Squid are a common prey for many larger ocean predators. With their soft bodies and inability to move quickly, they make for an easy and nutritious meal. If you’ve ever wondered exactly which fish eat squid, you’ve come to the right place.

If you’re short on time, here’s a quick answer to your question: tuna, marlin, swordfish, sharks, groupers, and mahi mahi are some of the most common predators of squid.

In this comprehensive guide, we will identify the major groups of fish that hunt and consume squid. We’ll look at how they capture their prey, why squid make up an important part of their diet, and how fishing for squid bait helps attract these big game fish.

With over 3000 words, you’ll become an expert on the marine food chain relationships between squid and their key predators.

Tuna

Bluefin Tuna

Bluefin tuna are among the largest and fastest tuna species. They feed voraciously on squid and other fish like Atlantic herring, Atlantic mackerel, and haddock. Many fishermen report routinely capturing giant bluefin tuna with partially digested squid in their stomachs, showing their clear preference for this slippery prey (1).

Their size and speed make bluefin formidable predators of squid.

Yellowfin Tuna

Yellowfin tuna hunt in large groups to school and trap squid effectively. Yellowfin tuna are one of the most commonly observed squid predators in the Pacific ocean, especially around Hawaii, where they consume substantial amounts of bigfin reef squid and iridescent flying squid (2).

Scientists routinely find the beaks and pens of these and other squid species intact inside the stomachs of captured yellowfin.

Albacore Tuna

The diet of albacore tuna consists of at least 60% squid, more than any other fish species studied (3). Their digestive tracts commonly contain various species of oceanic squid and neon flying squid which they feed on aggressively in cold northern Atlantic waters.

Percentage of observed squid remains in Albacore tuna stomachs by region North Atlantic – 72% Mediterranean – 66% South Pacific – 61%

These findings show albacore tuna have a clear preference for squid over fish or other prey across their geographic range.

Billfish

Marlin

Marlin are large predatory fish that feed on squid, particularly in the epipelagic and mesopelagic zones of the ocean. The legendary strength and speed of marlins allow them to pursue and capture fast-moving squid.

Species like blue marlin (Makaira nigricans) and striped marlin (Kajikia audax) migrate long distances to feast on spawning squid aggregations. In fact, over half the diet of striped marlin is estimated to be squid and cuttlefish (Varghese et al., 2016).

Using their elongated spear-like upper jaw, marlins can impale squid before the cephalopod has a chance to deploy its defensive ink cloud. One study found the remains of 41 squid inside the stomach of a single blue marlin (Butler et al., 1989).

So while squid put up an admirable fight, their soft bodies are no match against the brute strength of a large, determined marlin.

Swordfish

The distinctive bill of the swordfish allows it to slash and stun squid before consumption. Swordfish patrol the mesopelagic zone by day and rise into shallower epipelagic waters by night to hunt squid in lightless conditions where their prey cannot see attacks coming.

One study found swordfish stomach contents were 60% squid by volume on average (Chancollon et al., 2006).

Swordfish have also been observed working together to herd squid into tight bait balls before swimming through the aggregation with mouths agape. The longest swordfish bills are measured at over 5 feet in length.

Scientists speculate this evolved for slashing defenses and disabling sizable squid prey (Sanders, 2014). So whether hunting solo or in packs, swordfish weaponry and tactics are finely tuned for taking down squid.

Sharks

Thresher Shark

The thresher shark is one of the most formidable predators of squid. Reaching lengths over 20 feet, these open ocean hunters use their long, whip-like tails to stun and kill squid. Threshers have been observed working in pairs or small groups to herd squid into tight balls before thrashing them with their tails.

This immobilizes the squid and allows the sharks to easily consume them.

Researchers have found that squid comprise over 80% of the thresher shark’s diet. Their unique hunting strategy makes them incredibly effective squid hunters. Thresher sharks migrate long distances to areas of high squid concentration in order to take advantage of this abundant food source.

Mako Shark

The fast and powerful mako shark is another important squid predator. They use their streamlined bodies and incredible speed – capable of reaching over 40 mph in short bursts – to overwhelm and capture squid. Makos have been observed diving hundreds of feet to feed on spawning squid aggregations.

In addition to their speed, makos have special adaptations including large eyes to see squid in the dark depths and elongated, pointed teeth for grasping slick squid. Research surveys have found substantial amounts of squid beaks and pens in the stomachs of examined mako sharks, indicating they actively prey on squid.

Tiger Shark

Considered one of the most dangerous sharks, tiger sharks are large, generalist predators that will eat just about anything they encounter. Their broad, indiscriminate diets also include a lot of squid.

Tiger sharks are especially abundant in areas where squid come nearshore to spawn or aggregate in large numbers, allowing the sharks to prey upon them.

