Wavy Turban Snail

Megastaea undosa

wavy_turban_snail
Glenn E. Vedder

The Science

turban_snail
diverkevin.com

Taxonomic description

  • Shell’s color of sun-ripened apricots, has longitudinal white stripes on carapace and distinctive white spots on sides of first and fifth abdominal segments [1,2]
  • Pereopods and antennae banded dark red & lighter red or white [2]
  • 5 pairs swimming legs (pleopods), 5 pairs walking legs (pereopods) [2]
  • 2nd pair pereopods—left one is longer than right one [2]
  • Juveniles may be red, brown, or green [2]
  • Abdomen smooth and shiny
  • Transitionals become females averaging 1.75 inches (44 millimeters) [1]
  • Grows 15-27cm in size [2]
  • Max observed age is roughly over 6 years [1]

Distribution

  • Northeast Pacific from SD, CA to Unalaska Island, Alaska & Sea of Japan to Korean Strait [1,2]

Life history

  • Adults migrate through water column to feed at night from depths of up to 1,500 ft 
  • Spot prawns start off as males during the first few years of life and then change to females [2]
  • Migrate seasonally to breed [2]
  • Breed in late October & hatch March or April [2]
  • Males live up to 4-5 years, females die after brooding eggs [2]

Habitat

  • Deep cold water [2]
  • Rocky habitats along seafloor from intertidal zone to depths greater than 400m [2]
  • Nighttime vertical migration to shallower waters to find prey, return to deeper water at sunrise [2]
  • Feeds on worms, algae, small mollusks, sponges, shrimp & scavenges dead

The Fishery

turban_snail
Linda Tsoi

Seasonal availability

  • Available year-round [6]

Managing authority

  • Regulated by the California Fish and Wildlife Department under the Invertebrate Management Project [3]
  • Commercial tidal invertebrate regulations prohibit harvest of any snail species within 1,000 feet of low tide mark on shore [3,5]
  • Simply need a valid California commercial fishing license to harvest the snails [5]

Gear type

Typically harvested by divers [5,7]

  • Divers use handheld tools and net bags to collect the snails, gear which is identical to that used to collect red sea urchins [5,6]
  • Snails are hand-picked by divers, resulting in very little (or no) bycatch [6]
  • Divers make little contact with the seafloor [6]

Status of the fishery

  • Recorded landings began in 1992, with overseas markets for the meat and the shell [5]
  • Landings peaked in 1993, but crashed in 1994 after market demand plummeted; landings continued to fluctuate from 1995-97, and peaked again in 1998 [5]
  • Fishery centered in San Diego, with most landings coming from Point Loma [5]

Potential ecosystem impacts

  • Because wavy turban snails are hand-picked by divers, the fishery is at low risk for bycatch [6]
  • Wavy turban snails are abundantly available and have a high productivity rate, so over-harvesting is less likely [4]
  • El Niño-Southern Oscillation (ENSO) events seem to trigger recruitment, and increase mortality of larger individual turban snails; this suggests that knowledge of ENSO will be helpful in setting harvest quotas in the future [8]
  • Impacts of harvesting wavy turban snails may cascade upward to their predators, like the giant-spined sea star (P. gigantus) [8]

The Seafood

wavy_turban_recipe
kelpmonkey, spearboard.com

Edible portions

  • Current market demand is for the foot [14]
  • The operculum should be removed [10]
  • The snail’s intestines are bitter in taste, and are sometimes eaten, sometimes removed [10.11]

Description of meat

  • Has an abalone-like texture and taste; foot of the snail is processed and sold to restaurants as an abalone-like product, “wavalone” [11,14]

Culinary uses

  • Most recipes for abalone and sea snails can be adapted to the wavy turban snail
  • Wavy turban snails can be prepared many ways: grilled, sautéed, battered and fried, in pastas, in chowders and soups, and in stir fries [12]

Nutritional information 

  • Turban snail, raw [9,13]

Toxicity report

  • There are no known contaminants

Seasonal availability

  • Available year-round in San Diego

References

[1] Taniguchi, Ian, and Laura Rogers-Bennet, California Department of Fish and Game. 2001. California’s Living Marine Resources: A Status Report, pgs. 140-41. Available: https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=34371

[2] NOAA Encyclopedia of the Sanctuaries. “Wavy Turban Snail.” Available: http://www8.nos.noaa.gov/onms/Park/Parks/SpeciesCard.aspx?refID=4&Creatu...

[3] California Department of Fish and Wildlife. 2015. Invertebrate Management Project. Available: https://www.wildlife.ca.gov/Conservation/Marine/Invertebrates    

[4] Micheli, F., et al. 2014. A risk-based framework for assessing the cumulative impact of multiple fisheries. Biological Conservation 176: 224-235. Available: http://micheli.stanford.edu/pdf/a%20risk%20based%20framework.pdf

[5] Taniguchi, Ian, and Laura Rogers-Bennet, California Department of Fish and Game. 2001. California’s Living Marine Resources: A Status Report, pgs. 140-41. Available: https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=34371

[6] Tuna Harbor Dockside Market. 2015. Gear. Available: http://thdocksidemarket.com/new/index.html#gear

[7] Tuna Harbor Dockside Market. 2015. Species. Available: http://thdocksidemarket.com/new/#species

[8] Zacharias, Mark, and David J. Kushner. 2006. “Sea temperature and wave height as predictors of population size structure and density of Megastraea (Lithopoma) undosa: Implications for fishery management.” Bulletin of Marine Science 79.1: 71-82.

[9] CalorieSlism. 2015. “Turban Shell (Sazae)”. http://slism.com/calorie/110295/#foodDataDetail

[10] Dong, Michael. “How To: Wavy Top ‘Turban’ Snails.” Spearboard.com. Available: http://www.spearboard.com/showthread.php?t=99314 

[11] “Grilled Sea Snails: Sazae no Tsubuyaki.” Oh My Omiyage, blog. Available: https://ohmyomiyage.wordpress.com/2012/10/04/grilled-sea-snails-sazae-no...

[12] Monterey Abalone Company. “Abalone Recipes.” Available: http://montereyabalone.com/recipes2.htm#Saut%E9ed_Abalone 

[13] SELF nutrition data. 2013.  “Mollusks, snail, raw”. http://nutritiondata.self.com/facts/finfish-and-shellfish-products/7742/2 

[16] Taniguchi, Ian, and Laura Rogers-Bennet, California Department of Fish and Game. 2001. California’s Living Marine Resources: A Status Report, pgs. 140-41. Available: https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=34371