Tag Archive: gastropods


TAXONOMY
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Clade: Vetigastropoda
Superfamily: Trochoidea
Family: Turbinidae

Genus/specie: Megastraea undosa

GENERAL CHARACTERISTICS: The Wavy Turbin Snail has a heavy, sculptured shell with undulating ridges in a turbinate-conical shape with a thick, pearly lining.
The light brown or tan shell color is caused by the fibrous periostracum covered with coralline algae and other epiphytes.

Size: up to 6 inches

DISTRIBUTION/HABITAT: Found from Point Conception and the coastal Channel Islands to northern Baja California, Mexico. They range from the intertidal zone down to depths of over 250 feet.

DIET IN THE WILD: M. undosa are herbivores feeding on various types of algae.

REPRODUCTION; Year around with peaks in spring and fall.

CONSERVATION: Because wavy turban snails are hand-picked by divers, the fishery is at low risk for bycatch .
Wavy turban snails are abundantly available and have a high productivity rate, so over- harvesting is less likely.

REMARKS: The shells of wavy turban snails are used to make buttons!

The meat has an abalone-like texture and taste; foot of the snail is processed and sold to restaurants as an abalone-like product, “wav alone”.  They can be prepared many ways: grilled, sautéed, battered and fried, in pastas, in chowders and soups, and in stir fries.

References

California Academy of Sciences Steinhart Aquarium Tidepool 2017

Ron’s flickr https://www.flickr.com/photos/cas_docents/34539982943/in/dateposted-public/

Spearboard.com www.spearboard.com/showthread.php?t=99314

U of CA San Diego caseagrant.ucsd.edu/sites/default/files/fact-sheet-wavy-t…

Gastropods.com www.gastropods.com/2/Shell_292.shtml

Ron’s WordPress Shortlink  http://wp.me/p1DZ4b-1Qf

TAXONOMY
Phylum: Mollusca
Class: Gastropoda (slugs, snails, nudibranchs, abalone)
Order: Archaeogastropoda (sea snails)
Family: Haliotidae (abalones)

Genus/species: Haliotis rufescens

GENERAL CHARACTERISTICS: The red abalone is a large limpet-like snail with a flattened and rounded shell. The shell can reach up to 30 cm (11.8 in) in length and is usually brick-red and overgrown with fouling organisms. Color varies with diet and varies between aquamarine, green, or white. Water enters anteriorly through row of holes parallel to the rim of the shell and exits posteriorly carrying waste products and gametes. When in danger, the abalone clamps its shell tightly to the substrate, protecting soft parts of its body. The shell’s color is influenced by the animal’s diet. The red color is from the pigment phycoerythrin consumed in its red alga diet. Color varies with a diet of brown algae (varies between aquamarine, green, or white).

DISTRIBUTION/HABITAT: Red abalone are found from Oregon to Baja California. They are uncommon in the lower intertidal zone in rocky areas with heavy surf. Most are now found at six to 17 m (20 to 56 ft) depth in central California.

 

DIET IN THE WILD: Small abalones feed on diatoms and algae; larger animals browse the seaweeds. Red abalone eat algae, especially red and brown species. Usually foraging at night, they trap drifting pieces of algae (kelp) with the tentacles that extend from the foot. The algae is then carried by the foot to the mouth, and is torn and consumed with by the radula.

flickr Feeding Video http://www.flickr.com/photos/cas_docents/6393536637/in/set-72157626486149324

 

PREDATORS: Sea stars, crabs, octopuses, sea otters and human divers are among the abalone’s primary predators.

REPRODUCTION: After spawning takes place, fertilized eggs sink. Larvae develop in the plankton until they settle to the bottom, metamorphose, and begin to graze. Growth slows with increasing size and age. Mortality is very high in the planktonic stages. Mature individuals can live more than 20 years.

REMARKS: Red abalone are highly endangered due to overexploitation by the abalone fishery. The population plummeted in the late twentieth century, but poaching continues to be a problem. California passed many strict regulations to protect the red abalone: abalone smaller than 20 cm (8 in) in diameter are protected, the canning of abalone is prohibited, and the shipment of fresh or frozen meat out of California is prohibited. Red abalone is the only species that can still be fished. Aquacultured abalone is now increasingly available.

Abalone blood is blue-green and cannot clot making injury possibly fatal.

Red Abalone Shell19600303421_7eae835178_z

Color of Life note: Iridescence is caused by two or more semi-transparent, inorganic and/or organic surfaces that cause multiple light reflections. An example found in our tidepool is the Red Abalone inner shell surface which produces an impressive vibrant luster when exposed to light.  The aragonite and conchiolin secreted by the abalone in forms a crystalline structure that reflects light, causing the shell’s iridescence. The inner surface of the shell is known as mother-of-pearl, or nacre. Ref: California Academy of Sciences, Color of Life Exhibit 2015   Jewelry is still made from abalone shells and is quite popular.                        Ref: www.best-deal.com/search/landing/query/red+abalone+shells...

 

Other references

Marine Biology Coloring book, T.M. Nielsen, 2nd Ed. Harper Resource 1982, 2000.

Encyclopedia of Life  eol.org/pages/620396/details

Monterey Bay Aquarium  www.montereybayaquarium.org/animal-guide/invertebrates/ab…

California Fish and Game www.dfg.ca.gov/marine/pdfs/response/abalone.pdf

Ron’s flickr https://www.flickr.com/photos/cas_docents/6393536637/in/album-72157608597736188/

 

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