The Fishing Report
Fishing seasons & conditions by region
Marlin vs Swordfish
Two fish anglers routinely mix up. Here is what actually separates them — and when and where you are likely to meet each.
Side by Side
Marlin Makaira nigricans
Typical: 8–11 ft, 150–400 lb
Key field mark: A pointed first dorsal fin shorter than the body is deep marks a marlin, versus the sailfish's towering full-length sail.
- Stout, round-sectioned bill (spear)
- Pointed, stiff first dorsal fin lower than body depth (blue marlin)
- Cobalt/blue-black back, silver-white belly
- Often pale blue vertical bars on the flanks
- Two keels on each side of the tail base
- High shoulder, heavy body
Swordfish Xiphias gladius
Typical: 50–200 lb
Quickest tell: The flat, broad sword (vs. the round spear of marlin and sailfish) plus the total absence of pelvic fins makes swordfish unmistakable among billfish.
- Long, wide, flattened (sword-like) bill — over a third of body length
- No pelvic fins; adults are scaleless
- Tall, rigid, crescent first dorsal; very large eye
- Dark brown-purple to black back; no body bars or spots
- A single large keel on each side of the tail base
When Each Is Running July — current month highlighted
Peak Good Fair Slow
Where Marlin and Swordfish Overlap
Both run in South Florida & the Keys — that is where telling them apart actually matters.