Saltwater · Winter best off the Pacific deep slopes; year-round deep fishery
Splendid Alfonsino
Beryx splendens
A brilliant red deep-sea fish with a huge golden eye, and one of the few deep fish caught mainly by hook and line in Japan. Boats fish multi-hook rigs over deep slopes off Boso and Izu. Its flesh is prized, especially in winter.
Seasons · Peak
Identifying features
- Brilliant scarlet-red body, silvery below
- Huge golden eye, very large for the body
- Deeply forked tail and a compressed, fairly deep body
- Small sharp scales and a steep forehead
- Larger eye and brighter red than the rosy seabass
Habits
- Schools over deep rocky slopes and seamounts at night and day
- Feeds on small fish, squid, shrimp and deep crustaceans
- Rises somewhat at night but stays in deep water
- A smaller relative, the nanyou-kinme (Beryx mollis), occurs in the same fishery and is generally smaller and duller
- Slow-growing and long-lived for a fish of its size
Distribution
Regional coverage expanding
Where to find them
- Deep grounds off the Boso Peninsula near Katsuura and Choshi
- Deep slopes around the Izu Islands
- Suruga Bay deep slope grounds
Where they live
How to catch them
Deep multi-hook drop Boat
Rig: Long multi-hook rig with a heavy sinker and electric reel, lowered to deep rocky slopes from a boat
Bait/lure: Squid and mackerel strips
Key tip: Keep hooks just off the rocky bottom to avoid snagging and watch the rod tip at depth.
Deep boat fishing off Boso and Izu Boat
Rig: Drifting boat deep rig over seamounts and steep drop-offs, fished in winter for the fattest fish
Bait/lure: Squid strips and shrimp
Key tip: Use firm bait for the long drop and bring fish up steadily.
Best baits & lures
Baseline setup
- Rod: Stiff deep-water boat rod with an electric reel
- Line: 40-60 lb braid
- Terminal: Multi-hook deep rigs, heavy sinkers for 650-2,000 ft (200-600 m)
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 12-16 in (30-40 cm); large fish to about 24 in (60 cm)
On the table
Excellent — rich white flesh, prized simmered, grilled or as sashimi from professionally handled fish.
Similar species
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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