Journal of the Marine Biological Association of the UK

Research Article

Natural egg mass deposition by the Humboldt squid (Dosidicus gigas) in the Gulf of California and characteristics of hatchlings and paralarvae

Danna J. Staafa1 c1, Susana Camarillo-Coopa2, Steven H.D. Haddocka3, Al C. Nyacka4, John Paynea5, Cesar A. Salinas-Zavalaa2, Brad A. Seibela4, Lloyd Trueblooda4, Chad Widmera6 and William F. Gillya1

a1 Hopkins Marine Station of Stanford University, Oceanview Boulevard, Pacific Grove, CA 93950 USA

a2 Centro de Investigaciones Biológicas del Noroeste, SC Unidad Sonora. Mar Bermejo # 195 Col. Playa Palo de Santa Rita. La Paz, B.C.S. Mexico

a3 Monterey Bay Aquarium Research Institute, 7700 Sandholdt Rd., Moss Landing, CA 95039 USA

a4 Department of Biological Sciences, University of Rhode Island, 100 Flagg Road, Kingston, RI 02881 USA

a5 POST project, 13639 SW 224th Street, Vashon, WA 98070 USA

a6 Monterey Bay Aquarium, 886 Cannery Row, Monterey, CA 93940 USA

Abstract

The jumbo or Humboldt squid, Dosidicus gigas, is an important fisheries resource and a significant participant in regional ecologies as both predator and prey. It is the largest species in the oceanic squid family Ommastrephidae and has the largest known potential fecundity of any cephalopod, yet little is understood about its reproductive biology. We report the first discovery of a naturally deposited egg mass of Dosidicus gigas, as well as the first spawning of eggs in captivity. The egg mass was found in warm water (25–27°C) at a depth of 16 m and was far larger than the egg masses of any squid species previously reported. Eggs were embedded in a watery, gelatinous matrix and were individually surrounded by a unique envelope external to the chorion. This envelope was present in both wild and captive-spawned egg masses, but it was not present in artificially fertilized eggs. The wild egg mass appeared to be resistant to microbial infection, unlike the incomplete and damaged egg masses spawned in captivity, suggesting that the intact egg mass protects the eggs within. Chorion expansion was also more extensive in the wild egg mass. Hatchling behaviours included proboscis extension, chromatophore activity, and a range of swimming speeds that may allow them to exercise some control over their distribution in the wild.

(Received August 24 2007)

(Accepted February 06 2008)

Correspondence:

c1 Correspondence should be addressed to: Danna J. Staaf Hopkins Marine Station of Stanford University Oceanview Boulevard, Pacific Grove, CA 93950 USA email: joyshul@stanford.edu