arrow squid hauled up in vast midwater trawls

Size
Length: 30–50 cm, Weight: 200–500 g
Lifespan
1–2 years
Diet
Carnivorous. Feeds on small fish, crustaceans, and other squid. Hunts in open water using jet propulsion. Uses tentacles to grab prey and beak to tear flesh. Feeds most actively at night. A fast and agile predator in the open ocean environment.
Habitat
Open ocean and coastal waters from surface down to 500 metres depth. Prefers temperate waters with high productivity. Often found in large schools near current boundaries and upwelling zones. Migrates toward surface at night to feed on prey.
Range
Found in coastal waters around New Zealand from Northland to the Campbell Plateau. Most common on the Chatham Rise and off the east coast of the South Island. Also found in southern Australia. Distribution follows temperate currents.
Endemism
Native
Main Threats
Commercial trawl and jig fisheries are primary threat. Overfishing occurs in some years due to natural population fluctuations. Climate change affects prey distribution. Bycatch in other fisheries is a risk. Important prey species for tuna, sharks, seabirds, and marine mammals.
Population
Populations are managed under New Zealand's quota management system. Arrow squid populations fluctuate dramatically from year to year depending on ocean conditions. In good years, the fishery is one of New Zealand's largest. In poor years, the fishery may be closed entirely.
Conservation Status
Not Threatened
From the fish and chip shop to the deep-sea trawler, this squid dominates New Zealand's commercial catch. Two almost identical species, Nototodarus gouldi and Nototodarus sloanii, are caught together. They are processed together. They are sold together as calamari. Telling them apart requires a microscope and patience. The fishery treats them as one unit. Distinction is irrelevant to the market. Boom or bust defines the life of the arrow squid. Some years, the Chatham Rise teems with millions of them. The jigging fleet works around the clock. Other years, they simply do not appear. The boats stay in port. This volatility is not a sign of overfishing. It is a natural rhythm. Short-lived creatures reproduce explosively when conditions favour them. They vanish when the ocean turns hostile. Survival depends on timing. Luck plays a role. Speed defines everything about this animal. It swims by jet propulsion. Water is drawn into its mantle cavity and forced out through a flexible funnel. The funnel can rotate. This allows the squid to move in any direction. Forward, backward, sideways. The acceleration is startling. When hunting, it extends two long tentacles to grab prey. The victim is drawn back to its arms and its sharp, parrot-like beak. Efficiency is key. Waste is minimal. Night brings the arrow squid up from the depths. During daylight hours, it stays deep. It avoids predators that hunt by sight. After dark, it rises toward the surface. It follows the daily migration of small fish and crustaceans. The squid becomes the hunter. The open water becomes a killing field lit only by stars and the bioluminescence of disturbed plankton. Darkness offers cover. It also offers opportunity. The commercial fishery targets spawning aggregations. Squid jigs, lines of barbed lures, are dropped into the water and jerked upward. The squid attacks the lure. The barbs catch in its tentacles. On a good night, a single boat can harvest tonnes. The catch is frozen at sea. It is shipped overseas, mostly to Europe and Asia. There it becomes fried calamari rings or seafood mix. Distance does not diminish demand. Predators also rely on the arrow squid. Tuna follow the schools. Sharks patrol beneath them. Seabirds dive from above. Fur seals tear through the aggregations, scattering the squid in all directions. The squid sits in the middle of the food web. It eats small creatures. It is eaten by larger ones. Its abundance determines the health of the entire pelagic ecosystem. Balance is fragile. Disruption has consequences. Climate change now threatens this balance. Warming waters alter the distribution of the squid's prey. Currents shift. The upwellings that drive productivity become less reliable. The boom years may become less frequent. The bust years may last longer. The arrow squid has survived natural fluctuations for millions of years. But the pace of change is accelerating. Whether it can keep up is an open question. Adaptation has limits. Time is short.