Estimates of the Frequency Distribution (FTL%) for the Length-Classes Present in the Stocks of Ohrid Trout (Salmo letnica) and Belushka (Salmo ohridanus) from the Albanian Part of Lake Ohrid

Abstract

Based on morphometric analyses of individuals sampled from commercial catches, the frequency distribution of length classes present in the stocks of Ohrid trout (Salmo letnica) and belushka (Salmo ohridanus) in the Albanian part of Lake Ohrid was assessed. No significant differences were found in mean total length (TL, cm) among the three spatial fractions of either stock (P > 0.05), suggesting the existence of a single stock for each species. The dominant length class in the Ohrid trout stock was 31.8–35.8 cm (F% = 44.39), whereas in the belushka stock the dominant length class was 30.1–33.0 cm (F% = 30.99).  The length-frequency distributions of both species were monomodal. Polynomial relationships were identified between total length (TL, cm) and frequency of occurrence (F%). For Ohrid trout, the relationship was described by: F% = -0.6724TL³ + 7.2586TL² – 16.559TL + 10.847 (R² = 0.624; r = 0.790), whereas for belushka the relationship was: F% = -0.3256TL³ + 4.0984TL² – 11.486TL + 12.028 (R² = 0.697; r = 0.834). The results provide useful information for stock assessment, sustainable fisheries management, and conservation of these endemic salmonid species in Lake Ohrid. 

CONFLICT OF INTEREST

The authors declare no conflict of interest.

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