The black-ray goby or nematode Stonogobiops belongs to the Gobiidae family. Black ray is endemic to the western Indo-Pacific region. It inhabits the sandy bottoms of the ocean and rocky outcrops off the coasts of the Philippines and Indonesia at depths ranging between 15 and 30 meters.
This species of goby has a long, thin, white body with black vertical markings. Its head is yellow and its fins are translucent. This is a smaller marine species. It only gets a length of about two inches when fully grown.
The saltwater aquarium industry also markets this species under the following names; Black Stripe Prawn Goby, Black Stripe Prawn Goby and Highfin Prawn Goby. You will notice that each of these names contains a reference to a crustacean in them. This is due to its symbiotic relationship with Randall’s shrimp and pistol shrimp (candy stripes). These shrimp will share a burrow with a pair of gobies to protect each other. It is recommended to add two species rather than one to your reef tank.
One word of caution: pistol shrimp don’t share the benign nature of their roommates. Guns will exhibit predatory behavior towards most other smaller shrimp species.
These little ones are docile to the point of being shy. They are considered completely benign and pose no threat to the typical inhabitants of a marine reef aquarium. They are so shy that they will instinctively seek refuge when their new surroundings are first introduced to them. It can take weeks for them to gather the courage to leave their sanctuary and begin to explore their new surroundings. They show their aggression by opening their mouths wide and yawning at their potential attacker. If that doesn’t scare the bees out of their confrontational, they will turn around and run. The only thing that starts an aggressive streak in these little ones is trying to keep the males together in a smaller tank. Black rays are the perfect tank mates for more fragile species like seahorses and pipefish.
These gobies are bottom dwellers. They have a tendency to burrow into sandy substrate to hide when scared. Therefore, you will want to use sand as a substrate. They should also have other hiding places on the aquarium floor. Avoid cluttering your reef tank with bottom dwellers. You don’t want them to have to compete for hiding places and food.
Black-ray gobies are primarily carnivorous fish. They can be fed vitamin-enriched brine shrimp, mysis shrimp, and meat-based frozen foods prepared for marine fish. They can also be fed small amounts of finely chopped seafood from your grocery store. They are known to eat algae on occasion. This may be to meet a nutritional requirement that is not in your main diet.
Between their beautiful coloration, benign temperament, and their symbiotic relationship with shrimp, these small reef fish are in high demand among saltwater aquarists. Matched pairs are a rare find.
Black rays are monogamous by nature. It is best to keep a pair. A single goby will not feel at home in your aquarium.
