Otolith size—fish size relations in the jewel lanternfish, Lampanyctus crocodilus (Actinopterygii: Myctophiformes: Myctophidae), from deepwater environment of the southern Aegean Sea

Abstract

Otoliths are widely used in stomach content analysis because they are one of the last species-specific features to be digested by piscivorous predators and they may be used as an important tool for prey classification. The linear regressions between otolith size (length and height), otolith weight versus fish length and weight of the benthopelagic species, Lampanyctus crocodilus (Risso, 1810), living in the Sigacik Bay were provided. The specimens were collected during the period of July–September 2007 throughout the southern Aegean Sea, using bottom trawls. There were no differences detected between the size and weight of left and right otolith.  A single linear regression was applied to measurements of both the otolith and the fish (length and weight). All calculated regressions showed a high coefficient of determinations ranging between 0.842 and 0.965. Analyzing the morphometric relations, I concluded that otolith sizes and weight are good indicators of the standard length and weight of L. crocodilus. The aim of this study was to examine the otolith and fish size relation of the jewel lanternfish in the Aegean Sea in order to provide a reliable tool—for researchers studying food habits of top predators—to determine the size and weight of prey fish from the length or weight of the otoliths recovered.

Keywords

• myctophid
• fish food item
• prey size estimation
• s