Shortbill Spearfish

Shortbill Spearfish, Tetrapturus angustirostris

Shortbill Spearfish, Tetrapturus angustirostris. Fish caught from coastal waters off Ensenada, Baja California, August 2007. Length: 2.03 m (6 feet 8 inches). Weight: 51 kg (112 lbs). Tyler did not submit the fish for an IGFA record, noting that the current IGFA all-tackle record is 101 lbs.

The Shortbill Spearfish, Tetrapturus angustirostris, is a member of the Billfish or Istiophoridae Family, that is known in Mexico as marlina trompa corta. They are the rarest and least studied species within the family. Globally, there are only four species in the genus Tetrapturus, of which two are found in Mexican waters, one in the Atlantic and one in the Pacific Ocean.

The Shortbill Spearfish has a narrow very elongated very compressed body. They are dark blue dorsally and silver ventrally with touches of brown on their sides. Their first dorsal fin is dark blue, while their other fins are brown or dark brown. Their anal fin base has tinges of silvery white. They have a very short spear extending from their upper jaw, which is less than 15% of their total length. They have small eyes and a mid-sized mouth equipped with small teeth. Their first anal fin has 12 to 15 rays; their second anal fin has 6 to 8 rays; their caudal fin is deeply forked with very narrow lobes; their first dorsal fin has 45 to 50 rays that form a triangular peak at the front with the rest of the fin being relatively high and greater than the body depth; their second dorsal fin has 6 or 7 rays; their pectoral fins are short and narrow and fold against the body; and, their pelvic fins are slender and about twice the length of the pectoral fins. Their body is covered with small triangular scales. Their lateral line is dark and arches over the pectoral fin.

The Shortbill Spearfish is a highly migratory epipelagic and oceanic species usually found in surface tropical and temperate waters above the thermocline far offshore and are seldom seen in coastal waters. They are found at depths up to 1,830 m (6,000 feet) via satellite tagging but normally do not go much below 300 m (1,000 feet). They are only found in waters with temperatures between 20oC (68oF) and 28oC (82oF). They can reach 2.3 m (7.5 feet) in length and 52 kg (132 lbs) in weight. As of January 1, 2023, the International Game Fish Association world record stood at 50 kg (110 lbs) with the fish caught in coastal waters off Australia in May 2008. They consume cephalopods, crustaceans and fish. Males and females are indistinguishable by their external features, however, they are dimorphic with females being slightly larger than males. Reproduction is via pelagic eggs. The Shortbill Spearfish 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 Shortbill Spearfish has a wide global distribution but are not abundant. In Mexican waters they are a resident of all waters of the Pacific with the exception that they are absent from the Sea of Cortez.

The Shortbill Spearfish is not easily confused with other species due to its short sword and wide dorsal fin.

From a conservation perspective the Shortbill Spearfish is currently considered to be Data Deficient with global populations and population trends poorly documented. Like other billfish, their population is considered to be in decline. Globally, this fish is poorly managed with virtually no conservation measures in place. The Shortbill Spearfish is caught as a by-catch of commercial fishermen utilizing purse seines and longlines targeting swordfish and tuna. Catch rates are approximately 3,000 tons per year, although global catch levels are poorly documented and subject to interpretation. The quality of the flesh is considered “marginal”. They are marketed frozen and utilized primarily in fish cakes and sausages and for sashimi on a limited basis, with a large market in Japan.

A word of caution: these fish are ginormous wild animals and their spears are very dangerous!