PART III
BREEDING OF ABALONE: PRACTICAL EXERCISES
PRACTICAL I
APPEARANCE AND INTERNAL STRUCTURES OF ABALONE
(Haliotis discus hannai Ino
OBJECTIVE: To be able to describe morphological features of the abalone by observing the appearance and internal structures of the abalone.
PROCEDURE:
1.1 Appearance of abalone
Place the abalone in a glass tank to observe their behaviour. Allow them to creep on the bottom and walls of the tank.
A pair of tentacles protrude from the front end of the body. Observe the length and location of the tentacles and touch their tips. Upon disturbance they disappear under the shell, however they reappear after a short interval. These sensitive and chemotactic organs are protrusile.
Immediately below the tentacles, the pair of eyes are visible. The eyestalk is named after its shape. Observe the tentacles of the mantle protruding from beneath the shell. Identify the location and number of tentacles of the upper foot. Count the number of brown spots on the upper foot.
Observe the abalone moving its foot in an undulating and gliding fashion. Observe the abalone grazing on benthic diatoms attached to the bottom of the holding tank, with the aid of its calyx lobe and radula. The calyx lobe and radula are located on the anterior part of the body.
1.2 Shape of the abalone shell
The abalone shell is shaped like an ear and although it is relatively thin it is strong. The shell length is about one-fifth of the width. The spiral is very small. The soft part of the body is broad and wide and occupies most part of the shell.
As for the respiratory pores, only the last two to three stomas are perforated, while old pores are closed to form bosses. The row of respiratory pores and bosses divides the shell into two parts, the upper part which is wide, and the genital slope which has a rough surface and wave-shaped wrinkles.
The abalone shell has a narrow and thickly laid growth-line which is commonly used to calculate the age of the specimen. The outer surface of the shell is blue-brown or ash-brown in colour, however occasionally it may also be red.
The anterior end of the shell is wide and is of an ovate shape. The outer tip is thin, with a sharp edge, while the inner tip is much thicker. The inner tip has a slimy edge.
The inner part of the shell is blue-white or copper-white in colour, with a nacreous lustre.
1.3 Internal organs
Remove the shell from the body by cutting the ligament. While separating the shell from the body, take care to avoid injury to the intestine and other soft organs.
Place the abalone on a dissecting plate, with its foot downwards and its head facing forward. Pour seawater on the plate. Observe the overall body of the abalone and note the mantle structure.
Observe the shape of the tentacles, eyes and mouth located on the head at the anterior part of the body. Identify the tentacles of the mantle and observe the feather-shaped gills and anus. Observe the heart (left side), the spiral part of intestine (left side and posterior end), and the liver (right side). Identify also the ramiform tentacles at the margin of the upper foot and separate them for better analysis.
When the above observations have been carried out, draw the organs on paper, making notes on their location, size and colouration.
Cut off the mantle with the aid of dissecting scissors in order to observe the internal organs.
Observe the shape of the gills and locate the two auricles and atrium.
Separate the gills and observe the ciliary movement under a dissecting microscope.
Separate the muscular mouth and radula. Observe under microscope the pair of calyx lobe and the long radula zone connecting the two lobes.
The radula is a distinctive feature of all gastropods and it is commonly used for their classification. It consists of numerous minute teeth shaped like knives. The radula is usually long and broad in shape. An abalone with a shell length of about 80 mm has a 39 mm-radula with 104 lines of teeth. The middle teeth are rather small with rounded tips and quadrangular bases. The lateral teeth vary in shape while the marginal teeth resemble one another in shape. They are sharp, narrow and relatively long. The uppermost tip is shaped like a surgical spoon with a dentate edge.
Observe the digestive organs of abalone: the gullet, stomach, intestine and anus.
The digestive organ is in the soft tissue of the intestine capsule and therefore rather difficult to identify its shape. Identify the mouth and anus. Then, using a dissecting needle, locate the digestive tube.
The saccate V-shaped stomach can be seen next to the gullet. Microscopic examination will show that the food in the stomach is mainly composed of seaweed fragments. The vermiform appendix and liver are attached to the stomach and the cavity connecting to the liver is placed at the curve of the stomach.
The liver is located on the left side of the ligament. It is well developed and relatively bulky.
