The life history of weedy seadragons, Phyllopteryx taeniolatus (Teleostei:Syngnathidae)

Abstract

The aim of this study was to provide a detailed description of the life history of weedy seadragons, Phyllopteryx taeniolatus. Weedy seadragon development was described based on morphological characters and categorised into four periods: incubation, larval, juvenile and sub-adult. Hatching occurred 35–42 days post-fertilisation, most hatchlings exhibited juvenile characteristics upon hatching or shortly thereafter. The von Bertalanffy growth parameters generated from weedy seadragon length-at-age data were L ∞ = 285 ± 3 mm standard length (SL; mean ± s.e.) and k = 2.20 ± 0.05 year−1. Females possessed a higher gonosomatic index (GSI; 1.25 ± 1.18%; mean ± s.d.) than males (0.34 ± 0.20%), which increased substantially for females over 230 mm in length. Mature female weedy seadragons (290 ± 32 mm SL) ovulated 110 ± 27 eggs per female per spawning. Additionally, three females produced more than one clutch per season. Male weedy seadragons (319 ± 9 mm SL) successfully incubated 91 ± 40 eggs per spawning event. In addition to improving our understanding of the life history of weedy seadragons, this information can be used to estimate population demography and develop management strategies.