Jack-knife fish

Jack-knife fish (Eques lanceolatus) — field identification starting point: an elongate to moderately deep-bodied fish with spiny and soft dorsal-fin sections; many members can produce croaking or drumming sounds.

Most are around 6 in (15 cm).

Up to about 10 in (25 cm) long. Source: FishBase

It eats mainly small shrimp and crabs, but also marine worms and sea snails.

It lives in bays and sounds and on deep coral reefs, and young ones sometimes come near shore. It is easy to get close to.

Found in Puerto Rico. Start in coastal channels, flats, beaches, sand/grass edges, passes or estuary mouths that match the species habitat, especially where current concentrates bait. Habitat reference:

Habitat: reef, sand bottom, mud bottom and coastal waters.

From 33 ft to 197 ft deep (10–60 m).

Start from very shallow water to the first channel/drop-off; follow bait, current seams and depth changes rather than one fixed number.

Water: marine. Habitat: reef, sand bottom, mud bottom and coastal waters.

Use current local reports and legal rules; choose days with manageable wind and good water conditions instead of relying on one universal month.

Early morning, late afternoon and lower-light periods are common starts; tide/current changes can outweigh the clock.

Moving water around points, cuts, passes and troughs is a common trigger; watch where bait is concentrated.

Choose sea state, wind and visibility that let you hold position and handle the fish safely. Avoid treating rough weather as a feeding advantage.

Shrimp, small crabs, sand fleas, mullet, sardines and cut bait are common inshore choices; match the bait to the species and bottom.

Soft plastics, bucktails, small jigs, spoons, plugs and topwaters are common; imitate the local forage and work current edges.

Start with a medium spinning rod, 10–15 lb braid/mono, 15–25 lb leader and a #1–2/0 hook or small jig; scale up for large tarpon/snook.

Roughly #1 to 4/0 is a common inshore bait range, scaled to bait and species; use stronger/larger hooks for tarpon-size fish.

8–20 lb line covers much inshore fishing; 20–40 lb is more appropriate around heavy cover or large tarpon/snook-class fish.

10–30 lb fluorocarbon/mono is a common flats/inshore start; move to 40–80 lb around abrasive mouths, structure or large tarpon/snook.

Sight-fish, drift, cast current edges, work troughs/channels or present bait near mangrove and structure edges where access is legal.

Let it go quickly if you're not keeping it.

BigJoe does not classify Jack-knife fish as a routine food species from the current source set. That is not a claim that it is poisonous; before eating, confirm exact identification, lawful retention, documented local food use and current public-health advisories.

Not a common food fish — most anglers release it.

Ice it right away. Use a clean board and sharp knife; scale or skin only when appropriate, remove the viscera or fillet cleanly, trim damaged tissue/bloodline as desired, minimize warm-water exposure, and keep the edible portion cold. If the fish carries venomous spines, dangerous teeth or a toxin advisory, follow the safety warning before cleaning.

For routine cooked preparation, FDA seafood guidance uses 145°F (63°C) as the safe internal-temperature target for fish; flesh should be opaque and separate easily with a fork. Grilling, baking, broiling, steaming or pan-cooking can all work after the fish is positively identified, legally retained and cleared for applicable toxin/mercury advisories.

Wet hands for release, use pliers/dehooker and watch for sharp gill plates, teeth or dorsal spines depending on species.

No species-specific size, bag or season limits are listed here.

Avoid needless kills and follow protected-species, area and season rules.