Threadfin Goosefish, Lophiodes spilurus
The Threadfin Goosefish, Lophiodes spilurus, whose common Spanish name is rape de hebra, is a species in the Goosefish or Lophiidae Family, known collectively as rapes pescadores in Mexico. Globally, there are fifteen species in the genus Lophiodes, three of which are found in Mexican waters, one in the Atlantic and two in the Pacific.
The Threadfin Goosefish have bodies that are wide at the front and that flatten and taper towards the back. They have a uniform dark brown coloration and their fins have clear edges. Their caudal fin has a row of small clear spots; their second and third dorsal spines are black; and their gut cavity is black. Their head is covered with bony prickles and features a large wide mouth bearing long and sharp teeth. Their eyes are on top of the head, their top jaw is protractile, and their lower jaw is projecting. They have large gill openings that extend from behind to in front of their pectoral fin base. Their anal fin has 6 rays. Their dorsal fin has 3 standalone spines followed by 3 attached spines and 8 rays; their first dorsal spine, located at the tip of their snout just above the mouth, has been modified into an angling apparatus (illicium) that bears a bulb-like lure (esca) used to attract prey; their second and 3 dorsal spines have a row of small papilla along the front edge. Their pectoral fins are somewhat unique being long and “arm-like” bony structures with 15 to 18 rays. Their body and fins are covered with tiny ciiri. They have smooth skin and are devoid of scales.
The Threadfin Goosefish are found over and within sandy and muddy bottoms at depths between 240 and 1,500 feet. They reach a maximum length of 35 cm (14 inches). They are “lie in wait” ambush predators, feeding on small fish and crustaceans. They are a poorly studied species and very little is known about their behavioral patterns.
In Mexican waters the Threadfin Goosefish are found in all waters of the Pacific with the exception that they are absent from the extreme northern portions of the Sea of Cortez.
The Threadfin Goosefish is very similar to, and can easily be confused with, the Spottedtail Goosefish, Lophiodes caulinaris (prominent row of white spots across caudal fin).
The Threadfin Goosefish are too rare and bony to be of interest to most. They are caught at a modest level by deep water trawlers and are a “catch-and-release.” I have provided a couple of specimens to one of the major countries within the European Community as they have an interest in establishing a testing protocol for this species to monitor imported goods – they are fearful that this might become (ho ho) the next Patagonia Toothfish aka Chilean Seabass.
Threadfin Goosefish, Lophiodes spilurus. Fish provided by the commercial fishermen of Bahía Kino, Sonora, November 2014. Length: 8.0 cm (3.1 inches). Photo courtesy of Maria Johnson, Prescott College Kino Bay Center, Kino Bay, Sonora.