title: Reproductive biology and spatiotemporal patterns of spawning in striped marlin Kajikia audax.
abstract: This study presents the first histology-based assessment of the reproductive dynamics of south-west Pacific striped marlin Kajikia audax. Maturity and reproductive status were assessed from histological sections of ovaries (n = 234) and testes (n = 243) of fish caught in commercial longline and recreational fisheries between 2006 and 2009. Spawning peaked in the Coral Sea during November and December at sea surface temperatures between 24.8 and 28.3° C. Lower jaw fork length (L(LJF)) at 50% maturity (L(LJF50)), a key variable for stock assessment, was estimated to be 2100 ± 102 mm (mean + s.e.) for females and 1668 ± 18 mm for males. Unlike large pelagic tunas Thunnus spp., the proportion of females increased with length and spawning fish formed multiple large-scale aggregations within a broad latitudinal band. This study provides a starting point for biological parameters needed for stock assessment and conservation of K. audax and introduces the multiple aggregation spawning concept as a reproductive mechanism to explain genetic heterogeneity observed in some highly migratory species.
authors.affiliation: Institute for Land, Water and Society, Charles Sturt University, Albury, NSW 2640, Australia.
authors.forename: R K
authors.initials: RK
authors.lastname: Kopf
authors.forename: P S
authors.initials: PS
authors.lastname: Davie
authors.forename: D B
authors.initials: DB
authors.lastname: Bromhead
authors.forename: J W
authors.initials: JW
authors.lastname: Young
mesh_terms: D000818:Animals; D005260:Female; D005298:Fertility; D008297:Male; D009865:Oocytes / Q000502:physiology; D010053:Ovary / Q000502:physiology; D010140:Pacific Ocean; D010473:Perciformes / Q000502:physiology*; D012098:Reproduction; D012621:Seasons; D012741:Sexual Maturation; D013737:Testis / Q000502:physiology