Who You Calling a Sissy?

Streamwater Gobies are the coolest; all the fish in this genus have the same, somewhat goofy looking head. While we don't see it, a long time ago, someone thought this head looked like a dog's, and they gave this grouping the name Cynocephalus, which loosely translated from Greek means “dogheaded.”  They live in fast flowing, clear water above gravel and boulders, usually far from the ocean. Interestingly, they need the ocean as part of their life cycle. They will lay their eggs upstream; in the well oxygenated streams they live their lives out in. After hatching, they will go through planktonic stage where the larvae will get washed out to the ocean, before the fish return to the streams to mature and spawn themselves.

The specific Streamwater Goby we're interested in today is most often called the Cleft-Lipped Goby, but also sometimes just gets called the Sicyopterus Goby because the scientific name is Cynocephalus sicyopterus. They are found in many streams across Australia, the Philippines, Indonesia, Borneo and the Solomon Islands. The females are a tannish brown with striped pectoral fins. The males have a pale-yellow back, and a light blue belly with a dark saddle and mottling along their backs with a dark bar below their eye.

In the fast-flowing water of their home streams, algae and biofilm grows tightly to rock, which is then grazed on by the Cleft Lipped Goby. This is actually a potential reason for the small cleft in Cynocephalus sicyopterus' lips, that it helps the fish scrape up dinner from the rocks and crevices within. In your aquarium, you should feed a diet that is heavy on the algae like Nutramar's Algae and Color Boost Shots, which when stuck to the rocks or glass will allow the Goby to graze as it naturally would. They will also take frozen foods like Gamma Brine Plus Spirulina, Brine Plus Omega 3, Tubifex or Mosquito Larvae. They'll also get some meals from grazing the algae in your aquarium, but this should never be counted as the primary source of their nutrition, as they'll quickly run out of it and starve. You could farm algae rocks in another aquarium; just place a rock in a tank in the sun and let it grow algae, then add that rock to the display tank to be fed upon. Aquarists often do this with herbivore fish.

Since you're almost certainly never going to have a personal river that flows to the ocean for you to try and breed these fish, we can talk about housing them in a more traditional aquarium. They are very active, and will like a good bit of flow, that preferably moves through the display in one general direction. Cynocephalus sicyopterus is a medium sized aquarium fish, and as an adult could get up to about six inches long, but a more common adult size is in the low five-inch range. An appropriate aquarium could be as small as 55 gallons depending on what else it stocked with. The display should mimic their wild habitat. Clear, clean water that moves a lot, rounded pebbly substrate and some larger smooth rocks and perhaps some water worn driftwood as well. The tank should be covered as pretty much all Gobies can bolt when startled, leaving them on the floor if they do it in the wrong direction.

On the topic of stocking, you'll want fish that like the same kind of conditions that the CLG likes and Hillstream / Butterfly Loaches come immediately to mind. Other good choices might be a variety of different smaller Tetras and Rasboras, Halfbeaks and Aksis Cats, maybe even some Danios would be good. Avoid aggressive fish and notorious fin nippers as your Goby is a peaceful little dude and is easily bullied.

Cleft Lip Gobies will do best in very clean, very well oxygenated water so the display should be aggressively filtered. Overturning the tank will help the oxygenation level, and if set up correctly, it will help establish the directional current we're going for. Try to turn over the whole volume of the display at least 10-15 times per hour. More flow can be added with airstones or powerheads if you choose. The water should be relatively warm, in the mid 70's would be ideal. They're a tropical fish that needs warm water, but on the other hand, the laws of physics say that cooler water holds oxygen better and so a balance must be struck. Other than the water being nice and clean (so keep up the large and regular water changes) they aren't super picky water chemistry wise. The profile should be fairly neutral in pH (6.5-7.5) and they are not overly sensitive about hardness as long is it isn't way out of whack and you acclimate them to it slowly.

Cleft Lip Gobies are fairly rare fish in the hobby, and they a perfect fit as an addition to hillstream style displays or as a feature on their own. They're peaceful and interesting to watch and look completely different than most freshwater fish. Are you planning the right kind of display? Maybe you have enough capacity for one more medium-sized, beautiful fish in your already existing river-tope aquarium? If so, Cynocephalus sicyopterus is definitely worth consideration as a feature in that tank! Ask your LFS about getting you one from Aquatropic today!