Sensation Mystery #110 (July-Aug.), 1952 © DC Comics
Sensation Mystery is the mostly-forgotten offspring of Sensation Comics, picking up its numbering and continuing on from #110 to #116. While the art is solid by DC’s stable of reliable pros such as Carmine Infantino, Murphy Anderson & Frank Giacoia, the stories are generally uninspiring. Still, there are a few gems scattered amongst the run of the book.
A new study shows how an amphibious fish stays alive for up to two months on land. Mangrove killifish are small fish that live in temporary pools in coastal mangrove forest. During dry seasons when their pools disappear, the fish hole up in leaf litter or hollow logs. As long as they stay moist, they can survive for extended periods out of water by breathing air through their skin.
The key to their survival is found in special cells called ionocytes, normally found on the gills of other fish that are clustered on the skin of the killfish. Other fish species have skin ionocytes in their larval stages of development, but usually these cells disappear from the skin during development.
The skin of the mangrove killifish is also equipped to help the fish deal with varying salinity. When out-of-water fish were placed on a surface moist with salt water, the skin ionocytes got bigger, indicating that they're working overtime to keep the right salt balance. When those fish were placed back in water, the skin ionocytes returned to normal size.
It's adaptations like this that make this fish special—even among amphibious fish. Lungfish, for example, need to alter their physiological state to live out of water. But with its special skin, mangrove killifish can maintain all of their normal physiological processes at nearly the same level as being in water—and they can do it for over 60 days. link
Ref. A Fish Out of Water: Gill and Skin Remodeling Promotes Osmo- and Ionoregulation in the Mangrove Killifish Kryptolebias marmoratus. 2010. D. M. LeBlanc, et al. Physiological and Biochemical Zoology, 83:932–949.