Gallery 3.1: Tuna Species
The three tuna species (adult forms) most likely to be encountered during tropical tuna purse seine fishing: skipjack (SKJ, top), yellowfin (YFT, middle), and bigeye (BET, bottom). The skipjack is easy to distinguish by the horizontal stripes that run down its body. (Photos, top to bottom: FAO, K. Schaefer, K. Schaefer)
Schooling tuna: note the uniformity of fish size (Photo: Jeff Muir)
Schooling yellowfin (Photo: Jeff Muir)
The same three species, but showing the small (juvenile) forms of yellowfin and bigeye more commonly occurring with the mature skipjack (Photos, top to bottom: FAO, K. Schaefer, K. Schaefer)
Mixed tuna (Photo: FADIO/IRD-Ifremer/M. Taquet)
With their characteristic horizontal stripes and fusiform shape (wide in the middle and evenly tapered at both ends), skipjack are relatively easy to identify. Distinguishing between small bigeye and yellowfin is more challenging and will be reviewed in detail in the next gallery. (Photo: David Itano)