Loligo opalescens

From ize

Other names: Opalescent Squid, Market Squid, ""Loligo stearnsii""

Taxonomy
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Teuthoidea
Family: Loliginidae
Genus: Loligo
Species: L. Opalescens

Contents 1 Range 2 Habitat 3 Identification 4 Misidentification 5 Life History 6 Predator and Prey Relationships 7 References 8 Sources

Range

Loligo opalescens can be found from Southern Alaska to Bahia Asunción in Baja California.^[1]

Habitat

Loligo opalescens inhabit shallow coastal waters near shore to deeper coastal waters. In Puget Sound Loligo opalescens are thought to move farther into Puget Sound to breed, but it is also possible that Puget Sound has a resident population of squid that move around the Sound.^[2] More research using tagging equipment is being conducted to better understand the movement and behavior of Loligo opalescens within Puget Sound.

Identification

Adult Loligo opalescens can reach a total size of 28 cm. Males are typically larger with a mantle length of 13-19cm and females 12-18 cm in mantle length.^[3] The mantle of Loligo opalescens is not fused to the head and its body is 4 to 5 times longer than it is wide with fins both equal in length and width. This squid has 8 arms with 2 longer tentacles with tentacle clubs equipped with suckers at their end. The tentacle clubs are narrow with 4 rows of suckers with 2 large rows in the center of the tentacle club bordered by outer rows of smaller suckers. The 8 arms have only 2 rows of alternating suckers running down their length.^[4] In male Loligo opalescens the left ventral arm is specialized or “hectocotylized” for spermatophore transfer during mating.^[5] The eyes of L. opalescens are covered with a non-perforated membrane known as a cornea which is a signature of myopsid squids.^[6] The color of Liligo opalescens can range from white to brown, and are able to change their color shades using chormatophores depending on mood and for camouflage. They are normally a blue white to mottled brown and gold, and they change to dark red or brown when excited, frightened or feeding.^[7]

Misidentification

Loligo opalescens is very similar to two other species of squid in the same genus, Loligo pealii from the North Atlantic Coast of North America, and Loligo gahi from the coast of Chile, which are not present in Puget Sound.^[8] Another squid specie in Puget Sound is Rossia pacifica, but its stubby body and smaller size make it easy to distinguish from Loligo opalescens.

Life History

The life cycle of L. opalescens begins from eggs laid in areas like Budd and Eld Inlets on shallow sandy bottoms in large groups anchored to the sea floor where the ocean currents keep them well oxygenated. The Washington breeding season is normally July through September with adults coming in shore to breed in large groups. During mating the male uses his modified ventral arm to deposit his spermatophore in the female who uses it to fertilize her egg capsule containing a few hundred eggs. The eggs are protected in a protein cover to protect the pickle shaped egg cases, and laid in large clumps on the sandy bottom. Loligo opalescens are known for having many adults dying after spawning but is unclear as to whether they spawn multiple times or live for multiple breeding seasons.^[9] The eggs will hatch after 3-5 weeks with small hatchlings called paralarvae emerging that begin hunting zooplankton such as copepods.^[10] After reaching a large enough size of about 15mm over a couple of months of growth the juvenile L. opalescens begin hunting in groups near shelfs and edges of kelp beds.

Predator and Prey Relationships

Loligo opalescens is a cannibalistic predator that feeds on smaller prey species such as fish, crabs and shrimp, mollusk, and other juvenile squids.^[11] It uses its two longer tentacles with tentacle clubs on the end to snare and catch its prey. Loligo opalescens itself is an important food source for many predators like larger fish, sharks, marine mammals, sea birds and also humans. In California L. opalescens has a large fishery and is sold in many grocery stores as a food item as calamari, hence its common name market squid. In Washington market squid has a large recreational fishery with the main fishing season occurring in the late fall and winter.

References

Sources

Berry, S. Stillman. “A Review of the Cephalopods of Western North American.” Bulletin of the Bureau of Fisheries Vol. 30 (1910): 294-297

Kozloff, Eugene N. Marine Invertebrates of the Pacific Northwest. Seattle: University of Washington Press, 1996

Gotshall, Daniel W. Guide to Marine Invertebrates Alaska to Baja California. Monterey: Sea Challengers, 1994

Lamb, Andy, and Hanby, Bernard P. Marine Life of the Pacific Northwest, A Photographic Encyclopedia of Invertebrates, Seaweeds and Selected Fishes. Madeira Park, BC: Harbour Publishing, 2005

Morris, Robert H., Donald P. Abbott, Eugene R. Haderlie. Intertidal Invertebrates of California. Stanford: Stanford University Press, 1980

Payne, John and O’Dor, Ron. “Comparing Squid Optimal Cost of Transport Speeds to Actual Field Migrations: New Data From 40-g Loligo opalescens” The Role of Squide in Open Ocean Ecosystems GLOBEC Report Number 24 (2006): 16-18

Recksiek, Conrad W., and Frey, Herbert W. “Biological, Oceanographic, and Acoustic Aspects of the Market Squid, Loligo Opalescens Berry” State of California The Resources Agency Department of Fish and Game Fish Bulletin No. 169 (1978)

Vojkovich, Marija. “The California Fishery for Market Squid (Loligo opalescens)” California Cooperative Oceanic Fisheries Investigations Report Vol. 39 (1998): 55-60

Wood, James B. “Loligo opalescens, California Market squid – The Cephalopod Page” The Cephalopod Page. 1995-2008 Bermuda Institute of Ocean Sciences. 26 April 2008 <http://www.thecephalopodpage.org/Lopal.php>