The Relationship between Body Condition and Gonadosomatic Index of the Bogue (Boops Boops) from the Middle Part of the Eastern Adriatic Sea

The bogue, Boops boops (Linnaeus, 1758), is an omnivorous fish species that often aggregates near fish farms. In addition to being attracted to food, bogues also hide from predators near floating cages. Some specimens can also be found in the cages, where they coexist for a time with farmed fish. In general, there is a relationship between food availability and gonadosomatic index (GSI) of the fish. Therefore, the aim of this work was to investigate the relationship between body condition and gonadosomatic index (GSI) of bogues. The research was carried out in May 2023, during the spawning period of bogue. Samples were collected from three locations in the middle part of the Eastern Adriatic: in the immediate vicinity of the cages (A), at the floating cage (C) and at a location far away from the cages (W). The females from all three locations were heavier (315.41±119.53g) than the males (281.47±79.20g), while the difference in length between the sexes was not statistically significant. The condition index (CI) and viscerosomatic index (VSI) were significantly higher in bogues from floating cage. The decomposition of the condition index was used to evaluate the influence of body condition on the gonadosomatic index. Fish with a higher condition index also had a higher gonadal condition index (CIg), which was 0.03±0.01 at location A, 0.05±0.01 at location W, with the highest value found in the bogues from location C (CIg=0.06±0.04). Bogues sampled in floating cages differed in most studied parameters from wild population samples, but also from specimens caught in the immediate vicinity of the cages indicating the direction for further research of interactions between wild fish populations and aquaculture.