title: Growth, development and temporal variation in the onset of six Chironex fleckeri medusae seasons: a contribution to understanding jellyfish ecology.
abstract: Despite the worldwide distribution, toxicity and commercial, industrial and medical impacts jellyfish present, many aspects of their ecology remain poorly understood. Quantified here are important ecological parameters of Chironex fleckeri medusae, contributing not only to the understanding of an understudied taxon, the cubozoa, but also to the broader understanding of jellyfish ecology. C. fleckeri medusae were collected across seven seasons (1999, 2000, 2003, 2005-07 and 2010), with growth rates, temporal variation in the medusae season onset and differences in population structure between estuarine and coastal habitats quantified. With a mean of 2 September ± 2 d (mean ± 95% confidence limits), the earliest date of metamorphosis was temporally constrained between seasons, varying by only 7 d (30 August to 5 September). Juvenile medusae appeared to be added over an extended period, suggesting polyp metamorphosis was an ongoing process once it commenced. At a maximum of 3 ± 0.2 mm d(-1) IPD, medusae growth to an asymptotic size of ~190 mm IPD was rapid, yet, with the oldest medusae estimated to be ~78 d in age, medusae did not appear to accumulate along the coastline. Furthermore, a greater proportion of juveniles were observed along the coastline, with estuarine populations typified by larger medusae. With key aspects of C. fleckeri's ecology now quantified, medusae season management protocols can be further developed.
authors.affiliation: School of Marine and Tropical Biology, James Cook University, Cairns, Queensland, Australia. matthew.gordon@jcu.edu.au
authors.forename: Matthew
authors.initials: M
authors.lastname: Gordon
authors.forename: Jamie
authors.initials: J
authors.lastname: Seymour
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001315:Australia; D044822:Biodiversity; D002138:Calibration; D037462:Cubozoa / Q000254:growth & development* / Q000502:physiology*; D004463:Ecology; D017753:Ecosystem; D016014:Linear Models; D011157:Population Dynamics; D015203:Reproducibility of Results; D012621:Seasons; D013997:Time Factors