What is the color of the back of the earthworm and what is the color of the ventral surface

Sorrel!!! The little earthworms are pink.

It's all red or pink.

The difference between the belly and back of an earthworm is mainly manifested in the fact that the earthworm has bristles on the abdomen and no bristles on the back.

Earthworms have segmented but not segmented bodies, vestigial verrucous feet, and bristles on the body surface. Hermaphroditic, 1-2 pairs of gonads, reproductive ducts of body cavity origin, rings (clitellum) appear on the body surface when sexually mature, mutual insemination can be done during mating, eggs are laid in the rings, and after falling off, egg cocoons are formed, and they develop directly.

The bristles are simple, 8, sometimes many, arranged in a ring, 1-2 pairs of sperm nests, usually at 10-11 nodes, male reproductive pores one pair, located on 2 or more somites after the posterior sperm nest, i.e. after 14 nodes. A pair of ovaries, located in the 13th segment, with a thicker annular band and less yolk.

The ventral surface is light-colored, with bristles in the middle of most body segments, which play a fixed supporting role and assist movement when earthworms crawl. After the 11 segments, there are dorsal holes at the dorsal line of each segment, which is conducive to breathing and keeps the body moist.

The color of earthworms is red and translucent.

Earthworms, also known as earth dragons, are terrestrial invertebrates of the phylum Annelids. Earthworms are one of the annelids, there are more than 3,000 species of earthworms in the world, and there are more than 200 species in China. There are ringworms, Aisheng worms, heterolip worms, dura worms and other varieties widely distributed throughout the country.

Earthworms dig holes to loosen the soil, decompose organic matter, create good conditions for the growth and reproduction of soil microorganisms, and play a special role in soil improvement, eliminating public pollution, protecting the ecological environment, in material cycle, biodiversity, etc.

Effects on soil physicochemical properties

Earthworm activities are conducive to the sustainable utilization of soil resources by improving soil chemical properties, enriching soil humus, decomposing organic matter synergistically between earthworms and microorganisms, and promoting C, N and P cycles. Earthworms have strong reproductive ability, short reproductive cycle, and developed digestive system, and their soil turning volume cannot be ignored, which greatly promotes the integration of soil and fertilizer.

At the same time, most of the nutrients transformed by the earthworm intestine are closely compounded with the soil and become a nutrient-rich and high-quality aggregate structure in the soil. These aggregate structures have the characteristics of looseness, porousness, strong water stability and more effective nutrients, which improve the aeration and permeability of the soil, the ability to store water and fertilizer, and the efficiency of water resource use.

Earthworm larvae are white, like white threads, as shown in the figure below

Although earthworms are hermaphrodites, they still need to mate for fertilization. The egg cocoons of earthworms are oval in shape and pale yellow, with eggs ranging from 1 to 20. A cocoon of eggs can be produced after a few days during the reproductive season, and several can be formed in succession.

The zygote develops in a cocoon, and the albumin in the cocoon provides abundant nutrients to the embryo.

Earthworms are directly developed, and the fertilized eggs form hollow slippery blastocysts through unequal complete cleavage, gastrulation is formed by invagination, mesoderm bands are formed by end cells, and body cavities are formed by fissure. The time taken to develop varies from species to species, ranging from a week to several months. It takes 2-3 weeks for ringworms and 12-13 weeks for normal worms.

Life expectancy ranges from one year to several years. Some worms can live for up to 6 years, usually reaching sexual maturity after one year.