Egg masses of two populations of the ascoglossan Costasiella with different developmental modes were examined. Costasiella ocellifera is an encapsulated developer; Costasiella sp. has an obligate plankto-trophic larval stage. Adults of the two populations were also separable by habitat, but could not be distinguished by external morphology. Comparison of capsule diameters and calorimetric analyses showed that C. ocellifera eggs have nearly eight times the capsule volume and 10 times the calories of eggs of its congener. Histochemical examination of extra-embryonic intra-capsular vesicles of C. ocellifera revealed the contents to be glycoprotein. No inclusions were visible in the capsular fluid of Costasiella sp. Egg masses from the two populations differed significantly in the amount of TCA-soluble carbohydrate, lipid, and NaOH-soluble protein per egg and per milligram dry weight of egg mass. These components were, however, similar when expressed on an ash-free dry-weight basis. The advantage of hatching directly onto a suitable food source that is temporally persistent, but patchily distributed might have provided the selective pressure to achieve extended intra-capsular development in C. ocellifera.

中文翻译：

---

COSTASIELLA [OPISTHOBRANCHIA: ASCOGLOSSA (= SACOGLOSSA)] 两个种群的生化成分和发育模式的比较

检查了具有不同发育模式的两个 ascoglossan Costasiella 种群的卵质量。Costasiella ocellifera 是一个封装的开发者；科斯塔西拉菌 具有专性浮游营养幼虫阶段。两个种群的成虫也可以通过栖息地分离，但无法通过外部形态区分。胶囊直径的比较和热量分析表明，C. ocellifera 卵的胶囊体积是其同类卵的近 8 倍和 10 倍。C. ocellifera 胚胎外囊内囊泡的组织化学检查显示内容物为糖蛋白。在Costasiella sp. 的荚膜液中没有可见内含物。来自两个种群的鸡蛋质量在 TCA 可溶性碳水化合物、脂质、每个鸡蛋和每毫克鸡蛋质量干重的 NaOH 可溶性蛋白质。然而，当以无灰干重表示时，这些成分是相似的。直接在合适的食物源上孵化的优势是暂时持久的，但不规则分布可能提供了选择压力，以在 C. ocellifera 中实现扩展的囊内发育。