The liver is surrounded by the genital gland of the abalone. Remove a fragment of the tissue with the aid of a sharp scalpel and place it under a microscope for detailed observation.
The male has a milk-white genital organ while the female organ varies in colour depending on the stage of development, fully matured organs being usually greenish-brown in colour. The degree of maturity of the genital glands can be identified and classified as follows:
Stage 1 (Granule stage) Granules are being formed but sperm and ovum cannot yet be identified.
Stage 2 (Green stage) The genital gland is not easily dissolved in seawater with many passive and amorphous elementary particles.
Stage 3 (Maturing stage) The genital gland becomes corpulent and most of the eggs are globular in shape.
Stage 4 (Pre-spawning stage) The genital product are released in small quantities.
Stage 5 (Active-spawning stage) About 50 % of the genital glands are released.
Stage 6 (Spent stage) Remaining genital glands can be seen with the naked eye. The mature eggs and sperm are visible by microscopic examination.
The measurement of maturity has a great significance in abalone culture.
1.4 Nervous system
Its central nerve ganglion is placed around the mouth. A little scraping will expose the cerebral nerve ganglion. Abalone also has a pair of nerve nodules (placed at the foot, intestine, etc.) and also a collection of nerves connecting them.
EXERCISE:
After the above observations, follow the instructions below:
Draw the appearance of abalone and make notes on its moving and feeding behaviour.
Draw the shape of the abalone deprived of its shell.
Remove the mantle and observe/draw the shape of the circulatory system, alimentary canal, etc.
Observe the genital gland and identify its stage of maturity.
PRACTICAL II
PREPARATION OF ADULT ABALONE
OBJECTIVE: To be able to select good abalone adults for seed production.
PROCEDURE:
2.1 Selection of adult abalone from the sea
The optimum size of abalone for spawning ranges between 7–9 cm.
The best way to collect abalone is through the use of divers or hookmen. Well-trained divers can catch abalone with minimum injury to the specimen.
The seriousness of the injury inflicted on the abalone will depend on the part of the body injured. Mortality increases when the abalones are injured on the head, intestine sac, ligament or around the foot. Injury may be minimized when hooks are placed around the middle part of the abalone. If injury occurs, blood flow may not be easy to control as it does not coagulate. The collected abalones are then placed into a holding tank for few days, after which the undergo a second selection. After 3–4 days in the tank, injured specimens can be easily detected as the injured part usually becomes swollen and therefore visible. At this stage the broodstock is selected from specimens which have no injury and appear healthy.
The suggested period for catching adult abalone is between March-May and October-November when the water temperature is low. During these periods the abalones are fairly inactive and can be easily caught. In addition, at higher water temperatures injuries inflicted during the catching process infect easily.
At water temperatures above 20 °C, the injured parts become inflamed and serious signs of bacterial infection can be seen at water temperatures between 25–27 °C. At temperatures below 20 °C, bacteria growth is restrained while it increases at temperatures above 20 °C. Compared with that of healthy abalone, the blood of injured abalone when tested will show impurities.
Sulfathiazole is applied in the treatment of a wide range of diseases and contaminations. Animal sulfathiazole is acknowledged for its effectiveness, and is applied in two ways: by reagent soaking and by surface application. When the abalone are soaked in the reagent, the concentration should be 5 % of the filtered seawater. After 2–3 minutes in the reagent, the abalone should be exposed to the air for about 10–15 minutes. The efficiency of the medication depends on the duration of the air exposure. When the temperature is high, exposure time should be shortened. The other method is the application of sulfathiazole on the injured part with the use of a brush or a sprayer. Sulfathiazole may also be injected, but this is not recommended as the needle pore causes bleeding. Treatment should be carried out for one week.
