Difference Between Aquatic and Terrestrial Animals

Aquatic vs Terrestrial Animals

The fundamental difference between aquatic and terrestrial animals is their habitat and their adaptation to that habitat. Almost all the habitats found in the world can be put into two major habitats; aquatic and terrestrial. Aquatic ecosystems are found in water bodies and can be categorized into two broad groups; marine ecosystem (oceans and seas) and freshwater ecosystem (rivers, lakes, etc). Terrestrial ecosystems are the habitats found on lands like forests, wetlands, deserts, grasslands, etc. Animals includingvertebrates and invertebrateshave developed various adaptations that enable them to live in either of these habitats. Most animals are entirely spending their lifetime in aquatic or terrestrial environments. However, some animals are adapted to live in both terrestrial and aquatic environments, thus called semi-aquatic animals (ex:amphibians, platypus, crocodiles, etc.).

What are Aquatic Animals?

动物wholive in water for entire life time or most of their lifetimeare called aquatic animals. Both aquatic invertebrates and vertebrates developed entirely different adaptions to live in water unlike the animals that live on land. Aquatic animals can be divided into two broad groups depending their aquatic habitat, namely;海洋动物和freshwater animals.Some examples for aquatic invertebrates include jellyfish,corals，海葵，九头蛇等。这些无脊椎动物可直接从水中获取溶解氧。水生脊椎动物包括骨鱼，软骨鱼,whales,turtles,dolphins,sea lions, etc. Except fishes, all the other vertebrates need to take air from the atmosphere as they are unable to extract dissolved oxygen from the water. Unlike the land animals, aquatic animals like fish, aquatic mammals have fins and streamline bodies that enable them to move fast in the water.

What are Terrestrial Animals?

Terrestrial animals are the animals wholive on land for most or all of their life span. Fossil records proved that a group of sea creatures, related toarthropodswas the first animals to invade the land around 530 million years ago. The other early aquatic animal groups who invade lands include primitive vertebrates, arthropods and mollusks. Scientists believed that these primitive animals are the early ancestors of modern terrestrial animals. Some animals likeroundworms, tardigrades and rotifers are not considered as truly terrestrial animals because they still need water to live. In the Kingdom Animalia, all known species of Arthropods, gastropods, andchordatesare true terrestrial animals with adaptations to live in dry terrestrial habitats. Moreover, the species of these three groups lack aquatic phase in their life cycles.

What is the difference between Aquatic and Terrestrial Animals?

•水生动物是全部或大部分一生中生活在水中的动物。陆地动物是完全或大部分一生在土地上的动物。

• Examples for aquatic animals include hydra, jellyfish, corals, sea anemones, whales, dolphins, and fishes, while examples for terrestrial animals include species of arthropods, gastropods, and chordates.

• Unlike the terrestrial animals, aquatic animals have adaptations like streamline bodies, webbed feet, fins, air bladder, etc.

•一些水生动物可以利用水中溶解的氧气，但陆地动物不能。

图像提供：

1. Jelly Fish通过Wikicommons（公共领域）
2. 非洲大象bysvein-magne tunli - tunliweb.no(CC BY-SA 4.0)