Geological Highlights: Special Marine Organisms – Sea Snails

because of liking, so focus

Boya Geography

2020.4.12

Introduction:

Cones are very ancient marine organisms, and the cone shell group can be traced back to 50 million years ago during the Cambrian period. In the vast sea, cone shells are really small and insignificant. In special geographical environments, cone shells also randomly adapt like chameleons, living inrocknear cone shells, the color will turn to pale blue.

Cone shells also have special habits, generally after spawning, when the water temperature rises to 20℃ above, it quietly moves to the deep sea’s rock crevices and hiding in the calm water beneath the current, sleeping for one to three months. Until the autumn equinox, when the water temperature drops, it wakes up and recovers activity, becoming ‘summer hibernation”. However, there are also exceptions, tropical common species jade foot cone shells have ‘winter hibernation’ habits.

Cone shells because of medicinal value received the market’s welcome, now cone shells are divided into natural wild cone shells and artificial breeding cone shells.Wild cone shellsusually live in 5-6 meters to 20 meters deep water, with little light, need 3-5 years growth period; artificial breeding cone shells live in 2 meters deep water, with plenty of light, generally only needs 1-2 years to harvest finished products.

Cone shells are fished up and landed on shore, about 6 hours, cone shells will lose their original appearance. Even turn into a pile of water, called: shed skin. This is why it is difficult to buy fresh cone shells, the only way to prevent shed skin is to quickly process it again.

Question:

Ancient people thought cone shells had medicinal value comparable to ginseng, so named cone shells. In the 18th century, China’s tropical cone shells were mainly from northern Australia coast, which was a luxury enjoyed only by officials and wealthy people. Tropical cone shells hide from day to night, when summer water temperature is high, attached to coral reefs ‘summer hibernation”. Every December, Mangassa people start fishing cone shells from Mangassa, then to the north of Australia coast to the east to Cape Perthelia, then return in April from Mangassa, then through Chinese merchants to import into China. Cone shell trade ended in the late 19th century because local governments banned cone shell fishing. The picture shows the Mangassa fishing cone shell route.

(1) Analyze the rationality of Mangassa’s departure to fish cone shells in December and return in April (6 points).

(2) Analyze the purpose of Mangassa processing cone shells into dry cone shells (6 points).

(3) Analyze the reasons why cone shells became luxury goods (6 points).

(4) Analyze the favorable conditions for the development of Mangassa’s deep-sea cone shell fishing (6 points).

Focus on: Indonesia and northern Australia’s natural environment (climate), cone shell’s specialness, industrial location selection.

Analysis and Answer:

(1) Ancient ships have no power, far-sea navigation relies on wind; (2 points) (The picture shows the sea area) because of wind belt, pressure belt seasonal movement, in December northwest wind prevails, in April southeast wind prevails, the whole voyage is smooth and favorable; (2 points) from December to the following year’s April, (the picture shows the sea area) seawater is high, cone shells ‘summer hibernation’ is easy to catch. (2 points)

(2) Cone shells are easily rotten and deteriorated, processing them into dry cone shells is conducive to long-term storage; (2 points) (Compared with live cone shells,) dry cone shells are small in volume, can save ship loading space; (2 points) through processing, improve the economic value of cone shells. (2 points)

(3) From cone shell’s special type, difficulty of breeding, medicinal value aspects. Cone shells have high medicinal value; (2 points) Catching cone shells has short time (cone shell yield is small); (2 points) Fishing, (remote) transportation cost is high. (2 points)

(4) China has a large cone shell demand and a broad market; the development of deep-sea cone shell fishing and catching technology; abundant cone shell resources in northern Australia coast; the favorable policy environment. (Each point is 2 points, you can answer 3 points)

PS, after-school thinking: Special areas of marine life, marine pollution, marine transportation.

PS