humboldtCA

How big are Humboldt squid? Adults can be up to 4 ft long and 30 lb! But when they hatch they are smaller than a grain of rice and weigh a hundredth of a gram. Squids are measured by the length of their mantle, since that is one of the only non-stretchy parts of their body. How long do Humboldt squid live? It's hard to tell how long squid live! They have little "ear bones" called statoliths that help them to keep their balance, and these bones grow as the squid does. Based off of counting statolith rings, we think they live 1.5-2 years. What do they eat? Lots of fishes and invertebrates. But nothing too big. When they are in deep water, Humboldt squid mostly eat lanternfish (family Myctophidae), which are small, mid-water fish. Closer to shore, they eat hake, rockfish, and market squid, all important fisheries in California (Field et al. 2007) Are they cannibals? Many feeding studies have shown that Humboldt squid will eat each other, especially when they are stressed. We think other Humboldt squid could be up to 15-20% of their diet. Are they dangerous? Humboldt squid do not prey on humans, but that does not mean they are harmless. They deserve the respect due any large wild animal. They are naturally curious and explore with their strong and dexterous arms, which are lined with toothed sucker cups. They also have a sharp beak: thus, they have the potential to do some damage if you jump into the water when they are feeding. How many are there? Great question. No one knows. Our lab is working with collaborators at NOAA, MBARI and Oregon State University to answer this question. It is important to know in order to assess ecosystem impacts and fisheries implications. Where do they live? Traditionally, they have been found from Chile north to San Diego but in the last ten years their range has expanded all the way up to the panhandle of Alaska! They are now seasonally seen along California, Oregon, Washington and the British Columbia. Why are they in California/Oregon/Washington/Canada/Alaska? This is probably a combination of the environment changing to be more favorable for the squid, along with changes in the abundance of their competitors and predators. They are likely driven by the availability of food, Are they reproducing off of coastal USA and Canada? So far, we haven't found any baby squid in the water north of Mexico. We keep looking, though! We have found both mature males and mated females in California waters but have never found any egg masses or larvae. Reproductive studies conducted in our lab suggest that their eggs don't develop well in our cold waters. So this likely means that they return to warmer waters to reproduce, and are just in California to feed as adults. Who eats them? Humboldt squid are prey for sperm whales, Risso's dolphins, mako and thresher sharks, tunas, and other large fishes and mammals. And people! Can people eat them? Yes, in fact, the Humboldt squid fishery is the largest invertebrate fishery in the world, at 671,168 metric tonnes (ftp://ftp.fao.org/fi/stat/summary/a1e.pdf) ! They are mostly caught in Peru, Chile and Mexico. Currently, there is no commercial fishery for Humboldt squid in the US, although there is an enthusiastic and thriving sport fishery. Is the fishery sustainable? Without an estimate of the abundance of the stock (population) size, it is not possible to say whether or not it is a sustainable fishery. What is a typical day in the life of a Humboldt squid? Our tagging studies have shown that Humboldt squid diurnally migrate, which means that they spend the daytime deep (>400m) and at sunset they travel to the surface and spend the night feeding in shallow waters. At sunrise they dive deep again. We think that this whole time they are following and feeding on their main food source, lantern fish (Markaida et al., 2008). Fun Facts Humboldt squid grow really fast! When they are born, they are only one millimeter long--smaller than a grain of rice. We think that they grow to their maximum size (see FAQ #1) in less than two years, maybe less than one. They have to eat a lot to fuel that kind of growth! They have teeth in their suckers! Humboldt squid, like all squids, have suckers along their arms and at the ends of their tentacles. In many squid, these suckers are only muscular suction cups, but in Humboldt squid and their oceanic cousins, the suckers have a hard toothed ring inside the suction cup. It is made of chitin, which is similar to the keratin in our hair and fingernails. These teeth help them to hold onto their prey--like having hundreds of patches of velcro on each arm. They communicate with each other by changing colors . . . . . . but we don't know what they're saying! The bodies of Humboldt squid can flash between red and white several times in a second in dramatic underwater displays. Other squid, cuttlefish, and octopus are known to communicate with each other by changing the color patterns on their skin, and it seems like Humboldt squid can do that too. References

Humboldt Squid in California
Frequently Asked Questions

Blaskovic ́, V., A. Alegre, and R. Tafur. 2007. The importance of hake in the diet of the jumbo squid Dosidicus gigas in the north of the Peruvian zone (2005–2007). In: J. Heine (Editor), CalCOFI Conference—Jumbo Squid Invasions in the Eastern Pacific Ocean. Californian Cooperative Oceanic Fisheries Investigations, Hubbs-SeaWorld Research Institute, San Diego, Cal, pp. 67.

Gilly, W. F., U. Markaida, C. H. Baxter, B. A. Block, A. Boustany, L. Zeidberg, K. Reisenbichler, B. Robison, G. Bazzino, and C. Salinas. 2006. Vertical and horizontal migrations by the jumbo squid Dosidicus gigas re- vealed by electronic tagging. Mar. Eco. Prog. Ser. 324:1–17.

Gilly, W. F. 2005. Spreading and stranding of jumbo squid. Ecosystems Observations for the Monterey Bay National Marine Sanctuary 2005:25–26.

Field, J. C., K. Baltz, A. J. Phillips, and W. A. Walker. 2007. Range ex- pansion and trophic interactions of the jumbo squid, Dosidicus gigas, in the California Current. Calif. Coop. Oceanic Fish. Invest. Rep. 48:131–146.

Keyl F, J Argüelles, L Mariátegui, R Tafur, M Wolff & C Yamashiro. 2008. A hypothesis on range expansion and spatio-temporal shifts in size-at-maturity of jumbo squid (Dosidicus gigas) in the Eastern Pacific Ocean. CalCOFI Report 49: 119-128.

Markaida, U., Gilly, W.F., Salinas-Zavala, C.A, Rosas-Luis, R., and Booth, J.T.A. (2008) Food and Feeding of Jumbo Squid Dosidicus gigas in the Central Gulf of California During 2005-2007. California Cooperative Oceanic Fisheries Investigations, Progress Report, 90.

Nigmatullin, C. M., K. N. Nesis, and A. I. Arkhipkin. 2001. A review of the biology of the jumbo squid Dosidicus gigas (Cephalopoda: Ommastrephidae). Fish. Res. 54:9–19.

Staaf, D. J., S. Camarilla-Coop, S. H. D. Haddock, A. C. Nyack, J. Payne, C. A. Salinas-Zavala, B. A. Seibel, L. Trueblood, C. Widmer, and W. F. Gilly. 2008. Natural egg mass deposition by the Humboldt squid (Dosidicus gigas) in the Gulf of California and characteristics of hatchlings and par- alarvae. J. Mar. Biol. Assoc. UK 88:759–770.

Zeidberg, L.D. & Robison, B.H. (2007) Invasive range expansion by the Hum- boldt squid, Dosidicus gigas, in the eastern North Pacific. Proceedings of the National Academy of Sciences, USA, 104, 12948–12950.