Using head measurements to distinguish white marlin Kajikia albida from roundscale spearfish Tetrapturus georgii in the western North Atlantic

Lawrence R. Beerkircher, Joseph E. Serafy

Research output: Contribution to journalArticle

3 Scopus citations


The morphometric characteristics that separate white marlin Kajikia albida (Poey, 1860) from roundscale spearfish Tetrapturus georgii Lowe, 1841 can be difficult for non-experts to distinguish, particularly when the animals are in the water. Using the measurements of the lower jaw tip to the longest branchiostegal ray(LJBR) and the opercle (LJOP ), a discriminant function is presented that will help field observers separate the two species. The function DR-W = LJBR (3.31861) + LJOP (-2.84856) - 6.37198 classified specimens as roundscale spearfish when DR-W was > 0 and as white marlin when DR-W < 0 with a 95% correct classification rate overall. Since only the head of a specimen needs to be closely observed, the method has particular utility for tournament anglers during the hook removal process.

Original languageEnglish (US)
Pages (from-to)147-153
Number of pages7
JournalBulletin of Marine Science
Issue number1
StatePublished - Jan 1 2011


ASJC Scopus subject areas

  • Oceanography
  • Aquatic Science

Cite this