DWARF MINKE WHALES: MORPHOLOGY, GROWTH AND LIFE HISTORY BASED ON SAMPLES COLLECTED FROM THE HIGHER LATITUDES IN THE SOUTHERN HEMISPHERE

DOI Web Site
  • Kato Hidehiro
    Tokyo University of Marine Science and Technology Institute of Cetacean Research
  • Fujise Yoshihiro
    Institute of Cetacean Research
  • Nakamura Gen
    Tokyo University of Marine Science and Technology
  • Hakamada Takashi
    Institute of Cetacean Research
  • Pastene Luis A.
    Institute of Cetacean Research Project Microbiome as Bioindicators of the Aquatic Ecosystem Health in Chilean Patagonia, Centro de Estudios del Cuaternario de Fuego-Patagonia y Antártica (CEQUA)
  • Best Peter B.
    Mammal Research Institute, University of Pretoria, c/o Iziko South Africa Museum

Search this article

Abstract

<p>This study examined the morphology, growth and life history of dwarf minke whales to identify and confirm any differences from other minke whale species and subspecies. The study was based on biological samples and data obtained from 16 whales (3 males and 13 females) collected through the 1987/88 to 1992/93 austral summer seasons by the Japanese Whale Research Program under Special Permit in the Antarctic (JARPA). The whales were collected between latitudes 58°23′S and 65°04′S in the Antarctic area between 90°E and 180°. Mean body length at physical maturity was estimated to be 7.16 m for females, approximately 1.5 m to 2.0 m smaller than equivalent values of Antarctic minke whales and North Pacific common minke whales. The characteristic feature of a white shoulder/flipper patch was confirmed and some variations in the overall color pattern was found. Skeletal observations confirmed the previously reported characteristic features on the vertex of the skull. In addition, this study found a longer rostrum, deeply curved mandible, and narrower nasal bone in dwarf minke whales in comparison with other minke whales. All pregnant females had conceived in mid-austral winter (middle of June to early August). Females are likely to attain sexual maturation at 6–6.5 m and at around 7–10 years of age. Stomach contents indicated that dwarf minke whales mainly fed on lantern fishes around the Antarctic Convergence in summer. Analyses by ANCOV revealed significant differences in both external body and skull morphology among different species and subspecies. Furthermore, cluster analyses on the skull morphology revealed differentiation between dwarf minke whales and other common minke whales but they are more closely related to North Atlantic common minke whales. These analyses concurred with previous genetic analyses results. The results of this study provided support for the proposed subspecific status of dwarf minke whales.</p>

Journal

  • Cetacean Population Studies

    Cetacean Population Studies 3 (0), 93-128, 2021-12-28

    Publication Committee for Cetacean Population Studies

Keywords

Details 詳細情報について

Report a problem

Back to top