Dragonets are often mis-categorized as gobies or blennies by fish sellers. Favoured prey fish include cichlids, gobies, carp, and clariid catfish. Round gobies eat mussels off the rocky shoreline. When acting as clients, blue tangs normally approach cleaning stations inhabited by cleaner gobies. Azov turbot, Azov gobies, and flounder. Even seemingly harmless guppies can spread disease to native gobies. Certain planktonic crustaceans are also present in the diet of adult gobies. Animals usually consumed in odorigui style include octopus, squids, ice gobies, and other similar animals. Its members include tadpole gobies, monkey gobies, and bighead gobies. Stiphodon is a genus of freshwater gobies. Adult male round gobies turn inky black during the spawning season and develop swollen cheeks. Fish in Lake Merritt include bat rays and gobies. Though often categorized as gobies, tilefish are a separate species. These gobiids are thus sometimes known as "watchmen gobies" or "prawn gobies". "Elacatinus" and "Gobiosoma", genera of gobies, feed on ectoparasites of their clients while cleaning them.