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Scanning electron microscopy and morphological analysis reveal size‐dependent changes in the scale surface ornamentation of tooth‐carp Aphaniops hormuzensis (Teleostei; Aphaniidae)
Author(s) -
Teimori Azad,
Esmaeili Mohammad Reza,
Motamedi Mina
Publication year - 2021
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/jemt.23729
Subject(s) - teleostei , biology , peduncle (anatomy) , scanning electron microscope , dorsum , morphology (biology) , anatomy , fish <actinopterygii> , zoology , physics , optics , fishery
Abstract Aphanius hormuzensis is an endemic tooth‐carp found in the Hormuzgan drainage in S‐Iran. This study aimed to investigate the size‐dependent alternations of scale surface ornamentation in this species by conducting scanning electron microscopy and morphological analysis. A total of 50 wild fish individuals were captured from Shur River, and were classified into five size classes based on the standard length; SC–I (SL = 10–20 mm), SC–II (SL = 21–30 mm), SC–III (SL = 41–50 mm), SC–IV (SL = 51–60 mm), and SC–V (SL = 61–70 mm), and their scales were removed from below the dorsal fin (key scale) and caudal peduncle regions. The results revealed a clear trend of scale structural development in A. hormuzensis . The scale of small‐sized (TL < 30 mm) and large‐sized fishes (TL > 30 mm) differed, respectively, in the following characters; the overall shape (often circular vs. polygonal), relative focus size (large, FL/SL = 440–610 μm vs. intermediate and small, FL/SL = 100–330 μm), types of radii (only primary vs. three types), relative radii length (short, RL/SL = 100–180 μm vs. long, RL/SL = 320–450 μm), lepidont (absent or undeveloped vs. present and developed), and the relative lepidont length (short, LL/SL = 0.83–0.90 μm vs. intermediate and long, LL/SL = 1.2–2.2 μm). These character alternations could explain certain developmental stages in this species. The size‐dependent changes in the surface micro‐ornamentations as shown in this study suggest that these characters should be used cautiously for taxonomic studies of the aphaniid fishes.