Are marine annelids similar to mice? Sea mouse (lat. Aphrodita aculeata) Sea mouse fish

The walkers leave entirely (c).

Type: Annelids - Annelides,
Class: Polychaetes - Polychaeta
Order: Phyllodocus - Phyllodociformes
Family: Aphrodite - Aphroditidae
Aphrodite australis- Aphrodite motley
Aphrodite aculeata - sea ​​mouse

Aphrodite aculeata- Sea mouse

A large class of predominantly marine annelids, numbering at least 10,000 species. The body of polychaetes is clearly divided into a small head lobe - the prostomium and a long body with numerous segments bearing special processes - parapodia - on each side. At the posterior end of the body there is a small anal lobe - pygidium. Parapodia in the vast majority of cases bear hard setae, also called setae. The structural features of the setae are an important systematic feature in the class of polychaetes. The parapodia are supported from the inside by special internal setae - aciculi. In addition, above and below the parapodia there are dorsal and ventral antennae (cirri) and lobes.

It can be said without any exaggeration that in no other class of marine invertebrates will we see such ecological plasticity, such richness and diversity of morphological structures as in polychaetes. They live both in the intertidal zone and at the extreme depths of the ocean and have very different lifestyles. Among them there are predators, herbivorous forms, and consumers of dead organic matter; Some species live in the water column, while others live in burrows or tubes on the seabed.
Source: Institute of Marine Biology named after A.V. Zhirmunsky Far Eastern Branch of the Russian Academy of Sciences

About sea mice: Aphrodite australis- Aphrodite motley. A very large polychaete (body length up to 13 cm, width up to 6 cm). The number of segments is 35-40. The body is oval, noticeably tapering towards the posterior end. The dorsal side is strongly convex, the ventral side is flat. The head lobe is small, spherical, equipped in front with two hemispherical tubercles, on which there is one pair of eyespots; there are no eye stalks. There are 15 pairs of dorsal scales hidden under a thick layer of felt made of hair-like setae. Parapodia biramous. The large dorsal setae are very long, curved, form dense tufts that partially cover the dorsal side of the worm and in the posterior part of the body their ends converge with each other along the midline of the back. On the dorsal side, the worm is strongly iridescent; large dorsal bristles are densely enveloped in adherent small silty particles. The lateral fringe of thin long hair-like setae is strongly iridescent. The ventral setae are smooth, with a somewhat blunt apex.
On the territory of Russia it is found on shelves in the Seas of Japan and Okhotsk, as well as in the Bering Sea.
It lives at a depth of 2 km, to shallow water, in the intertidal zone.
Source: Red Book of the Russian Federation

Aphrodite aculeata- Sea mouse.
A species similar to Aphrodite motley, but living near the coasts of Australia, England, and North America.
Interesting fact: The colored hair of the sea mouse has a very unusual structure. If you place these hairs under an electron microscope, their cellular structure, reminiscent of a honeycomb, becomes clearly visible. This structure is amazingly orderly, and linear dimensions cells are comparable to wavelengths in the visible light range. Thanks to this, the hair of a sea mouse has the ability to strongly scatter light, and the degree of scattering depends on the color of the beam, that is, on the wavelength. This means this: from a stream of light falling perpendicularly onto the hair, only the red component is reflected; in other words, if you look at the hair at the right angle, it appears bright red. From a stream of light falling obliquely on the hair, it reflects - depending on the angle - yellow, green, or blue. We can say that to the eye examining the hair from all sides, it appears in turn in all the colors of the rainbow spectrum. The structure that the sea mouse has evolved over millions of years is being studied today for use in next-generation fiber optic cables that have higher bandwidth, i.e. Having a small diameter, this fiber carries more information.

A bizarre sea animal was discovered on the beach by a Kent resident who was vacationing there with her child. It turned out to be a sea mouse - a type of sea worm that lives at a depth of more than 2 meters below the surface of the sea. She was thrown ashore during a storm. An unusual creature has been spotted Julia Sherrard, who drew attention to the strange a ball of fur shimmering with bright colors, lying among pebbles and shells. University worker Julia, 48, was walking along the banks of the Heath near Folkestone with her 6-year-old son when she spotted the creature, more than 10cm long.

Nature lover Julia said the following: “At first I thought it was some kind of unearthly creature - its fur shimmered in different colors. I had never seen anything like it before. It looked like a dead mouse - fluffy, very fluffy. The animal was still breathing, and so that it would not die, I decided to throw it back into the sea. I threw it into the water, and then thought with horror that it could not be a sea creature at all." She also added: "My son was amazed at the animal's small legs. He asked me not to touch them so that it wouldn’t grab my fingers, but I just wanted to save his life.”

