Mutton Snapper.
Riley's Hump May full moon. The Keys' largest snapper aggregation.
How they feed in the Keys
Muttons are the trophy-class Keys snapper — average 5–10 lbs, with double-digit and 20+ lb fish realistic on the deeper edges and during the May/June spawning aggregations. Riley's Hump (in the Tortugas) is the most famous mutton aggregation in the world, with thousands of fish stacking on the hump for the May full moon. Inshore, big resident muttons feed on crabs across hard bottom and patch reefs in 30–80 feet, and even occasionally tail on flats with bonefish.
72–82°F
Active 66–86°F
Strong tide. Mutton on patch reefs love an outgoing tide moving crabs off the structure.
1.5–3 knots ideal. They feed on prey moving past structure.
Pre-front falling pressure produces excellent bites. Calm to moderate seas.
Falling pressure 6–12 hours ahead of a front is the magic window.
Dawn and dusk strongest. Mid-day fish exist but harder.
MAY FULL MOON at Riley's Hump = the Keys' single most-famous reef fishery event. The aggregation runs late April through early June with peak around the May full moon. Federal closure of the Riley's Hump SPMA protects the aggregation.
80+ for productive deep-edge feeds and aggregation activity.
Riley's Hump Special Permit Management Area — closed to all fishing May 1 – July 31 to protect the spawn. The actual harvest happens just before/after the closure on the same fish that aren't in the SPMA boundary.
Inshore muttons sometimes show up on the flats tailing on crabs alongside bonefish. Sight-cast a small crab fly = trophy moment.
12-month outlook
What they eat, what catches them
Live ballyhoo
Big live ballyhoo on a 6/0 circle. The trophy-mutton bait. Drift it deep with a knocker rig.
Live blue crab
Smaller blue crabs irresistible to big muttons. On 5/0 circle, fluoro leader.
Live pinfish
5–7" live pinfish on a 7/0 circle. Reliable on the deep ledges.
- Whole squid· Reliable and tough — 9/0 circle.
- Cut bonito chunks· Strong scent for deeper drifts.
- Trophy mutton on the deep edge
Live ballyhoo on a 6/0 circle, 60 lb fluoro, drift the deep ledge in 80–120 ft.
- Inshore crab-feeding mutton
Live small blue crab or weighted crab fly on a 7'6" medium spin or 9 wt fly rod.
How top captains rig it
Spin: 30–50 lb braid. Heavier for deeper drifts.
Spin: 5000–8000 size.
Spin: 7' medium to medium-heavy.
50–80 lb fluorocarbon.
- Standard reef-edge drift
7' medium-heavy spin + 40 lb braid + 60 lb fluoro + 6/0 circle + live ballyhoo + 4–8 oz lead.
Recreational rules
18" total length minimum.
5 per harvester per day in the snapper aggregate of 10.
Open year-round outside SPMA closures. Riley's Hump SPMA closed May 1 – July 31.
Spearing rules vary by zone.
Note · SPMA closures shift periodically. Always check FWC and SAFMC current boundaries before fishing the Tortugas reef complex.
What actually moves the bite
Each factor is rated by how much it shifts the bite for this fish in the Keys. Calibrated against the Bite Score weights — see the Bite Score reference for what each factor measures.