In his early career, August Krogh made fundamental discoveries of the properties of cutaneous respiration in fish, frogs and other vertebrates. Following Krogh's example, the study of amphibious fishes provides an excellent model to understand how the skin morphology and physiological mechanisms evolved to meet the dual challenges of aquatic and terrestrial environments. The skin of air-exposed fishes takes on many of the functions that are typically associated with the gills of fish in water: gas exchange, gas sensing, iono- and osmoregulation, and nitrogen excretion. The skin of amphibious fishes has capillaries close to the surface in the epidermis. Skin ionocytes or mitochondrial-rich cells (MRCs) in the epidermis are thought to be responsible for ion exchange, as well as ammonia excretion in the amphibious mangrove rivulus Kryptolebias marmoratus. Ammonia gas (NH₃) moves down the partial pressure gradient from skin capillaries to the surface through ammonia transporters (e.g., Rhcg) and NH₃ is volatilized from the mucus film on the skin. Future studies are needed on the skin of amphibious fishes from diverse habitats to understand more broadly the role of the skin as a multifunctional organ.

在他的早期职业生涯中，奥古斯特·克罗格（August Krogh）对鱼，青蛙和其他脊椎动物的皮肤呼吸特性做出了基本发现。以克罗格为例，对两栖鱼类的研究提供了一个极好的模型，可以了解皮肤形态和生理机制是如何进化的，以应对水生和陆地环境的双重挑战。暴露于空气中的鱼皮具有许多通常与水中的鱼ill有关的功能：气体交换，气体感应，离子和渗透调节以及氮排泄。两栖鱼类的皮肤在表皮的表面附近具有毛细血管。表皮中的皮肤离子细胞或线粒体富集细胞（MRC）被认为负责离子交换以及两栖红树林小溪中氨的排泄。rypto虫（Kryptolebias marmoratus）。氨气（NH ₃）通过氨转运蛋白（例如Rhcg）从皮肤毛细血管的分压梯度向下移动到表面，并且NH ₃从皮肤上的粘液膜中挥发出来。需要进一步研究来自不同栖息地的两栖鱼类的皮肤，以更广泛地了解皮肤作为多功能器官的作用。