Cape Razorfish, Xyrichtys mundiceps
Cape Razorfish, Xyrichtys mundiceps, Terminal Phase (TP) Male. Fish caught off the beach at Playa Tecolote, La Paz, Baja California Sur. Length: 10.0 cm (3.9 inches). Catch, photograph and identification courtesy of Dr. Benjamin Victor, coralreeffish.com.
Cape Razorfish, Xyrichtys mundiceps, Initial Phase (IP) Female. Fish caught off the beach at Playa Tecolote, La Paz, Baja California Sur. Length: 12.0 cm (4.7 inches). Catch, photograph and identification courtesy of Dr. Benjamin Victor, www.coralreeffish.com.
Cape Razorfish, Xyrichtys mundiceps, Juvenile. Fish caught off the beach at Playa Tecolote, La Paz, Baja California Sur. Length: 15.0 cm (5.9 inches). Catch, photograph and identification courtesy of Dr. Benjamin Victor, www.coralreeffish.com.
The Cape Razorfish, Xyrichtys mundiceps, is a member of the Wrasse or Labridae Family, that is also known as the Gulf Razorfish, and in Mexico as cuchillo desnudo. Globally, there are twenty-seven species in the genus Xyrichtys, four of which are found in Mexican waters, three in the Atlantic and one in the Pacific Ocean. Their common name razorfish stems from their compressed bodies that have a sharp leading edge on their forehead and snout that allows quick entry into the sand.
The Cape Razorfish has a strongly compressed head and body that taper gradually from head to tail and have a depth that is 30% to 39% of standard length. Initial Phase (IP) females are uniformly pale brown and often have a prominent white patch over their abdomen. Terminal Phase (TP) males are darker brown with a narrow blue vertical line on each scale and a large black spot at the base of their caudal fin above the lateral line. They also have three concentric blue lines on the outer part of their gill covers and three narrow blue lines running obliquely from their eye across their cheek. Their lower jaw and the lower side of their head have blue stripes and lines. All fish have pale fins. Their head is large and 25% of total length; it has a steep profile and a longitudinal keel at the front. Their eyes are set on the upper half of the head and both jaws have canines at the front. TP males have a steeper forehead and deeper body than females. Their anal fin has 3 spines and 10 rays and originates under the last dorsal spine; their caudal fin is slightly convex; their dorsal fin has 9 spines and 11 rays and is continuous; their pectoral fins reach the anal fin origin; and, their pelvic fins are strongly pointed with an elongated first ray.
The Cape Razorfish are normally found half buried on the bottom within fine sand at depths between 6 m (20 feet) and 27 m (90 feet). They reach a maximum of 15.9 cm (6.3 inches) in length. The Cape Razorfish 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.
The Cape Razorfish is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found from Magdalena Bay, Baja California Sur southward along the southwest coast of Baja, from Loreto, Baja California Sur southward along the east coast of Baja, and from Acapulco, Guerrero, south to Guatemala along the coast of the mainland.
The Cape Razorfish is an easy fish to identify due to its unique markings, however, it can be confused with the Peacock Razorfish, Iniistius pavo (no tail spot; separate and elongated first dorsal spine).
From a conservation perspective the Cape Razorfish is currently considered to be of Least Concern with stable, widely distributed populations. They are small in stature and too rare to be of interest to most.