T. simonis mostly feeds on phytoplankton and macrophytes, but also takes zooplankton and small benthic invertebrates.[1][12] In Lake Tiberias, adults are found in open-water schools for much of the year, while the young live in sheltered habitats near the coast.[3] The species can reach maturity when 16 cm (6.5 in) long,[9] and breeding is from March to August, with a female being able to spawn two or three times in a season.[12] It is a mouthbrooder, but some sources indicate this only is done by the female,[4][9] while others indicate it is done by both parents.[12] There are up to 250 relatively large eggs,[9] which are laid on the open bottom in a "nest" in water less than 3 m (10 ft) deep.[5] Shortly after they are picked up in the parent's mouth.