SAGITTAL OTOLITHS MORPHOLOGY AND MORPHOMETRY: ANALYSIS OF SIX HAEMULIDAE FISHES FROM SOUTHEASTERN-SOUTHERN BRAZIL

Otoliths size and shape differ between species and populations and due to their high morphological specificity they are considered important tools for species determination. In this study we describe the sagittal otoliths of some species of Haemulidae indicating the main differences found. The Collection of Teleostei Fish Otoliths of the Southeastern-Southern of Brazil (COSS-Brasil) held at the Oceanographic Institute, (IOUSP) contains 1200 sagittal otoliths of six species of Haemulidae, represented by: Anisotremus surinamensis, Conodon nobilis, Haemulon aurolineatum, Haemulon steindachneri, Pomadasys corvinaeformis and Orthopristis ruber. Fifteen features of 202 left sagittae were analyzed following the methodology adopted by COSS-Brazil, based on the terminology of Assis (2004) and Tuset et al. (2008). For each feature the frequency of occurrence was calculated inside and among fish length classes (20 mm) and in order to verify statistical differences multiple χ 2 tests (p> 0.05) were applied. Morphometric analysis included length, height, thickness, perimeter, area, circularity and rectangularity data of the otoliths. The main features that characterized the Haemulidae were: Shape: elliptic or oval to elliptic; Anterior region : angled-round; Ostium morphology: funnel-like or rectangular; Cauda morphology: tubular strongly curved or tubular markedly curved. The six species analyzed showed as common characteristics: sulcus acusticus opening : ostial; sulcus acusticus morphology: heterossulcoide; and colliculum morphology: heteromorphic. The otolith shape and posterior region were diagnostic features between the two species of Haemulon : H. aurolineatum presented oval shape and posterior region oblique-round or round, whereas H. steindachneri presented elliptic to oval shape and posterior region angular or angular-round. This study is part of an otoliths atlas from the Southeastern-Southern Brazilian area which has been prepared and published.