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

Abstract

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.