The relationship between fish length and otolith size and weight of the two nearly threatened siluriformes species Ailia coila (Ailiidae) and Ompok pabda (Siluridae) collected from the Ganga River at Narora, India

Abstract

Relationships between fish length and otolith length, width and mass were investigated in the two nearly threatened silurid species (Siluriformes) Ailia coila (Hamilton, 1822) and Ompok pabda Hamilton, 1822) collected from the Ganga River at Narora, India. The relationships between otolith length (OL) and fish total length (TL), otolith width (OWd) and TL, and otolith weight (OWe) and TL are expressed by linear regression models; for A. coila, OL = 0.0291 TL + 0.8541, OWd = 0.0306 TL + 0.2241, OWe = 0.0246 TL + 0.8595, and for O. pabda, OL=0.0643 TL + 1.3848, OWd = 0.0377 TL + 0.7358, OWe = 0.0461 TL + 0.6761. This study symbolizes the first reference available on the relationship of fish size and otolith size and weight for A. coila and O. pabda in the Ganga River at Narora, India. The data obtained are useful for studying the feeding ecology of these fish, whose numbers are declining due to overfishing.