Reproductive potential of the long spined sea urchin Centrostephanus rodgersii in Tasmania

Recent poleward range expansion of the barrens-forming sea urchin Centrostephanus rodgersii (Diadematidae) from mainland Australia to Tasmania, has emphasized the need to understand the population dynamics of this ecologically important species in Tasmania. This work informs potential population dynamics of C. rodgersii in Tasmania by examination of its reproductive ecology. Reproductive periodicity (gonad index and propensity to spawn) was assessed bimonthly for 18 months at 4 sites in eastern Tasmania. Gamete viability was assessed by fertilization and early development trials. Temperature tolerance of Tasmanian C. rodgersii larvae was also assessed to determine whether this species has undergone an adaptive shift to the cooler Tasmanian environment. There was also no evidence for an adaptive shift in reproductive phenology. Reproductive phenology was assessed by determination of peak spawning period (gonad index analysis).

形成荒漠的长棘海胆科（Diadematidae）罗氏中心海胆（Centrostephanus rodgersii）近期从澳大利亚大陆向塔斯马尼亚的极地分布扩张，凸显了理解这一生态关键物种在塔斯马尼亚种群动态的必要性。本研究通过考察其繁殖生态学，为罗氏中心海胆在塔斯马尼亚的潜在种群动态提供信息。在塔斯马尼亚东部的4个位点，每两个月评估一次繁殖周期性（性腺指数及产卵倾向），持续18个月。通过受精及早期发育试验评估配子活力。还评估了塔斯马尼亚罗氏中心海胆幼体的温度耐受性，以确定该物种是否已对较冷的塔斯马尼亚环境发生适应性转变。此外，未发现繁殖物候存在适应性转变的证据；繁殖物候通过确定产卵高峰期（性腺指数分析）进行评估。