Extension's Sustainable Tourism Blog « http://tourism.oregonstate.edu

Finally, a critter with a purse…

Yes, you read the subtitle correctly. A purse. A pocket. A bursicle.

The common Black Turban Snail is an interesting little critter with an interesting organ in its pocket.

Black Turban Snails, photo by Steve Lonhart, NOAA MBNMS (Royalty free from SIMoN Sanctuary data base library)

Where Found

They are one of the most abundant snail species along the Pacific Coast and inhabit most of the North American Pacific Coast from Canada to Baja California, Mexico.

This rocky shore snail is commonly found between high and low tides in protected areas near boulders, tide pools, and close to shore.

Identifying

The snail is pretty easy to identify, and so is the age of the snail. Juvenile snails live in more shallow water compared to adults. As the snail ages, it also migrates to higher waters. A fully grown Black Turban shell may be just over an inch long (30 mm) and 30-years-old.

The name sake for the snail is not the shell but the head and foot which are also black. The shell is smooth, whorled and pyramidal shaped.

Predators

The Black turban snail has many predators including humans, crabs, stars, otters, birds, other snails, and more.

There is evidence that some humans also harvested the snail as part of their diet about 12,000 years ago. If the snail were the only food consumed, the average human would need to eat around 400 of them each day to survive. When they are easy to harvest, this is possible and the snail continues to be collected today.

But wait, what is IN that shell?

Don’t be too surprised to find something other than a snail living inside the Black Turban shell. Hermit crabs will frequently adopt empty Black turban snail shells as their new home.

Photo of Hermit crab living in a Black Turban shell by Steve Lonhart NOAA MBNMS (Royalty free from SIMoN Sanctuary data base library)

The black distinctively smooth shell helps protect the snail. The Black Turban can withdraw its entire body into it for protection.

Shark-like Teeth

Black Turbans shred alga using a rasp-like (like a file) structure full of teeth. These teeth are constantly breaking and wearing. Thus, replacement teeth are produced continually, much like a shark must do.

What’s ON that shell?

The shell of the Black Turban is covered with red algae. Limpets graze the shell eating the algae. Slipper shells (Crepidula adunca) also live on the Black Turban Snail’s shell. The Slipper shell is a filter feeder and eats phytoplankton, bacteria, and diatoms that are on the shells.

Foods

Tegula funebralis feed on algae such as Macrocystis sp., Nereocystis sp., Gigartina sp., and Mastocarpus sp..

So what’s up with the purse?

Black Turbans have a special organ that they carry in a pouch or purse like structure called more scientifically as a bursicle. This chemoreceptor will sense chemical changes that emanate from predators such as crabs and seastars.

Once detected, the snail can take defensive actions and attempt to escape. However, snails are not known to be speedy. Yes, they may flee, but not quickly.

They may move to higher, potentially safer ground, potentially out of the water, to try and avoid contact. They may also simply float away to esacpe.

And of course, they always take their purse.

REFERENCES:
–Merriam-Webster dictionary, bursicle (https://www.merriam-webster.com/dictionary/bursicle)
–SIMoN Species database (https://sanctuarysimon.org/dbtools/species-database/id/131/tegula/funebralis/black-turban-snail/ and photos from their gallery)
–iNaturalist, Black tegula (https://www.inaturalist.org/taxa/460365-Tegula-funebralis)
–Prezi, Black Turban Snail (https://prezi.com/0ac53jzexytf/black-turban-snail/)
–Biodiversity of the Central Coast (https://www.centralcoastbiodiversity.org/black-turban-snail-bull-tegula-funebralis.html)
–Wikipedia, several (https://en.wikipedia.org/wiki/Crepidula_adunca, … Microalgae, and chemoreceptors)

Bees sip honey from flowers and hum their thanks when they leave.
The gaudy butterfly is sure that the flowers owe thanks to him.
Rabindranath Tagore

The Oregon coast is very lucky to have a native butterfly species that is both colorful and spectacular.

The Oregon Swallowtail is part of a larger Papilionidae family that includes some of the largest and most beautifully colored butterflies in North America. North America has 40 species.

Territory

The Oregon swallowtail lives only in Oregon, Washington, Idaho, and south-central British Columbia. Swallowtail species can be found in the Arctic Circle south into Mexico. Most sightings in Oregon are along the mainstems and immediate tributaries of the Columbia, Deschutes and Snake Rivers.

There are over 550 butterfly species in this family. Most reside in tropic and subtropic regions. The Oregon Swallowtail may have originated there.

Food

Adults feed on wildflower nectar from thistles, balsamroot, phlox, daisies, asters, rabbitbrush, penstemon, milkweed, and dogbane. The larvae (juveniles) feed on tarragon sagebrush (also called wild tarragon or dragon wormwood, Artemisia dracunculus).

Swallowtail butterfly caterpillars feed on a wide range of plant families, and often depend on one of five families: Aristolochiaceae, Annonaceae, Lauraceae, Umbelliferae (Apiaceae) and Rutaceae. These plant families include toxic plants. Once eaten, the toxin makes both the caterpillar and butterfly also toxic which helps protects them from predators.

