American Lobster

American Lobster

Phylum : Arthropoda
Class : Malacostraca
Order : Decapoda
Family : Nephropidae
Genus : Homarus
Species : H. americanus

Length : 8-24in (20-61cm)
Weight : 2-9lbs (1-4kg)

IUCN Status : Not Listed

The American Lobster, as its name might suggest, can be found in the waters of the Atlantic, running from Canada down to the Carolinas. They do not swim, instead they move about by crawling thanks to four pairs of walking legs. The fifth pair, (or rather, the first if going from head to tail) makes up the large claws.

Molting is a very important activity in the life of a Lobster. As they grow towards adulthood, juvenile Lobsters will molt their carapace multiple times a year. They essentially grow a whole new shell under their old one, and then seek out a safe place to shed. The Lobsters are vulnerable for a time after their old shell has been discarded, because the new one is still soft. It will harden over time, and adult Lobsters molt about once a year.

Molting has a big part in Lobster reproduction, as females can only mate when their new carapaces are soft, right after molting. They can lay thousands of eggs at once, which are carried on the underside of the female's tail for as long as a year!

American Lobsters are opportunistic feeders. They dine on Plankton, Mollusks, Fish, Algae, Worms, and even other Lobsters. They have also been known to consume their own recently molted shells!

The harvesting of American Lobster is a $300,000,000 industry, and overfishing exists in some areas of southern New England. Measurements are in place by the NOAA that outline the protection of breeding females, the minimum size a Lobster must be at to be caught, and what types of traps can be used. The largest American Lobster ever caught weighed 44lbs (20kg).

American Lobster

American Lobster

Phylum : Arthropoda

Class : Malacostraca

Order : Decapoda

Family : Nephropidae

Genus : Homarus

Species : H. americanus



Length : 8-24in (20-61cm)

Weight : 2-9lbs (1-4kg)



IUCN Status : Not Listed



The American Lobster, as its name might suggest, can be found in the waters of the Atlantic, running from Canada down to the Carolinas. They do not swim, instead they move about by crawling thanks to four pairs of walking legs. The fifth pair, (or rather, the first if going from head to tail) makes up the large claws.



Molting is a very important activity in the life of a Lobster. As they grow towards adulthood, juvenile Lobsters will molt their carapace multiple times a year. They essentially grow a whole new shell under their old one, and then seek out a safe place to shed. The Lobsters are vulnerable for a time after their old shell has been discarded, because the new one is still soft. It will harden over time, and adult Lobsters molt about once a year.



Molting has a big part in Lobster reproduction, as females can only mate when their new carapaces are soft, right after molting. They can lay thousands of eggs at once, which are carried on the underside of the female's tail for as long as a year!



American Lobsters are opportunistic feeders. They dine on Plankton, Mollusks, Fish, Algae, Worms, and even other Lobsters. They have also been known to consume their own recently molted shells!



The harvesting of American Lobster is a $300,000,000 industry, and overfishing exists in some areas of southern New England. Measurements are in place by the NOAA that outline the protection of breeding females, the minimum size a Lobster must be at to be caught, and what types of traps can be used. The largest American Lobster ever caught weighed 44lbs (20kg).

Japanese Spider Crab

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Japanese Spider Crabs are the world's largest living arthropod, with a legspan that stretches nearly 13ft (4m). Their actually body, however, reaches only about 15in (37cm) across. These Crabs are found on the seafloor in the Pacific Ocean off the coast of the Japanese archipelago. They are found at depths of 150-800m, though 200m is very typical. Females will move to even shallower depths in order to lay their eggs.

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The body of the Japanese Spider Crab is made up of a body with eight legs and two long feeding arms that, in males, exceed the length of the legs. These arms are shorter in females. They are reddish-orange in color, with white spots. The eyes are located at the front of the body, and two horns protrude between them.

Japanese Spider Crabs hang out on the sea floor where they feed off of other crustaceans and material of dead animals that has floated downwards. They reportedly can live up to 100 years, making them a very long-lived species.

Japanese Spider Crabs have not been evaluated by the IUCN, but they are fished for consumption purposes. However, the number caught has gone down in recent years due to protection programs. Fishing continues in Saruga Bay, but overfishing in that area has caused fishermen to look deeper and deeper for these large crustaceans.

Giant Isopod

Of the nine members of the genus Bathynomus, B. giganteus is the largest. These crustaceans, closely related to shrimp, look like something out of science fiction, but they are in fact real, living creatures that crawl around in the deep sea of the Atlantic and Pacific oceans. Giant Isopods live at depths of over 2,000 feet and can grow to nearly a foot and a half in length!

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Like the Giant Squid and the Giant Tube Worm, Giant Isopods are an example of deep sea gigantism, which causes animals on the sea floor to grow far larger than their near-surface counterparts. One thought on why this happens is that the large size helps compensate for the huge amount of water pressure that is placed on the creatures by their deep habitat. Giant Isopods have a rigid exoskeleton that also lets them roll up into a ball to avoid danger.

Giant Isopods are opportunistic, carnivorous feeders, and they have to be! They live in an area where food is scarce, and so they will gorge on whatever they can find. This often includes parts of dead fish and larger marine creatures, and it is believed that they may also hunt slow moving deep sea dwellers as well. They are also capable of surviving for weeks without food, and adaptation that helps them to survive.

Another adaptation comes in the form of their reproductive habits. Giant Isopods lay eggs, rather large ones in fact, and these eggs are incubated in a pouch created by the female. When the eggs hatch, the young have already bypassed the entire larval stage, and look like tiny versions of the adults. This helps them to survive easier early in life.

