Black Abalone
Haliotis cracherodii

 

Physical Description

  • It has a relatively smooth oval-shaped shell, with five to nine holes on top side edge, used to breathe, remove waste, and reproduce.
  • Relatively small compared with most of the other abalone species.
  • The coloration of the shell is dark green, dark blue, or almost black.
  • Black-colored body (foot and tentacles) that can be seen around the edge of the shell.
  • Can grow to be up to 8 inches in length, 1.75 pounds in weight.

Range

  • From Mendocino County, California to Cabo San Lucas, Baja California, Mexico.

Habitat

  • Live in low intertidal zone, on rocky substrates.
  • Live up to 20 feet deep.
  • Typically found wedged into crevices, cracks, and holes during low tide.

Reproduction

  • They are broadcast spawners, meaning they release eggs and sperm into the water.
  • They can release millions of eggs and sperm when the conditions are right.
  • When one abalone starts to spawn, it usually triggers others to start in the area.

Diet

  • Drift algae, kelp, giant kelp, feather boa kelp, bull kelp.

Predators

  • Eggs and larvae are eaten by filter-feeders.
  • Juveniles and adults eaten by crabs, lobsters, octopuses, sea stars, fish, sea otters, and predatory snails.
  • Humans have harvested black abalones along the California Coast for at least 10,000 years.

Interesting Facts

  • This used to be the most abundant large marine mollusk on the west coast of North America, numbering in the millions, but now, because of overfishing and withering syndrome, it has much declined in population and the IUCN Red List has classed the black abalone as critically endangered.
  • Fishing for black abalone has been illegal in California since 1993, but they are still often caught by poachers.
  • Black abalone and other abalone species were eaten by native people along California’s coasts for thousands of years, and abalones shells are often found in large piles called middens at their settlement sites.

Sources: IUCN Red List; NOAA Fisheries; World Register of Marine Species; FishTech.com; UC Santa Cruz; Aquarium of the Pacific

Photo: Laurel Bartels

NOAA’s Southwest Fisheries Science Center here in La Jolla is researching abalone and how to help them recover.