Chrysiptera rex. A common damsel,it is most likely to break in or cycle a new aquarium. These damselfish are mostly aggressive towards their other tank mates. However, they form groups and act peacefully with the same species. A beautiful member of the Pomacentridae family, a damselfish easily marks its territory (when in majority). They grow up to 14 inches or 36 centimeters. These bight-hued fish are mostly found in lower stretches of fresh water rivers. They have a regular diet which includes everything from crustaceans, plankton, to algae. These omnivorous feeders can also derive nutrition out of prepared flakes, pallet feed, and frozen marine origin foods. Various studies have revealed that these damselfish are engaged in filial cannibalism. The mating or courtship is called the signal jump as a damselfish rise in a water column and swim back downward. This attracts females to look for the most vigorous damsel male fish.