Pomacentrinae – small but feisty
Pomacentrinae fish refer to individuals in the subfamily Pomacentrinae and a group of species with a similar appearance. These small, vibrantly colored fish are ideal for smaller aquariums. However, they are highly territorial and can exhibit aggressive behavior toward members of their own species. During spawning, they may even become hostile toward larger fish.
The Pomacentridae family is a large group of popular aquarium fish, divided into three subfamilies: Amphiprioninae, Pomacentrinae, and Chrominae. This description, however, focuses exclusively on the Pomacentrinae subfamily.
Many Pomacentrinae species are available in the aquarium trade, including Chrysiptera springeri, Chrysiptera parasema, Chrysiptera cyanea and Pomacentrus coelestis.
One of the calmer species is Chrysiptera parasema, commonly known as a yellowtail damselfish, though it is far from being a peaceful fish. When multiple yellowtail damselfish are introduced into the same aquarium, they divide the available space among themselves. Unfortunately, territorial disputes can lead to the weakest individuals’ death.
Characteristics
The most common Pomacentrinae species in aquariums rarely exceed 5–6 cm in length. Males and females look identical, making it difficult to distinguish between the sexes. Despite their small size, these fish are extremely territorial and can fend off intruders much larger than themselves. In an aquarium, they usually choose crevices in rocks or spaces beneath corals for resting. Some species, just like clownfish, even live in symbiosis with anemones. During the day, Pomacentrinae vigilantly guard their chosen territories, displaying significant aggression, particularly toward other fish of the same species. They may even nip at an aquarist’s hand, but their small size makes them harmless. While they attack with impressive speed, they are not particularly dynamic swimmers.
Unlike other members of the Pomacentridae family, Pomacentrinae fish tend to stay close to their hiding spots, venturing into open water mainly during feeding. Males typically court females for spawning. Once the eggs are laid, the female departs, leaving the male to guard the nest and fend off intruders.
Aquarium requirements
In a 50-liter aquarium with sufficient hiding places among rocks, maintaining more than two individuals is challenging. While these fish are relatively sedentary, similar to clownfish, close proximity between individuals of the same sex will provoke aggression. A pair of Pomacentrinae can coexist peacefully if enough hiding spots are provided to minimize interaction. Therefore, an aquarium designed for these fish should include ample rocky shelters.
Reproduction – difficult but not impossible
In Pomacentrinae, the male typically prepares a nest and invites the female to spawn. If the female accepts, she enters the male’s hiding place for several minutes to lay eggs before returning to her territory. I have observed this ritual many times, marveling at mature Chrysiptera parasema eggs, with the larvae’s eyes already visible. However, as with clownfish, breeding adults in a main aquarium is not feasible.
Advanced breeders may succeed using a dedicated breeding setup and a consistent supply of high-quality live food.
Diet
Pomacentrinae are not fussy eaters. They readily consume frozen foods, Tropical Marine Power Oceanic Mix flakes, and, with patience, all small pellets from the Tropical Marine Power line. Like most Pomacentridae, these fish are tolerant of suboptimal water conditions. Some sources even recommend them as a first species to establish the nitrogen cycle in tanks with synthetic substrates. However, it’s best to introduce territorial and aggressive fish later in the aquarium stocking process.
In general, all members of the Pomacentridae family are relatively easy to care for in an aquarium. Primarily decorative, they pose no threat to invertebrates in the tank and can thrive in a variety of setups.
Bartek Stańczyk
