Biometric characteristics of Trachinus araneus Cuveir, 1829, Trachinus draco Linnaeus, 1758 and Trachinus radiatus Cuveir, 1829 (Pisces; Trachinidae) from the Egyptian Mediterranean waters.

The biometric characteristics of Trachinus araneus , Trachinus draco and Trachinus radiatus from the Egyptian Mediterranean waters at the West of Alexandria City, were studied. In total, 105, 96 and 55 specimens of these three Fish species were sampled, respectively, by the use of bottom trawls operated in the sectors of El-Dabaa and Sidi Abd El Rahman. The morphological characteristic and related index ratio were determined. The results showed that T. araneus total length varied from 10.9 to 30.0 cm TL with mean length of 19.87 ± 5.43 cm TL and a number of horizontal dots appear to be distributed along the lateral line, T. draco total length was 11.8 to 27.6 cm TL with a mean length of 17.85 ± 4.23 cm TL, and specimens of this Fish species showed yellow vertical oblique lines on the body. On the other hand, T. radiatus is characterized by a total length of 10.6 to 35.0 cm TL with a mean length 18.04 ± 4.87 cm TL, and by circular brown dots spread on the whole body and head. Furthermore, these three Fish species have poisonous spines, one on each operculum, and both spines on the internal border of the dorsal part of each eye orbit. The morphometric regression of each morphometric character showed close agreement between the observed and calculated values. [ABSTRACT FROM AUTHOR]