Metrics
25 File views/ downloads
77 Record Views
Thesis
AGE VALIDATION AND GROWTH OF GRAY TRIGGERFISH, BALISTES CAPRISCUS, IN THE NORTHERN GULF OF MEXICO
University of West Florida
Master of Science (MS), University of West Florida
2012
Abstract
A rearing experiment was conducted in which adult gray triggerfish dorsal spines and fin rays were chemically marked with oxytetracycline. Experimental results validated that one translucent zone was deposited in spines and rays during winter/early spring; however, fin rays proved to be less reliable than spines for age estimation (n = 27). Spines collected from fish (n = 2,391) sampled in the northern Gulf of Mexico between 2003 and 2010 were sectioned and aged by two independent readers via counts of translucent zones. Marginal increment analysis verified that a single translucent zone was formed in spines during winter/early spring. A von Bertalanffy growth function was fit to the entire data set [Lt = 521 (e (0.274*(t+0.12))], as well as by sex, fishery, and region. Results from a three-way analysis of variance indicated no significant difference in size at age between sexes, but fishery and region effects were significant. However, a significant interaction between region and fishery effects confounded interpretation of main effects and precluded inference about regional growth differences given that differences in selectivity among region-specific predominant fisheries may have resulted in observed regional differences in size at age. Overall, study results indicate dorsal spines can be used to age gray triggerfish accurately, and that aging data may be useful to estimate growth or as inputs to age-structured stock assessment models.
Details
- Title
- AGE VALIDATION AND GROWTH OF GRAY TRIGGERFISH, BALISTES CAPRISCUS, IN THE NORTHERN GULF OF MEXICO
- Resource Type
- Thesis
- Publisher
- University of West Florida
- Format
- text
- Copyright
- http://rightsstatements.org/vocab/InC-EDU/1.0/
- Identifiers
- 99380090738706600
- Academic Unit
- Biology
- Language
- English
- Awarding Institution
- University of West Florida; Master of Science (MS)
- Theses and Dissertations
- Master of Science (MS), University of West Florida