Biology: Fish and Reptiles

Fish

• Characteristics:
  • Cold-blooded (ectothermic)
  • Breathing through gills
  • Scales or bony plates for protection
  • Fins for movement and balance
• Types:
  1. Bony fish (Osteichthyes): majority of fish species, including goldfish and salmon
  2. Cartilaginous fish (Chondrichthyes): sharks, rays, and skates
• Habitat:
  • Freshwater (rivers, lakes, ponds)
  • Saltwater (oceans, seas)

Reptiles

• Characteristics:
  • Cold-blooded (ectothermic)
  • Scaly skin
  • Lay eggs (oviparous)
  • Breathe air through lungs
• Types:
  1. Snakes (Serpentes): limbless, elongated bodies
  2. Lizards (Squamata): varied species, including geckos and iguanas
  3. Turtles (Testudines): shell-protected, slow-moving
  4. Crocodilians (Crocodilia): large, carnivorous, semi-aquatic
• Habitat:
  • Terrestrial (land-dwelling)
  • Semi-aquatic (swampy or wetland areas)
  • Freshwater (rivers, lakes, ponds)

Fish

• Fish are cold-blooded, meaning their body temperature is regulated by the environment.
• They breathe through gills, which extract oxygen from water.
• Scales or bony plates provide protection and support.
• Fins enable movement and balance in the water.

Types of Fish

• Bony fish, such as goldfish and salmon, make up the majority of fish species.
• Cartilaginous fish, including sharks, rays, and skates, have a cartilage skeleton.

Fish Habitat

• Fish can be found in freshwater habitats, such as rivers, lakes, and ponds.
• Many fish species also inhabit saltwater environments, including oceans and seas.

Reptiles

• Reptiles are cold-blooded, meaning they rely on external sources of heat to regulate their body temperature.
• They have scaly skin that helps to prevent water loss.
• Reptiles lay eggs and breathe air through lungs.
• They have a three-chambered heart, except for crocodilians, which have a four-chambered heart.

Types of Reptiles

• Snakes are limbless, elongated reptiles that have evolved to thrive in a variety of habitats.
• Lizards, such as geckos and iguanas, are a diverse group of reptiles with a range of characteristics.
• Turtles have a shell that protects their body and provides support.
• Crocodilians, including crocodiles, alligators, and caimans, are large, carnivorous reptiles that inhabit semi-aquatic environments.

Reptile Habitat

• Many reptiles are terrestrial, meaning they live on land.
• Some reptiles, such as crocodilians and turtles, are semi-aquatic, inhabiting swampy or wetland areas.
• Freshwater habitats, including rivers, lakes, and ponds, are also home to some reptiles.

Learn about the characteristics, types and habitats of fish, as well as the characteristics of reptiles. A quiz covering the basics of these two animal classes.