A composição química, o teor de colesterol e a caracterização dos lipídios totais da tilápia e do pargo, espécies de peixes de água doce e salgada, respectivamente, foram avaliadas por serem consumidas e apreciadas no Nordeste do Brasil. A tilápia foi avaliada sob três condições distintas: I- tilápia em meio doce; II) tilápia adaptada em meio salgado; III) tilápia revertida, em meio doce. Determinou-se o teor de umidade, cinzas, proteína bruta, lipídios, colesterol e os lipídios neutros e fosfolipídios. Os teores de colesterol foram de 10,05; 8,22; 8,75 e 12,75mg/100g para as amostras de tilápia I, II, III e pargo, respectivamente. Os lipídios neutros variaram de 59,0 a 68,9% e os fosfolipídios de 17,1 a 31,0% nas tilápias e, no pargo variaram de 59,5 a 72,5% (neutros) e os fosfolipídios de 25,1 a 34,1%. A recuperação total variou de 85,4 a 97,7%. O teor de lipídios nas tilápias foi de 0,59 a 0,99% e no pargo 1,18%. As tilápias e o pargo apresentaram predominância de lipídios neutros. Mesmo sob condições diferenciadas, as tilápias apresentaram excelente qualidade nutricional além de baixo teor de colesterol, também presente no pargo.

The effect of growing conditions on chemical composition, cholesterol percentage and characterization of total lipids was determined for Nile Tilapia and Pargo, both species of river water and seawater, which present high consumption and are very well appreciated in the Brazilian Northeast. Tilapia fishes were analyzed under three different conditions: I- Tilapia growing in river water; II) Tilapia adapted to sea water; III) tilapia "reverted' in river water. The percentage of moisture, ash, protein total, total fat, cholesterol, neutral lipids and phospholipids were determined. Cholesterol levels were respectively 10.05; 8.22; 8.75 and 12.75mg/100g in tilapia samples I, II, III and Pargo fish. Neutral lipids changed from 59.0 to 68.9%, and phospholipids from 17.1 to 31.0% in tilapia fishes, also Pargo presented variations from 59.5 to 72.5% for neutral lipids and from 25.1 to 34.1% for phospholipids. The total recuperation of phospholipids changed from 85.4 to 97.7%. The fat content in tilapia changed from 0.59 to 0.99%, while in Pargo it was 1.18%. Neutral lipids were predominant in both species. Even when submitted to stressing conditions Tilapia presented excellent nutritional qualities and low percentage of cholesterol, qualities which were also observed in Pargo fish.