Diadema africanum is a recently described sea urchin from the Eastern Atlantic archipelagos, and adults play a major ecological role mediating the transition between two alternative ecosystem states: macroalgal beds and urchin barrens. The aim of this study was to describe for the first time the egg characteristics, fertilization and larval development. To determine basic life-history characteristics for this species, we reared larvae through to metamorphic competence under an energy shortage experiment and temperature–pH experiments to characterize the morphological plasticity of larval responses to actual and future oceanic conditions. D. africanum produces eggs that are larger both in diameter (82.7 μm) and volume (0.30 nl) than the eggs of both Diadema antillarum (70.0 μm, 0.18 nl) and Diadema mexicanum (68.0 μm, 0.16 nl). Larval development is similar to other species within the Family Diadematidae, with a Echinopluteus transversus larval type morphology. The combined effects of the climate change-related environmental factors resulted in a reduction in fitness of D. africanum at the warmer limit of its thermal range when combined with low pH. Results suggest that the egg and larval life-history characteristics of D. africanum may have evolved to facilitate long-distance oceanic transport; however, near-future oceanic conditions may compromise larval survival.

中文翻译：

---

具有重要生态意义的海胆浮游动物阶段：非洲水蚤：在不久的将来海洋条件下的幼虫表现

非洲水产线虫是最近描述的来自东大西洋群岛的海胆，成虫在介导两个替代生态系统状态（大型藻床和海胆贫瘠）之间的过渡中起着重要的生态作用。这项研究的目的是第一次描述卵的特性，受精和幼体发育。为了确定该物种的基本生活史特征，我们在能量短缺实验和温度-pH实验下，将幼体饲养到变态能力，以表征幼体对实际和未来海洋条件的形态可塑性。D. africanum产卵的直径（82.7μm）和体积（0.30 nl）都比两个迪亚迪玛（Diadema antillarum）的卵大（70.0μm，0.18 nl）和墨西哥迪达玛（68.0μm，0.16 nl）。幼虫的发育与Di科中的其他物种相似，具有横贯棘皮动物的幼虫类型形态。当与低pH值结合使用时，与气候变化相关的环境因素的综合作用导致非洲象。在其热范围的较热极限处的适应性降低。结果表明，非洲象。的卵和幼虫生活史特征可能已经演变为促进远距离海洋运输。但是，不久的将来海洋条件可能会损害幼体的生存。