CATDOLL : CATDOLL: Common species of apple snails

Pomacea bridgesii (Mystery Snail, Ivory Snail)

It is a close relative of the Pomacea canaliculata (Pomacea canaliculata), named by Reeve. The eggs of this snail are orange, and turn light pink in the later stage. The young snails inside are the same as the young snails of the Pomacea canaliculata at first, but after a few days, they turn into bright colors. The color of the body length from 1 cm to the adult snail varies depending on the species. Common species include: purple snail, pseudo-Pomacea canaliculata, white ivory snail, pseudo-gold snail, purple mystery snail, blue mystery snail, white mystery snail, etc.

Pomacea canaliculata (Pompanilla snail, Golden snail)

The golden apple snail is a mollusk of the family Apple Snails. It is large, has a wide range of diets, is highly adaptable, grows and reproduces quickly, and has a high yield. It is a delicacy on the table. It was introduced to China in 1981 and is currently listed as one of the first invasive alien species in China. Eating insufficiently heated golden apple snails may cause parasites such as Angiostrongylus cantonensis to infect the human body.

It has been listed as one of China's first batch of invasive alien species.

It was introduced to China in 1981. Its meat is tender and delicious, rich in protein, carotene, multiple vitamins and minerals, and is a delicacy on the table. Due to its low fat content, it is a high-quality tonic for patients with hypertension and coronary heart disease. In addition, it is also a feed for some precious aquatic animals. The golden apple snail is large, has a wide range of diets, strong adaptability, fast growth and reproduction, and high yield. It is cultivated in various parts of China. Eating insufficiently heated golden apple snails may cause parasites such as Guangzhou roundworms to infect the human body.

Angiostrongylus disease is caused by parasitic nematodes in the heart and lungs of rodents that parasitize the human central nervous system. Meningoencephalitis can occur. Eating raw or undercooked golden apple snails can cause infection, which can cause symptoms such as headaches, fever, and stiff neck. In severe cases, it can cause dementia or even death. Therefore, when eating golden apple snails, be sure to heat them thoroughly.

The golden apple snail belongs to the family Ampullariidae and the genus Pomacea. Known for its "golden shell", the golden apple snail [Pomacea canaliculata Lamarck] is one of the main pests in rice production. In 1989, the Food and Agriculture Organization of the United Nations estimated that the loss of rice production due to this pest was equivalent to 1% to 4% of the rice-planting area in the Philippine Islands, resulting in huge production losses.

To control this pest, many farmers use large amounts of synthetic molluscicides that are expensive, have a broad spectrum of activity and are harmful to non-target organisms, including humans.

This approach provides additional information on the management of golden apple snails, which contains a lot of new information to reduce the misuse of molluscicides. The biology of golden apple snails is discussed in detail, including several techniques that farmers use to control golden apple snails on their farms.

A new recipe for treating apple snails is now being developed, which is a water-free, odorless, long-life chicharon (cracker) product that can be used as an ingredient in other recipes.

We hope this approach will help our technicians, extension workers, and farmers better understand this natural, widespread strategy for managing golden apple snails.

The Golden Apple Snail [Pomacea canaliculata Lamarck], commonly known as the "golden shell", was introduced to the Philippine Islands between 1982 and 1984. The snail originated in South America (Brazil and Argentina) and was introduced to the Philippine Islands via Taiwan. The Golden Apple Snail has high nutritional value, is edible for humans and animals, and has high economic benefits, so it spread quickly. However, a few years after its introduction, the Golden Apple Snail became a major pest of rice.

Of the 3 million hectares of rice fields in the Philippine Islands, 1.2 to 1.6 million hectares are infested by golden apple snails. In 1990, P212M was sprayed to control this pest. In 1986, the first record of golden apple snails infesting about 300 hectares of irrigated rice fields in the Cagayan Basin was that they were severely infested. They have become a major pest of rice in the area. Since then, the area of ​​damage caused by golden apple snails in rice fields has become larger and larger, and has developed into a national pest.

- The reproductive rate of golden apple snails is high and they can live for 2-6 years

- The shell is brown and the flesh is creamy white to golden pink or orange

- Individual size depends on food utilization

- The most damaging period is when the shell length increases from 10mm (about the size of a corn seed) to 40mm (about the size of a ping-pong ball)*

- The operculum of the female golden apple snail is concave, while that of the male is convex.

- The shell of the female adult curves inwards, while the shell of the male curves outwards*.

* Based on research by Masters students Dela Cruz, RC Joshi, and AR Martin

Transplanted rice is most susceptible to damage from the time the rice seedlings are transplanted to 15 days after transplanting and from 4 to 30 days after direct-seeding rice.

The golden apple snails damage the base of the rice seedlings, and even destroy the rice seedlings in an entire rice field overnight. There are faint hills and damaged leaves floating on the water.

Life History

The eggs are laid at night on any vegetation, ridges and objects above the water (such as twigs, stumps, stones, etc.). The egg mass is bright pink to red, turning light pink when it is about to hatch. The egg hatching period is 7-14 days.

Juvenile snails grow and mature quickly. Juvenile snails feed on mixed vegetation around the year-round. Males can mate for 3-4 hours a day. Golden Apple snails reproduce very quickly, producing 1,000-1,200 eggs a month, so eliminating egg masses is a very effective control strategy.

