title: Comparative assessment of the reproductive status of female Atlantic bluefin tuna from the Gulf of Mexico and the Mediterranean Sea.
abstract: Despite attention focused on the population status and rebuilding trajectory of Atlantic bluefin tuna (Thunnus thynnus), the reproduction and spawning biology remains poorly understood, especially in the NW Atlantic. At present, the eastern and western spawning populations are believed to exhibit different reproductive characteristics and, consequently, stock productivity. However, our study suggests that the two spawning populations, the Gulf of Mexico and the Mediterranean Sea, could show similar reproductive features and spawning strategies. Between 2007 and 2009, gonad samples from female Atlantic bluefin tuna were collected in the northern Gulf of Mexico (n = 147) and in the western Mediterranean Sea (n = 40). The histological and stereological analysis confirmed that sampled eastern and western bluefin tuna exhibit the same spawning duration (three months) but the spawning in the Gulf of Mexico begins one month earlier than in the Mediterranean Sea. Western bluefin tuna caught in the peak of the spawning season (May) showed a similar spawning frequency (60%) to the spawning peak observed in the Mediterranean Sea (June). Fecundity for the Gulf of Mexico fish (28.14 eggs · g(-1)) was lower but not significantly different than for fish sampled in the Mediterranean Sea (45.56 eggs · g(-1)). Our study represents the first comparative histological analysis of the eastern and western spawning stocks whose findings, combined with new determinations of size/age at maturity and possible alternative spawning areas, might suggest basic life history attributes warrant further scientific and management attention.
authors.affiliation: Department of Biological Sciences, University of New Hampshire, Durham, New Hampshire, United States of America; Large Pelagics Research Center, University of Massachusetts Amherst, Gloucester, Massachusetts, United States of America.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Knapp
authors.affiliation: Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEI-MAR), Universidad de Cádiz, Puerto Real, Cádiz, Spain.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Aranda
authors.affiliation: Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEI-MAR), Universidad de Cádiz, Puerto Real, Cádiz, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Medina
authors.affiliation: Large Pelagics Research Center, University of Massachusetts Amherst, Gloucester, Massachusetts, United States of America.
authors.forename: Molly
authors.initials: M
authors.lastname: Lutcavage
mesh_terms: D000818:Animals; D005260:Female; D060851:Gulf of America; D008522:Mediterranean Sea; D010053:Ovary / Q000166:cytology / Q000502:physiology; D012098:Reproduction; D014413:Tuna / Q000502:physiology*