Sooty Sand Eel, Bascanichthys bascanoides

Sooty Sand Eel, Bascanichthys bascanoides. Fish provided by the commercial fishermen of Bahía Kino, Sonora, March 2015. Length: 100 cm (3 feet 3 inches). Tail 55%. Photograph courtesy of Maria Johnson, Prescott College Kino Bay Center, Kino Bay, Sonora. Identification courtesy of H.J. Walker, Jr., Scripps Institution of Oceanography.

The Sooty Sand Eel, Bascanichthys bascanoides, is a member of the Snake Eel or Ophichthidae Family, and is known in Mexico as tieso manchitas. Globally, there are seventeen species in the genus Bascanichthys, of which five are found in Mexican waters, two in the Atlantic and three in the Pacific Ocean.

The Sooty Sand Eel has an elongated slender cylindrical body with a rounded cross section. They are red-brown dorsally fading to white-yellow ventrally. There is a prominent pale streak along the entire base of their dorsal fin. Their head has a short blunt snout with small eyes and one row of small conical teeth. They have a prominent front nostril tubular on the tip of their lower jaw behind the base of their front nostril. Their anal and dorsal fins are low and the origin of their dorsal fin is midway between their gill openings and eyes; their caudal fin is hard, pointed, and finless; their pectoral fins are small consisting of narrow skin flaps of similar length and width. Their tail is equal to or greater than 50% of total length.

The Sooty Sand Eel is a demersal species that is found mostly within burrows in sandy and muddy bottoms at depths up to 21 m (70 feet). They reach a maximum of 100 cm (3 feet 3 inches) in length, as established by the fish photographed above. The Sooty Sand Eel is an exceedingly rare species and 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 Sooty Sand Eel is a resident of Mexican waters of the Pacific but has a limited distribution being found only along the west coast of Baja from Magdalena Bay, Baja California Sur, southward along the southwest coast of Baja and in the Sea of Cortez as far north as Kino Bay, Sonora, with the fish photographed above documenting a northerly range extension for this species.

The Sooty Sand Eel is difficult to identify and is quite similar in appearance to the Panamic Sand Eel, Bascanichthys panamensis and the Round Sand Eel, Bascanichthys cyclindricus, both of which have tails that are less than 50% of total length.

From a conservation perspective the Sooty Sand Eel is currently considered to be of Least Concern with stable, widely distributed populations They are exceedingly rare and of limited interest to most.