Tailspot Cardinalfish, Apogon dovii

Tailspot Cardinalfish, Apogon dovii. Fish caught from coastal waters off Puerto Chomes, Costa Rica, March 2021. Length: 9.2 cm (3.6 inches). Catch, photograph and identification courtesy of Eli (obsessiveangling.wordpress.com).

The Tailspot Cardinalfish, Apogon dovii, is a member of the Cardinalfish or Apogonidae Family, that is also known as the Onespot Cardinalfish and the Tailspot Flame and in Mexico as cardenal colimanchada. Globally, there are one hundred ninety species in the genus Apogon, of which seventeen are found in Mexican waters, twelve in the Atlantic and five in the Pacific Ocean.

The Tailspot Cardinalfish has a small, laterally compressed, oblong body. They are red in color with a large black spot at the base of the caudal fin. They have a broad dusky stripe that is bordered in white that extends from the snout, through the eye, to the edge of the gill cover. Some fish have a narrow dusky stripe on the front half of the lateral line. Their head is large with a short, pointed snout, large eyes, and a large oblique mouth equipped with bands of small teeth. Their anal fin has 2 spines and 8 rays; their caudal fin is concave; their first dorsal fin has 6 spines; their second dorsal fin is well separated with 1 spine and 9 rays; and, their pectoral fins have 11 or 12 rays. They have 18 or 19 gill rakers. They are covered with rough scales. Their lateral line is complete and extends into the tail base.

The Tailspot Cardinalfish is found within coral and rocky reefs at depths up to 45 m (148 feet). They reach a maximum of 10.0 cm (3.9 inches) in length. They are nocturnal predators emerging at night and forming small schools while remaining secluded during the day. They consume phytoplankton and zooplankton. They are one of the rare marine species exhibiting oral brooding; males incubate the fertilized eggs in their mouth for several days before releasing hundreds of larvae measuring 2 to 4 mm into the ocean. Larvae remain in planktonic form for several weeks before developing into juveniles. The Tailspot Cardinalfish is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction

In Mexican waters the Tailspot Cardinalfish is a resident of Pacific Ocean but is has a limited distribution being found in coastal waters from Mazatlán south to Guatemala.

The Tailspot Cardinalfish can be confused with the Barspot Cardinalfish, Apogon retrosella (black bar under second dorsal fin), the Pink Cardinalfish, Apogon pacificus (bar thru a golden eye; bar below second dorsal fin), and the Plain Cardinalfish, Apogon atricaudus (dark stream through the first dorsal fin).

From a conservation perspective the Tailspot Cardinalfish are currently considered to be of Least Concern with stable widely distributed populations. They are utilized by the aquarium trade as they are easy to maintain and known to be friendly toward their tank mates. They are known to spawn in captivity.