Saltwater · Year-round in Hawaiʻi; best in summer when schools gather over reef slopes and at FADs

Opelu (Mackerel Scad)

Decapterus macarellus

The opelu is Hawaiʻi's slender mackerel scad, prized fresh as food and above all as the premier live bait for mahimahi and ahi. The traditional ʻōpelu koʻa fishery of Hawaiʻi, built around known offshore schooling grounds tended for generations, is famous and still respected today.

Seasons · Peak

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Opelu (Mackerel Scad) — Photo: Williams, J. T.; Carpenter, K. E.; Van Tassell, J. L.; Hoetjes, P.; Toller, W.; Etnoyer, P.; Smith, M., CC BY 2.5 — Wikimedia Commons

Identifying features

Slender, streamlined mackerel-like body, bluish-green above and silver below
A small black spot at the base of the pectoral fin
A single small finlet behind both the dorsal and anal fins
Scutes along the straight rear part of the lateral line
Pointed snout with a small mouth and a deeply forked tail

Habits

Schools in open water over reef slopes, feeding on plankton and tiny shrimp
Gathers at traditional offshore grounds (koʻa) in predictable seasons
Caught day and night, often best at dawn and around lights
A key forage fish for mahimahi, tuna and other pelagic predators
Kept alive in bait wells, it is the premier live bait for mahimahi and ahi

Distribution

Honolulu, HI · Hawaii★ Primary

Where to find them

Hawaiian FADs and offshore buoys
Outer reef slopes and drop-offs off the Hawaiian Islands
Harbour mouths and deep bays at dawn

Where they live

Open water over outer reef slopes and drop-offsAround FADs, buoys and harbour mouthsDeep bays where schools feed on plankton near the surface

How to catch them

Sabiki fishing over reef slopes Boat

Rig: Sabiki rig of tiny skin hooks with a small sinker, worked day and night over reef slopes and at FADs from a boat

Bait/lure: Bare sabiki hooks or tiny shrimp slivers

Key tip: Keep hooked opelu alive in a bait well — a swimming opelu is the premier live bait for mahimahi and ahi.

Small jigs at FADs and harbour mouths Boat

Rig: Light spinning rod, small feather or glow jigs cast and retrieved around FADs, buoys and harbour mouths

Bait/lure: Small jigs

Key tip: Fish the up-current edge of the structure at dawn, when schools rise to feed.

Best baits & lures

Sabiki rigs with tiny skin hooksSmall feather and glow jigsTiny shrimp pieces on small hooks

Techniques for Opelu (Mackerel Scad) →

Baseline setup

Rod: Light 6-7 ft spinning rod
Line: 6-10 lb mono or braid
Terminal: Sabiki rigs, size 8-12 hooks, small jigs and sinkers

Recommended gear for this species

Rod · Best value

9' 5-weight fly rod outfit

≈ US$180-260

Covers chironomid lakes and small rivers with one setup.

Flies · Budget

Chironomid assortment (30 patterns)

≈ US$25-40

Chironomids are 60% of a lake rainbow's diet in spring.

Picks come from our rule library — never paid placements. Prices are guides; affiliate links may earn us a commission.

Typical size

Common 9-12 in (23-30 cm); large fish to about 14 in (35 cm)

On the table

Good fresh — eaten grilled, fried or raw in Hawaiʻi; best known and most valuable as live bait.

Similar species

Akule (Bigeye Scad)Akule is deeper-bodied with a huge eye and a dark spot on the gill cover; opelu is slimmer with a black spot at the pectoral-fin base and finlets behind the dorsal and anal fins

Pacific Jack MackerelPacific jack mackerel is a cooler-water fish with a larger mouth and no finlets; opelu is the warm-water Hawaiian scad with a pectoral-base spot and single finlets

Regulations vary by area and can change in-season — always check the official rules for your area before you fish. Regulations guide →

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