Everything About The Giant Isopod, From Anatomy To Habitat

One of the world’s Giant isopod is the gigantic isopod, which might be any of the 20 species of Giant isopods. The Pacific, Indian, and Atlantic oceans are home to these species in their deep, chilly waters. It belongs to the isopod family and is the biggest crustacean.

They are crustaceans that live on land, just like pill bugs. The marine gigantism phenomena led to the massive size of these Giant isopods, which serve as the ocean’s cleanup crew.

Giant Isopod Anatomy

The Giant isopod is a crustacean and a distant relative of the crab. It possesses jointed legs and an exoskeleton, a hard outer shell, just like all other crustaceans. The head (cephalon), thorax (pereon), and abdomen (pleon) are the three parts that make up its body.

It explores the ocean below with the aid of its 14 legs. It swims by flapping swimmerets on its uropod, which resembles a fan, and pleopods. The Giant isopod’s pleopods aid in breathing as well! It uses two sets of antennae—a short pair and a long pair—along with its huge eyes to sense its environment. Nearly half of its body is covered by these spindly sensors!


A Giant isopod can reach a length of 16 inches (40 cm). Compared to the pillbug, which is just around an inch (2.5 cm) long, this is significantly larger. It is a prime example of deep-sea gigantism due to its size. This phrase refers to the occurrence wherein relatives of deep-sea animals have grown significantly larger than those who inhabit other habitats.

The two principles that are frequently employed to describe deep-sea gigantism are Kleiber’s rule and Bergmann’s rule, despite the fact that scientists are unsure of what causes it.  According to Kleiber’s rule, larger animals are typically more productive. According to Bergmann’s rule, sea creatures that live in cooler water are bigger.

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Giant isopods differ from regular isopods because they get quite big. Abyssal gigantism, which causes them to grow between 6.7 and 19.7 inches in size for super-Giant isopods and up to 6 inches for gigantic isopods, is the cause of their size. The largest member of the group, the Bathynomus giganteus, can grow to a length of almost 30 inches. The morphology matches that of the pill bug and woodlouse. They have segmented calcareous exoskeletons that overlap.

They have enormous compound eyes on each side of their heads, each with 4,000 facets. The initial shell segments of the Giant isopod are united to the head, and they have two pairs of antennae. As a result, they can roll up into a ball and leave their shell exposed to ward off predators. 


They are foragers, which means they look for food all day long. They eat both live and dead creatures, such as whale corpses, crab, fish, squid, sea sponges, and shrimp. They are carnivores and scavengers. Some will consume trawl catches as well.

Since they consume similarly to terrestrial isopods, they serve as one of the ocean’s most useful cleanup workers. Some people in the southern Gulf of Mexico have a lot of plastic inside of them. most likely sank to the ocean’s floor and was devoured by their ferocious teeth.

They use chemoreception or mechanoreception to locate their prey, which enables them to react to mechanical pressure in order to sense their food. These animals hunt in packs, which enables them to eat a lot of food at once and makes them swift to finish off a large dead or dying whale that has fallen to the bottom of the ocean.


They can be found in Georgia, Brazil, the Caribbean, the West Atlantic, the Gulf of Mexico, and Australia’s east coast. The Atlantic, Pacific, and Indian oceans, as well as Australia, all include five species of Giant isopod.

They live in cold, deep waters that are 550 to 7020 feet deep. They spend their time on the mud- or clay-covered ocean floor. These marine organisms scavenge for food by crawling among rocks, sediment, and aquatic flora. They do not dwell on land.


Even though Giant isopods are found miles below the surface of the ocean, our actions nonetheless have an effect on them. Recent research from the Aquarium and the Monterey Bay Aquarium Research Institute (MBARI) has demonstrated that microplastic, or plastic trash less than 5 millimeters across, is present in the ocean’s deepest regions from the surface of the water to the seafloor.

The study also discovered that creatures like giant larvaceans and pelagic crabs consume microplastic. Microplastic enters ocean food webs in this way, from the surface to the depths. According to the study, consumer products are where most microplastic is found. By reducing our daily usage of single-use plastic, each of us can make a difference. Find out how you can reduce ocean plastic usage.

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