Tortoise with Green Hair

Tortoise with Green Hair

　　The tortoise with green hair is an ornamental animal that makes for a unique desk decoration. Especially when kept in a white porcelain bowl filled with clear water, its "hair" appears even more vibrant and lovely, a delightful sight to behold. The tortoise with green hair originates from the shaded areas of mountain streams on Yu Mountain. A poem by Qin Huaihai goes, “A turtle hides in the watery depths, and all its hair turns green.” Among these turtles, those with ivory-colored shells, white heads, and red eyes are considered especially precious. Those who raise them must diligently clean them regularly. The water used should be fresh or from mountain streams; if exposed to bleaching powder water, the hair will definitely fall off and rot. In spring, when it warms up, take it out of the basin. In early summer, feed it fish and shrimp daily. By early winter, it begins hibernation, at which point it should be placed in a basin or jar—remaining still and not eating. Come next year’s Qingming Festival, take it out again, placing only one per container; housing multiple in one vessel will cause them to jostle and their hair to fall out without regrowing.

　　The tortoise with green hair, known in ancient times as the divine turtle, is an organic fusion of green algae and a turtle. An authentic tortoise with green hair is created by inoculating the shell of a yellow-margined box turtle, flat-shelled turtle, or eyed turtle with the base branch algae, resulting in green hair that grows to over 4–5 cm in length. The “green hair” of the tortoise with green hair is actually the tuft-like, filamentous base branch algae.

　　Base Branch Algae: Base branch algae belong to the phylum Chlorophyta, class Chlorophyceae, order Cladophorales, and family Cladophoraceae. The plant body of base branch algae is upright and filamentous, branching at the base. The organism is made up of multiple cells, which are cylindrical in shape, with relatively thick cell walls and netted chloroplasts growing near the perimeter of the cell wall. There is one or more cell nuclei, along with a large vacuole. The base cell has pseudorhizoid-like protrusions at the end, which allow it to attach and parasitize the back of a turtle, thus forming the “green hair.” Base branch algae is a perennial algal plant that thrives in warm waters and is found in rivers, lakes, streams, and wells, attaching itself to calcium-rich surfaces such as turtle shells.

　　I. Selectable Turtle Species

　　In China's natural environment, there are 23 species of freshwater turtles. Generally speaking, any freshwater turtle can be used to cultivate a tortoise with green hair, as long as the conditions for green algae growth are met—but they must fulfill the following two criteria:

　　1. Base branch algae or turtle-back base branch algae are aquatic algae plants, so a power source must be available.

　　2. The water where the turtle lives must contain free-swimming spores of base branch algae or cladophora.

　　Commonly cultivated tortoises with green hair in China usually use species such as the Chinese pond turtle, yellow-margined box turtle, flat-shelled turtle, four-eyed turtle, and golden-headed box turtle, among which the yellow-margined box turtle is the most frequently used.

　　II. Selection of Algal Species

　　Whether the correct algal species is chosen is key to ensuring the successful cultivation of a tortoise with green hair. Therefore, before beginning the cultivation process, it is essential first to understand what the “green hair” on the tortoise actually is. Scientific research has found that the “green hair” on the tortoise with green hair consists of Basicladia crassa and Basicladia chelonum, both belonging to the phylum Chlorophyta, class Chlorophyceae, order Cladophorales, and family Cladophoraceae. The base branch algae are emerald green in color, resembling aquatic jade, with thick, sturdy filamentous strands that are not easily broken. These are typically found in rivers, lakes, streams, ponds, and mountain streams in the wild but are relatively scarce. However, they are more commonly found attached to stones in mountain stream beds, well walls, boat hulls, and similar surfaces. While many various types of algae grow abundantly in nature and can also attach to a turtle’s carapace, some have thin and brittle filaments, while others live attached during their juvenile stage and then float freely in later stages. Such algae are unsuitable for cultivating a tortoise with green hair. Therefore, correctly identifying the algal species is a crucial step in the selection process.

