Sailfish Feeding Habits

This is a summary of research reporting the stomach contents of Sailfish. The Sailfish is a warm water inhabitant and seems to be very opportunistic in its feeding habits. From big-water prey to reef and shallow-water ocean creatures, the Sailfish seems to adapt to whatever is available, wherever it is found.

Common themes among the studies listed are:

• Sailfish thrive in equatorial zones.
• Sailfish prefer 77-85 F water temperatures.
• Sailfish seem to prefer the smaller juvenile stages of the same prey that larger billfish consume.
• Sailfish seem to eat a lot of beltfish and needlefish when available.
• A higher percentage of Sailfish were found with empty stomachs than other pelagic species studied.
• Sailfish have been observed using their sails to 'wall off' their prey, and using their bills to stun them.

Below are some excerpts from various studies, with links to the outside sources. If any of these links become broken over time, let me know and I'll remove them.

Research has not only helped us catch sailfish, it's helped us design better BFDs (see photo... yes, that is a much younger me!) My hope is that this research will help someone in their pursuit of sailfish, if they're nerdy enough to read through all of this.

Taiwan

According to the index of relative importance (%IRI), the most important prey items were Priacanthus macracanthus (Red Bigeye), followed by Auxis (Frigate-Bullet Tuna), and Trichiurus lepturus (Largehead Hairtail or Beltfish). However, the most important prey groups for adult sailfish as estimated by the stable isotope-mixing model were T. lepturus (Beltfish), Katsuwonus pelamis (Skipjack Tuna), and P. macracanthus (Bigeye), and for maturing sailfish were K. pelamis (12.9%), P. macracanthus (10.4%), and T. lepturus (32.6%), respectively.

Taiwan Study here: www.sciencedirect.com/science/article/pii/S0165783614003154

Brazil

68.2% of stomach content corresponded to Sardinella brasiliensis  (Brazilian or Orange Spot Sardine), Auxis Thazard (Frigate Tuna-Mackerel), Selar crumenophthalmus (Bigeye Scad), and Exocoetus volitans (Flying Fish). They totalized 210 specimens and 18 species

Link to PDF: https://www.iccat.int/Documents/CVSP/CV064_2009/n_6/CV0640601903.pdf

Florida

Though it is common to find sails around around flying fish and schools of mullet, biologists apparently indicate that they eat a lot of baby mackerel and little tunny, ballyhoo and needlefish, and squid, and shrimp. Study citation needed - this is from an excellent, albeit very old, Florida Sportsman article that can be found here: https://www.floridasportsman.com/editorial/sportfish_0001_sailfish_at_a/401959

While this is not a technical data chart of stomach contents, its an excellent read and far less mind-numbing than the other sources listed here.

Mexico (Mazatlan 2002 Study)

From a Bulletin of Marine Science, researchers analyzed the stomach contents of 533 sailfish taken by the sport fishing fleet off the coast of Mazatlán, Sinaloa, Mexico. A total of 62 different prey taxa was classified, 53 were identified by species, and according to index of relative importance, the most important prey species were Dosidicus gigas (Humboldt Squid), Argonauta (Pelagic Octopus referred to as “Paper Nautilus”) Balistes polylepis (finescale triggerfish), and Auxis (Frigate-Bullet Tuna).

In spite of the high prey diversity here, Sailfish in this particular area appear to be specialist predators, feeding mainly on cephalopods (D. gigas and Argonauta spp.). Note that this differs from the generalist findings of other studies.

Link to data: http://www.ingentaconnect.com/content/umrsmas/bullmar/2006/00000079/00000003/art00028

Southern Gulf of California, Mexico 

576 fish were sampled from 1989 to 1991 from the sport fishing fleet at six tourist ports of the Mexican Pacific (La Paz, Cabo San Lucas, Mazatlan, Puerto Vallarta, Barra de Navidad, and Manzanillo). 

The variety in stomach contents among these different areas of Mexican Pacific waters suggest more that Sailfish are are generalist predators, feeding mainly on whatever epipelagic species are available. (Generally speaking, this zone reaches from the sea surface down to approximately 200 meters or 650 feet.)  In other words, while one study showed sailfish in Mazatlan to be specialized predators for cephalapods, this wider study determined that their diet related more to abundance and distribution of prey than preferences.

Link to study: https://www.sciencedirect.com/science/article/abs/pii/S0165783601003447

Generalizations

Based on numerous oceanographic studies, in general, sailfish in Atlantic Ocean waters primarily consume cephalopods (squid and octopus) and bony fishes such as mackerels, tunas, jacks, halfbeaks, and needlefish. Feeding occurs at the surface, midwater, along reef edges, and occasionally along the bottom substrate.

Sailfish in the Pacific Region feed on in general, fishes and cephalopods including squid, sardines, achovies, jacks, dolphin, ribbonfish and triggerfish.

Other excellent resources:

From the Florida Museum Educational Archives: https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/istiophorus-platypterus/

From Oceana: https://oceana.org/marine-life/sailfish/

Nerd Bonus:

A complex but excellent resource from an Atlantic expedition in 2002 that is skinny on sailfish but has a wide overview of multiple pelagics: https://www.iccat.int/Documents/CVSP/CV056_2004/n_3/CV056031096.pdf