Spotfin Jawfish – Opistognathus robinsi add personality to an aquarium. They make burrows under rocks in the sand of the aquarium and spend most of the day with their heads swaying and bobbing out of them. They open their large mouth in reaction to other fish swimming by, but don’t normally act aggressive to other fish or invertebrates in the aquarium. That being said, they are not picky eaters and will readily consume pellet, frozen, and live food. Additionally, Spotfin Jawfish are mouth brooders, and the eggs will be visible inside the males mouth. Because Spotfin Jawfish burry, a heavy sand or rubble bottom is desirable. Furthermore, it’s very important to make sure the rock structures in the aquarium are stable because the burrowing of the Spotfin Jawfish can cause these structures to collapse, possibly injuring the jaw fish and other inhabitants.