Relationships among Egg Size, Composition, and Energy: A Comparative Study of Geminate Sea Urchins
Relationships among Egg Size, Composition, and Energy: A Comparative Study of Geminate Sea Urchins
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卵大小、成分和能量之间的关系：双生海胆的比较研究
作者：
J. Mcalister;A. Moran
卵的大小是海洋生物生活史的基本参数之一。然而，很少有研究探讨鸡蛋的大小，成分和能量含量之间的关系，在一个遗传控制的背景下。我们调查了蛋的大小，成分和能量之间的关联使用比较系统，成对的物种关闭中美洲航道。我们研究了西大西洋（WA）和东太平洋（EP）的三个海胆属，Echinometra，Eucidaris，和迪亚德马的物种。在卵大小差异最大的属（Echinometra）中，WA种的卵较大，富含脂肪，蛋白质贫乏，而EP种的卵较小。此外，较大的WA鸡蛋有显着更大的鸡蛋总能量和总生化成分，但显着降低鸡蛋能量密度（能量每单位体积）。然而，属较小（Eucidaris）或没有（迪亚德马）在鸡蛋大小的差异并没有显着不同的生化成分，总蛋能量，或能量密度。理论模型通常假设蛋的大小和繁殖力之间的一个很强的权衡，限制精力充沛的投资和约束生活史的进化。我们表明，即使在密切相关的类群，大鸡蛋不能被认为是按比例放大的小鸡蛋无论是在能量或成分。虽然我们的数据完全来自棘皮类棘皮动物，这种模式可以推广到其他海洋无脊椎动物类群。由于卵的组成和卵的大小不一定同步进化，选择性因素，如精子限制，可以作用于卵的体积，而不一定影响母体或幼虫的能量。
Egg size is one of the fundamental parameters in the life histories of marine organisms. However, few studies have examined the relationships among egg size, composition, and energetic content in a phylogenetically controlled context. We investigated the associations among egg size, composition, and energy using a comparative system, geminate species formed by the closure of the Central American Seaway. We examined western Atlantic (WA) and eastern Pacific (EP) species in three echinoid genera, Echinometra, Eucidaris, and Diadema. In the genus with the largest difference in egg size between geminates (Echinometra), the eggs of WA species were larger, lipid rich and protein poor compared to the smaller eggs of their EP geminate. In addition, the larger WA eggs had significantly greater total egg energy and summed biochemical constituents yet significantly lower egg energy density (energy-per-unit-volume). However, the genera with smaller (Eucidaris) or no (Diadema) differences in egg size were not significantly different in summed biochemical constituents, total egg energy, or energy density. Theoretical models generally assume a strong tradeoff between egg size and fecundity that limits energetic investment and constrains life history evolution. We show that even among closely-related taxa, large eggs cannot be assumed to be scaled-up small eggs either in terms of energy or composition. Although our data comes exclusively from echinoid echinoderms, this pattern may be generalizable to other marine invertebrate taxa. Because egg composition and egg size do not necessarily evolve in lockstep, selective factors such as sperm limitation could act on egg volume without necessarily affecting maternal or larval energetics.
海胆蛋果冻外壳由与纤维状岩藻聚糖上层结构结合的球状糖蛋白组成。
影响因子：
2.7
作者：
Bonnell,BS;Keller,SH;Vacquier,VD;Chandler,DE
通讯作者：
Chandler,DE