Antarctic Krill

Antarctic Krill (Euphausia superba) are the largest of all the krill, small, semi-transparent crustaceans that can be found the world over. They grow up to two inches long, and have a slight hint on red on their backs.

It is estimated that there are over 500 million tonnes of Krill in the ocean, and that that biomass is the most for any multi-celled creature on the entire planet. They swim in dense swarms that can contain 10,000-30,000 individuals per square meter.

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Antarctic Krill feed on phytoplankton, which is abundant due to updrafts of nutrients from the cold waters. Phytoplankton feed from nutrients and the sun, and Krill feed on them, meaning they lose very little energy as they are so close to the source on the chain. This make Krill a desirable meal for larger animals because they too will lose very little energy. Baleen Whales feed almost exclusively on Krill, scooping up these swarms in a mouthful. Good thing female Krill lay up to 10,000 eggs at a time!

Unfortunately, Antarctic Krill numbers, and the numbers of other Krill species, have dropped nearly 80% since the 1970s. Increased Carbon Dioxide levels have already proven to be a huge detriment to the species. A continued downward trend could have drastic implications for the large marine animals that depend on them for food.

Atlantic Ghost Crab

As the name might imply, Ocypode quadrata is found in the Atlantic coastal areas of North and South America. They are one of 28 extant species within Ocypode that share the common name of Ghost Crab. Members of the genus are found throughout the world. They get their name from their ability to blend in with their surroundings and their partially translucent bodies.

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Atlantic Ghost Crabs live in burrows that they dig themselves. These are placed above the tideline, go down at a 45 degree angle, and can become 3-4 feet deep. They are built from wet sand for sturdiness, and the crabs use burrows for both shelter and for hibernation. Atlantic Ghost Crabs cannot swim, but they must live near water as it is required for their respiration. When hibernating, oxygen is stored in special sacs, allowing them to remain dormant for about 6 weeks. Females also need water in order to reproduce, as that is where they lay their eggs. Young crabs are even more camouflaged than the adults, and can be extremely difficult to see.

The eyes of the Atlantic Ghost Crabs can rotate a full 360 degrees, which is a good thing when you have so many natural predators. Birds and Raccoons regularly feed on Ghost Crabs, and in some areas the crabs are consumed by Humans as well. Atlantic Ghost Crabs are most active at night, and are very opportunistic omnivores.

Pistol Shrimp

The common name Pistol Shrimp can refer to one of the 600 species belonging to the family Alpheidae. They are also sometimes referred to as Snapping Shrimp. Most species are found in tropical and temperate saltwater, though others are able to live in colder seas, and even in freshwater caves. They feed off of fish and other crustaceans and typically live within burrows.

Shrimp and Goby

They are an interesting little family of Crustaceans in that they share a handful of bizarre characteristics. The first is physical: all species have one "normal" sized claw, while the second claw is much, much larger. They use these claws for what is probably their most interesting trait; their title as one of the loudest creatures in existence. Even though they are small, growing not much larger than a few inches, Pistol Shrimp are able to produce 218 decibel sounds. This is louder than a gunshot, (typically around 190 decibels) and comparable to sounds made by the 50 ton Sperm Whale. They do so by snapping their large claws closed, which creates something called a cavitation bubble. When this bubble collapses, it not only produces an incredible loud pop, but it also, very briefly, creates extremely hot temperatures, up to 4700 degrees Celsius! (that's nearly 8,500 Fahrenheit) This bubble is able to stun prey, and on a human beings feels like getting snapped hard by a rubber band.

Pistol Shrimp also have an interesting relationship with Goby fish. The two creatures share a burrow and remain in physical contact at all times. The Shrimp have terrible eyesight, but the Goby's is exceptional. If the Goby spots danger, it twitches to warn the Shrimp, and both are able to move to safety. In return, the Shrimp maintains the den that they share. This relationship exists even with captive shrimp and fish.

Alaskan King Crab

There are three species of King Crab fished commercially in Alaska, the Red King Crab, the Blue King Crab, and the Golden King Crab. A fourth species, the Scarlet King Crab, is also found in Alaskan waters, but is rare and does not support a commercial fishing industry. All four species belong to the overall super-family, Lithodoidea, which houses 113 living species overall.

Golden King from Calacademy.com

King crabs have five pairs of legs. The back pair are much smaller then the rest, and are usually hidden in the crab's carapace (body). They serve an important function during the mating season however, as females use them to tend to the embryos that she keeps under her tail, and they males use them in the fertilization process. The middle three sets of legs are used for walking, and the final set, that which is closest to the front of the body, sports pincers. In most crabs, the right claw is substantially larger than the left.

Like most animals, the King Crab grows larger as it ages. However, its carapace does not grow with it. As they age, the crabs must molt and grow new shells (which are made primarily of calcium). This molting process happens much more often when they are juveniles, and less when they are adults and have more or less plateau'd in size. King Crabs can live 25-30 years, and crabs that make it to those ages can be as many as five feet in leg span. King Crabs feed on all sorts of small marine life, including each other. They are preyed upon by fish, octopuses, and otters.

Red King from Alaska Fisheries Science Center

The Red King Crab is the most harvested of the Alaskan King Crabs. Crab fishing is also one of the most dangerous of all professions, with fatalities over 20 times greater than the average U.S. rate. The amount of danger involved in the Alaskan King Crab Industry has led to the creation of the Discovery Channel series, Deadliest Catch.