Are there “water armies” in the spider world?

There are more than 50,000 species of spiders discovered around the world. Among them, there are not only "air forces" such as garden spiders, dish spiders, and funnel-web spiders that weave webs in the air to catch insects, but also "land forces" such as jumping spiders, wolf spiders, and flower-skin spiders that hunt on land. So, are there also "navy forces"? The answer is yes. The fishing spider is one of them.

Fishing spiders are mostly found in mountain streams in southern my country. They either hide by the water or float on the water like water striders, so they can catch small fish or insects in the water at any time.

Xiuxi River is located on a section of the Shajiang River in Pingle, Guangxi. On the stone walls on both sides of the river, you can often see gray-brown or brown-yellow-bodied spiders. They are ferocious by nature and mainly feed on plankton and insects on the water surface. They are also experts at hunting small fish.

The robber spider often extends its two long legs into the water to detect the movement of small fish, just like "Jiang Taigong" fishing and waiting for them to "fall into the trap". Once the small fish swims into the hunting range, the robber spider will suddenly pounce on it, hold the small fish tightly with its two long legs, and drag it into its own cave.

Some robbing spiders will use their rear pair of legs to hold onto floating objects on the water surface, and extend the other pairs to drift with the current. However, when they encounter a suitable target, such as fish, tadpoles or insects, they will quickly pounce on it, first bite the prey with their mouthparts, and then inject venom into its body, causing the prey to become poisoned and unconscious. At this time, the robbing spider will quickly drag it out of the water, and secrete digestive fluid from its mandibular glands into the prey's body to decompose and dissolve its internal organs and muscles. Finally, it will start to enjoy the feast, that is, suck up the delicious "broth".

Fishing spiders have a special ability, which is the ability to float on water. They can not only float on the water, but can even run on it. This is mainly due to the fact that fishing spiders have a very light weight and densely hydrophobic hairs on their toes, which can easily support the surface tension of water.

In addition, there are many excellent "divers" in the "water army", such as water wolf spiders and cunning spiders living in rice fields. They can prey on leafhoppers, rice planthoppers, borers, aphids, rice stem borers and other rice pests.

Water wolf spiders and cunning spiders have different ways of catching pests. Some can weave webs between rice plants to catch food, some patrol the ground between plants day and night to find food, and some can jump to catch pests.

Image source: Xinhua News Agency

Surprisingly, in order to avoid predators, these spiders can stay submerged in water for up to 60 minutes. This is because they are covered with a dense layer of hydrophobic hair that helps capture and retain air, like a portable "oxygen bottle" for them to breathe. Not only that, the hair is also a "protective suit", like a silver "armor" that prevents heat loss underwater and prevents water from entering the spider's respiratory organs.

The "submarine" made by the silver spider is also very unique. The silver spider, also known as the water spider, lives underwater all its life. Although it does not have gills like fish to breathe in water, it has "book lungs" and trachea as thin as paper to breathe in the air.

Silver spiders weave a web like an upside-down teacup among water plants, then swim to the surface, quickly scrape their buttocks with their two hind legs and dive into the water, carrying the air between the villi and the pores of their abdomen underwater and into the spider web, thus forming a bubble chamber like a submarine, in which they live and raise their children. Such a "submarine" looks like a shining silver ball under the sun, hence the nickname.

Silver spiders do not use their webs to hunt. During the day, they rest in the webs and extend their front legs out of the webs to sense the ripples in the water. Once they sense the ripples caused by prey, they will go out to catch them. At night, they pull the spider silk to hunt at a longer distance, and then follow the spider silk back to the "submarine". The "submarine" is where they live for the rest of their lives.

Silver spiders are often found in "water bubbles" on the grasslands of Inner Mongolia and Jilin. The main reason is that there is a plant called "water sponge" in the "water bubbles". It is as thin as a hair and can be up to 2-3 meters long. This is the main material for silver spiders to "settle down". However, since silver spiders are sensitive to environmental changes, due to the influence of land desertification and water pollution, there are fewer and fewer places suitable for them to live.

The real "navy" among the spider's "navy" is the tide spider. They live on coral reefs by the sea. Although their body length is only about 1 cm, their well-developed chelicerae make it easier for them to catch small creatures such as springtails and sandworms.

The tide spider can swim in the seawater and walk on the water surface like a water strider. They choose the hollows on the reef or the shells to build their nests. Before the tide rises, the tide spider will drill into the nest, weave a "door" with spider silk to prevent the invasion of seawater, and use the oxygen stored in the gaps in the nest to survive the high tide period of more than ten hours.

The spider world has all kinds of "army", which can be said to be "different places and different soils nurture different spiders".

Source: Tadpole Musical Notation