PART IIIผสมพันธุ์ของหอยเป๋าฮื้อ: ฝึกปฏิบัติปฏิบัติฉันลักษณะและโครงสร้างภายในของหอยเป๋าฮื้อ(Haliotis ปลาปอมปาดัวร์ hannai ไอวัตถุประสงค์: เพื่อให้สามารถอธิบายถึงลักษณะสัณฐานของหอยเป๋าฮื้อจะ โดยการสังเกตลักษณะและโครงสร้างภายในของหอยเป๋าฮื้อขั้นตอน:1.1 ลักษณะของหอยเป๋าฮื้อหอยเป๋าฮื้อในถังแก้วสังเกตพฤติกรรมของพวกเขา อนุญาตให้เลื้อยบนล่างและผนังของถังคู่ของ tentacles ป่องจากส่วนหน้าของร่างกาย สังเกตความยาวและตำแหน่งของ tentacles และสัมผัสเคล็ดลับของพวกเขา เมื่อรบกวน พวกเขาหายไปภายใต้เปลือก แต่พวกเขาปรากฏขึ้นอีกหลังจากช่วงเวลาสั้น ๆ อวัยวะเหล่านี้สำคัญ และ chemotactic protrusile ได้ทันทีใต้ tentacles คู่ของตามองเห็น Eyestalk การตั้งชื่อจากรูปร่างของ สังเกต tentacles ของหิ้งเขยิน from beneath shell ระบุตำแหน่งและจำนวน tentacles เท้าด้านบน นับจำนวนของจุดสีน้ำตาลบนเท้าด้านบนสังเกตเป๋าฮื้อย้ายของเท้าในลำบาก และ gliding สังเกตเป๋าฮื้อ grazing บนกับด้านล่างของถังถือ ด้วยความช่วยเหลือของสมองกลีบคาลิกซ์ radula diatoms ธรรมชาติ สมองกลีบคาลิกซ์และ radula ตั้งอยู่บนส่วนของร่างกายแอนทีเรียร์1.2 ทรงเปลือกหอยเป๋าฮื้อเปลือกหอยเป๋าฮื้อมีรูปร่างคล้ายหู และแม้ว่าจะค่อนข้างบาง ไม่แข็งแรง ความยาวเปลือกประมาณ 1 5 ของความกว้างได้ เกลียวมีขนาดเล็กมาก ส่วนอ่อนของร่างกายกว้าง และหลากหลาย และครอบครองส่วนใหญ่ของเปลือกAs for the respiratory pores, only the last two to three stomas are perforated, while old pores are closed to form bosses. The row of respiratory pores and bosses divides the shell into two parts, the upper part which is wide, and the genital slope which has a rough surface and wave-shaped wrinkles.The abalone shell has a narrow and thickly laid growth-line which is commonly used to calculate the age of the specimen. The outer surface of the shell is blue-brown or ash-brown in colour, however occasionally it may also be red.The anterior end of the shell is wide and is of an ovate shape. The outer tip is thin, with a sharp edge, while the inner tip is much thicker. The inner tip has a slimy edge.The inner part of the shell is blue-white or copper-white in colour, with a nacreous lustre.1.3 Internal organsRemove the shell from the body by cutting the ligament. While separating the shell from the body, take care to avoid injury to the intestine and other soft organs.Place the abalone on a dissecting plate, with its foot downwards and its head facing forward. Pour seawater on the plate. Observe the overall body of the abalone and note the mantle structure.Observe the shape of the tentacles, eyes and mouth located on the head at the anterior part of the body. Identify the tentacles of the mantle and observe the feather-shaped gills and anus. Observe the heart (left side), the spiral part of intestine (left side and posterior end), and the liver (right side). Identify also the ramiform tentacles at the margin of the upper foot and separate them for better analysis.When the above observations have been carried out, draw the organs on paper, making notes on their location, size and colouration.Cut off the mantle with the aid of dissecting scissors in order to observe the internal organs.Observe the shape of the gills and locate the two auricles and atrium.Separate the gills and observe the ciliary movement under a dissecting microscope.Separate the muscular mouth and radula. Observe under microscope the pair of calyx lobe and the long radula zone connecting the two lobes.The radula is a distinctive feature of all gastropods and it is commonly used for their classification. It consists of numerous minute teeth shaped like knives. The radula is usually long and broad in shape. An abalone with a shell length of about 80 mm has a 39 mm-radula with 104 lines of teeth. The middle teeth are rather small with rounded tips and quadrangular bases. The lateral teeth vary in shape while the marginal teeth resemble one another in shape. They are sharp, narrow and relatively long. The uppermost tip is shaped like a surgical spoon with a dentate edge.Observe the digestive organs of abalone: the gullet, stomach, intestine and anus.The digestive organ is in the soft tissue of the intestine capsule and therefore rather difficult to identify its shape. Identify the mouth and anus. Then, using a dissecting needle, locate the digestive tube.The saccate V-shaped stomach can be seen next to the gullet. Microscopic examination will show that the food in the stomach is mainly composed of seaweed fragments. The vermiform appendix and liver are attached to the stomach and the cavity connecting to the liver is placed at the curve of the stomach.The liver is located on the