CATDOLL : CATDOLL: How do fish embryos develop? Discuss the process of fish embryo development?

1. How do fish embryos develop?

Thanks for the invitation!

There are three types of fish reproduction: oviparous, ovoviviparous and viviparous.

1. Oviparity is the reproductive method of most fish. Fish lay eggs outside the body, and the embryonic development takes place outside the body. The embryonic development process completely relies on the nutrients in the eggs.

2. Ovoviviparous fertilized eggs develop in the female reproductive tract, mainly relying on yolk nutrition during development, and have no nutritional relationship with the mother, or the mother's reproductive tract mainly provides water and minerals, and finally the mother produces fry. Such as guppies.

3. The embryos of some viviparous elasmobranch fish are connected to the mother through blood circulation. The nutrients needed for embryonic development are not only provided by the yolk of the embryo itself, but also by the mother. There are some protrusions on the wall of the oviduct where the embryo develops, which are connected to the embryo, forming a structure similar to the placenta. The mother sends nutrients to the embryo through this structure. For example, the gray star shark.

2. Discuss the embryonic development process of fish?

The embryonic development of fish can be divided into two periods: pre-embryonic development and post-embryonic development, with the period before and after the embryo hatches as the boundary. It is also called early development.

Pre-embryonic development takes place within the egg membrane, gradually developing from a fertilized egg into an active larva, and finally breaking the egg membrane to hatch. This period is often called hatching.

Post-embryonic development refers to the period from hatching to the ability to begin to ingest external nutrients or the differentiation of major organs.

1. Pre-embryonic development

It takes place inside the egg membrane and uses the yolk as nutrition.

Three major stages: cleavage stage, embryo formation stage, organ differentiation stage

(I) Temperature and incubation speed

Within the suitable temperature range, the lower the water temperature, the slower the development.

The four major fish species are sensitive to temperature changes around the blastopore closure period.

2. Hatching

Hypoxia often causes the embryo to hatch early, while increasing oxygen saturation inhibits hatching.

Within the range of normal oxygen content, the higher the oxygen content, the more normal embryos will hatch.

3. How do carnations develop?

In short, can it not develop? But carnations should rely on the root system, right?

4. What is fish developmental biology?

Developmental biology is one of the important basic branches of biological sciences. Its research content is interpenetrating and interconnected with many other disciplines, especially genetics, cell biology, and molecular biology. It uses modern scientific technology and methods to study and analyze the processes and mechanisms of organisms at the molecular level, submicroscopic level, and cellular level.

A discipline that studies the mechanism of individual development using the methods of molecular biology and cell biology. It was developed from experimental embryology. Experimental embryology studies the relationship and properties of the various parts of the developing embryo, and how they affect each other. Developmental biology investigates the essence of this relationship, what substances (or substances) are at work, how the substances that work make embryonic cells differentiate in a certain direction, how the differentiating cells form tissues or organs to ensure the development of tissues and organs, how the normally developing embryo grows, matures, and becomes a growing individual, why the latter gradually ages after developing to a certain stage, and how to complete the entire development of the individual in a specified time and space sequence.

5. Summarize the types of fish fertilization, reproduction and development?

Fertilization in fish can be external or internal; reproduction can be oviparous, viviparous, or ovoviviparous.

Oviparous: fertilized and developed outside the body. Some species are fertilized inside the body, but the fertilized eggs are hatched outside the body, so they are still oviparous, such as the medaka.

Ovoviviparous: Fertilization and hatching inside the body, the young fish are expelled from the mother as lively ones, but they do not use the mother's nutrition, so it is called ovoviviparous, such as guppy.

Pseudoviviparity: The oviduct of some cartilaginous fish has developed into a structure similar to the uterus of mammals, and is connected to the embryo by blood circulation through a "yolk placenta" structure, supplying nutrients for embryonic development.

The developmental stages of fish: embryonic stage - larvae stage - juvenile stage - young fish stage - adult stage - aging stage.

Development includes embryonic development and post-embryonic development.

6. How do fish on the seabed make sounds?

Radar fish Radar fish has a body length of 7-9cm and is cylindrical in shape.

The eyes are close to the front of the body and the dorsal fin is divided into two.

The spines of the first dorsal fin are tall and straight, standing on the fish's back like an antenna.

The second dorsal fin and anal fin are symmetrical.

The front half of the fish is silvery white, the back half is pink, and the tail fin is purple-red.

The petite radar fish is no more than an inch long and looks like a small wild fish in a river pond, but its body glows like a firefly, which makes people realize its extraordinaryness.

Batfish The batfish is shaped like a pancake, with a white body and brown stripes.

It has many thorns on its body, a small mouth, and the "fishing rod" on its head is short and above its mouth.

The batfish, which lives in the deep sea, has a glowing organ at the tip of its fishing rod.

It uses its pectoral and pelvic fins to walk, and when in danger or frightened, it jumps and escapes like a frog.

7. How do fish in the ocean resist danger?

Fish in the ocean usually defend themselves against danger in the following ways:

1. Color camouflage: Some fish adapt to the environment and camouflage themselves by changing their body color so that they blend in with the surrounding water or seabed environment, thus hiding from potential predators.

2. Body shape and structure: Some fish use their special body shape and structure to defend themselves from danger. Some fish have barbs, sharp teeth and hard scales to protect themselves from attack.

3. Speed ​​and Agility: Many fish have fast swimming abilities and quick body reactions, allowing them to quickly escape from predators. They can use rapid acceleration and flexible turns to escape danger.

4. Schooling behavior: Some fish form schools, and large groups can increase the chances of survival for each individual. By gathering together, they can jointly resist potential predators and protect each other with other members.

5. Venom and poison: Some fish have special venom and poison that can be used to defend against predators. These venoms can cause pain, itching, even paralysis, and other discomforts, so that potential predators stay away from them.

In summary, fish in the ocean defend themselves against danger through color camouflage, body shape and structure, speed and agility, schooling behavior, and venom and poison. These adaptations help them survive in the ocean and protect themselves from predators.

8. What animal doesn’t look like a fish but is a fish?

The lancelet is known as the least fish-like fish.

Amphioxus, also known as Bai's lancelet, slug fish, double-pointed fish or sea hair, is a precious marine animal. Due to its extremely special morphological structure, it has the characteristics of both invertebrates and vertebrates. It is a typical representative of the transitional type from invertebrates to vertebrates. Therefore, it is highly valued by the biological community at home and abroad.

The appearance of lancelet is very strange and interesting. It has a very small body, flattened on the left and right sides, pointed and thin ends, and a spindle-shaped body. It is generally only 4 to 5 cm long.

9. What type of fish is tilapia?

Tilapia - native to Africa, it is a tropical fish. The genus Tilapia includes more than 100 species, including subspecies. Tilapia has the characteristics of fast growth, high yield, omnivorous diet, few diseases and strong reproductive capacity.

10. Which hero in Dota 2 relies on jungle to develop?

Heroes that rely on jungle development include Axe, Void, Phantom Assassin, and Spectre.