Once about three-fourths of the egg mass protrudes from the female, the male takes the eggs from her. This process is immediate, taking no more than 2 seconds. Eggs may be lost in the process if the male drops them, as they are usually immediately consumed by other fish in the area. Males also have the ability to detect dead eggs and expel them from their mouths. The male broods the eggs in his mouth up to 30 days, during which he does not feed. After spawning, the female stays with the brooding male for at least a few days. Females aggressively defend their territory by immediately chasing any intruders that approach the brooding males. They also exhibit a relaxed form of 'side-by-side trembling', and confine the males to a small space. Juvenile behavior Juvenile Banggai cardinalfish do not go through any pelagic larval phase. Instead, they experience a high growth rate. Although the free embryos maintain their size difference after hatching, they increase several times in weightwhile being brooded inside their father's mouth. Therefore, at release, juveniles are many times heavier than they were at hatching. Juveniles settle directly within the parents' habitat upon release from their father's mouth. They form a tight school around different structures such as sea urchins, corals, and anemones, and swim around together while the father does not exhibit much caring behavior. Grouping Banggai cardinalfish live in shallow lagoons in groups that include up to 500 individuals. They are often found near sea urchins, where the fish hide when threatened. They are capable of hiding among the spines of sea urchins without being stung. In addition to sea urchins, other living benthic substrates such as soft corals, anemones, hydrozoans, and mangrove roots also serve as microhabitats around which the Banggai cardinalfish group. These groups of fish are rather sedentary, and movements between groups are observed to be very limited, especially because they feed on plankton that pass through water currents. Such limited dispersal of Banggai cardinalfish prevents them from spreading over large geographic ranges, thus serving as a major risk of extinction along with heavy exploitation by aquarium fish collectors, as well as low fecundity. Gallery References External links Apogoninae Fish of Indonesia Endemic fauna of Indonesia Fish described in 1933