ABSTRACT: Echinoderms such as sea urchins are important in marine ecosystems, particularly as grazers, and unhealthy sea urchins can have important ecological implications. For instance, unexplained mortalities of Diadema antillarum in the Caribbean were followed by algal overgrowth and subsequent collapse of coral reef ecosystems. Unfortunately, few tools exist to evaluate echinoderm health, making management of mortalities or other health issues problematic. Hematology is often used to assess health in many animal groups, including invertebrates, but is seldom applied to echinoderms. We used a standard gravitometric technique to concentrate fixed coelomocytes from the collector sea urchin Tripneustes gratilla onto microscope slides, permitting staining and enumeration. Using Romanowsky stain and electron microscopy to visualize cell details, we found that urchin cells could be partitioned into different morphotypes. Specifically, we enumerated phagocytes, phagocytes with perinuclear cytoplasmic dots, vibratile cells, colorless spherule cells, red spherule cells, and red spherule cells with pink granules. We also saw cell-in-cell interactions characterized by phagocytes apparently phagocytizing mainly the motile cells including red spherule cells, colorless spherule cells, and vibratile cells disproportionate to underlying populations of circulating cells. Cell-in-cell interactions were seen in 71% of sea urchins, but comprised <1% of circulating cells. Finally, about 40% of sea urchins had circulating phagocytes that were apparently phagocytizing spicules. The coelomic fluid collection and slide preparation methods described here are simple, field portable, and might be a useful complementary tool for assessing health of other marine invertebrates, revealing heretofore unknown physiological phenomena in this animal group.

中文翻译：

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细胞学研究揭示了正常收集器海胆中曲霉的多种细胞形态和细胞间相互作用

摘要：海胆等棘手动物在海洋生态系统中尤其是放牧者中很重要，不健康的海胆可能会对生态产生重要影响。例如，在加勒比海，由于不明原因的迪达玛（Didadema antillarum）死亡，海藻过度繁殖，随后珊瑚礁生态系统崩溃。不幸的是，几乎没有任何工具可以评估棘皮动物的健康状况，从而使死亡率或其他健康问题的管理成为问题。血液学通常用于评估许多动物群体（包括无脊椎动物）的健康状况，但很少应用于棘皮动物。我们使用标准重量分析技术从海胆中收集了固定的腔皮细胞Triptristes gratilla到显微镜载玻片上，允许染色和计数。使用罗曼诺夫斯基（Romanowsky）染色和电子显微镜观察细胞细节，我们发现海胆细胞可分为不同的形态型。具体来说，我们列举了吞噬细胞，具有核周质点的吞噬细胞，振动细胞，无色小球细胞，红色小球细胞和带有粉红色颗粒的红色小球细胞。我们还看到以吞噬细胞为特征的细胞间相互作用似乎主要吞噬了活动细胞，包括红色小球细胞，无色小球细胞和可动细胞，与循环细胞的基础种群不成比例。在71％的海胆中发现了细胞间的相互作用，但构成循环细胞的比例不到1％。最后，大约40％的海胆具有循环吞噬细胞，这些吞噬细胞显然是吞噬针。这里描述的腔积液收集和玻片制备方法简单，可现场携带，并且可能是评估其他海洋无脊椎动物健康的有用补充工具，揭示了该动物群迄今未知的生理现象。