Humboldt Squid, Dosidicus gigas

Humboldt Squid, Dosidicus gigas, Juvenile. Beach wash-up at Cero Colorado, Baja California Sur, January 2007. Length: 30 cm (11.8 inches).

Humboldt Squid, Dosidicus gigas, Juvenile. Collected off the beach Cabo Real, Baja California Sur, January 2020 Length: 40 cm (16 inches).

Humboldt Squid, Dosidicus gigas. Caught from coastal waters off Point Palmilla, Baja California Sur, May 2004. Length: 1.52 m (5 feet 0 inches).

Humboldt Squid, Dosidicus gigas. Caught from coastal waters off Point Palmilla, Baja California Sur, December 2008. Length: 1.52 m (5 feet 0 inches).

 Phylogeny:  The Humboldt Squid, Dosidicus gigas (A. d’orbigny, 1835) is a member of the Ommastrepihidae Family of Ommastrephid Squids. The genus Dosidicus is one of eleven genera in this family. This species is the only species in this genus. Humboldt Squid are also called Jumbo Squid, Jumbo Flying Squid, and Red Devils. In Mexico they are known as diablo rojo or calamar gigante.

Morphology:  Humboldt Squid have a cylindrical mantle that tapers to a point at the tail. Two triangular, well-developed fins are mounted at the tail. Like all squid, they have eight arms and two tentacles. The tentacles are elastic and can extend and retract in a fraction of a second. The tentacles are equipped 100-200 suckers, each having sharp teeth for grasping prey. They are generally rusty to dark brown in color. Humboldt Squid have two modes of chromogenic (color generating) behavior- a rapid red and white flash and a slow flickering. The rapid flash is thought to be for communication between Humboldt Squids. The slow flickering is thought to mimic sunlight refracted through the water and is used for camouflage. Humboldt Squid average 50 cm to 80 cm (19 to 32 inches) in mantle length, with a maximum total length of 4.0 m (13 feet). Large Humboldt Squid can weigh up to 50 kg (110 pounds).

Habitat and Distribution:  Humboldt Squid are generally found in deep, open ocean. During the day they are found in deep water, 800 m (2,600 feet) to 1,200 m (3,900 feet) in depth. At night they migrate to shallower waters, from the surface to 200 m (660 feet). They range from British Colombia to Chile. In Mexican waters they are found along the entire Pacific Coast, including the entire Gulf of California. Population numbers in a local area vary greatly from year to year, possibly impacted by El Niño weather events.

Diet: Humboldt Squid are fast moving predators that feed on copepods, hyperiid amphipods, Pelagic Red Crabs, Pleuroncodes planipes, euphausiids, various fish, Pelagic Red Crabs, Pleuroncodes planipes, heteropod molluscs, octopod, pelagic shrimps, and squid. They also prey on other Humboldt Squid and in some cases they become the majority of their diet. They have been observed using coordinated pack hunting techniques.

Predators:  Adult Humboldt Squid are eaten by dorado, striped marlins, fur seals, large shark, swordfish, larger tunas, large sharks, swordfish, striped marlins, sperm whales, and short-finned pilot whales. Juvenile Humboldt Squid are also prey for smaller fish, other squids, and sea birds.

Reproduction:  Humboldt Squid are gonochoric (male or female for life). Reproduction is sexual, with internal fertilization. During mating, the male grasps the female and inserts the hectocotylus (modified arm for delivering sperm packets) into the female’s mantle cavity where fertilization occurs. Female squid lay gelatinous egg masses that are almost entirely transparent and float freely in the water column. The size of the egg mass correlates with the size of the female that laid it; large females can lay egg masses up to 3 to 4 m (10 feet to 13 feet) in diameter. The egg masses can contain up to 4.1 million eggs. The embryos hatch into a planktonic stage and live for some time before they grow larger and develop into swimming juveniles.  Male and female adults usually die shortly after spawning and brooding, respectively.

Ecosystem Interactions: Humboldt Squid host several species of internal parasites including trematodes, nematodes, and cestodes. There is no mention in the available literature of ectoparasitic or commensal relationships for Humboldt Squid. Because of their large populations they play a major role in the Eastern Pacific food web.

Human Interactions:  Humboldt Squid are targeted by commercial, artisanal, and sport fisheries. They are an important food source and economic resource for many countries. Humboldt Squid are known to cause injuries to fishermen and divers. The sharp teeth on their tentacles and their large sharp beak can easily cut human skin. Divers report that they act aggressively while feeding, but not during other times. Humboldt Squid are common, widespread and reproduce rapidly. Therefore, from a conservation perspective, they are considered of Least Concern.

Synonyms:  Dosidicus eschrichtii, Dosidicus steenstrupii, Loligo gigas, Ommastrephes giganteus, Ommastrephes gigas, Sepia nigra, and Sepia tunicata.