Question

Порівняйте зовнішню будову хрящових і кісткових риб?​

Answer 1

Ответ:

Зовні легко відрізнити хрящових риб від кісткових. У хрящових риб видно зяброві щілини, а у кісткових вони прикриті зябровими кришками. У акул є рострум, парні плавці розташовані в горизонтальній площині, хвостовий плавець йерівнолопатевий, плакоїдна луска.

Answer 2

External Structure of Cartilaginous and Bony Fish

Cartilaginous fish, such as sharks and rays, have a skeletal structure made primarily of cartilage. On the other hand, bony fish, which include the majority of fish species, have a skeletal structure made of bone. Let's compare the external structures of these two types of fish:

1. Body Shape: - Cartilaginous fish: Most cartilaginous fish have a streamlined body shape, which helps them move efficiently through the water. They often have a fusiform (torpedo-like) body shape, with a pointed snout and a tapering tail. - Bony fish: Bony fish exhibit a wide range of body shapes. They can have elongated bodies, compressed bodies, or even laterally flattened bodies, depending on their species and habitat.

2. Fins: - Cartilaginous fish: Cartilaginous fish have paired pectoral fins and pelvic fins, which are used for stability and maneuverability in the water. They also have a single dorsal fin and a caudal fin (tail fin) for propulsion. - Bony fish: Bony fish also have paired pectoral and pelvic fins, but they may have additional fins, such as anal fins and adipose fins. The dorsal fin and caudal fin are also present in bony fish, but their shapes and sizes can vary among different species.

3. Scales: - Cartilaginous fish: Most cartilaginous fish have placoid scales, also known as dermal denticles. These scales are small, tooth-like structures embedded in their skin, which provide protection and reduce drag in the water. - Bony fish: Bony fish have scales that are composed of bone or enamel. These scales can vary in size, shape, and arrangement depending on the species. Some bony fish have cycloid or ctenoid scales, while others have ganoid or placoid scales.

4. Mouth and Jaws: - Cartilaginous fish: Cartilaginous fish have a wide variety of mouth shapes and jaw structures. Some species have large, protrusible jaws with multiple rows of sharp teeth, while others have specialized jaws for filter-feeding or suction-feeding. - Bony fish: Bony fish also exhibit a wide range of mouth shapes and jaw structures. Some species have terminal mouths (located at the front of the head), while others have inferior or superior mouths. The teeth of bony fish can vary in shape and function, depending on their diet.

5. Gills: - Cartilaginous fish: Cartilaginous fish have gill slits on the sides of their bodies, which allow water to pass over their gills for respiration. These gill slits are not covered by a bony operculum. - Bony fish: Bony fish also have gill slits, but they are covered by a bony operculum, which helps protect the delicate gill filaments. The operculum allows water to be pumped over the gills, facilitating respiration.

6. Swim Bladder: - Cartilaginous fish: Most cartilaginous fish do not have a swim bladder, which is an internal gas-filled organ that helps bony fish control their buoyancy. - Bony fish: Bony fish have a swim bladder, which they can inflate or deflate to adjust their buoyancy in the water. This allows them to maintain their position in the water column without expending much energy.

In summary, cartilaginous fish and bony fish differ in their body shape, fin structure, scales, mouth and jaw characteristics, gill structure, and the presence or absence of a swim bladder. These differences reflect the diverse adaptations that have evolved in these two groups of fish to thrive in their respective aquatic environments.