Morphology and morphometry of pharyngeal bone and teeth in cyprinid species from the Kurdistan Region, Iraq.

The morphology of pharyngeal bones and teeth was determined on seven cyprinid species caught from the Greater Zab River, a tributary of Tigris River, located in the northern part of Iraq in the Kurdistan Region. Eleven morphological characters of the pharyngeal bone and teeth were identified, measured and compared from photographs of the 152 individual species collected. The relationship between pharyngeal bone total length and four-dimensional measurements of the pharyngeal bone were determined using linear regression and multivariate analysis. Results show bone characteristics of the studied species are distinctly different in terms of shape, tooth number, tooth formulae and dimensions of the pharyngeal bones. Regression analysis shows positive coefficients of TL with all parameters PL, DL, PW and DP while multivariate linear discriminate analysis shows distinct groupings of each species using non-dimensional measurements of the bone characters. The measurements gathered and application of biometric relationships to ease the identification of the cyprinid species contributes to the morphological information on cyprinid species in a data deficient region of the world. This work provides a new set of morphological characters of the pharyngeal bone and teeth of the seven cyprinid species from Northern Mesopotamia that may enable their separation from the members of their cyprinid genera.

Bilateral asymmetry in size of otolith of Otolithes ruber (Bloch & Schneider, 1801) collected from the marine waters of Iraq.

The otolith length and width of adult teleost Otolithes ruber (Bloch & Schneider, 1801) were used to calculate the fluctuating asymmetry in these two characters. The results displayed that the amount of asymmetry of the otolith width was the highest between the two asymmetry values attained for the otolith of O. ruber. Further, the lowest level of asymmetry in the two otolith characters is at the fish length ranging between 150 and 180 mm and the highest at the fish length ranging between 461 and 2490 mm. The conceivable reason for the asymmetry in this species has been deliberated relative to different pollutants and their presence in the area. A tendency of increase in the asymmetry levels with the fish length was observed for the otolith length and width.