Sheep Crab

Loxorhynchus grandis

Matthew Meier, matthewmeierphoto.com

       

The Science

Masters of Disguise! Young sheep crabs mask their bodies with barnacles, bryozoans, hydroids, and algae. As they mature, adults develop a film of fuzzy green algae over their bodies

The Fishery

Sheep crabs were of little commercial value until Santa Barbara fishermen experimented with marketing the claws in 1984 

The Seafood

Sheep crab can be eaten steamed or grilled—makes for a luxurious camping meal!

The Science

Matthew Meier, matthewmeierphoto.com

Taxonomic description

  • Has an oval-shaped body covered in spines and bumps [1]
  • Largest species in the family of California spider crabs (Majidae) with long, crawling legs and big, knobby joints [1]
  • Male adults have massive claws and legs longer than female adult [1]
  • Males’ bodies grow up to 17 cm (6.5 inches) and females’ bodies up to 11 cm (4.5 inches) [1]

Distribution

  •     Point Reyes, California to Baja California, Mexico [1]

Life history

  •     Life span is at least four years [2]
  •     Maturity defined by size—females mature with abdomen width of 10.7 – 17.3 cm (4.2 to 6.8 inches), males from 10.7 –  24.4 cm (4.2 to 9.6 inches) wide [2]
  •     Egg-bearing females peak in late spring through summer and can store sperm for the future in the absence of males [2]
  •     Male and females pile up on shore and hook back-to-back to mate [2]
  •     Each brood ranges from 125,000 to 500,000 eggs [2]

Habitat

  •     Male crabs spend winter in deep water, and both sexes migrate toward shallower waters during warmer weather. They dwell in water depths ranging 6 to 152 meters (20 – 500 ft) [1,2]
  •     Prefers to hide out in reefs and pilings [1]
  •     Diet consists of carnivores and bottom-dwelling scavengers [1]
  •     Small individuals preyed upon by cabezon, California sheephead, octopus, sharks, and rays [2]
  •     Parasitic infections potentially impact young crabs, including the ribbon worm and rhizocephalan barnacle [2] 

The Fishery

Ken Jones, kenjonesfishing.com

Seasonal availability

  • All year long [2]

Managing authority

  • Not specifically regulated but falls under jurisdiction of California Department of Fish and Wildlife: California Spiny Lobster Management Plan, since the crab is incidental catch in these fisheries and/or state rock crab fishery regulations [10]

Gear type

  • During spring and summer, crab and lobster traps are set in shallow, sandy-bottom areas about 9 to 21 meters (30 to 70 feet) [2]
  • During fall and winter, crab and lobster traps are moved to deeper waters about 37 to 73 meters (120 to 240 feet) [2]
  • Common rock crab trap made of wire mesh with entry funnel either on top or sides made of PVC pipe [11]

Status of the fishery

  • The market for sheep crab peaked in 1988 when 108,000 pounds of whole crabs and 96,000 pounds of claws were caught [2]
  • Landings declined in 1991 after the Marine Resources Protection Act (1990) phased out gill and trammel nets within 3 miles of mainland shore south of Point Arguello and near the Channel Islands, which heavily reduced catch of sheep crabs [2]
  • Fishing efforts for whole crabs are relatively low due to low profitability [2]
  • An experimental sheep crab fishery was recently established off Baja California, Mexico to increase crab landings. If successful, California commercial fisheries might adopt [2]

Potential ecosystem impacts

  • Overfishing of sheep crab (or other related crabs) can result in unregulated populations of bottom-dwelling scavengers and algae; for now, not a concern [10]

The Seafood

food.com

Edible portions

  • Meat in the claws and body [3]

Description of meat

  • Delicate flavor and firm texture [3]

Culinary uses

  • Immediately place live crabs in freezer to humanely numb them [6]
  • To clean, break the crab down into sets of two legs and a body section [3,4]
  • To steam, wrap in heavy duty foil and add diluted clean ocean water or salted water, and put foil-wrapped crab on charcoal or hot grill or place frozen crabs in pot of shallow water and steam (8 minutes per pound) [3,4,6]
  • Season crab meat with Old Bay seasoning, butter, lemon, and/or pepper [6]

Nutritional information 

  • Low in saturated fat and good source of riboflavin, niacin, magnesium, phosphorous, and potassium. Excellent for protein, vitamin B12, zinc, copper, and selenium [8]
  • High in cholesterol and sodium, values listed in table [8]

Toxicity report

  • Domoic acid, a naturally occurring biotoxin in California crabs, can occasionally occur in the guts of crab during harmful algal blooms. Check for warnings before buying fresh, and be sure to clean out guts before preparing [9]

Seasonal availability

  • All year long [2]

References

[1] Monterey Bay Aquarium. Sheep Crab. https://www.montereybayaquarium.org/animal-guide/invertebrates/sheep-crab . Accessed: 15 April 2017

[2] Culver, C. S., A. M. Kuris. 2003. Status of the Fisheries Report Through 2003. California Department of Fish and Wildlife, Marine Region (Region 7), Monterey, CA, USA.

[3] Jones, K. 2012. California Crabs. Ken Jones: Writer & Pierfisherman. http://kenjonesfishing.com/2012/01/california-crabs-%E2%80%94/. Accessed 18 April 2017

[4] Spearboard.com. 2015. Sheep Crab AKA California King Crab—cleaning and meat yield. http://www.spearboard.com/showthread.php?t=180705&page=2. Accessed 18 April 2017

[5] Spearboard.com. 2015. Recipe for Sheep Crab. http://www.spearboard.com/showthread.php?t=147591. Accessed 18 April 2017

[6] Hoch, A. 2015. Box Crabs- The First Taste. http://backyardgourmandsandiego.blogspot.com/2015/01/box-crabs-first-taste.html. Accessed 1 May 2017.

[7] Food.com. Grilled Crab Legs. http://www.food.com/recipe/grilled-crab-legs-64991. Accessed 1 May 2017.

[8] SelfNutritionData. Crustaceans, crab, Dungeness, Nutrition Facts & Calories. http://nutritiondata.self.com/facts/finfish-and-shellfish-products/4248/2. Accessed 1 May 2017. 

[9] Culver, C., C. Pomeroy, and J. Tyburczy. 2016. California Sea Grant. Frequently Asked Questions: Domoic Acid in California Crabs. https://caseagrant.ucsd.edu/project/frequently-asked-questions-domoic-acid-in-california-crabs. Accessed 1 May 2017.

[10] California Department of Fish and Wildlife. 2016. California Spiny Lobster Fishery Management Plan. California Department of Fish and Wildlife. https://www.wildlife.ca.gov/Conservation/Marine/Lobster-FMP. Accessed 1 May 2017.

[11] NOAA. 2017. CA Rock Crab Pot Fishery. http://www.nmfs.noaa.gov/pr/interactions/fisheries/table1/wcr/ca_rock_crab.html. Accessed: 30 May 2017.