| Preliminary study on the system dissection for Tench Tinca tinca(L) |
| Study on the Artificial Propagation of Tench Tinca tinca(L) |
| The Study on Embryonic Development of Tench Tinca tinca (L) |
| Study on the Nursing of the Fry and Fingerling of Tench Tinca tinca (L) |
| Study on the Flesh Content and Nutrition Component of Tench Tinca.tinca (L) |
| Jiaxi Wang1
Shaohua Hu2 Min Guan1 Jie Ren1 Lin zhang1 Zhonghua Han2 Zhen Huang1 Chunyi Wang2 1 Hubei Provincial Fisheries Research Institute, 96 Donghu Road, Wuchang,430071,Hubei,PRC (E-mail:hbssyjs@public.wh.hb.cn) 2 Asian and Pacific Aquaculture Co.Ltd(Wuhan).96 Donghu Road,Wuchang,430071,Hubei,PRC (E-mail:chinafishery@263.net) |
Tench Tinca tinca(L),
belonging to Leucisicinae, Cyprindiae, Cypiniforms, is originally
distributed in Europe. It was first introduced from Czech Public
into China by Hubei Provincial Fisheries Institute in 1999.The paper
reports on the system dissection of Tench and the results comparing
with some other Cyprinformes. The dissection method used in this
study was from Comparative Anatomy Of Fishes written by Qingwen
Meng(1960) and Common Carp Dissection written by Zhi Bin(1960).The
fish was provided by the fishfarm of Hubei Provincial Fisheries
Institute in March,2001. The outline of Tench is a little similar to anguillform. It has 2 short barbells.The head is dark- green, but the body color is yellow-green and becomes lighter and whiter from back to belly. Its eyes are small, and nasal anteriors are covered by a prominent nasal flap, which are different from most other Carps. The body scales are tiny and dense. There are 101~109 scales on each lateral line. There are no spines on fins. There are 22 gill rakers and about 100 gill filaments in the gill arch, which are similar to common Carps. Tench has no oral-cavity teeth, there is a line of pharyngeal teeth on the pharyngeal. The formula of pharyngeal teeth is 5/4.Its bladder has two rooms, the former is smaller than the latter. Tench has no stomach. It intestine connects directly with the mouth. The length of intestine is 1.1~1.3 times of the body length. There are abundant of red muscles in the body, and the length of tail is 0.26~0.32 time of the body. So the fish has strong movement ability. No intermuscular bone is in muscles. The head skeleton is made of 108 bones. The vertebral column usually consists of 38 segments, maybe more or less. It is generally said that there are 21 segments in the thoracic region and 17 segments in the caudal region. The brain of Tench has its characteristic. The cerebellum is half size of the midbrain in volume. In front of the medulla oblongta, there are facial lobe and vagal lobes. On the base of the morphology and characteristics of Tench, we can conclude that Tench is a benthic omnivorous fish with high sense and activity ability .So it can adapt to various environments |
| Jiaxi Wang1
Shaohua Hu2 Min Guan1 Lin zhang1 Jie Ren1 Zhonghua Han2 Zhen Huang1 Chunyi Wang2 1 Hubei Provincial Fisheries Research Institute, 96 Donghu Road, Wuchang,430071,Hubei,PRC (E-mail:hbssyjs@public.wh.hb.cn) 2 Asian and Pacific Aquaculture Co.Ltd(Wuhan).96 Donghu Road,Wuchang,430071,Hubei,PRC (E-mail:chinafishery@263.net) |
| Artificial propagation of Tench has gotten success
in China in 2001.We have obtained about 1,600,000 eggs and incubated
more than 100,000 fries. 1 The maturation period of Tench is 2 years. But the best brood stock used for artificial propagation should be more than 400g in weight and be about 3 years age or more. 2 Tench can lay eggs under the natural condition, so male brood stocks must be separated from the females. Brood stock should be fed with compound pellet with protein contents no less than 25%. 3 The best propagation time of Tench is from May to August in China .The spawn temperature is 18~ 30.5℃ , but 22~27℃ is the best. 4 Common Carp hypophysis (PG), human chronic gonadotrophin (HCG) and Luteinizing hormone-Luteinizing release hormone (LH-RH) adding DOM could all be used as spawn-inducing agents.The ecbolic effect of these three spawn-inducing agents is according to the following order: PG>LH-RH+DOM>HCG (82%>64%>43%) 5 The insemination rate of artificial fertilization is often more than 90 percent, which is higher than that of natural fertilization. Because of the low maturational degree of male fish and little soft roe, there must be a previous inducement process before fertilization. 