CATDOLL : CATDOLL: River lice?

The river lice refer to the water fleas commonly known as water lice.

Daphnia: A crustacean of the order Cladocera, subclass Branchiopoda, with about 450 species distributed worldwide. Most are found in freshwater, a few in the sea. The most common species is Daphnia, found in ponds and rivers throughout Europe and North America. Daphnia are small, about 0.5 to 3.0 mm (0.02 to 0.12 in) long. The head is exposed outside the carapace, and the antennae are large. The carapace is divided into two parts, covering all or most of the trunk and abdomen. However, the Leptodora, which can be up to 18 mm long, has a carapace that degenerates into a small brooding capsule. Most Daphnia swim by powerfully striking the water with their large antennae. The continuous striking of the antennae causes the Daphnia to swim with a unique jumping and sinking motion. Except for a few predatory species, most use specialized thoracic limbs to filter tiny organic particles from the water. Daphnia are food for fish. For example, in the five Great Lakes of North America, Daphnia provide the basic food for almost all economic fish and relatives.

Daphnia are small insects that live in stagnant water and feed on microorganisms. They swim using strong, forked antennae and are an important food source for fish and other insects.

Water flea (Daphnia) is an invertebrate belonging to the phylum Arthropoda, class Crustacea, subclass Branchiopoda, family Daphnia. It is called "Daphnia". It is 1 to 3 mm long. It has two shell valves outside the body, with a ridge connecting the back. There are sharp spines (shell spines) extending from the rear end. The head extends out of the shell, with a distinct and sharp snout. The compound eyes are large and obvious, and can rotate continuously. There is a simple eye between the compound eyes and the first antennae. The first antennae under the snout are short and cannot move; the second antennae are short and small, and the second antennae are short and small, and the second antennae are short and small. The antennae are well developed with eight or nine swimming bristles. There are 3 to 4 ventral processes on the dorsal side of the abdomen, the front one is particularly developed, and it extends forward. The rear abdomen is slender and gradually tapers backward. There are 5 pairs of thoracic limbs, and the tail is claw-shaped. The male is smaller, and the dorsal margin of the shell is straight. The snout is short and blunt or absent. The ventral process is degenerate. The first antenna is long and movable, with long flagella. The first thoracic limb has hooks and flagella. Daphnia uses antennae The bristles on the worms move the water upward and forward; when the antennae are raised, the body sinks, as if jumping in the water. In spring and summer, only females can be seen. They reproduce parthenogenetically and produce eggs called "summer eggs". They are smaller, thinner in shell, less in yolk, and can develop directly into adults without fertilization. Most of these adults are females, and then parthenogenetic reproduction. Therefore, they can reproduce in large numbers in a short period of time and appear red, so they are called red worms. In autumn, some small male worms hatch from summer eggs and begin to reproduce sexually. The eggs they produce are called "winter eggs". Winter eggs are larger than summer eggs, with thicker shells and more yolk. Fertilized winter eggs, also known as "dormant eggs", survive the severe cold or dry environment and develop into new females in the spring of the following year when the temperature is higher. Except for a few that live in seawater, most of them are the most common zooplankton in various freshwater areas and are excellent bait for fish.

Daphnia refers to two major types of aquatic zooplankton, namely, cladocerans and copepods. They are rich in nutrition, easy to digest, and are a palatable bait for fish fry and fingerlings. Artificial cultivation of Daphnia is low-cost for feeding fish, fast-growing fish, and good for increasing production.

1. The water beetle, also known as the water beetle, river beetle, and bear bug, belongs to the Hemiptera suborder, Betelgeuse family, and is a large aquatic insect. It has a small head and a flat and wide body. It lives in water, and its breathing tube is at the end of its abdomen. It feeds on small fish and insects in the water. It is ferocious and can catch fish larger than itself, so it is called the "water tyrant". The female insect lays eggs on the back of the male insect until the larvae hatch.

2. Dytiscidae

Dytiscidae

predaceous diving beetle

Overview

Also known as diving beetle or true water beetle.

A carnivorous, aquatic beetle of the family Dytiscidae in the order Coleoptera. There are more than 4,000 species of beetles, and their prey ranges from insects to fish larger than themselves. They are flat and oval in shape, ranging from 1.5 to more than 35 mm (0.06 to more than 1.4 in) in length. They are adapted to the aquatic environment, with flat and long hind legs and hairs to increase the surface area, which is conducive to floating and swimming. There is a valve under the top of the dorsal elytra to facilitate breathing. When at rest, they tilt their heads underwater, lift the ends of their elytra, and expose the valve to breathe. Before preparing to dive, they store air under their wings for underwater breathing. Their bodies are streamlined, and some species of males have suction cups on their front legs, which they use to lie on the smooth back of the female beetle during mating.