays a large role in sex
determination. Thus, global climate change could have significant effects on southern
flounder (Paralichthys lethostigma), a commercially and recreationally important flatfish
whose populations have steadily declined in Texas in the last 25 years. The most
susceptible areas to global climate change are shallow water environments, particularly
estuaries, which serve as essential nursery habitats for juvenile southern flounder. While
in the estuaries, juveniles develop, and sex is determined. Juvenile southern flounder
possess genotypic sex determination; however, the sex of females is highly influenced by
temperature and can result in sex reversal. The temperature-sensitive enzyme complex
responsible for estrogen biosynthesis in vertebrates is aromatase cytochrome P450
(P450arom), a critical component in ovarian differentiation that can be used to measure
presumptive males and females exposed to a gradient of temperatures. This research
identifies that sex is influenced by temperature between 35 and 65 mm total length (TL)
and establishes that increases in temperature from 18 °C during this size range produce
increasingly male skewed sex ratios in southern flounder from Texas. The findings
presented here are critical for optimizing production of females in culture and for
developing stock enhancement programs of southern flounder in Texas. / text
| Identifer | oai:union.ndltd.org:UTEXAS/oai:repositories.lib.utexas.edu:2152/ETD-UT-2010-12-2564 |
| Date | 16 February 2011 |
| Creators | Montalvo, Avier José |
| Source Sets | University of Texas |
| Language | English |
| Detected Language | English |
| Type | thesis |
| Format | application/pdf |
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