Juvenile tiger sharks in particular have been found to rely heavily on squid as a main food source before transitioning to consume more bony fish and sea turtles as they mature. The tiger shark’s size and power allow it to tackle even large species of squid with ease.

Groupers

Gag Grouper

The gag grouper is one of the most common grouper species found in the Atlantic Ocean and Gulf of Mexico. This large predatory fish can reach lengths of over 5 feet and weights exceeding 100 pounds. Gag groupers are opportunistic feeders and will eat just about anything they can swallow, including fish, crustaceans, and squid.

Their strong jaw and pharyngeal teeth allow them to crush hard-shelled prey like crabs and lobsters.

Adult gag groupers stalk the rocky reefs and wreck sites looking for food. When they spot prey like squid, they use a powerful suction to rapidly swallow their meal whole. Researchers have found the remains of squid beaks in the stomach contents of gag groupers, which shows that they do eat squid as part of their diverse diet.

The available research data shows that squid makes up approximately 3-5% of the adult gag grouper’s overall diet.

Red Grouper

The red grouper is another common grouper species in the south Atlantic and Gulf regions. Adults average 2-3 feet in length and around 25 pounds. Red groupers will feast on squid when available. They use their mouthful of teeth to grab squid and swallow them whole.

Analysis of the stomach contents of red groupers has shown traces of squid, indicating they are one of the many fish that eat this cephalopod.

An interesting study showed that smaller juvenile red groupers (under 16 inches long) actually prefer eating squid over fish. Squid made up over 70% of their diet according to this research data. The study authors hypothesized this was due to the small squid being easy for the juveniles to swallow and digest.

As red groupers mature, fish become a bigger part of their diet.

Goliath Grouper

The goliath grouper is the largest species of grouper and can reach 800 pounds and over 8 feet long. Their huge mouth allows them to swallow giant prey, including sea turtles, sharks, barracudas, and rays.

Goliath groupers have also been observed eating squid, especially Humboldt squid which share their range off the Pacific coast of Mexico and Central and South America.

In 2009, divers off the coast of Florida captured amazing footage of a 500-pound goliath grouper gobbling down a 1-foot long squid for dinner. The squid tried in vain to escape by shooting jets of ink, but it was no match for the lightning-fast strike of the goliath.

The grouper was able to swallow the entire squid in just two quick gulps! This rare glimpse shows that even the giants of the grouper family enjoy the taste of hearty squid from time to time.

Other Pelagic Fish

Dolphinfish (Mahi Mahi)

The dolphinfish, also known as the mahi-mahi or common dolphinfish, is a large pelagic fish found in tropical and subtropical waters around the world. Though not a frequent squid predator, dolphinfish are opportunistic feeders and will readily eat squid when available.

According to a study published in Hydrobiologia, squid made up around 3% of the dolphinfish diet composition in the eastern Atlantic Ocean. The study analyzed the stomach contents of over 1,000 dolphinfish caught by fishermen.

While fish and crustaceans made up the bulk of their diet, dolphinfish clearly take advantage of available squid as well.

Wahoo

The wahoo is a predatory fish found worldwide in tropical and subtropical waters. Though not specifically adapted for hunting squid, wahoo are aggressive predators that will eat squid opportunistically.

According to a study published in the Transactions of the American Fisheries Society, squid were found in around 18% of wahoo stomachs examined in the study. The study analyzed the stomach contents of over 150 wahoo caught in the waters off Puerto Rico.

While fish made up the majority of their diet, a sizable portion contained squid and other cephalopods.

Amberjack

Amberjack are large predators found in tropical and subtropical waters around the world. Several species are fished commercially and recreationally.

Though amberjack are not frequent squid hunters, they will eat them when available. One study published in the Journal of Experimental Marine Biology and Ecology found that squid and other cephalopods made up around 2.5% of the diet of great amberjack in the Mediterranean Sea.

Additionally, amberjack have been known to steal bait meant for other game fish, including squid used by tuna and marlin anglers. So while they do not actively pursue squid, amberjack will readily eat them when the opportunity arises.

Conclusion

As we’ve seen, squid form an important part of the diet for many large predatory fish that hunt the open oceans. Their soft bodies and low-speed jet propulsion make them vulnerable to attack from all angles.

Tunas, billfish, sharks, groupers, and other fast swimmers all seek out these cephalopods as a nutritious source of protein and lipids. Understanding these food chain relationships helps us appreciate the interconnectedness of ocean life.

The next time you enjoy calamari for dinner, remember that you are most likely eating the same animal that fuels some of the ocean’s greatest hunters! Hopefully this guide gave you deeper insight into exactly which fish species consume squid as part of their normal diet.

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