6 The eggs incubation in cement pools with slow flowing water at water temperature of 22~27 ℃ takes about 2 days; The hatching rate is about 28~85%; The newly hatched fry is 3.8~3.9mm of total length whose ability to move is limited. Most of them “hung” passively by means of their adhesive glands on the walls of the jars or submerged affix objects, a minor part of them are not “hung” but lie on the bottom of the jars .The yolk is mostly absorbed and the bladder is filled with gas 3 days after hatched .Then the fry enter mixed nutrient period. The yolk is absolutely absorbed 7 days after hatched. |
| Jiaxi Wang1
Shaohua Hu2 Jie Ren1 Zhonghua Han2 Min Guan1 Zhen Huang1 Lin zhang1 Chunyi Wang2 1 Hubei Provincial Fisheries Research Institute, 96 Donghu Road, Wuchang,430071,Hubei,PRC (E-mail:hbssyjs@public.wh.hb.cn) 2 Asian and Pacific Aquaculture Co.Ltd(Wuhan).96 Donghu Road,Wuchang,430071,Hubei,PRC (E-mail:chinafishery@263.net) |
| This paper describes the development of the Tench
Tinca tinca (L) during the embryonic period. The eggs are obtained
by artificial fertilization. The egg is round and yellow-green.Their
mean size before activation and water intake is 0.79±0.01mm. After
fertilization and when discharged into water, the eggs develop a rather
voluminous and vitelline space, the mean size increases to 1.44 times. Under the condition of our experiment ,at the mean water temperature of 24.5℃,the embryonic period of development ,starting with the moment of fertilization and ending with the incubation stage up to the peak hatching ,lasts 46 hours by 25 minutes .lasts 58.5 hours at the mean water temperature of 21℃ .According the remarkable morphologic characteristic, the embryonic development can be divided into six periods. The water temperature during the incubated varied between 21.8 and 27℃.The blastodisc appeared in the 40th minutes after fertilization. In comparison with other teleost fishes, the blastodisc is relatively large, making up 1/3~1/2 of the yolk volume .The cleavage period lasts 1.5 hours and takes place between the 2nd and 4th hour of the development .The first blastomeres is larger than the yolk volume .The final stage of this period, the blastodisc is cleaved into small-celled morula , distinctly protruding above the yolk sphere .The blastula period took place between the 4th and 5th hour. The subsequent 2 hours is gastrulation. From the 8th to 15th hours the embryo entered the neurulation and organgenesis period .The beginning of the origin of the tail bud takes place at 17 hours by 10 minutes, which marks the development of caudal part and its segmentation .At the age of 46 hours, the first embryos begins to hatch; Half of the embryos hatched at 46 hours by 25 minutes. Newly hatched fish is 3.8~3.9mm of total length, whose movement is limited. Most of them “hung” passively by means of their adhesive glands on the walls of the jars and submerged affix objects, the others are not “hung” and lie on the bottom of the jars .The yolk is mostly absorbed and the bladder is filled with gas 3 days after hatched ,then the fry entered mixed nutrient period .The yolk was absolutely absorbed 7 days after hatched. |
| Jiaxi Wang1
Shaohua Hu2 Min Guan1 Zhonghua Han2 Lin zhang1 Jie Ren1 Zhen Huang1 Chunyi Wang2 1 Hubei Provincial Fisheries Research Institute, 96 Donghu Road, Wuchang,430071,Hubei,PRC (E-mail:hbssyjs@public.wh.hb.cn) 2 Asian and Pacific Aquaculture Co.Ltd(Wuhan).96 Donghu Road,Wuchang,430071,Hubei,PRC (E-mail:chinafishery@263.net) |
| The paper describes the results of nursing of fry