Predation

Oregon Swallowtails have wingspans up to 4-inches that sport a bright yellow with black-lined pattern and a ‘tail’ that extends off the back wing. The yellow wing markings of the Oregon swallowtail are brighter than the common swallowtail.

The tail is not required for flight, and may be sacrificed to escape predation. The hope is that the bird may ‘swallow the tail’ rather than a more critical body part and allow the butterfly to survive.

Several Swallowtails can also change their behaviors to help reduce predation. They will imitate the behaviors of other distasteful species, and several studies show females imitating males as a way to reduce predation.

Predators can include birds, wasps, spiders, and preying mantis, skinks, skunks and human collectors.

When to look

Look for Oregon Swallowtail butterflies in flight between April and September. Those seen early in the year are generally lighter in color than those seen later and blend well with the color of early plants.

Swallowtails are wary and strong fliers. This butterfly was selected as Oregon’s official insect on July 16, 1979, not only because it is a native but also because it has ‘Oregon’ in is common and scientific names. Oregon Swallowtail butterflies are a wonderful aesthetic gift.

REFERENCES:
–Oregon Dept. of Fish & Wildlife, Oregon Swallowtail Factsheet (https://www.dfw.state.or.us/conservationstrategy/docs/Swallowtail_factsheet.pdf)
–Butterfly Identification, Oregon Swallowtail (https://www.butterflyidentification.com/oregon-swallowtai.htm)
–EReference desk (https://www.ereferencedesk.com/resources/state-insect/oregon.html)
Wikipedia, Papilio machaon oregonius (https://en.wikipedia.org/wiki/Papilio_machaon_oregonius)

Is it possible to say something good about Gorse?

Maybe. Depends on if you have ever tried to get rid of it or not.

Some consider Gorse as a pretty, fragrant shrub. Others class it as something akin to devil spawn.

Gorse maintains a love-hate reputation not only with humans but other plants. In both cases, it has earned this reputation well.

Is anything good?

Gorse was commonly used in several ways including as a:
–Food source (the flowers are edible). Plant can be used as livestock feed as it is high in protein. Pollen from the various varies help pollinators, such as bees.
–Product creation such as soap making, yellow dye, cleaning tools
–Traditional Medicines (listed as one of 38 plants in the Bach’s Flower Remedies.

Lots o’ Bad

Gorse has earned a dubious reputation in several ways and is now on several invasive and noxious lists for States and countries. Bandon is no stranger to this plant that arrived over 100 years ago thanks to ‘Lord’ George Bennett, an Irish immigrant. In Ireland, the plant had many uses and natural biological controls generally not present here.

Bandon is ‘ground zero’ for gorse removal and fire risk reduction. The rumor is that gorse helped fuel the Bandon Fire of 1936 that burned down most of the town. A Gorse Action Group in Bandon is working on the problem (see What’s the Deal with Gorse? (https://sea-edu.org/2019/12/17/whats-the-deal-with-gorse/). Then again, dried gorse was used as kindling and a fire fuel for bread making ovens.

More Hate than Love

There is a lot more hate than love now-a-days, and fortunately controls that can help manage this noxious weed. Here is a quick comparison:

A Small Gorse Spider Mite Experiment

Mites control gorse through extensive feeding pressure. The mites will through feeding kill shoots, reduce plant growth and overall plant biomass, and abort the production of flowers. It can take a long time for these mites to control the gorse. What if we could help this along?

This is our little experiment:
Year 1: We took a few, small cuttings from mite-infected plants and threw them on some bushes. Result: Mite spread slow but evident, and did not persist on some bushes.
Year 2: We took larger cuttings off of several bushes that exhibited mite infestation. Placed several 6-inch sprigs on approximately 12 other bushes with light or relatively no infestation. Result: All bushes infected; most showed some stress.
Year 3: Mechanical removal employed on several large, bushes. Result? Can’t wait to plant the area. More mechanical and hand removal is in progress. It will be interesting to look back next year and see the results. I think I also spotted a Gorse soft shoot moth on my shovel handle. There is hope.

OTHER REFERENCES:
–Wikipedia, Ulex (https://en.wikipedia.org/wiki/Ulex_europaeus)
–Tasty Natives, Ulex europaeus (https://www.greenlab.org/tastynatives/2018/11/01/gorse/
—6 organic ways to get rid of gorse (https://thisnzlife.co.nz/5-organic-ways-get-rid-gorse/) (Note: link does say 5 rather than 6 as in title, error in link naming)
—What are the effects of gorse on the ecosystem? (http://agriculture.vic.gov.au/agriculture/pests-diseases-and-weeds/weeds/a-z-of-weeds/gorse)
–University of Washington, 66-8633 Gorse Soil Effects (https://portal.nifa.usda.gov/web/crisprojectpages/0213036-66-8633-gorse-soil-effects.html)
—Victorian Gorse Taskforce (https://www.vicgorsetaskforce.com.au/biological-control/)

Extension's Sustainable Tourism Blog

http://tourism.oregonstate.edu

Black Turban Snail (Tegula funebralis)