Perron Frank E, Corpuz Gladys C
Pacific Biomedical Research Center, 41 Ahui St, 96813, Honolulu, Hawaii, USA.
Department of Zoology, University of Hawaii, 96822, Honolulu, Hawaii, USA.
Oecologia. 1982 Dec;55(3):319-324. doi: 10.1007/BF00376919.
Age-specific changes in the allocation of reproductive energy to protective capsules, ova and intracapsular fluid are documented for the marine gastropod Conus pennaceus. As female snails grow in shell length they produce larger capsules with thicker and stronger walls. Because large capsules contain lower densities of ova than do small ones, growing females must increase the number, as well as the size, of egg capsules they produce. As a result of this pattern of ova packaging, per ovum costs of encapsulation (parental care) increase with increasing female size and age. The data suggest that the number of embryos a capusle can support may be limited by respiratory constraints related to capsule surface area or wall thickness. As capsule size increases, surface/volume ratios decline and capsule wall thickness increases. Either of these processes should result in a reduction in net gas transport per unit of capsule contents.
已记录了海洋腹足纲动物笔尖芋螺在将生殖能量分配到保护胶囊、卵子和囊内液体方面随年龄的变化。随着雌螺壳长的增长，它们会产出更大的胶囊，其壁更厚且更坚固。由于大胶囊所含卵子的密度低于小胶囊，成长中的雌螺必须增加所产卵囊的数量以及大小。由于这种卵子包装模式，每个卵子的包囊成本（亲代抚育）会随着雌螺体型和年龄的增加而增加。数据表明，一个胶囊能够容纳的胚胎数量可能受到与胶囊表面积或壁厚相关的呼吸限制。随着胶囊尺寸的增加，表面积与体积之比下降，胶囊壁厚度增加。这两个过程中的任何一个都应导致单位胶囊内容物的净气体传输减少。
