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Comparative morphology of the scales of roundscale spearfish T etrapturus georgii and white marlin K ajikia albida
Author(s) -
Loose E. L.,
Hilton E. J.,
Graves J. E.
Publication year - 2017
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/jfb.13248
Subject(s) - biology , morphology (biology) , systematics , zoology , scale (ratio) , variation (astronomy) , taxonomy (biology) , cartography , astrophysics , geography , physics
The comparative morphology of the scales of roundscale spearfish Tetrapturus georgii and white marlin Kajikia albida was investigated. In addition, variation in scale morphology across different body regions within each species was analysed. Although considerable morphological variation was observed among scales from different body regions in both species, scales of K. albida generally have pointed anterior ends, fewer posterior points and are more heavily imbricated than those of T. georgii , which are frequently rounded anteriorly, often have many posterior points and are separated farther within the skin. In all sampled body regions and individuals, scales of T. georgii are significantly broader and have a lower length‐to‐width aspect ratio than those of K. albida . Superficial to the scales are denticular plates, which are ossified formations occurring on the surface layer of the epidermis; these were observed and described for T. georgii , K. albida and blue marlin Makaira nigricans . Detailed scale descriptions allow for a more accurate characterization of the variation within and differences between these two species and could potentially be a valuable tool for investigating istiophorid systematics.