　　III. Preparations for Cultivating Algal Species

　　1. Containers

　　Clay pots or porcelain jars may be used, but regardless of the type chosen, the inner walls should be smooth and free from rough spots or decorative elements that might damage the green algae. The size of the container should be suitable for the turtle to move around freely inside.

　　2. Selection and Rearing of Turtles

　　Turtles selected for breeding a tortoise with green hair should be healthy, actively feeding, with no damage to their carapace or plastron, and able to quickly sink to the bottom when placed in water. The size depends on need. If starting with a common turtle, a female should be chosen because males tend to emit a fishy odor and are not ideal. Before inoculation, the turtle’s shell should be thoroughly cleaned, especially the carapace and plastron, removing any miscellaneous algae—this can be done by soaking in an 8 mg/L copper sulfate solution for 30 minutes, followed by a thorough rinse with clean water. Finally, soak in a 2 mg/L - solution for 30 minutes. After cleaning, the turtle should undergo enhanced feeding—fed twice a day—and then fasting for 1–2 weeks before inoculation to ensure all feces are expelled and avoid water contamination during the process.

　　3. Treatment of the Turtle Shell

　　Before inoculation, the carapace and plastron should be treated by sanding them with a grinding wheel or sandpaper to make the surface rough, though care must be taken not to damage the outer layer excessively to prevent inflammation or other adverse effects.

　　4. Water for Inoculation

　　The best water for inoculation is water from tanks previously used to house tortoises with green hair, which should be allowed to settle and filtered to remove impurities. If unavailable, well water or tap water that has been left to sit in the sun can also be used. The ideal pH of the water is 7.5–9.5.

　　5. Cleaning the Algal Species

　　Before inoculation, any miscellaneous algae on the base branch algae must be cleaned off, and organisms such as ciliates, rotifers, and chironomid larvae should be removed with tweezers. This is because some base branch algae segments are rootless, fragmented, or consist of fresh green juveniles that do not form sporangia but reproduce via budding.

　　IV. Timing of Inoculation

　　Base branch algae are aquatic plants, and their growth rate is influenced by factors such as light and water temperature. The spores of base branch algae are released within a minimum water temperature of 13.5°C, a maximum of 28.5°C, and an optimal range of 20–24°C. Therefore, the best time to inoculate for cultivating a tortoise with green hair is during spring and autumn.

　　V. Inoculation Methods

　　There are many methods for inoculating base branch algae in China. Below are some of the simplest and most effective ones:

　　1. Natural Inoculation Method

　　The natural inoculation method involves placing a tortoise with green hair together with a turtle to be cultivated. The spores released by the algae swim freely in the water and may attach to the carapace of the turtle being cultivated.

　　The specific method is as follows: divide a larger container into 4–5 small compartments using metal mesh, place the green-haired turtle and the turtle to be cultivated inside. After 2–3 months of cultivation, if short green fuzz begins to grow on the back of the turtle to be cultivated, it should be immediately separated for individual care. The downside of this method is that it takes a long time.

　　2. Nutrient Solution Soaking Method

　　Retain the water used for cultivating green-haired turtles, let it settle for 24 hours, then use a rubber tube to suction out the sediment at the bottom. Discard two-thirds of the upper layer of water, and soak the turtle to be cultivated in artificially prepared nutrient solution for 24 hours to promote the regrowth of green algae.

　　The method for preparing the nutrient solution is as follows: take one plant of white grass root, 1 gram of white sugar, 1 gram of white ginseng, and 5 grams of fish scales (preferably blackfish scales), grind and crush them, then mix with water until evenly blended. Place a clump of green algae in the container, roughly the same size as the turtle’s back. During this period, do not change the water or feed the turtle. After 10 days, change the water every 2–3 days, keeping the water temperature difference within 3 degrees Celsius. Using this method, green algae can be cultivated within one month.