Side by Side

Albacore Thunnus alalunga

Typical: 26–34 in, 15–30 lb

Key field mark: Albacore's pectoral fins are exceptionally long (reaching past the second dorsal and anal fins) and the tail has a clean white trailing margin — both unique among the local tunas.

• Steel-blue back grading to dusky silver sides
• Extremely long pectoral fins reaching past the anal fin origin
• White trailing edge on the tail (caudal) fin
• Rounded football body with a relatively small second dorsal
• Finlets dusky/dark, not bright yellow

Full Albacore guide — season, gear and rules →

Bluefin Tuna Thunnus thynnus

Typical: 40–73 in, 50–300 lb

Key field mark: The distinctly SHORT pectoral fin (not reaching the second dorsal), the dull dusky finlets, and the heavy football body separate bluefin from the long-pectoraled bigeye and the long-finned, yellow-striped yellowfin; bluefin alone has a heavily striated liver, the definitive lab check.

• very short pectoral fins (clearly not reaching back to the second dorsal)
• short second dorsal and anal fins
• dark metallic blue-black back, silver-white belly with no bright yellow stripe
• dusky/grayish finlets edged with a thin black line (not bright yellow)
• stout, deep, football-shaped body

Full Bluefin Tuna guide — season, gear and rules →

When Each Is Running July — current month highlighted

Where Albacore and Bluefin Tuna Overlap

Both run in Southern California — that is where telling them apart actually matters.

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