Negative effects of artificial diets on growth and the digestive tract of 1-month- old Redhead cichlid (Vieja melanura, Günther, 1862)

" The redhead cichlid (Vieja melanura) is a neotropical Heroini species from Central America, which is currently an emerging species in the ornamental trade, but it is also a promising fish in terms of aquaculture production. So far, research shows that this species is herbivorous or omnivorous; however, larvae and young juveniles mostly feed on zooplankton. A 3-week experimental rearing was carried out (in triplicates of tanks) using either natural food (Artemia sp., group Art) or one of three commercial fish diets (groups D1–D3), from inception of exogenous feeding (5 days post hatching). No differences in survival occurred (all groups above 95%), but the mean body weight in the Art group was 3.0–7.1 times higher when compared with the D1-D3 groups (p < 0.05). Histological measurements showed that mucosal fold length in Art group was the highest in both the anterior and posterior intestine, while in D3 it was the lowest. Furthermore, abnormal fatty degeneration was found in the livers and pancreas of fish in D1–D3. The experiment showed that using commercial feeds available on the market to rear newly hatched redhead cichlids is not advisable, because they negatively impact both its growth and overall condition "