left side of the ligament. It is well developed and relatively bulky.The liver is surrounded by the genital gland of the abalone. Remove a fragment of the tissue with the aid of a sharp scalpel and place it under a microscope for detailed observation.The male has a milk-white genital organ while the female organ varies in colour depending on the stage of development, fully matured organs being usually greenish-brown in colour. The degree of maturity of the genital glands can be identified and classified as follows:Stage 1 (Granule stage) Granules are being formed but sperm and ovum cannot yet be identified.Stage 2 (Green stage) The genital gland is not easily dissolved in seawater with many passive and amorphous elementary particles.Stage 3 (Maturing stage) The genital gland becomes corpulent and most of the eggs are globular in shape.Stage 4 (Pre-spawning stage) The genital product are released in small quantities.Stage 5 (Active-spawning stage) About 50 % of the genital glands are released.Stage 6 (Spent stage) Remaining genital glands can be seen with the naked eye. The mature eggs and sperm are visible by microscopic examination.The measurement of maturity has a great significance in abalone culture.1.4 Nervous systemIts central nerve ganglion is placed around the mouth. A little scraping will expose the cerebral nerve ganglion. Abalone also has a pair of nerve nodules (placed at the foot, intestine, etc.) and also a collection of nerves connecting them.EXERCISE:After the above observations, follow the instructions below:Draw the appearance of abalone and make notes on its moving and feeding behaviour.Draw the shape of the abalone deprived of its shell.Remove the mantle and observe/draw the shape of the circulatory system, alimentary canal, etc.Observe the genital gland and identify its stage of maturity.PRACTICAL IIPREPARATION OF ADULT ABALONEOBJECTIVE: To be able to select good abalone adults for seed production.PROCEDURE:2.1 Selection of adult abalone from the seaThe optimum size of abalone for spawning ranges between 7–9 cm.The best way to collect abalone is through the use of divers or hookmen. Well-trained divers can catch abalone with minimum injury to the specimen.The seriousness of the injury inflicted on the abalone will depend on the part of the body injured. Mortality increases when the abalones are injured on the head, intestine sac, ligament or around the foot. Injury may be minimized when hooks are placed around the middle part of the abalone. If injury occurs, blood flow may not be easy to control as it does not coagulate. The collected abalones are then placed into a holding tank for few days, after which the undergo a second selection. After 3–4 days in the tank, injured specimens can be easily detected as the injured part usually becomes swollen and therefore visible. At this stage the broodstock is selected from specimens which have no injury and appear healthy.The suggested period for catching adult abalone is between March-May and October-November when the water temperature is low. During these periods the abalones are fairly inactive and can be easily caught. In addition, at higher water temperatures injuries inflicted during the catching process infect easily.
At water temperatures above 20 °C, the injured parts become inflamed and serious signs of bacterial infection can be seen at water temperatures between 25–27 °C. At temperatures below 20 °C, bacteria growth is restrained while it increases at temperatures above 20 °C. Compared with that of healthy abalone, the blood of injured abalone when tested will show impurities.
Sulfathiazole is applied in the treatment of a wide range of diseases and contaminations. Animal sulfathiazole is acknowledged for its effectiveness, and is applied in two ways: by reagent soaking and by surface application. When the abalone are soaked in the reagent, the concentration should be 5 % of the filtered seawater. After 2–3 minutes in the reagent, the abalone should be exposed to the air for about 10–15 minutes. The efficiency of the medication depends on the duration of the air exposure. When the temperature is high, exposure time should be shortened. The other method is the application of sulfathiazole on the injured part with the use of a brush or a sprayer. Sulfathiazole may also be injected, but this is not recommended as the needle pore causes bleeding. Treatment should be carried out for one week.
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