Aulonocara nyassae, an African cichlid, exhibits pronounced social hierarchies with distinct behavioral patterns among males. Thus, the aim of the present study was to investigate the effects of social hierarchy of males of A. nyassae on hematological and biochemical parameters of males and females.
The experiment was carried out at the Laboratório de Aquacultura (Laqua) at Universidade Federal de Minas Gerais (UFMG), Brazil. Four males of each social status (dominant, subdominant, and submissive) (9.62±1.50 g) were individually allocated to 12 aquaria in a Completely Randomized Design (CRD) with three initial social statuses of males, one male with three females (7.52±1.55 g) per aquarium (male to female ratio 1:3; FAO, 2009). The 36 females selected had a mean initial weight of. After 66 days, individual blood samples were collected by caudal venipuncture. The results are presented in Table 1. Among males, total hemoglobin (Hg) and plasma protein concentrations (TPP) were higher for subdominant and submissive, however, glucose (GLU) was higher for dominant males and lower for subdominant and submissive males. Triglycerides (TG) levels were higher for dominant and subdominant males and lower for submissive males. Cholesterol (TC) was higher for submissive males and lower for dominant and subdominant males. Hg and GLU concentrations were higher for females kept with dominant and lower for females kept with subdominant and submissive males. However, the concentration of TG and TPP was higher for females with submissive males and lower for females with dominant and subdominant males. TC concentration was higher for females with dominant and subdominant males and lower for females with submissive males. In conclusion, the social status of males influences hematological and biochemical parameters of males and females of A. nyassae, and, thus, it is not advisable to use submissive males as broodstock.