Jackknife Fish
Eques lanceolatus
| Stock | Variations | Price | Quantity |
|---|
Every order ships with our standard 3-hour live arrival guarantee. Need more time? Add our 5-Day Guarantee at checkout.
Full guarantee terms →Ships Monday – Thursday for next-day arrival at your nearest FedEx Hold location — typically ready by 9 AM. We monitor every delivery.
Shipping details →
Monday – Friday 8 AM – 9 PM
Saturday 12 PM – 4 PM
Sunday 12 PM – 9 PM
Healthy, stable animals from vetted suppliers — inspected before packing, shipped overnight. Decades of experience built this model so we can deliver premium livestock at 30%+ less than you'd pay elsewhere.
| Care Level | Moderate |
|---|---|
| Temperament | Peaceful |
| Reef Safe | With Caution |
| Functional Benefit | Pest Control |
| Diet Type | Carnivore |
| Mininum Tank Size | 120 gallons |
| Max Size | 10 inches |
| Temperature | 72–78°F |
| pH Range | 8.1–8.4 |
| Specific Gravity | 1.022–1.025 |
The Jackknife Fish is a sand-foraging hunter that can help reduce nuisance worms by combing the bottom for prey. Its long dorsal and tail fins and bold black-and-white barring give it a very distinct “knife-blade” silhouette as it cruises. Native to the Western Atlantic/Caribbean region, it’s often kept in larger peaceful community systems where it has room to settle in and search the sand.
What You’ll Observe:
- Spending its first stretch in the tank staying close to rockwork, then gradually making longer passes over the sand
- Methodically “scanning” the substrate and picking at small foods along the bottom
- Showing the strongest activity right before and during feeding
- Keeping a calm presence in the water column while it moves between caves and open sand
Provide a mature, stable aquarium with open sand, plus abundant live rock ledges and caves so it can hide and forage naturally. Offer regular meals of meaty foods (and start with more enticing options if it’s new), and feed in a way that lets food reach the lower water column. If you plan to keep more than one, add them at the same time so they can settle in together.
Will it bother corals even if it’s “With Caution” reef compatible?
It’s generally not a coral picker, but “With Caution” reflects its tendency to hunt smaller animals in the tank.
Will it eat ornamental shrimp or small crabs?
It may view small crustaceans and other motile invertebrates as food, especially if they share its foraging zone.
How can I encourage a new Jackknife Fish to start eating?
Start with smaller, meaty items that move or drift naturally, then expand variety once it’s feeding confidently and coming out regularly.
Do they change a lot as they grow?
The bold black-and-white barred pattern remains the main look, but the body becomes more robust as it approaches adult length.
Can I keep more than one in the same tank?
Yes, when they’re introduced together and given enough space to establish routines around the rockwork and sandbed.
We work with trusted suppliers who keep our specimens healthy and well-fed before shipping.
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