The longfin mako shark ("Isurus paucus") is a species of mackerel shark in the family Lamnidae, with a probable worldwide distribution in temperate and tropical waters. An uncommon species, it is typically lumped together under the name "mako" with its better-known relative, the shortfin mako shark ("I. oxyrinchus"). The longfin mako is a pelagic species found in moderately deep water, having been reported to a depth of . Growing to a maximum length of , the slimmer build and long, broad pectoral fins of this shark suggest that it is a slower and less active swimmer than the shortfin mako.