Carmine Triplefin, Axoclinus storeyae
The Carmine Triplefin, Axoclinus storeyae, whose common Spanish name is tres aletas carmín, is a member of the Triplefin or Tripterygiidae Family, known collectively as tres aletas in Mexico. Its common name stems from the division of its dorsal fin into three parts, two of which have spines. Globally, there are 145 members in the Tripterygiidae Family placed in thirty genera. There are five known species in the genus Axoclinus, of which three are found in Mexican waters of the Pacific.
The Carmine Triplefins have short and robust bodies. The upper half of their body is brown or greenish and the upper three-fourths of their body has three vertical red-brown bars and four vertical rows of white spots. They are sexually dimorphic: breeding males have a uniform bright red body with black caudal and first dorsal fins and females are green with a wide black stripe on the base of their tail. Their caudal fin is white with red bars that extend into the tail base. They have a large head covered with spines with small simple cirri on top of their head, one pair over their nostrils, and one pair over their eyes. Their anal fin has two spines and 16 to 17 rays. They have three dorsal fins, the first with 3 spines, the second with 12 spines, and the third with 9 or 10 rays. Their pelvic fins are serrated. They are covered with small scales except on their head, breast, belly, and pectoral fin base.
The Carmine Triplefins are found in shallow water reef environments around rocks and boulders with abundant algae at depths up to 18 feet. They reach a maximum length of 4.3 cm (1.7 inches). They consume small invertebrates. Reproduction is oviparous with hemispherical eggs that attach themselves to the substrate via sticky threads. The larvae are planktonic. They are a poorly studied species and very little is known about their behavioral patterns.
In Mexican waters the Carmine Triplefins have a limited distribution being found from Magdalena Bay southward along the southwest coast of the Baja, in the lower half of the Sea of Cortez, and along the coast of the mainland south to Acapulco.
The Carmine Triplefin is straightforward to identify due to its coloration, however, its body structure is similar to that of the Cortez Triplefin, Axoclinus nigricaudus (body and tail with five wide oblique black bars) and the Panamic Triplefin, Axoclinus lucillae (pectoral fins with pink bars).
From a conservation perspective, the Carmine Triplefins are currently considered of Least Concern. They are seldom seen by humans and are of limited interest to most.
Carmine Triplefin, Axoclinus storeyae, male. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, March 2013. Length: 2.9 cm (1.1 inches). Identification courtesy of Dr. Phil Hastings, Scripps Institution of Oceanography, La Jolla, CA.