Red-tail dottyback

Geographical Origin and Habitat: Pseudochromis coccinicauda is native to the warm tropical waters of the central Indo-Pacific, with a presence concentrated mainly along the coral reefs of Indonesia, the Philippines, Palau, and the Solomon Islands. It inhabits tidal flats, protected coastal lagoons, and detrital zones rich in coral rubble and madrepores adjacent to the main reefs, at depths between 2 and 20 meters.

Taxonomy and Morphology: It belongs to the family Pseudochromidae. It features a slender, elongated, and moderately laterally compressed body, with a robust head equipped with large mobile eyes and a terminal mouth with small canine teeth suitable for grasping fast prey. It reaches small dimensions, with a maximum length of around 6-7 centimeters in adult specimens.

Social Behavior: It is a solitary and distinctly territorial fish. It establishes a fixed territory within a small rocky cavity or among the branches of hard corals, which it actively defends against any invader. It exhibits strong intraspecific aggression and does not tolerate the proximity of specimens of the same species or related species, demonstrating a brave and bold temperament.

Coloration and Sexual Dimorphism: The coloration is remarkable and contrasting: the anterior and dorsal portion of the body is typically dark brownish-gray or black, while the chest area and belly take on yellowish or orange hues. The caudal fin is a bright red-orange color, from which the specific epithet derives. Adult males show much more pronounced red coloration of the tail and yellow hues on the body.

Aquarium Setup: Requires an aquarium of at least 80 liters for a single specimen. The setup must include an abundance of live rock rich in small holes, caves, and narrow tunnels to allow the fish to establish its territory and find shelter. The rocks must be positioned stably. It is advisable to have a bottom of fine sand mixed with small fragments of coral.

Diet and Feeding: It is a predominantly carnivorous species with a voracious appetite. In the wild, it feeds on small benthic crustaceans, marine insect larvae, and zooplankton. In the aquarium, it quickly accepts high-quality frozen foods such as mysis, brine shrimp, chopped krill, and lobster eggs. It is recommended to feed the fish once or twice a day in portions suited to its activity.

Water Quality: Water parameters must be maintained within the range typical of marine aquariums: temperature between 24 and 26 °C, pH between 8.1 and 8.4, specific gravity stable at 1.020-1.025, and KH between 8 and 12. Efficient filtration is required to keep nitrogenous pollutant levels close to zero, making regular partial water changes and ensuring good water movement.

Compatibility and Cohabitation: Due to marked territoriality, it should not coexist with other dottybacks or with shy, delicate species such as small gobies, pipefish, and small wrasses that could be attacked. It is, however, an ideal companion for robust, active community fish such as damselfish, tangs, dwarf angelfish, and clownfish. It is safe for corals but may prey on small shrimps.

Aquarium Breeding: Breeding in the home aquarium is possible but complex. They are demersal spawners: after courtship, the female deposits a spherical mass of adhesive eggs inside the male's cave, who fertilizes them and guards them by fanning them and driving away intruders. Hatching occurs in a few days and rearing the larvae requires microscopic live foods (rotifers).

Risks and Diseases: It is an extremely robust fish and resistant to common marine fish diseases if kept in a stable environment. The main risk is mutual territorial aggression in tanks that are too small or lack hiding places. It is sensitive to sudden temperature and salinity changes. It is advisable to cover the tank as it is a skilled jumper when frightened.