About Periophthalmus gracilis Eggert, 1935
Periophthalmus gracilis, commonly called the slender mudskipper and known as belacak in Malay, is a species of mudskipper. It is native to marine and brackish waters of the eastern Indian Ocean and the western Pacific Ocean, where it lives in the intertidal zone. This species is able to spend time out of water, and can grow to a length of 4.5 centimetres (1.8 in) in standard length.