Cortez Barnacle Blenny, Acanthemblemaria hastingsi

Cortez Barnacle Blenny, Acanthemblemaria hastingsi. Underwater photograph taken in coastal waters of the greater Los Cabos area, Baja California Sur, May 2018. Photograph courtesy of Bob Hillis, Ivins, Utah.

Cortez Barnacle Blenny, Acanthemblemaria hastingsi. Underwater photograph taken in coastal waters of the greater Los Cabos area, Baja California Sur, October 2019. Photograph courtesy of Bob Hillis, Ivins, Utah.

The Cortez Barnacle Blenny, Acanthemblemaria hastingsi, is a member of the Tube Blenny or Chaenopsidae Family, and is known in Mexico as tubícola de Cortés. This fish was first reported in 2010 by H.-C. Lin and Dr. Grant Galland and named after Dr. Phil Hastings, all of whom belong to my historical scientific support team of contributors. Globally, there are twenty species in the genus Acanthemblemaria, of which six are found in Mexican waters, two in the Atlantic and four in the Pacific Ocean.

The Cortez Barnacle Blenny has an elongated body. They have a mid-lateral row of large brown spots or blotches and seven to nine dark brown saddles along the base of their dorsal fin. Their head is gray with the upper portions covered with pale blue spots and the lower portions being black. They have black and white blotches on their cheeks, across the top of their head behind the eyes, and along the rear edge of their gill covers. Their eyes have a black iris with a cream inner ring. Their coloration is dimorphic with males having a black stripe along the base of the front portion of their dorsal fin (which is absent in females) with the upper portion above the black stripe being a dull orange. Their head is long and blunt with short pointed head spines set in a diamond-shaped patch between the rear of the eyes. They have one pair of cirri over their eyes and cirri on their nostrils. They have two rows of well-developed teeth set on the sides of the roof of their mouth. Their anal fin has 2 spines and 24 to 26 rays; their dorsal fin has 13 to 15 spines and 12 to 14 rays; and, their pectoral fins have 13 rays.

The Cortez Barnacle Blenny inhabits abandoned barnacles, mollusks tubes, and worm tubes on rocky reefs in shallow waters at depths up to 15 m (50 feet). They reach a maximum of 6.0 cm (2.4 inches) in length. They enter tail first in the various types of shelter in which they reside and are found with only their head exposed. They are known to have very poor eyesight and to exhibit fearless and extremely aggressive behavior in captivity and will attack anything large or small that approaches their home. They feed primarily on zooplankton. The Cortez Barnacle Blenny 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 Cortez Barnacle Blenny is a resident of Mexican waters of the Pacific Ocean but has a limited range being found from Santa Rosalia to Cabo San Lucas, Baja California Sur, along the east coast of Baja.

The Cortez Barnacle Blenny can be confused with the Clubhead Barnacle Blenny, Acanthemblemaria balanorum (one row of spots on sides) and the Mexican Barnacle Blenny, Acanthemblemaria macrospilus (front portion of dorsal fin is red with a black spot).

From a conservation perspective the Cortez Barnacle Blenny has not been formally evaluated. They are fairly abundant in the greater Los Cabos area of Baja California Sur and should therefore be considered of Least Concern. They are small in stature and of limited interest to most.