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In this study, some morphometric characters of Rudd, Scardinius erythrophthalmus and Elmah Rudd, Scardinius elmaliensis were determined and compared. One S. erythrophthalmus samples collected from different locations and 27 S. elmaliensis samples collected from Avian Lake (ElmahAntalya) were examined and morphometric characters, were measured at each specimen. In addition, meristic characters including the number of fin rays, the number of lateral line scales and the number of gill rakers were counted. The ratios between the morphometric characters were also calculated. The total length of S. erythrophthalmus individuals varied between 5.5 and 22.5 cm while the total length of S. elmaliensis individuals varied between 6.8 and 20.1 cm. The maximum body heightstandard height, eye diameter-nose length, eye diameter-head length and nose length-head length ratios revealed that the two species were statistically different from each other. [ABSTRACT FROM AUTHOR]

Different branchial muscles associated with the gill arches and gill filaments in a hill-stream cyprinid fish Neolissochilus hexagonolepis have been studied. The main branchial muscles observed are the constrictors branchiales, levatores arcuum branchialium epiarcualia obliqui, epiarcualia recti, subarcualia obliqui, subarcualia recti and subarcualia transversi. In the general plan the branchial muscles of N. hexagonolepis show similarity with those of other cyprinid fishes. However, the fish bears three pairs of coracobranchiales, common to cyprinid fishes. [ABSTRACT FROM AUTHOR]

Abstract: The surface ultrastructure of the gill arches and the gill rakers of the three concerned species Oreochromis niloticus, Chrysichthys auratus and Clarias gariepinus was investigated by scanning electron microscopy. These structures show significant adaptive modifications associated with the food and feeding habits of these fishes. Short and tuberous type gill-rakers in O. niloticus, are a well interesting filter of food. In C. auratus gill rakers were short with broad base, they serve to strain water which was to bathe the gills and prevent any solid particles from passing over it. Gill rakers in C. gariepinus were long, cylindrical in shape and arising at acute angles to the arch, they help to strain food and other materials, thus protect gill filaments from damage. Prominent epithelial protuberances on the gill rakers and gill arches enable the taste buds, located at their summit, to project well above the surface of the epithelium. This could increase the efficiency of the taste buds in selective sorting of palatable food. Co-occurrence of teeth and taste buds on the epi-and hypopharyngeal bones (Types I–III) denotes that food processing and gestation occur simultaneously in the pharynx. Caniform, villiform and papilliform teeth on the epi- and hypopharyngeal bones of the three studied species respectively in O. niloticus, C. auratus and C. gariepinus were associated with a complex food-processing cycle. Mucous secretions, oozing through mucous cell openings, provide lubrication facilitating smooth passage of food through the pharynx. [Copyright &y& Elsevier]