After eggs have been laid in a clean nest, meticulously cleaned to prevent the spread of mould, defended at all costs from predators, and hatched, parental care continues for this species. Even after hatching, discus (Symphysodon aequifasciatus) continue to guard their precious offspring until they are able to fend for themselves. Most larval fish have to rely on passing microscopic organisms as a food source, but in a manner similar to mammals, discus secrete a nutritious mucus from their flanks for their fry to consume. Not only does this secretion give them nutritional support, but the mucus is also rich in immunity-building factors ensuring their larvae can be primed for dealing with common infectious agents. This type of provisioning makes these fish the most mammal-like non-mammals!
Tagged in: Aquatic Adaptations