(IMAGE) Max Planck Institute for Chemical Ecology Caption Rival male Mozambique tilapias (<i>Oreochromis mossambicus</i>) in an aquarium: The dominant male (right) defends the nest, an excavation in the sand he made with his mouth. Females are mouthbrooders, meaning they take up the eggs in their mouths, once they have been externally fertilized in the nest by the males. Oral incubation is a strategy for protecting offspring. Credit Olinda G. Almeida / Peter C. Hubbard, Centre of Marine Sciences (CCMAR), University of the Algarve, Faro, Portugal Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.