Philippine halfbeak

Where they come from

Philippine halfbeaks (Zenarchopterus philippinus) come from the Philippines and nearby areas, where they hang out in slow rivers, ditches, and weedy backwaters. A lot of the ones in the hobby are used to warm, calm water with loads of surface cover - basically the kind of place where insects drop in all day.

Setting up their tank

Think "surface fish" first. Halfbeaks live in the top couple inches most of the time, and they really appreciate a long tank with calm flow more than a tall tank with a big current.

• Tank size: 20 gallons long is a comfortable starting point for a small group. Bigger is easier, especially for spreading out any squabbles.
• Lid: non-negotiable. They jump, and they jump well.
• Flow: gentle. Aim your filter output at the glass or use a sponge filter if your tank is on the smaller side.
• Plants: floating plants (frogbit, salvinia, water lettuce) make them act way more relaxed. Stem plants around the edges help too.
• Lighting: moderate is fine, but give them shade with floaters so they do not feel exposed.
• Water: freshwater, warm-ish (mid 70s F is a good target), neutral-ish pH is usually fine. They are less fussy about numbers than they are about stability.

One more setup thing people miss: give them line-of-sight breaks near the surface. A mat of floating plants or a couple of tall stems reaching up does a lot to reduce sparring.

What to feed them

They are surface hunters. If food sinks fast, a lot of it will get ignored, and your midwater fish will steal it. You will get the best results feeding small floating foods and adding some real meaty stuff regularly.

• Good staples: floating micro pellets or small floating sticks that soften quickly.
• Frozen foods: daphnia, cyclops, baby brine shrimp, chopped bloodworms (use sparingly if your tank gets messy).
• Live treats: fruit flies, mosquito larvae (from a safe source), small crickets cut up for bigger adults.
• Feeding style: small meals 1-2 times a day beats dumping a big pinch. They are snackers by nature.

Watch their bellies and their backs. A well-fed halfbeak looks sleek but not pinched. If they look hollow behind the head, they are getting outcompeted or the food is sinking too fast.

How they behave and who they get along with

Halfbeaks are neat because they look calm... right up until they decide the top six inches belong to them. They are not usually murderous, but they are nippy and can be pushy at the surface, especially males with each other.

• Best kept in a group: aim for 6+ if you have the space. It spreads attention and they look more confident.
• Male/female mix: more females than males tends to reduce constant sparring.
• Good tankmates: peaceful midwater/bottom fish that do not live at the surface (corydoras, smaller loaches, calm tetras/rasboras, peaceful rainbows depending on tank size).
• Avoid: slow surface fish with long fins (bettas, fancy guppies) and anything that needs calm surface access for breathing (they will get stressed). Also avoid aggressive fish that will harass them back.
• Shrimp: adults might ignore big shrimp, but small shrimp and babies are usually snacks.

Breeding tips

They are livebearers, which is the fun part. Females carry the young and drop free-swimming fry. If you keep them well-fed and not stressed, you may end up with surprise babies.

• How to tell sexes: males are slimmer and often more feisty; females get noticeably rounder when gravid. Depending on the fish, males can show a more modified anal fin.
• Gestation: variable, but plan on roughly a month or so in warm water.
• Save the fry: floaters are your best friend. A thick mat gives fry somewhere to vanish immediately.
• Fry food: powdered fry food, baby brine shrimp, microworms, and crushed flakes that stay near the surface.
• If adults eat fry: move the pregnant female to a breeder tank right before she drops, then return her after. Do not keep her isolated for weeks - it stresses them out.

Common problems to watch for

Most halfbeak issues come from three things: surface stress (no cover), food problems (wrong type or not enough), and injuries from jumping or sparring.

• Jumping and lid injuries: they rocket out of the water when startled. Use a tight lid and keep the water line a bit lower.
• Mouth and snout damage: they can scrape their beaks on hard decor or during chasing. Avoid sharp rocks right at the surface and give them space.
• Getting skinny: usually they are being outcompeted, the food sinks, or they are stressed and not eating. Fix surface cover and feed floating foods.
• Nipping and fin damage: too few fish, too many males, or a cramped top zone. Add floaters, increase group size, or adjust the ratio.
• Water quality swings: they react poorly to sudden changes. Do smaller, steady water changes instead of huge ones, and match temperature.

If you set up for them like a "surface community" instead of a generic freshwater tank, they get a lot easier. Calm top water, shade from floaters, and food that actually stays up top will solve most of the headaches people run into with this species.