Senegal needlefish

Where they come from

Senegal needlefish (Strongylura senegalensis) come from West African coastal waters - think river mouths, lagoons, and mangroves where fresh and salt mix. They are built for cruising the surface in open water, picking off small fish, and they act like it in an aquarium too.

Setting up their tank

Give them length more than height. They are surface missiles, and they spook fast. A long, open tank with calm flow beats a tall show tank every time.

• Tank size: I would not bother under 5 ft long, and bigger is better once they start putting on size
• Lid: tight and heavy. They jump, and they can hit a lid hard enough to hurt themselves
• Water: brackish with marine salt mix, not table salt. Keep it stable instead of chasing numbers daily
• Filtration: oversized, but aim the returns so the surface is not a washing machine
• Decor: open swimming lanes with plants/wood along the edges. They like cover nearby but hate clutter in the middle
• Lighting: not crazy bright. Floating plants can help them relax as long as you still have open areas

For salinity, treat them like a true brackish fish that wants consistency. A common mistake is bouncing between fresh and salty during water changes. Mix new water in a bucket, match temperature and salinity, then add it. Your fish will look a lot less jumpy.

What to feed them

They are hunters, and most want moving food at first. Once they recognize you as the food-person, they get bolder, but this is still not a flake-food fish.

• Best staples: silversides, smelt, lancefish, shrimp, krill, squid pieces (rotate, do not lock into one food)
• Frozen works: many will take thawed foods if you present it like prey (tongs near the surface, gentle movement)
• Live foods: use sparingly. If you rely on feeders, you will fight parasites and nutrition issues
• Vitamins: soak foods now and then, especially if you feed a lot of plain fish flesh
• Feeding rhythm: smaller meals a few times a week beats stuffing them daily

Training tip: start with a favorite (often silversides or shrimp), then sneak in other items. I have had the best luck feeding with long tweezers at the surface, lights slightly dim, and no sudden movement around the tank.

How they behave and who they get along with

They are surface-oriented, fast, and predatory. They are not usually mean in the bullying sense, but anything that fits in that beak is food, and they do not hesitate.

• Good tankmates: sturdy brackish fish too big to swallow and not overly nippy (think larger monos/scats, archerfish-sized companions, some robust brackish cichlids depending on your salinity and tank size)
• Avoid: small fish, slow long-finned fish, and fin-nippers (they can shred a needlefish tail and stress it into constant dashing)
• Best layout: keep the surface mostly theirs, and stock midwater/bottom fish that do not compete right at the top
• Group vs single: some do fine alone, some settle better with a companion, but multiple needlefish in a small tank can turn into a stress fest

They also have a habit of 'testing' things at the surface. If you keep floating feeders or leave airline tubing dangling, do not be shocked if they investigate it with their mouth.

Breeding tips

Breeding Senegal needlefish in home aquariums is not something you see often. In the wild they spawn in coastal waters and the eggs are typically adhesive, sticking to plants or structure. In a tank, the hurdle is getting a mature pair, giving them enough space, and getting the seasonal cues right.

• If you want to try: aim for a big, calm, mature brackish system with lots of floating or upper-level plant cover for eggs to stick to
• Condition heavily with varied meaty foods, but keep water quality tight
• If eggs appear: move the adults or the eggs. Predators do predator things
• Fry are tiny and need live micro-foods at first (this is where most attempts fall apart)

Common problems to watch for

Most issues with this fish trace back to stress, shipping damage, and inconsistent brackish husbandry. They can look fine right up until they are not, so you want to be a little paranoid in a good way.

• Jumping and impact injuries: the big one. Tight lid, calm lighting changes, and no chasing with nets
• Refusing food: common after import. Offer moving foods, dim lights, and keep the tank quiet for the first week or two
• Skin damage on the snout: from hitting glass or lids. Check for spooking triggers and sharp decor near the surface
• External parasites: often come in with live foods or wild imports. Quarantine is your friend
• Bloat/constipation: usually from huge meals or fatty feeder routines. Feed smaller, rotate foods, and avoid overdoing squid-only diets
• Salinity swings: show up as rapid breathing, flashing, or just a fish that acts 'wired' all the time

If you keep the tank stable, give them room, and feed like a predator keeper (variety, quality, and not too much), they are one of those fish that makes you slow down and just watch. But they are absolutely not forgiving of shortcuts.