Animales VERTEBRADOS e INVERTEBRADOS 🐸🦀 (Características, Clasificación y EJEMPLOS)

Understanding Vertebrates and Invertebrates

Characteristics of Vertebrates

• Vertebrates possess a backbone or spinal column that supports and protects the spinal cord and nerves.

• They exhibit bilateral symmetry and have a skeleton made of bones or cartilage, with bodies typically consisting of a head, trunk, and limbs.

• Most vertebrates have tails aiding in balance and movement; they also feature complex nervous systems with brains protected by skulls.

• Reproduction is primarily sexual, though some vertebrates like certain reptiles can reproduce asexually.

Classification of Vertebrates

• Vertebrates are classified into three superclasses: Agnatha (jawless), Gnathostomata (jawed), and Tetrapoda (four-limbed).

• Superclass Agnatha includes jawless fish like lampreys.

• Superclass Gnathostomata divides into Chondrichthyes (cartilaginous fish) and Osteichthyes (bony fish).

• Superclass Tetrapoda encompasses amphibians, reptiles, birds, and mammals.

Additional Classifications

• Vertebrates can be categorized as amniotes (mammals, reptiles, birds with protective membranes during embryonic development) or anamniotes (fish and amphibians).

• They are also divided into endotherms (warm-blooded animals like mammals and birds that maintain constant body temperature) versus ectotherms (cold-blooded animals such as reptiles, amphibians, and fish that rely on external temperatures).

Examples of Major Groups

Mammals

• Mammals nourish their young with milk from mammary glands; they breathe through lungs.

• Notable examples include horses, dolphins, bats; some mammals like monotremes lay eggs.

Birds

• Birds are characterized by feathers covering their bodies along with wings for flight; they possess lightweight skeletal structures.

• Examples include eagles, penguins, ostriches.

Reptiles

• Reptiles have tough scales covering their bodies; they are cold-blooded requiring sun exposure to regulate body temperature.

• Examples include crocodiles, turtles, snakes.

Amphibians

• Amphibians require water for reproduction; they undergo significant anatomical changes during development.

-Examples include frogs , salamanders , newts .

Fish

-Fish have scales covering their bodies , adapted for aquatic environments ; they breathe through gills .

-Examples include salmon , sharks , eels .

Transition to Invertebrates

Invertebrates: Classification and Characteristics

Overview of Invertebrates

• Invertebrates lack an internal skeleton like vertebrates, typically being small-sized animals. Many possess protective structures such as shells or coverings.

• They inhabit diverse environments on Earth, from hydrothermal vents to the frozen surfaces of Antarctica, representing a significant portion of global biodiversity.

• A basic distinction exists between invertebrates with and without body protection, leading to various classifications.

Common Phyla of Invertebrates

Porifera (Sponges)

• Poriferans are among the most primitive aquatic organisms, anchored to substrates with bodies featuring numerous pores and a larger opening called the osculum.

Cnidaria (Corals, Jellyfish, Hydras)

• Cnidarians have sac-like bodies with a single opening serving as both mouth and anus. They feature tentacles equipped with specialized cells called nematocysts for defense and capturing prey.

Platyhelminthes (Flatworms)

• This group includes tapeworms and planarians. Unlike previous groups, they possess a central nervous system capable of processing sensory information.

Additional Invertebrate Groups

Mollusca (Snails, Clams, Squids)

• Mollusks have soft bodies often protected by hard shells. Their anatomy includes a muscular foot for movement and gills for respiration.

Annelida (Segmented Worms)

• Annelids like earthworms exhibit cylindrical bodies divided into segments. Each segment contains repeated organs and is covered in mucus to aid movement.

Nematoda (Roundworms)

• Nematodes are abundant in soil and aquatic habitats. They have unsegmented bodies with specialized muscles for movement; some are free-living while others are parasitic.

Arthropoda (Insects, Arachnids, Crustaceans)

• Arthropods represent the largest group of invertebrates (80% of all animals). They possess an exoskeleton made of chitin and undergo molting as they grow.

Echinodermata (Starfish, Sea Urchins)

• Echinoderms are marine animals closely related to vertebrates. Their bodies consist of five symmetrical parts without bones but supported by an external skeleton made up of calcareous plates.

Intelligence Among Invertebrates