Mimetic Midshipman, Porichthys mimeticus
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, California.
The Mimetic Midshipman, Porichthys mimeticus, is a member of the Toadfish or Batrachoididae Family, and is known in Mexico as known as sapo mimético. 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 Ocean.
The Mimetic Midshipman have elongated bodies with an oval cross-section. They are brown in color with a golden sheen and have 4 to 6 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. They have smooth skin and do not have scales.
The Mimetic Midshipman is a demersal species that is found found over sandy and muddy bottoms at depths between 76 m (250 feet) and 180 m (600 feet). They reach a maximum of 28 cm (11 inches) in length, as established by the fish photographed above. They consume crabs, echinoderms, fish, mollusks, and shrimp. The Mimetic Midshipman 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 Mimetic Midshipman is a resident of Mexican waters of the Pacific Ocean but has 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, Baja California Sur.
The Mimetic Midshipman can be easily confused with the Darkedge Midshipman, Porichthys analis (33 to 39 anal rays).
From a conservation perspective the Mimetic Midshipman is currently considered to be of Least Concern with stable, widely distributed populations. They are small in stature, seldom seen by humans, and is of limited interest to most.