Named for their translucent, shimmering appearance, glassfish of different shapes and sizes belonging to various fish families, are always fun to encounter. Usually schooling in an effort to escape predation, these lovely little fish are found in tropical waters the world over. Let’s take a closer look at these fascinating creatures.
Indian Glass Fish
Sometimes referred to as Disco Fish or Glassy Fish, these small freshwater fish are native to south Asia, and can be found in natural environments from Pakistan to Malaysia. Never growing to more than about three inches long, these little fish have completely translucent bodies that reveal their bones as well as their internal organs. Males have dark edges on their dorsal fins, which run the length of their bodies, and females’ fins are completely clear. These fish feed primarily on tiny crustaceans, worms, and insects. Almost prehistoric in appearance, these little fish spawn during the rainy season. They are sometimes captured for the aquarium trade, although most seen in pet stores have been raised in captivity. You’ll find them in the wild at shallow dive and snorkel sites.
Glassy Sweepers
Usually growing to a maximum length of about eight inches long, and found throughout the Indo-Pacific region as well as throughout the Western Atlantic and in some Caribbean areas, Glassy Sweepers are nocturnal fishes that inhabit the areas beneath ledges and inside caves during the day. Favorite prey for tarpon and other predatory fish, these fish are extremely shiny and have deep, almost boat-shaped bodies. They are eaten in Japan, but in most other places, they are not a fisheries target due to their small size. You’ll find them mostly in shallow reef environments and along rocky shorelines; at times, their schools are so thickly populated that you can find yourself completely surrounded by a shimmering fishy curtain.
Red Sea Dwarf Sweepers
Commonly referred to as Glassfish, but not to be confused with the Indian variety, these small fish are also referred to as Pygmy Sweepers. They inhabit Red Sea dive sites around Sharm el Sheikh, where caves and overhangs are plentiful. Just like their cousins, these fish often fill spaces almost completely, and when schooling in open water and viewed from a short distance away, they look almost like a swirling underwater cyclone. While they are technically considered to be baitfish, and while they provide a steady source of food for larger predatory fish, they are just as fascinating to watch as are colorful reef species. You’ll typically encounter them in shallow water at depths of less than twenty meters.
These are just a few of the many different types of fish nicknamed glassfish; depending on where you dive, you might encounter different types. If you hope to capture these active little fish on film, err on the side of caution and go with underwater video instead of trying to get good still shots. Last, but not least, don’t be afraid to swim right into their schools. They might bump you or even nibble, but they don’t bite.