Other Names: Arca noae or the Noah’s Ark shell
Species: A. noae
Common Names: Cockle shell or Wa Leng Zi in mandarin,
Distribution & availablity: Arca noae or Ark shell is found in the Mediterranean and Adriatic Seas. It used to be common in the Adriatic but in 1949/50 there was a sudden unexplained, catastrophic decline in numbers. Since then populations have been creeping back upwards and in 2002, densities of up to 13 individuals per square metre (11 square feet) were recorded but, because of lack of records, it is unclear whether a return to prior population levels had been reached.
The shell of Arca noae grows to about 10 cm (4 in) in length. It is shortened at the anterior end and elongated posteriorly. It is irregularly striped in brown and white and has fine sculptured ribs running from the umbones to the margin. The hinge is long and straight and the shell is attached strongly to the substrate by byssal threads. There are pallial eyes on the edges of the mantle, especially at the posterior end. There are 42 to 48 radial ribs outside.
They are characterized by boat-shaped shells with long, straight hinge lines bearing many small, interlocking teeth. The shells are usually coated with a thick, sometimes hairy periostracum (outer organic shell layer). Many of these clams have rows of simple eyes along the mantle margins. Most of the 200 or so known species are found in tropical seas, with only a few species occurring in temperate areas. Ark shells are slow-moving or sedentary.It lives shallowly buried in sands and silts.
In the lower part of the intertidal zone in the Adriatic, Arca noae often grows in association with Modiolus barbatus.The shells are often heavily encrusted with epibionts. Water is drawn into the shell mainly at the posterior end. Plankton and fine organic particles are filtered out as the water passes over the gills and inedible particles are rejected at the same time. Its shell contains a large amount of calcium carbonate and a small amount of calcium phosphate. Besides, it also contains aluminum silicate and inorganic elements, such as chlorine, chromium, copper, iron, potassium, manganese, sodium, nickel, phosphorus, sulfur, silicon, strontium, and zinc. And it has a specific enrichment capacity of nuclide manganese.
Collection & Uses:
Arca noae is fished commercially in the Adriatic Sea, either by divers gathering individual shells by hand or from boats using specially adapted rakes which are pulled along the seabed. The shellfish are then sold in local markets. In China it is produced around the coastal areas and captured all year round for medicinal purpose. And the subsequent steps are to clean, slightly boil in boiling water, remove the meat, and finally dried in sun. Medicinally it is used broken and raw or calcined.
Modern pharmacology reveals that its ability of reducing gastric ulcer pain comes from calcium carbonate, which can neutralize stomach acid.
Ark shell, clam shells (Hai Ge Ke), and pumice (Fu Hai Shi) have quite similar medicinal uses in traditional Chinese medicine. However, it doesn’t mean that they are interchangeable. On the contrary, they need to be well distinguished clinically for proper uses.
All of the three are of salty in flavor and have the common function of eliminating phlegm, softening hardness and dissipating binds. As a result, all of them can be used to treat phlegm-fire stagnation induced scrofula, subcutaneous nodule, goiter and tumor; clam shell and pumice stone can also treat cough and asthma accompanied with thick yellow sputum that is caused by lung heat and phlegm-fire since both of them is capable of clearing lung and eliminating phlegm; clam shell and ark shell are also good at treating stomach discomfort and acid reflux since they can neutralize acidity and relieve pain.
And they do have their own advantage respectively on healing properties. Clam shell is still capable of inducing diuresis to alleviate edema. So it is often used for the treatment of edema and difficult urination; pumice stone can treat bloody stranguria and urolithiasis by inducing diuresis; ark shell removes blood stasis and disperses phlegm. Hence, it treats mass in the abdomen and hepatosplenomegaly.
Sample ark shell recipes on herbal remedies: The Chinese Pharmacopoeia says that it is salty in flavor and neutral in nature. It covers meridians of lung, stomach, and liver. Crucial functions are dissolving phlegm, dispersing blood stasis, resolving hard lump, relieving hyperacidity, and stopping pain. Prime ark shell uses and indications include substantial amounts of lingering phlegm, difficulty coughing up thick, sticky mucus, goiter and tumor, scrofula, abdominal mass, stomachache, and acid regurgitation. Recommended dosage is from 9 to 15 grams in decoction. And please keep in mind to decoct it before other ingredients.
1) Han Hua Wan from Zheng Zhi Zhun Sheng (The Level-line of Patterns and Treatment). It is formulated with Hai Zao (Sargassum Seaweed), Kun Bu (Kombu), etc. to treat scrofula, goiter and tumor;
2) Wa Long Zi Wan from Wan Shi Jia Chao Fang (Wan’s Heirloom Prescriptions). It is fried, processed with vinegar, and used alone to cure abdominal mass and eliminate phlegm;
3) Wa Leng Zi Wan from Nu Ke Zhi Zhang (Full Knowledge of Gynecology). It is formulated with Xiang Fu (Cyperus), Tao Ren (Peach Seed), Mu Dan Pi (Tree Peony), Chuan Xiong (lovage), Da Huang (rhubarb), and Hong Hua (Safflower) to heal pain and no blood flow during menstruation. Lower abdomen is hard and full when pressed and it is kind of excess pain.
Clinical research of ark shells: 50 cases of burns and scalds, including second degree, have been treated with the combination of ark shell and vegetable oil at the ratio of 1:1. The oil was directly applied to the wounds and wall of them were cured. – Si Chuan Yi Xue (Sichuan Medicine), 1982; 1:44.
Ark shell side effects and contraindications:
Generally ark shell causes no adverse reaction when it is used in the treatments a variety of diseases like gastric and duodenal ulcers. But there were individual cases reported with facial swelling, blood in the urine, cloudy urine, recurrent urinary tract infections and others. Ben Cao Yong Fa Yan Jiu (Studies of The Uses of Drugs in Chinese Materia Medica) says that it shouldn’t be used in the patients with no blood stasis and sputum retention.
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider.