Ultrastructure of the Sagitta Otolith in Different Body Size Groups of Climbing Perch Anabas testudineus (Anabantidae)

The developmental variations of the sagitta otolith in the young and mature male of a hermaphrodite polynemidae fish, Eleutheronema tetradactylum (Shaw, 1804)

“…The development of the sagitta constituents varies in different stages of the sexual maturity of the male E. tetradactylum. This kind of developmental differences in different body size groups are also reported in other Perciformes fishes; i.e., Chlorurus sordidus (Jawad et al, 2018), Anabas testudineus (Bardhan et al, 2021), Umbrina cirrose (Başusta & Khan, 2021). The characteristics of various sagitta constituents of E. tetradactylum slightly differ from those of the other Polynemidae fish (e.g., Polydactylus virginicus, Santificetur et al, 2017) and considerably differ from other protandrous marine Peciformes fishes (e.g., Sparidentex hasta, Acanthopagrus berda, and Acanthopagrus latus; Abdulsamad, 2017) (Table 4).…”

“…One pair of sagittae were removed from the saccule of the inner ear of each individual of the four groups (Ruck, 1976;Jawad et al, 2018), cleaned with water and 70% ethanol, and stored dry in individual plastic tubes. For ultrastructural studies on the medial (inner) surface of the sagittae, the right sagitta was examined (Bardhan et al, 2021). The sagittae were dried and mounted on an aluminium stub using double-sided carbon tape.…”

“…In the work, all the terminologies used for the description of the structural constituents of the medial surface of the sagitta are following Smale et al (1995), Jawad (2007) and Bardhan et al (2021).…”

“…The sagitta has two surfaces which are the lateral (outer) and medial surface (inner). The medial surface of the sagitta is well-decorated with different morpho-structural features (Smale et al, 1995;Jawad et al, 2018;Bardhan et al, 2021), which characteristically varies with the fish groups and various environmental factors in their respective habitats (Kumar et al, 2012;Omar & AMohamed, 2016;Abdulsamad, 2017;Sanchez & Martinez, 2017;Jawad et al, 2018;Pracheil et al, 2019). Several studies have dealt with the morphological descriptions of the sagitta of marine Perciformes fishes (Hunt, 1992;Smale et al, 1995;Gierl et al, 2018;Jawad et al, 2018), but no ultrastructural studies on the sagitta are available in the hermaphrodite perciformes fishes.…”

“…It has been stated that the development of the sagitta components (i.e., sulcus, ostium, rostrum, etc.) is associated with the body size (length/weight) groups of the sexually dimorphic fishes (Harvey et al, 2000;Jawad et al, 2018;Bardhan et al, 2021). However, there is no information regarding the developmental variations of the otolith morphologies among the young male and the mature male of the protandrous, hermaphrodite fishes.…”