Schinner Gottfried O, McClintock James B
Department of Biology, The University of Alabama at Birmingham, Campbell Hall, Birmingham, Alabama 35294-1170.
J Morphol. 1993 Apr;216(1):79-93. doi: 10.1002/jmor.1052160109.
Marsupial spines, tubercles, and pedicellariae of the antarctic brooding spatangoids Abatus nimrodi and Abatus shackletoni have been examined by scanning electron microscopy. Individual brood pouches of A. nimrodi may hold up to 28 embryos and juveniles and those of A. shackletoni may hold up to 38 lecithotrophic embryos and juveniles. Juveniles can be divided into (a) those with early development of external elements and a mean size of 2.0 and 1.6 mm, respectively, and (b) those equipped with fully developed external elements and a mean length of 4.3 and 2.8 mm, respectively. Mean diameters of aboral brood pouch openings of A. nimrodi and A. shackletoni were 6.5 and 4.1 mm, respectively. Brood pouches contain tall, distally enlarged spines, and smaller, layered cover-spines, which form a protective arch over the marsupia. There are also slender brood-pouch-bottom spines, which have an extremely thickened spinal epidermis. A. nimrodi has mainly bidentate, but also triand quadrodentate pedicellariae. A. shackletoni has two forms of tridentate, rostrate, and globiferous pedicellariae. In A. shackletoni, marsupial spine density is significantly lower than in A. nimrodi. These differences may be related to distinct sediment characteristics in their respective habitats. © 1993 Wiley-Liss, Inc.
利用扫描电子显微镜对南极育幼心形海胆属的尼氏心形海胆（Abatus nimrodi）和沙氏心形海胆（Abatus shackletoni）的育儿袋棘、瘤和叉棘进行了检查。尼氏心形海胆的单个育儿袋可容纳多达28个胚胎和幼体，而沙氏心形海胆的育儿袋则可容纳多达38个卵黄营养型胚胎和幼体。幼体可分为两类：（a）外部结构发育早期，平均大小分别为2.0毫米和1.6毫米；（b）外部结构完全发育，平均长度分别为4.3毫米和2.8毫米。尼氏心形海胆和沙氏心形海胆育儿袋口的平均直径分别为6.5毫米和4.1毫米。育儿袋内有高大、远端膨大的棘，以及较小的分层覆盖棘，它们在育儿袋上方形成一个保护拱。还有细长的育儿袋底部棘，其棘表皮极度增厚。尼氏心形海胆主要有双齿叉棘，但也有三齿和四齿叉棘。沙氏心形海胆有两种形式的三齿叉棘、喙状叉棘和球根状叉棘。在沙氏心形海胆中，育儿袋棘的密度明显低于尼氏心形海胆。这些差异可能与它们各自栖息地不同的沉积物特征有关。© 1993威利 - 利斯出版公司。
