Marine Fish

Saltwater fish , also called marine fish , are fish that live in ocean water . Saltwater fish can swim and live alone or in a large group called a school . Saltwater fish are very commonly kept in aquariums for entertainment . Many saltwater fish are also caught to be eaten , or grown in aquaculture

The National Zoological Gardens of South Africa ( NZG ) has the largest inland marine and freshwater aquarium in the country . Housing a total of 1692 freshwater and marine fish . The marine fish boasts a variety of vivid colours in different shapes and sizes adding a vibrancy to the aquarium but they're not just pretty to look at , some of the marine fish have special characteristics . Here are interesting facts about some of the marine fish housed at the NZG aquarium

. Not all marine fish are the same - they are divided into herbivores , carnivores and omnivores each requiring different types of food . Marine fish drink water - unlike Freshwater fish that do not actively drink water , but absorb the water through their skin and gills . Saltwater fish do actively drink sea water . Their gills process the water and take out the salt . . Fish can drown in water - fish need oxygen , and they can suffocate and drown as they require a consistent intake of oxygen to survive . Their gills absorb oxygen from water molecules as water passes through the gill membranes .
Sharks are the only fish that have eyelids- All sharks have at least two eyelids , an upper lid and a lower lid ; however , these eyelids can't move , which means sharks can't blink . Blacktip female sharks are capable of self reproduction - This phenomenon is called Parthenogenesis and results in the production of female offspring . This happens only when a female cannot find a partner for reproduction