and fingerling of Tench Tinca tinca (L). Nursing of the fry: cement poor, nursing trough, net cage and pond are adopted to nurse the fry of Tench. 1. Nursing in cement poor: The pool is two square meters in area, and one meter deep. Different densities are used from 400 to 2000 fries of Tench in each square meter. The fries are fed with soybean milk after placed in cement pool. One month after rearing, the fries reach 2.5--3.5cm in body length with an average survival rate of 92.5%. 2 Nursing in trough: 1500 fries are placed in each trough which feed with yolk and soft compound pellet with a protein content of 41.2%. 25 days later, the body length reaches 1.5--2.5cm.The average survival rate is 83.5%. 3. Nursing in net cage: The net cages (1.6 square meters) are put into a pond with plenty of plankton. 1000 fries are placed in each net cage. One month later, the body length reaches 3-4cm. The survival rates of feeding group and control are 87% and 80.95% separately. 4. Nursing in pond: The best area of the pond used for nursing fry is from 1 to 3 mu. 30000--50000 fries are placed in each mu. No.1 pond without fertilized and fed with soybean milk and soft compound pellet with a protein of 41.2% after fry stock, No.2 pond fertilized to multiply plankton before fry stock. One month after rearing, the body length is 3--5cm .The average survival rate of the No.1 pond (81.2% ) is higher than that of No.2 pond (74.4% ). To improve the survival rate of nursing, we should pay great attention to the following steps: 1.The hatched fry must be cultured 3 or 4 days before putting into the pond; 2. The pond should be no big zooplankton before putting fries; 3. The pond should have zooplankton enough for the fries; 4. Keep the culture water fresh. Nursing of Fingerling: cement pool and pond are adopted to culture the fingerling of Tench: 1. Nursing in cement pool: The pond is 25 to 80 square meters in area where 60--80 fingerlings with 3.2--3.7 cm in body length are placed in each square meters . The fingerlings are fed with soft compound pellet (36.1% protein). After three month rearing, the average body length is over 12.5cm and the average survival rate is 93.5%. 2. Nursing in pond : The area of pond is 2—5 mu , 2000--2500 fingerlings with 3.2—3.6cm in body length are placed in each mu. The fingerlings are fed with soft compound pellet (36.1% protein). After three month rearing, the average body length is 12--16cm and the average survival rate is 83.7%. There are five keys steps about the culture of the Tench fingerlings as follows: 1.Stock density should be suitable; 2. Keep plenty of zooplankton through the whole nursing period; 3. To have some aquatic plants in the habitat will be better; 4.Keep the culture water fresh; 5. Disinfect water periodically to prevent bacterial disease. |
|
Jiaxi Wang1 Shaohua Hu2 Min Guan1
Lin zhang1 Zhonghua Han2 Jie Ren1 Zhen Huang1 Chunyi Wang2 1 Hubei Provincial Fisheries Research Institute, 96 Donghu Road, Wuchang,430071,Hubei,PRC (E-mail:hbssyjs@public.wh.hb.cn) 2 Asian and Pacific Aquaculture Co.Ltd(Wuhan).96 Donghu Road,Wuchang,430071,Hubei,PRC (E-mail:chinafishery@263.net) |
| This paper provides the flesh content and nutrition
of Tench. Besides comparison with some fresh-water fish .The result
is as following : 1 The determination of flesh content was carried out by “weighing method”, the flesh content of Tench is 70.7%.It is more than that of common carp (63.5～?9.1%) and crucian carp (62～65.4) and shows a remarkable difference. 2 The flesh protein was determined by “1030 auto-determine machine”. Result: Protein content of Tench was 18.85% which was remarkably more than that of black carp (15.8%),grass carp (15.5%),bighead carp (15.3%), crucian carp (14.4%),common carp (17.3%),river catfish (15.43%),channel catfish (16.3%),African catfish (15.58%),pelteobagrus fulvidraco (14.9%),mutton (11.1%), and egg(14.7%). 3 The fat determination was done by extractive distillation. Result: The fat content Tench was 1.73% which was more than that of grass carp (1.4%),bighead carp (0.9%),pelteobagrus fulvidraco (0.93%),crucian carp (1.03%) and river catfish (1.11%).It was less than that of black fish (2.62%),channel catfish (2.99%) and African catfish (3.59%). 4 The amino-acid was determined by “835-50 auto-analysis machine”. Result: The nutritive value of Tench was very high .The total content of amino-acid was 18.03%.It was more than that of mandarin fish. And the total content of four kind of amino-acids (we called“ fresh taste amino acids”) was 6.97% .It was higher than that of channel catfish (6.36%),catfish (5.35%),pelteobagrus fulvidraco (5.3%) and African catfish (5.52%).First and last, the Tench was high in nutrition and delicious. |