Scomberomorus lineolatus (Cuvier), an interspecific natural hybrid (S. commerson (Lacépède) × S. guttatus (Bloch & Schneider)) off Visakhapatnam, India

Abstract

The nominal Scomberomorus lineolatus (Cuvier) is recognized as a natural hybrid between the putative parents S. commerson (Lacépède) and S. guttatus (Bloch and Schneider) on the basis of morphological and osteological intermediacy, narrow stable hybrid zone and circumstantial evidence indicating scarcity of one species and environmental disturbances at the time of hybridization. Nine morphometric and nine meristic characters are used in the principal components analyses (PCA) done separately on small (<130 mm, TL) and medium-sized (130–300 mm) fish. The absolute loadings on the discriminating axis, PC II, are the highest for snout length in the small size fish; diameter of eye in the medium-size fish; and prehaemal vertebrae in both size groups. The total vertebral count is the most consistent and widely differing parental character, in which S. lineolatus showed intermediacy. Marked osteological intermediacy of S. lineolatus between the putative parents is observed in 35 characters.

Keywords :

• Scombridae
• Scomberomorus lineolatus
• interspecific hybrid (S. commerson × S. guttatus)
• India