Pholidichthys leucotaenia grow to almost , but never leave the tunnels to feed. They frequently take in mouthfuls of juveniles and spit them out again. An inspection of adult stomachs showed only a green slime. Pholidichthys leucotaenia Pholidichthys leucotaenia, commonly known as the convict blenny/goby or the engineer blenny/goby, is a marine fish from the west-central Pacific Ocean. It is neither a blenny nor a goby, but is in fact one of two species in the family Pholidichthyidae. A small eel-shaped fish, it can grow up to in length. Juveniles resemble the striped catfish "Plotosus lineatus", which is venomous, having a black
Monkey goby as amphipods and shrimp. In the Danube lakes Yalpug and Kugurluy, the diet of the monkey goby consists of amphipods, molluscs, and Oligochaeta. In the Khadzhibey Estuary a dozen species of prey make up the diet of monkey goby. Polychaetes, larvae of insects, and shrimp are present in the diet year round. Seasonal dietary additions include crabs such as "Rhithropanopeus harrisii", sea weed such as "Zostera marina", and amphipods such as "Marinogammarus olivii". Certain planktonic crustaceans are also present in the diet of adult gobies. In the northwestern Black Sea, twelve parasite species are known to infect the monkey goby.