Aphanius dispar (Rüppell, 1829) is a common marine-euryhaline teleost fish in the Near East that has undergone considerable intraspecific differentiation. Otolith morphology is used to analyse the diversity within A. dispar in the Gulf of Oman (Sea of Oman) and the Persian Gulf. A total of 134 individuals from lagoons and inland habitats of Oman, the United Arab Emirates and southern Iran are analysed. The results revealed that otolith traits that are under genetic control are strikingly different from those that are under the influence of environmental factors. A clear spatial structure of the populations is detectable, suggesting that the environmental flexibility of A. dispar, vicariance events during the last glacial maximum (21000-18000 BP), dispersal in the course of the Early Holocene sea-level rise, and Holocene to present-day interruption of gene flow at the Strait of Hormuz have shaped the intraspecific differentiation of A. dispar. These factors may also be responsible for diversification within other marine-euryhaline fishes in the Near East and Mediterranean Sea, and thus the findings can contribute to successful conservation management.

The scale morphology of four teleost fishes, Barbus arabicus, B. exolatus, Labeo niloticus (Cyprinidae), and Lates niloticus (Centropomidae), was studied using both light and scanning electron microscopy. The considerable variation in scale shape on different parts of the body makes it difficult to nominate a typical scale for particular species to be used in taxonomic studies. However, some character states of the inter‐radial denticles, cteni, and the focus area appear to be good taxonomic criteria.

Hyperostotic conditions are described in three teleost fishes. Pomadasys stridens, (Haemulidae; 326 mm TL, 314 mm SL), Drepane longimana (Drepanidae; 450 mm, TL, 440 mm SL), and Platax teira (Ephippidae) captured off the coast of Muscat City. There are regions of hyperostosis in four bones in P. stridens, three in D. longimana and seven in P. teira. Size, shape, position, and species‐specific characteristics showed wide variation in these three species.

Seven osteological characters of the axial skeleton are studied in the eight species of the genusPampus. The characters include: pattern of interdigitation of the dorsal- and anal-fin pterygiophores with the neural and haemal spines of the vertebrae, structure of the vertebral column, distribution of the dorsal- and ventral- procurrent caudal-fin rays, distribution of the principal caudal-fin rays and the morphology of the caudal-fin skeleton. All these features appear to be useful in the characterization of the eight species of the genusPampus. Formulae for the structure of the vertebral column, the dorsal- and anal-fin pterygiophores’ interdigitation with the neural and haemal spines of the vertebrae, distribution of the dorsal and ventral procurrent caudal-fin rays, and distribution of the principal caudal-fin rays were developed.Pampus nozawaewas recently considered a synonym ofP. argenteus. However, according to the characters used in the present study, this species is notably distinct fromP. argenteus.