Adult sea mice can reach a length of more than 30 centimeters and live, as a rule, just below the intertidal zone, both on the shores of the Atlantic Ocean and in the Mediterranean. The backs of the animals are covered with bristles, which shimmer in red, green and blue colors, which serve the animals defense mechanism.

Sea mice are blind and move by tentacles, using small, bristly paddle-like appendages to rummage through the decaying carcasses of dead sea animals. They are hermaphrodites with functional reproductive organs of both sexes. According to experts, sea mice are often washed ashore by storms.

The body of adult worms is oval in shape, can reach 10-20 cm in length and up to 5 cm in width. One of the features of the sea mouse is large iridescent bristles secreted by the dorsal branch of the parapodia. These bristles, due to the structure of the crystal lattice, refract light falling at different angles differently.

The animal we call a sea mouse is actually a worm. It got its “mouse” name thanks to the long bristles that give it the image of this gray animal. Depending on the angle of incidence of light, they can change their color. This unusual phenomenon has interested scientists involved in the development of nanoelectronics. You will find out further what this led to.

Sea mice belong to the class of polychaetes. These worms are common in the Mediterranean Sea and the northeastern Atlantic Ocean. They live at various depths, from shallow waters to depths of 2000 meters.

The sea mouse can live at depths of up to 2000 meters

Among sea mice there are both predatory and herbivorous species. Predators feed on gastropods, worms, small crustaceans, etc.

pet

The length of the worms can reach 15-20 centimeters. Their oval body is divided into 35-40 segments, each of which has special processes (parapodia), with which they move along the seabed.

The whole body is divided into segments

Parapodia

The back of the worms is partially covered with long bristles, which, depending on the angle of incidence of the light (beam length), can change their color. At right angle The falling bristles appear red. When the light falls obliquely, they can be reflected in yellow, green or blue.

Hairs shimmering in the light

Greenish tint

They have a cellular structure, reminiscent of a honeycomb, which is amazingly orderly.

This phenomenon was of great interest to scientists from the Norwegian University of Science and Technology. They decided to find out whether the hollow channels of the bristles could serve as templates for producing nanowires. Their expectations were met. According to one of the authors of the study, the length of nanowires usually did not exceed 0.2 mm, and the resulting structures could grow up to 2 cm. In addition, the use of this manufacturing method is simpler and more economical.

You see, even annelids have some use.

Basic information: planaria are free-moving worm-like creatures. Class: animals. The worm is a multicellular organism with a flat body. Systematic position: included in the class of ciliated worms - primitive invertebrates, which are characterized by bipolar symmetry of the body.

Bilateral symmetry allows worms to live both in water and on land. If planaria had a different body structure (radical), then it could fully exist only in an aquatic environment.

The family Planariidae has 12 genera, the white planaria belongs to Planaria (there are 25 other invertebrate species in this category).

Habitat and lifestyle

Habitat: marine and terrestrial. Common habitat: freshwater reservoir. Worms can be found under pebbles at the very bottom. White planarians can live in different conditions. Sometimes they end up in aquariums along with untreated soil, snails and small fish (live food). Flatworms can crawl, so they move freely along the surface of the bottom or land.

The freshwater milky white planaria constantly consumes protein because it needs it to maintain normal life. It feeds on caviar, small fish and crustaceans.

This worm-like predator makes the process of obtaining food easier for itself in every possible way. The creature releases threads into the water, which swell due to exposure to the liquid. With their help, the worm captures and, if necessary, holds prey.

External structure of planaria (Planarii)

This worm-like animal usually does not exceed 2–2.5 cm in length. The milk planaria, like many representatives of its species, has a pointed body, similar in shape to an oblong leaf. The thickness of its body is from 2 to 5 mm. At the base of the extended part of the body there are two eyes. At the front end there are also tentacles resembling ears.

Planaria has an ideal white-milky, more often white, color. The body cover is strewn with cilia, but they can only be clearly seen in close-up photos.

The worm has a transverse cut that divides its body into two (unequal) parts. In this case, one side of the body is a mirror image of the other due to bipolar symmetry.

What systems and organs does a worm have?

The milky white planaria has characteristics that set it apart from the group of flatworms. This creature has additional tissue (mesoderm) located between the endoderm and ectoderm. This factor indicates the development of a multicellular organism.

Worm sensory organs:

• vision;
• touch (due to the tentacles on the front of the body);
• equilibrium;
• chemical feelings.

Digestive system

This creature has an unusual structure of the mouth opening - it is located in the center of the abdomen and leads into a cavity with a retractable pharynx. When a worm eats prey, it presses tightly and swallows it with the help of a “catching apparatus”. Subsequently, food is distributed through 2 branches of the blind intestine: anterior and posterior. In this case, the hindgut is also divided into 2 branches.

