The Broadbarred Mackerel, Scomberomorus semifasciatus, also known as Broadbarred King Mackerel,
Broad-barred king mackerel, Broadbarred Spanish mackerel, Grey mackerel, Tiger mackerel,
broad-barred and brownie, is a species of fish in the family Scombridae distributed in Western
Pacific: southern Papua New Guinea and northern Australia, from Shark Bay, Western Australia to
northern New South Wales. Reports of this species from Thailand and Malaysia are based on
misidentifications.
Description
The Broadbarred Mackerel has a robust, elongate and streamlined body with two distinct dorsal fins,
generally separated, the first one supported by spines and the second only by soft rays. The pelvic fins
are inserted below the base of the pectoral fins. The caudal fin is deeply notched. Gill rakers on first
arch moderate from 6 to 13 total, usually 11 or fewer. 1 or 2 on upper limb; 5 to 11, usually 7 to 9 on
lower limb. First dorsal fin with 13 to 15 spines; second dorsal with 19 to 22 rays, usually 20 or more,
followed by 8 to 10 finlets, usually 9; Anal fin with 19 to 22 rays, usually 21 or 22, followed by 7 to
10 finlets; many pectoral fin rays, 22 to 25, usually 23 or 24. Lateral line gradually curving down
toward caudal peduncle. Vertebrae 18 or 19 precaudal plus 25 to 27 caudal, total 44 to 46, usually 45.
Interpelvic process small and bifid. Lateral line gradually curving down toward caudal peduncle.
Intestine with 2 folds and 3 limbs. Swim bladder absent. Body covered with small scales. Juveniles (less
than 10 cm) marked with 12-20 vertical bands which becomes less distinct or break into spots in larger
fish.
Distinguishing characteristics: Interpelvic process small and bifid. Lateral line gradually
curving down toward caudal peduncle. Intestine with 2 folds and 3 limbs. Swim bladder absent. Body
covered with small scales. Juveniles (less than 10 cm) marked with 12-20 vertical bands which becomes
less distinct or break into spots in larger fish.
13โ15 Dorsal spines with 19-22 soft rays
19โ22 Anal soft rays
44โ46 Vertebrae
Maximum weight: 10 kg
Maximum size: 1.2 m
Adults have the bronze-green coloration of the back turns greenish blue. The vertical bands on the back
are most marked in specimens less than 50 cm and in larger fish there is a tendency for these markings
to become less distinct, break into spots or fade out more or less completely. Above 70 cm, dead fish
assume a drab greyish-yellow blotchy appearance with little or no evidence of markings.
Juveniles (less than 10 cm) marked with 12 to 20 broad vertical dark grey bands; bars
confined to region of body above lateral line, number increasing with age; cheeks and belly silver
white; snout dark slate grey, patch of green above orbit; first dorsal fin jet black with contrasting
areas of white in central region; second dorsal fin cream with yellow anteriorly; anal fin and finlets
transparent white; caudal flukes creamy white at margins and dusky or blackish near hypural; pectoral
fins dusky.
Often mistaken for Spanish mackerel Broad-barred mackerel have indistinct, broad vertical
bars on their sides and have a black area on the front of the dorsal and anal fins which is absent in
Spanish mackerel. Juveniles have distinct broad bands, which either fade or break into spots as fish
grow larger. The pectoral fin is also relatively long in this species compared with Spanish mackerel.
Habitats
The Broadbarred Mackerel is found in tropical waters of the western Pacific, along the northern coast of
Australia and the southern coast of Papua New Guinea, in surface waters down to 100 m (330 ft). Found
more commonly around coastal headlands and rocky reefs but are also caught offshore. Broad-barred
Mackerel can tolerate low salinity waters and thus can inhabit near shore areas such as river mouths and
estuaries. Juveniles (4.5 to 10 cm length) are commonly encountered during November along the beaches of
Townsville, Queensland and grow to twice this size by January. They are migrating within oceans
typically between spawning and different feeding areas, as tunas do. Migrations should be cyclical and
predictable and cover more than 100 km.
They are pelagic predators, feeding exclusively on baitfish like herring, sardines,
hardheads, white bait and pilchards.
Spawning:
Broadbarred mackerels reach their age of maturity between 2 and 3 years of age at 67.45 cm length for
males and 81 cm for females, and longevity is estimated to be 12 years. They spawn in batches with
fecundities range from 300 000 to 1 500 000 eggs and each egg mass can reach up to 50 cm in total length
a seasonal breeder, that repeatedly spawns between September and February.
Broadbarred Mackerel is spawn in open water close to the surface. Eggs are released by
females in several batches in areas where the survival of their larvae is greatest. Species spawn only
in warm waters. The larvae inhabit coastal bays and the lagoon areas between the coast and the Great
Barrier Reef. Larvae and juveniles are dependent on estuarine and coastal nursery habitats. These areas
are typically influenced by freshwater runoff and low salinity surface waters.
Broadbarred King Mackerels are one of my favorite fish to catch and with a bit of practice, are readily
available and great sport to match. They feed on baitfish like herring, sardines, hardheads, white bait
and pilchards. Fishing gear includes set nets and lines. Popularly, anglers operating from small
outboard powered boats troll with small lures or cut bait. Broadbarred King Mackerels are also taken by
trawlers in the Gulf of Papua.
Broadbarred King are usually found where a good current flow runs around a point or
headland or where the baitfish is herded up against a rocky shoreline with deep water right up to edge.
They are also found out on the Barrier Reef along the deep drop offs and where the current runs around a
point sticking out. The other places where they can be found is over patches of reef, rocks or pinnacles
and areas where there is a gravel or shale bottom, even if the bottom is a hundred feet below they still
patrol the top ten feet or so of the water column as this is where the bait schools often ball up.
Trolling rigged ribbon fish or wolf herring is one of the best methods. These can be
caught easily by trolling a small spoon. The ribbon fish are rigged with up to ten hooks along the
underside of the bait and a large ball sinker tied under the chin to stop spinning. Rigging ribbons is a
bit of an art but once perfected, it is probably the best method of catching the really big mackerel.
The second most popular method for Mackerel is the floating bait. Whenever we stop to do a
bit of bottom fishing, we always run out floating bait. This can be a pilchard or a live bait fish
caught on the spot or a dead sennit or mullet, it doesn't seem to matter as long as it is presented
well.
Mackerel has a strong, distinctly, fishy, flavor and oily, firm flesh. It's best prepared
with stronger flavors such as bay, basil, citrus, curry, garlic, mustard, onion, oregano, pepper, red
wine, tomato and vinegar. The thin skin can be eaten, but it's usually sold skinned, and it has few
bones which are easily removed. It is considered as a very good game fish with very good taste. It can
be eaten pan-fried, baked, grilled, barbecued, smoked or pickled.
