The *Mauremys annamensis*, commonly known as the yellow-throated turtle in Guangxi and Guangdong, belongs to the family Geoemydidae under the order Testudines. It is widely distributed across regions such as Jiangsu, Zhejiang, Anhui, Guangxi, Guangdong, Hainan, Fujian, and Taiwan, with its range extending into Vietnam. This species is highly valued for its nutritional benefits, ornamental appeal, and medicinal properties.
**1. Morphology and Life Characteristics**
**(1) Physical Features**
The yellow-throated turtle has a small head, smooth carapace with a central groove, and a clear tympanic membrane. Two pale yellow lines run behind the head, while the throat is yellow. The carapace is brownish or dark brown, with a flat plastron that lacks deep engravings. The plastron is yellow, and each scute has large dark spots on the outer edge. A distinct bridge connects the carapace and plastron, and the limbs are flattened with webbed digits and claws. The tail is short and well-proportioned.
**(2) Behavior and Diet**
These turtles are primarily aquatic, inhabiting rivers, rice fields, and lakes. They often move to nearby bushes and grasslands. Their diet consists mainly of fish, shrimp, snails, clams, and worms, but they also consume tender plants. Breeding occurs from May to October, and they hibernate from mid-November to early March. In Guangdong, the breeding season is slightly later, from late April to late August, with hibernation starting in mid-December.
**2. Selection and Breeding of Yellow-Throated Turtles**
**(1) Selecting Breeding Stock**
Yellow-throated turtles reach sexual maturity after more than five years. Wild individuals weighing over 450 grams are typically suitable for breeding. Males have longer carapaces, a concave plastron, and a long tail, while females have shorter shells, a flat plastron, and a short tail. Healthy turtles should be free from injuries, diseases, or deformities. Signs of poor health include cloudy eyes, swollen limbs, or skin inflammation. A healthy turtle should have shiny skin, a flexible neck, strong limbs, and no visible trauma.
**(2) Breeding Management**
Turtle ponds are usually constructed with cement, featuring a 25-degree slope at the bottom. The pond is divided into three sections: a shallow water area (30 cm deep), an activity zone, and a sandy nesting area covered with shade cloth. Aquatic plants like water lilies occupy about one-third of the surface, and the environment should be cool and quiet. Before introducing turtles, the pond must be thoroughly cleaned using disinfectants like bleach (200 ppm) or potassium permanganate (150 ppm). Turtles are often bathed in a solution of potassium permanganate (150 ppm), malachite green (50 ppm), or furazolidone (250 ppm) for 30 minutes to prevent disease.
Breeding stock is stocked at a ratio of 2:1, with 4–6 turtles per square meter. Newly purchased turtles should not be fed immediately due to environmental stress. Feeding begins after three days, using fresh animal organs like fish, shrimp, and poultry, along with fruits and vegetables. Feeding frequency depends on temperature: once daily when above 25°C, and twice daily (morning and evening) when above 26°C.
**3. Spawning and Hatching**
In Guangzhou, yellow-throated turtles begin spawning at the end of April, peaking in May and June, and ending by late August. Each female can lay 1–7 eggs per clutch, with an average of 2.5 eggs. Eggs weigh between 10–20 grams, with an average of 14 grams, and measure 3.41–5.53 cm in length and 1.75–2.67 cm in width.
Spawning occurs at night or during dawn. The female digs a nest with her front legs and uses her hind legs to cover the eggs. After laying, she compacts the sand and leaves the site. Incubation is done in foam or wooden boxes filled with 10 cm of sand, with eggs buried 3–4 cm deep. Sand humidity must be maintained at 5–10%, and the incubation temperature kept between 25–32°C. Humidity is maintained at 80–93% indoors, and hatching takes 54–112 days, with an average of 73.8 days.
**4. Rearing Juvenile Turtles**
Juvenile turtles are housed in pools with a 3/4 water section (20 cm deep) and 1/4 land area, shaded with cloth. Hatchlings weighing 6.4–13 g (average 9.75 g) are placed in special containers until their yolk sacs are fully absorbed. They are then transferred to hatchling pools and disinfected with a 10 ppm potassium permanganate solution. Initially, they are fed boiled chicken or duck egg yolks, gradually transitioning to minced fish or meat.
Stocking density is around 100 per square meter, with water changed every two days. Food is provided on land, and leftovers are removed promptly. Feeding is done twice daily, adjusting based on temperature. After three months, hatchlings grow from 9.75 g to 23.14 g, gaining about 0.149 g per day. Some individuals can reach up to 40 g. Care must be taken to protect young turtles from predators like snakes, rats, and cats.
Hydroxylamine Hydrochloride Basic Information
CAS: 5470-11-1
MF: NH2OH·HCl
MW: 69.49
Gadolinium Oxide Basic Information
CAS: 12064-62-9
MF: Gd2O3
MW: 362.5
EINECS: 235-060-9
Gadolinium Oxide Chemical Properties
Melting point 2330 °C(lit.)
density 7.407 g/mL at 20 °C(lit.)
storage temp. Storage temperature: no restrictions.
form nanopowder
color White
Specific Gravity 7.407
Water Solubility insoluble
Hexamethylenetetramine Basic Information
CAS: 100-97-0
MF: C6H12N4
MW: 140.19
EINECS: 202-905-8
Hexamethylenetetramine Chemical Properties
Melting point 280 °C (subl.)(lit.)
Boiling point 246.7°C (rough estimate)
density 1.33
storage temp. Store at RT.
solubility H2O: 1 M at 20 °C, clear, colorless
form Solid
Hydroxylamine Hydrochloride,Hexamethylenetetramine,Chloro Pre Tadalafil,Isopropyl Acetoacetate,Gadolinium Oxide
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