Ponds, swamps, irrigation land, canals and wetlands During the dry season, golden apple snails bury themselves in the moist soil and hibernate for 6 months, becoming active again when the rainy season arrives. They can survive adverse environmental conditions such as pollutants in the water or low oxygen levels.

Feeding habits and host range

Apple snails feed on a wide range of plants, such as algae, Azolla, Duckweed, Water Hyacinth, rice seedlings, and other succulent leafy plants. Apple snails prefer soft, tender plant tissues because they use their rough tongues to break up the surface of the plant. They will also feed on any decomposing organic matter.

Naturally occurring biological control agents

Red ants eat apple snail eggs, ducks eat snail meat and young snails, apple snails are cooked into dishes, people eat snail meat, and field mice bite snail shells and eat snail meat.

Governance Strategy

During the soil preparation stage

Catch by hand in the morning and afternoon before final tillage when the snails are most active and easiest to spot.

Use plants that are toxic to apple snails such as eye bean (twig) [Entada phaseikaudes K Meer], tubangkamisa (leaf), sambong (leaf) [Blumea balsamifera], tuba-tuba (leaf), gabihan (leaf) [Monochoria vaginalis], tobacco leaf Nicotiana tabacum L calamansi (leaf) [Citrus microcarpa Bunge], tubli (root), makabuhay (leaf) [Tinospora rumphii Boerl] and chili (fruit).

Other plants reported to be toxic to Apple snails include Calatropis giganta, Azadirachta indica and asyang [Mikania cordata]. Use of these plants is highly recommended before transplanting rice. A simple method is to dig trenches to restrict the activity of Apple snails and place some leaves of the above plants.

Collect Pomacea apple snails using attractants such as Colocasia esculenta, Musa paradisiaca L., Carica papaya L., morning glory and old newspapers. During the final tillage, dig trenches (at least 25 cm wide and 5 cm deep) in the paddy field by dragging large bags filled with heavy objects. The distance between the trenches is 10-15 cm. Also, dig small trenches (25 cm wide and 5 cm deep) along the edge of the paddy field.

Place a wire or bamboo net at the main irrigation water inlet and outlet to prevent the entry of larvae and adults of the golden apple snail. This method can also be used to collect golden apple snails.

Rice transplanting process

Sowing seeds at a standard speed and distance allows the rice plants to grow strong stems.

If the snails are a serious problem, transplant early-maturing rice varieties with a seedling age of 25-30 days. In the rice-growing areas of the Cordillera highlands, late-maturing rice varieties with a seedling age of 30-35 days can be used.

Place bamboo stakes in water areas of rice fields or near ditches to attract adults to lay eggs. This method makes it easy to collect large numbers of egg masses and destroy them.

Maintain shallow paddy water (2-3 cm deep) for 3 days after transplanting

Occasional irrigation of rice fields can limit the movement and feeding activities of golden apple snails.

The collected snails are eaten as vegetables or crushed and fed to ducks and pigs. They are very easy to collect using plants such as gabi, papaya and morning glory leaves as attractants.

Use rice varieties with strong tillering ability that are least favored by Pomacea apple snails, such as PSB Rc36, Rc38, Rc40, and Rc68.

【Species name】Pomacea canaliculata

【Scientific name】Pomacea scalaris

【Named by】 Orbigny, 1835

[Classification] Shellfish, Mollusca, Gastropoda, Mesogastropoda, Apple Snails

Appearance characteristics

The shell is slightly oval, dark brown, with a flat shoulder, a small spiral, a round shell mouth, and a small umbilicus. Apple snails love to eat all kinds of aquatic plants. If there is a lack of food in the water, they will crawl out of the water and nibble on the green plants on the shore. Both the golden apple snail and the ladder-shaped golden apple snail are dioecious, and they lay eggs about a week after mating. During mating, the male snail crawls on the female snail's shell, and the male snail's penis sheath turns out and inserts into the female snail's female hole. Spawning occurs after sunset. When laying eggs, the female snail crawls out of the water and lays eggs more than 10 cm above the water surface. After laying eggs, it dives back into the water. The egg particles are about 2 mm in diameter and are bonded to each other by mucus. After drying, they are fixed into grape-like red egg masses, ranging in length from 2 cm to 7 cm and about 1.5 cm wide. After mating, the ladder-shaped golden apple snail also crawls out of the water to lay eggs. The egg mass is dark yellowish brown and larger than that of the golden apple snail, with a diameter of 2.5-3mm. The egg mass is covered with mucus secreted by it, unlike the egg mass of the golden apple snail, where each egg can be counted. The incubation period of the two golden apple snails is about 2 weeks. After hatching, the young snails eat the egg shells and fall into the water to continue growing. After about 50 days, they are mature and can mate and lay eggs.

Distribution

Worldwide distribution

Distributed in freshwater or semi-fresh brackish water in the northern and southern hemispheres, tropical and subtropical regions.

Habitual environment

Habitat: Lakes, ponds, ditches and other still waters. Inhabits the edge of the water at a depth of 10-100 cm, with a suitable water temperature of 25-30 ℃. The ladder-shaped apple snail seems to prefer living in clear, slightly flowing waters than the apple snail. The shell of the large horn snail is flatter than that of the Pomacea species, white with black stripes or yellow. It has an operculum. The eggs are mass-shaped, white, and trapped inside by a transparent substance.