Can tilapia be cultured in Weihai, Shandong Province?

1. Tilapia can be cultured in Weihai, Shandong Province.

Second, the climate characteristics of Weihai, Shandong

1, Weihai belongs to the continental climate of north temperate monsoon, with obvious changes in four seasons and monsoon advancing and retreating. Compared with inland areas at the same latitude, it has the characteristics of abundant rainfall, moderate annual temperature and mild climate. The continental degree of Weihai is 54. 1%. Being close to the Yellow Sea and regulated by the ocean, Weihai has the characteristics of maritime climate, such as cool in Leng Xia in spring, warm in autumn and warm in winter, small temperature difference between day and night, long frost-free period, strong wind and high humidity.

2. Spring

From March to May, warm air began to be active, but cold air still had considerable influence, which led to frequent movement and alternation of high and low pressure systems and changeable climate. From April to May, strong winds alternate from north to south, which is a windy month all year round. The temperature is low, rising slowly, 2-3℃ lower than that in the inland areas of the same latitude, and the season is delayed by about half a month. Because warm and humid air cannot be transported in large quantities, the precipitation is still very small, accounting for only 14% of the total precipitation in the whole year. Because of the strong wind, less precipitation and large evaporation, spring drought often occurs.

3. Summer

(June-August) Due to the adjustment of the ocean, the temperature is low. June-July is 3-4℃ lower than inland latitude, and August is 65438 0℃ lower. The cool and pleasant climate makes Weihai a famous summer resort. The highest temperature is in August, and the extreme highest temperature in the whole year appears in July and August. With the strengthening of the Pacific high northward, the summer monsoon begins, mostly with the south to southeast wind of grade 3-4, which is beneficial to warm and humid air northward, so there is much precipitation and high humidity, and the precipitation accounts for 59% of the whole year. The flood season begins in late June and early July and ends in early September. Heavy rains are concentrated in July, August and early September, and frequent heavy rains often lead to floods. However, in some years, due to the control of the Pacific high, Shandong Peninsula is stable and inactive, resulting in high temperature, high humidity and sultry weather, resulting in short-term drought. Due to the guidance of atmospheric circulation, typhoons in the Pacific Ocean move northward, often causing heavy rain and windy weather.

4. Autumn

In early autumn (September-165438+1October), the cold air in the north began to be active, but the warm and humid airflow still had some influence, so there was still a lot of rain in early September, and sometimes it rained continuously, which might be hit by a typhoon. The total precipitation in autumn accounts for 23% of the whole year, mostly concentrated in September. From late September to 10, the cold air in the north strengthened and the warm and humid air flow decreased obviously. The temperature is higher in the whole autumn, and it is slightly higher in September than in inland areas of the same latitude, 10-1-2℃. On June 5438+ 10, the weather is clear and the visibility is the best, but autumn drought often occurs. From the middle of 165438+ 10, a strong Mongolian high began to establish and cold air became active. The temperature drops rapidly with a temperature difference of 3℃ every ten days, the number of northerly winds increases, and the winter wind becomes more and more obvious.

5. Winter

(12-February) controlled by the strong Mongolian high pressure, cold air broke out southward continuously, and the climate was dry and cold, mostly northward. Weihai and Yantai are called snow nests. 65438+ 10 is the coldest month in the whole year, and the extreme minimum temperature of the whole year generally appears in 65438+ 10 or early February. The temperature in the whole winter is 2℃ higher than that in the inland areas of the same latitude, and the temperature difference between day and night is small. Seasonal precipitation is the least in the whole year, accounting for 5% of the whole year. From the end of June to May 438+February, due to the influence of the ocean, the local cloudy and snowy weather increased, the amount of rain and snow was more than three times that of inland areas at the same latitude, and the sunshine hours were less.

Growth habit of tilapia

1, tilapia has the characteristics of miscellaneous eating habits, tolerance to hypoxia, intolerance to high and low temperatures and strong reproduction;

Tilapia has a wide range of eating habits, mostly plant omnivores, very greedy and eat a lot; It grows rapidly, especially in its infancy. The growth of tilapia is closely related to temperature. The growth temperature is 16 ~ 38℃, and the optimum temperature is 22 ~ 35℃. It is a euryhaline fish, which can survive in both seawater and fresh water. Resistant to hypoxia, generally inhabiting the lower layer of water, but inhabiting the water layer with the change of water temperature or fish size.

2. The diet of tilapia is mixed

Tilapia is an omnivorous fish based on plants. In tilapia ponds, the contents of digestive tract are mostly organic debris and other plant feeds (such as aquatic plants and commercial feeds), followed by phytoplankton, zooplankton and a small amount of benthos.

3. Tilapia is anoxic.

Tilapia has a strong tolerance to hypoxia, and the asphyxiation point is 0.07 ~ 0.23 mg/L. When the dissolved oxygen in water is 1.6 mg/L, tilapia can still survive and reproduce. When the dissolved oxygen in water is higher than 3 mg/L, the growth is not affected.

4. Tilapia is intolerant of low temperature and high temperature.

The survival temperature range of tilapia is 65438 05 ~ 35℃. When the water temperature is lower than 15℃, tilapia is dormant. The highest critical temperature of tilapia is about 40 ~ 4 1℃, the optimum growth temperature is 28 ~ 32℃, and the breeding temperature of tilapia is above 20℃.

5. Tilapia is very fertile.

Tilapia has early sexual maturity, short spawning cycle, low requirements for breeding conditions when young fish hatch in their mouths, and naturally breed in water with large water area. Tilapia reached sexual maturity in 6 months, and about 200 grams of female fish had about 1000 ~ 1500 eggs. The male fish in the breeding period has beautiful wedding smoke color, and there are two orifices in the abdomen: anus and urogenital orifice, and white semen flows out from the squeezed abdomen. There are three holes in the abdomen of female fish, namely anus, genital hole and urogenital hole. When the water temperature is 18 ~ 32℃, the mature male fish has the ability to dig the nest, and the mature female fish enter the nest to pair, lay mature eggs and immediately put them in the mouth for fertilization. The fertilized egg develops in the female fish's mouth, and when the water temperature is 25 ~ 30, the young fish can hatch in 4~5 days. The young fish leave the mother when the yolk sac disappears and has certain ability.