Blue Belly Red Goby (Lentipes Ikeae)

A scarlet goby whose electric-blue belly flashes in fast-flowing island streams.

Blue Belly Red Goby (Lentipes ikeae): a striking, peaceful freshwater goby for mature, high-flow tanks with cool, oxygen-rich water and abundant biofilm.

• Water conditions: The Blue Belly Red Goby is a rheophilic, amphidromous species that does best in cool, highly oxygenated freshwater with brisk circulation. Aim for a temperature of roughly 18–24°C, pH around 6.8–8.0, and moderate hardness (GH approximately 5–12). Keep ammonia and nitrite at zero, nitrate low (ideally under 20 ppm), and maintain stable parameters with regular partial water changes. These gobies are sensitive to declining oxygen levels, so use a powerhead or filter outlet to create strong surface agitation and visible flow across rockwork. They are freshwater adults and should not be kept in long-term brackish conditions; their larval stage is marine in the wild, which is why captive breeding is uncommon. A mature tank with established biofilm is far more important than pristine, sterile water.
• Suitable tank mates: Choose peaceful, cool-water or subtropical companions that tolerate flow. Good options include white cloud mountain minnows, small danios, hillstream loaches, and robust shrimp such as Amano shrimp. Avoid large, boisterous, or predatory fish, as well as species that aggressively compete for grazing space. Other small rheophilic gobies can work in a generously sized, well-structured aquarium, but expect territorial displays between males. Provide plenty of visual barriers, cobbles, and driftwood to break sightlines. If keeping a group, a longer tank with multiple rocky territories is safer than a small cube. Do not mix with cichlids, large loaches, or fish that will bully them away from biofilm.
• Feeding habits: In nature, Lentipes ikeae grazes on aufwuchs—algae, biofilm, and tiny associated organisms—so a mature aquarium with visible biofilm is essential. Offer spirulina-based wafers, algae tabs, Repashy-style gel foods, and blanched vegetables such as zucchini, cucumber, and spinach. Supplement occasionally with small frozen foods like daphnia, baby brine shrimp, and finely chopped bloodworm to provide protein, but keep these secondary. Feed small portions two or three times daily rather than one heavy meal. New arrivals may ignore prepared food at first, so allow them to graze and observe carefully; a goby that stays thin is likely not getting enough biofilm or supplemented algae. Avoid overfeeding, which fouls the high-flow system and raises nitrate.
• Care requirements: Set up a mature aquarium with rounded cobbles, porous rock, driftwood, and steady current. A tank of at least 60–90 cm is preferable for a small group, with a powerhead creating riffles and calmer pockets behind rocks. Use a tight-fitting lid: sicydiine gobies are capable climbers and can escape through small gaps. Acclimatise carefully with a drip method, especially if the water chemistry differs from the supplier. Keep the tank well oxygenated and avoid copper-based medications. These gobies are peaceful but sensitive to unstable parameters, high nitrate, and low oxygen. Observe regularly for weight loss, clamped fins, or lethargy. Because they are amphidromous, breeding in captivity is rare; treat them as a display species rather than a breeding project. With stable cool water, strong flow, and abundant grazing surfaces, the Blue Belly Red Goby is a rewarding centrepiece for the specialised river-style aquarium.