Fluctuating asymmetry and organosomatic indexes in fish: the Corocoro grunt as a case study (Haemulidae)

Fluctuation asymmetries (FA) are random on the bilateral symmetry plan of paired morphological characters, and other types of symmetry, such as: for instance, translational or rotational symmetry, in response to environmental, and genetic stress. The relationship of FA with gonadossomatic (GSI), hepatosomatic (HSI), and fullness (RI) indexes and condition factor (K) for juveniles (n=8), adults (n=32), males (n=9), and females (n=26) of Corocoro grunt Orthopristis ruber were evaluated in this paper. The composite fluctuating asymmetry (CFA) was used to calculate the combined effects of FA over these four organosomatic indexes of 66 Corocoro grunt caught during 2011 in Guanabara Bay, Brazil, one of the most eutrophic coastal bays in the world. Redundancy Analysis (RDA) confirmed a significant relationship between CFA and the physiological descriptors (HSI, RI, K), but without clear differences among juveniles, adults, and sexes. Our results support the potential of CFA to be used as a proxy of environmental effects over reef-associated fish species in a tropical bay, but the relationship between CFA and physiological descriptors is complex, and further studies, such as experimental trials, are needed.