Mimetic Midshipman

Mimetic Midshipman, Porichthys mimeticus

The Mimetic Midshipman, Porichthys mimeticus, whose common Spanish name is sapo mimético, is a species in the Toadfish or Batrachoididae Family, known as peces sapo in Mexico. The species was discovered and introduced as recently as 1988 by Dr. Richard Rosenblatt and my good friend and scientific fish mentor H.J. Walker, Jr. Globally, there are fourteen species in the genus Porichthys, seven of which are found in Mexican waters, one in the Atlantic and six in the Pacific.

The Mimetic Midshipman have elongated bodies with an oval cross-section. They are brown in color with a golden sheen and have four to six dark saddles on their back. Their anal and caudal fins are white with dark margins and their dorsal fin is dark with a few white vertical lines. Their pectoral and pelvic fins are dark. They have a large head with eyes on top, canine teeth, and a prominent non-venomous spine on their gill cover. They have two stout dorsal spines followed by a separate second dorsal fin with 32 to 36 rays and a long base. Their anal fin has no spines and 29 to 33 rays. They have four conspicuous rows of light organs along their lateral lines and the lower line on their flank has approximately 18 pores before the end of the light-organ row (a key to identification). They have 10 to 12 lower gill rakers and are scaleless.

The Mimetic Midshipman are bottom dwellers found over sandy and muddy bottoms at depths between 250 and 600 feet. They reach a maximum length of 28 cm (11 inches), as established by the fish photographed below. They consume crabs, echinoderms, fish, mollusks, and shrimp. The Mimetic Midshipman are poorly studied and very little is known about their behavioral patterns.

In Mexican waters the Mimetic Midshipman have a limited range being found only in the southern three-fourths of the Sea of Cortez. However I have collected fish that extends the range to include the southwest coast of Baja as far north as Todos Santos.

The Mimetic Midshipman can be easily confused with the Darkedge Midshipman, Porichthys analis (33 to 39 anal rays).

The Mimetic Midshipman is small, seldom seen by humans, and is of limited interest to most.

Mimetic Midshipman (1)Mimetic Midshipman (2)Mimetic Midshipman (3)

Mimetic Midshipman, Porichthys mimeticus. Fish provided by the commercial bait salesmen of Puerto Los Cabos, Baja California Sur, June 2009. Length: 28 cm (11 inches). Identification courtesy of H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, CA.