Elongate mudskipper (pointed-tailed goby)

1) Where they come from

Elongate mudskippers (Pseudapocryptes elongatus) come from muddy, brackish estuaries—think tidal creeks, mangrove edges, and silty flats where the water level and salinity swing around all the time. They’re built for that messy in-between zone: not quite “fish tank,” not quite “land animal.”

2) Setting up their tank

This is one of those fish where the tank layout matters more than the label on the box. Give them floor space, soft-ish mud/sand, and places to claim. They’re not a “pretty aquascape centerpiece” fish—they’re a “build a habitat” fish.

• Tank size: I’d start at 30–40 gallons for one, bigger if you want tankmates or multiples. Long footprint beats tall every time.
• Substrate: fine sand mixed with a bit of silt/clay if you can manage it (or just fine sand). Depth helps—aim for 2–4 inches so they can root around and feel secure.
• Hardscape: smooth driftwood, mangrove-style roots, piles of rounded rocks, and PVC sections half-buried work great for “burrow vibes.”
• Brackish water: don’t wing it—use marine salt mix (not aquarium/table salt) and a refractometer or decent hydrometer.
• Salinity: keep it in the low-to-mid brackish range (roughly SG 1.005–1.012). Consistency matters more than chasing a magic number.
• Filtration: they’re messy eaters, and the substrate gets funky—oversize your filter and don’t skimp on flow/oxygenation.

I’ve had the best luck treating them like a brackish “mud flat” fish: stable temperature (mid 70s°F / ~24–26°C), regular water changes, and not letting the bottom turn into a swamp. They can handle imperfect water better than they can handle sudden changes.

3) What to feed them

These guys are predators and opportunistic scavengers. Mine ignored flakes like they were invisible, but went nuts for meaty foods. Feeding them is fun—just be ready for a little chaos at the bottom.

• Staples: frozen bloodworms, brine shrimp (better as a treat), mysis shrimp, chopped prawn/shrimp, chopped clam/mussel
• Live foods (great for conditioning): blackworms, small earthworms, live brine, ghost shrimp (if they’re not too big)
• Pellets: some will take sinking carnivore pellets, but it can take patience—mix pellets in with frozen so they “accidentally” learn

Feed small portions and watch the leftovers. In brackish setups with deep substrate, extra food turns into nitrate and funk fast. I prefer 4–5 smaller feedings per week over huge daily dumps.

4) Behavior and tankmates

Elongate mudskippers are mostly bottom-focused, nosy, and surprisingly bold once settled. They’re also “territorial in a sneaky way”—not always constant fighting, but they’ll stake out a zone and defend it if another fish keeps invading their personal mud.

• Best setup: species-only or a calm brackish community with lots of hiding spots
• Good tankmates (if your tank is big): hardy brackish fish that stay out of their face—things like larger bumblebee gobies in well-planned tanks, some monos/scats (if you’re okay with bigger, higher-waste fish), or brackish-tolerant livebearers in lower SG
• Avoid: fin-nippers, hyperactive bottom fish, aggressive puffers, and anything small enough to be viewed as lunch
• With their own kind: possible, but you need space, breaks in line-of-sight, and multiple shelters—expect squabbles

A lot of their “personality” is hiding behavior. If yours vanishes for days, that’s not automatically a disaster. They’ll wedge into caves, sit under wood, or bury. You’ll see them more once they trust the routine (and learn that you’re the food source).

5) Breeding tips

Breeding Pseudapocryptes in home tanks isn’t common, mostly because they like to spawn in burrows and the fry life is tricky in brackish water. That said, you can stack the odds in your favor if you’re persistent and set the tank up like a breeding project, not a display.

• Give them burrow options: deeper sand, half-buried PVC, and stable shelters they can claim
• Condition heavy: lots of live/frozen meaty foods over a few weeks
• Keep the tank calm: fewer tankmates, less “hands in the tank,” steady salinity/temperature
• If you suspect eggs/fry: be ready with tiny foods (infusoria/rotifers, then baby brine) and a gentle rearing setup

6) Common problems to watch for

Most issues I’ve seen with these come from the tank being “kinda brackish, kinda dirty, kinda open-top.” They’re tough, but they don’t forgive sloppy setups forever.

• Jumping/escaping: tight lid is non-negotiable
• Skin/fin infections after shipping: they often arrive stressed; keep lights low, feed well, and keep water clean and stable
• Internal parasites (wild-caught fish): weight loss despite eating, stringy poop—quarantine and treat if needed
• Bottom going anaerobic: deep substrate + overfeeding = sulfur smell, lethargy, sudden losses
• Salinity swings: topping off with saltwater instead of freshwater (or vice versa) can mess them up—mark your routine clearly

If you get one and it hides constantly, breathe. Focus on stable brackish water, cover, and feeding the right foods. Once they settle, they’re one of those oddball fish that makes you stop and watch the bottom of the tank like it’s a nature documentary.