Thus, the digestive system of the worm includes: the mouth, the hindgut and the foregut, connected to the pharynx.

Nervous system

The worm has a paired brain, from which two chains of nerves extend, connected by jumpers. The nerve trunks form a thickening (knot) in the front of the body. Nervous system planaria differs in that the cells are not scattered throughout the body, as, for example, in hydra, but are collected in 2 compactions.

Reproductive system

Planaria is a hermaphroditic (bisexual) creature, since male and female reproductive cells are formed in its body. In the front part of the body of the worm there are ovaries in which eggs develop. The testes are located along the body, presented in the form of small bubbles. The testes contain sperm.

The eggs develop in the inner part of a kind of mucous cocoon. The worm lays several eggs at once, protected by a dense shell (cocoon) from exposure environment. The worm-like animal, as a rule, attaches its future offspring to plants located at the bottom of the reservoir.

The internal reproductive organs of the worm are the ovaries and testes.

Excretory system

This system is presented in the same way as in all flatworms. The main organs responsible for the release of decay products are branched tubules, which in large numbers penetrate the body of the animal. The worm also has excretory pores and protonephridia.

How does he move? The skin-muscle sac is responsible for movement - a muscle layer located under the epithelium and tightly adjacent to it. It consists of longitudinal, circular and spinal muscles. The movement and change in shape of the worm-like animal is carried out through contraction of the skin-muscular sac.

Development cycle

The development of the white planaria can be considered unique, since this animal, unlike its closest relatives, does not require definitive or intermediate hosts. The development scheme consists of only 2 stages: first an egg is formed, and then a small worm emerges from it. Over time, the creature grows and grows into an adult.

How do white planarians reproduce?

Since planaria is a bisexual animal, its reproduction can occur in 2 ways:

1. Asexual. The worm's body is divided in half. Subsequently, an adult individual grows from each particle.
2. Sexual. To implement this method During reproduction, 2 individuals must touch their abdomens for a few seconds (at this moment fertilization occurs). After contact, the female reproductive system of one worm contains male cells of the other. Eggs that have been fertilized form zygotes and begin to accumulate the necessary substances. Final stage: formation of a protective shell and release into external environment. After 2–3 weeks, small worms emerge from the cocoons.

This worm is characterized by pronounced and rapid regeneration. It is for this reason that the creature is highly durable.

The white planaria is characterized by nocturnal and evening activity. These animals move very smoothly in the water due to the constant movement of cilia on the body.

A sea mouse is a worm from the class of polychaetes. It received this name because its body is covered with “fur”, and the size of an adult individual is the same as that of a small rodent. Its Latin name is Aphrodita aculeata.

What does it look like

The worm grows up to 20 cm in length and up to 5 cm in width. The body is divided into 35-40 segments, each of which ends with black processes - parapodia. They help move along the seabed and burrow into the sand.

On the “face” there are two pairs of jaws, with which the polychaete catches its prey.

The body of sea mice is covered with amazing bristles that resemble felt. They reflect even the weakest light and change color depending on the angle at which it falls.

Interesting!

This includes the presence of marine life and what a sea mouse looks like in the photo. Its cover, washed from silt and dirt, shimmers with all the colors of the rainbow and sparkles under the rays of light.

If the rays go straight, the bristles turn red. If the light falls at an angle, the worm's "fur" glows blue, yellow or green.

Mouse hairs are not for beauty at all. They perform several important functions:

1. Provide breathing.
2. Protect his body.
3. They help bury themselves in the sand.
4. Serve as a “home” for eggs.
5. They scare away natural enemies by turning red.

The structure of the bristles resembles an ordered honeycomb. Scientists from the Norwegian University of Science and Technology studied this phenomenon. They were trying to find out if the bristle channels could be used to make a nanowire. The experiment showed that in this way it is possible to create a structure up to 2 cm in length.

Where does it live and what does it eat?

The sea mouse spends its life at the bottom of the Mediterranean Sea, as well as in the northeastern part of the Atlantic. It can live at a depth of up to two kilometers. It chooses a muddy bottom where it can bury itself in the sand for resting or hunting.

Some sea mice prefer a plant-based diet. Others are predators. The latter use wool as bait. They burrow into the mud, leaving bristles on the surface that reflect light. “Sparks” attract crustaceans, small mollusks, and worms, which Aphrodite preys on. A worm can also feast on its relative if it is smaller in size.

Interesting!

Aphrodite the sea mouse is not an exemplary parent. She can eat her offspring. Therefore, the larvae that emerge from the eggs quickly swim away from the careless mother.

Living at depth makes it difficult to study the worm. But thanks to him, scientists made a breakthrough in nanotechnology.