 Also, Gobies' pelvic fins are fused to form a sucker, similar to Remoras.The engineer goby is a close relative of cichlids and leaf fishes, the juvenile can often be found in aquarium trade, while the adult is rare.Members of the family Tetraodontidae, Boxfish, Blowfish or Pufferfish and their cousins Cowfishes and Porcupinefishes can be very personable and quirky pets, for the prepared.