Laboratory of Histology, Biosciences Institute, Faculty of Medicine and Pharmacy, University of Mons, Mons, Belgium.
J Fish Biol. 2020 Oct;97(4):1097-1112. doi: 10.1111/jfb.14472. Epub 2020 Aug 18.
Sandy bottoms are a ubiquitous environment found from sea bottoms to intertidal and freshwater zones. They are inhabited by many invertebrates and vertebrates which have developed morphological and physiological adaptations to sustain life under these particular conditions. Sandy habitats exhibit three potential constraints: abrasion, hypoxia and mechanical resistance. Here, three teleost species living in sandy environments were investigated: Ammodytes tobianus (Ammodytidae), Gorgasia preclara and Heteroconger hassi (Congridae). These teleost fishes were studied for their integument and muscular systems, which are potentially subject to sand abrasion and hypoxia, respectively. Based on histochemistry and transmission electron microscopy, we found the complex mucus system of G. preclara and H. hassi consists of two types of goblet cells and one type of sacciform cell. The secretions of both species are made of complex polysaccharides. In contrast, the scaly integument of A. tobianus has only a few goblet cells and no sacciform cells. We also highlighted, by immunohistochemistry, that the epidermal cell proliferation was much higher for this latter species, potentially resulting from the high rate of sand abrasion when A. tobianus buries itself quickly in the substrate. For all species, the major muscle fibre type was revealed by histoenzymology and corresponds to fast glycolytic fibres followed by intermediate fibres with slow fibres in the lowest proportion. Ammodytes tobianus possesses the highest fast fibre proportion (about 87% for A. tobianus and 75-78% for both garden eels). Our results provide new insights into the previously poorly studied teleost species, such as G. preclara, and allow us to highlight the complex skin histology of both garden eel species. Furthermore, the previously unknown muscle typing of these three species was determined.
沙质底部是一种无处不在的环境，从海底到潮间带和淡水区域都有分布。许多无脊椎动物和脊椎动物栖息在那里，它们已经发展出形态和生理适应能力，以在这些特殊条件下维持生命。沙质栖息地存在三种潜在的限制因素：磨损、缺氧和机械阻力。在这里，研究了三种生活在沙质环境中的硬骨鱼：Ammodytes tobianus（Ammodytidae）、Gorgasia preclara 和 Heteroconger hassi（Congridae）。这三种硬骨鱼的皮肤和肌肉系统分别受到沙磨损和缺氧的影响，因此受到了研究。基于组织化学和透射电子显微镜，我们发现 G. preclara 和 H. hassi 的复杂黏液系统由两种类型的杯状细胞和一种类型的囊状细胞组成。这两种鱼类的分泌物均由复杂的多糖组成。相比之下，A. tobianus 的鳞片皮肤只有少数杯状细胞，没有囊状细胞。我们还通过免疫组织化学强调，后者的表皮细胞增殖率更高，这可能是由于 A. tobianus 快速将自己埋在基质中时受到的高磨损率所致。对于所有物种，组织化学酶学揭示了主要的肌肉纤维类型，对应的是快速糖酵解纤维，其次是中间纤维，最慢的是慢纤维。A. tobianus 具有最高的快肌纤维比例（A. tobianus 约为 87%，两种花园鳗约为 75-78%）。我们的研究结果为以前研究较少的硬骨鱼物种（如 G. preclara）提供了新的见解，并使我们能够突出两种花园鳗物种复杂的皮肤组织学。此外，还确定了这三种鱼类以前未知的肌肉类型。
