The reproductive biology of Chesapeake Bay striped bass with consideration of the effects of mycobacteriosis

• Gervasi, Carissa L ^[1] ; Susan Lowerre Barbieri ; Wolfgang K. Vogelbein
  1. [1] Florida International University

     Florida International University

     Estados Unidos

     
• Localización: Bulletin of Marine Science, ISSN 0007-4977, Vol. 95, Nº. 2, 2019, págs. 117-137
• Idioma: inglés
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• Resumen

  • The Chesapeake Bay spawning population of striped bass, Morone saxatilis (Walbaum, 1792), is the principal contributor of juveniles to the coastal Atlantic population, but a thorough reproductive study has not been conducted since the early 1990s, prompting questions about temporal changes and stock density–related impacts on reproduction. Additionally, mycobacteriosis, a chronic lethal bacterial disease, is currently affecting >50% of Chesapeake Bay striped bass, and disease-associated impacts on reproductive biology are unknown. To provide a contemporary description of Chesapeake Bay striped bass reproduction and examine possible effects of mycobacteriosis, we obtained reproductive data and disease prevalence information from females collected from 2002 to 2016. Fecundity-at-length generally was consistent with published literature suggesting that fecundity has not changed over time. Prevalence of mycobacteriosis had no significant effect on fecundity, but most disease-positive fish were only mildly infected. Age at 50% maturity (2.84 yrs) was lower than all previous reports (range 3–7 yrs). It is possible that the discrepancy is due to a lack of standard methodology for staging striped bass oocytes or to spatiotemporal differences in maturation rates. Disease-positive fish generally matured earlier and at smaller sizes than disease-negative fish (age at 50% maturity = 2.65 and 2.94 yrs, respectively; length at 50% maturity = 322.21 and 342.62 mm, respectively). The results of this study reveal that the maturity ogive for striped bass needs to be re-evaluated throughout the species range, and that mycobacteriosis may have a negative impact on reproductive success. Future research should assess how disease severity effects reproductive biology.