2026/01/29 by Christophe Pampoulie, Valérie Chosson, Sverrir Daníel Halldórsson +4 · 1 voice
Environmental Science · Biochemistry, Genetics and Molecular Biology · #Marine animal studies overview #Ichthyology and Marine Biology #Animal Vocal Communication and Behavior
paper · doi:10.22541/au.176969551.15355859/v1
Hybrids between blue (Balaenoptera musculus) and fin (B. physalus) whales have been reported since commercial whaling in the late 1800s. Even while species descriptions were still at their infancy, whalers described whales with intermediate characteristics between blue and fin whales. In more recent decades, hybrid reports have come mainly from sighting surveys or genetic analysis from biopsies or caught individuals. Over the past three decades, hybrids have been confirmed genetically with various methods, which have provided information related to maternal lineages. Furthermore, recent whaling operations have captured hybrids, enabling genetic verification and detailed assessment of their morphological traits. In this review, we synthesize available information on blue–fin whale hybrids across ocean basins, encompassing historical accounts and contemporary observations, including recently documented specimens. We document 46 possible hybrids. Of these, 17 have been genetically confirmed: 15 from the North Atlantic, one from the Mediterranean, and one from the north-east Pacific. We also highlight possible bias in current knowledge and recommend the collection of biopsies when atypical whales are encountered that exhibit characteristics of both species.