spinycheek sleeper

Where they come from

Spinycheek sleepers are island-stream gobies. Think warm, clear creeks that slide through forest, hit sandy pools, and eventually meet mangroves. They hang around the lower reaches over sand and leaf litter, slipping between fresh water and a hint of salt in the estuary. Juveniles drift out as larvae and return upstream as mini gobies, which is why you sometimes see them near brackish edges.

Tank setup

Give them footprint over height. A single adult is comfy in a 40 breeder (36 x 18 in / 90 x 45 cm). If you want a pair or mixed community, 55+ gallons with lots of sight breaks is safer.

• Substrate: Fine sand, 5-7 cm deep. They like to settle in and will push sand around their cave.
• Hardscape: Stack rock on the tank bottom (not on sand) so they cannot topple it while digging. Add wood and a few snug caves (PVC elbows, coconut shells, rock piles).
• Plants: Low light, tough stuff tied to wood/rock (Anubias, Java fern, Bolbitis). Rooted plants get uprooted unless they are potted.
• Flow and oxygen: Moderate current with strong aeration. A canister plus a large sponge filter works well.
• Cover: Tight lid. They jump. Block cable cutouts and the gap around HOB filters.
• Light: They relax under dimmer light. Floating plants help.
• Water: Freshwater is fine for adults. Mine perk up with a pinch of salt (SG 1.002-1.004), but not required.

Feeding

They are ambush carnivores. New arrivals often want moving food first, then you can wean them onto prepared stuff.

• Staples that work: thawed mysis, chopped prawn, chopped fish fillet, earthworms/nightcrawlers (cut), live or frozen bloodworms/blackworms, krill, small snails.
• Dry foods: Sinking carnivore pellets and prawn sticks. Wiggle them with tongs at first.
• Schedule: Juveniles daily, adults 4-5 small feeds per week. I do smaller portions at dusk; they wake up at that time.
• Training trick: Use feeding tongs at the cave mouth for a week, then drop food on the smooth rock. After a bit they will cruise out for pellets too.

Behavior and tankmates

Expect a chill, sit-and-wait fish that claims a base camp. Mine would watch the room from his cave, then dart 2 feet for a worm and disappear again. Once settled, they patrol more, especially at dusk.

• Temperament: Peaceful to anything they cannot swallow, but territorial with similar bottom fish in tight quarters.
• Numbers: One per tank unless the tank is big and broken up. A well-matched pair can work if introduced carefully with multiple caves.
• Tankmates: Medium, fast midwater fish that are too big to be a snack. Good fits: larger rainbowfish, Congo tetras, giant danios, peaceful larger barbs. Avoid tiny tetras/rasboras and ornamental shrimp.
• Bottom neighbors: Keep it light. A single bristlenose or a few medium Corydoras can work if there are multiple hides, but skip other goby-like fish and territorial loaches.

Breeding tips

They court and lay eggs in a cave, and the male fans the clutch. The hard part is the larvae. Like many sleepers, they are amphidromous: the larvae drift to sea and grow up in plankton before returning to fresh water. In a home tank, eggs hatch into tiny pelagic larvae that do not take normal fry foods.

• If you want to try: Provide multiple snug caves, warm stable water, and a high-protein diet. You might see spawning and hatching.
• Raising larvae: You will need a separate marine or very brackish rearing setup with greenwater and live microfoods (rotifers/copepods) and a plan for gradual salinity shifts. This is advanced and rarely pulled off at home.

Common problems to watch for

• Jumping: They are powerful jumpers. Tight lids save lives.
• Refusing prepared foods: Start with live or wiggled frozen, then step down to pellets. Feeding at dusk helps.
• Internal parasites: Wild-caught sleepers are often skinny with stringy white poop. Quarantine and treat (praziquantel + levamisole have worked well for me).
• Scrapes and infections: They wedge into tight spots. Keep rocks stable, edges smooth, and substrate clean to avoid bacterial fuzz.
• Low oxygen: Gasping at the surface or hugging filter outflow is a hint. Increase aeration and flow.
• Parameter swings: They sulk and stop eating after big changes. Do smaller, regular water changes and keep your hands out of the tank as they settle.
• Brackish temptation: Some individuals perk up with a little salt, but sudden salinity jumps stress them. If you try it, creep up slowly over several days.