Crustaceans form a very large group of arthropods that are usually treated as a sub-phylum and have about 67,000 species worldwide. They range in size from the Stygotantulus stocki at.1mm or.004 in. to the Japanese spider crab with an impressive leg span of up to twelve and a half feet or 3.8 meters. Like all arthropods, crustaceans wear their skeleton on the outside of their bodies. These outside skeletons are known as exoskeletons. Due to having an exoskeleton, crustaceans like all arthropods, must shed their exoskeleton periodically in order to grow. This process is called moulting. After moulting, they are in a very vulnerable state until their new soft exoskeleton hardens.
Crustaceans live mostly in the water but some are terrestrial such as woodlice, fish lice and tongue worms. Some, like barnacles or sessiles live in the water but as the tide rolls out find themselves in the open air attached to rocks, pilings, hulls of ships or boats and even on whales. Some of the familiar crustaceans that live in the water include crabs, lobsters, crayfish, shrimp and krill; all of which are tasty treats to seafood lovers with the exception of krill, which is a favorite delicacy of Humpback whales.
Crustaceans have been around for millions of years and have evolved some unique body designs. The body of a crustacean is composed of three distinct body segments; the head or cephalon, the thorax, and the pleon or abdomen. Depending upon the species, the head and the thorax may be fused together to form a cephalothorax, which may be protected by a large carapace. It is common for each body segment to bear a pair of appendages.
These appendages make up unique tools for the animal to use in its environment. The head segment has a pair of antennae and a pair of mandibles. The thorax is where the legs grow, which may be used for walking or feeding. The abdomen bears pleopods or swimming legs and is often flanked by a fan-shaped tail.
The circulatory system of crustaceans is located in the main body cavity and is usually referred to as an open circulatory system. Blood is pumped through this system by a heart near the dorsum. The kidneys or a structure that works similar to kidneys are located near the antennae. Also close to the antennae in the form of ganglia lies the brain.
Crustaceans have three main ways to reproduce. Most species are made up of males and females and reproduce sexually. A small percentage are hermaphrodites, which means they have both male and female reproductive systems. In the crustacean's world, it is not unusual for a male to change into a female or a female to change into a male; this usually happens when there is a shortage or lack of a certain sex. Many crustaceans reproduce through parthenogenesis, by which viable eggs are produced by a female without fertilization.
Next time you dip that delicious piece of crab meat in garlic butter, take a moment to ponder that you are filling your belly with one of the oldest and numerous animals on Earth.
Christopher spends his time on freelance writing, writing for change, seminars and private sessions to help people manifest the life they want to live. For weekly tips and information about upcoming events, subscribe to his periodic email list. http://quantumworthhealing.com
Crustaceans live mostly in the water but some are terrestrial such as woodlice, fish lice and tongue worms. Some, like barnacles or sessiles live in the water but as the tide rolls out find themselves in the open air attached to rocks, pilings, hulls of ships or boats and even on whales. Some of the familiar crustaceans that live in the water include crabs, lobsters, crayfish, shrimp and krill; all of which are tasty treats to seafood lovers with the exception of krill, which is a favorite delicacy of Humpback whales.
Crustaceans have been around for millions of years and have evolved some unique body designs. The body of a crustacean is composed of three distinct body segments; the head or cephalon, the thorax, and the pleon or abdomen. Depending upon the species, the head and the thorax may be fused together to form a cephalothorax, which may be protected by a large carapace. It is common for each body segment to bear a pair of appendages.
These appendages make up unique tools for the animal to use in its environment. The head segment has a pair of antennae and a pair of mandibles. The thorax is where the legs grow, which may be used for walking or feeding. The abdomen bears pleopods or swimming legs and is often flanked by a fan-shaped tail.
The circulatory system of crustaceans is located in the main body cavity and is usually referred to as an open circulatory system. Blood is pumped through this system by a heart near the dorsum. The kidneys or a structure that works similar to kidneys are located near the antennae. Also close to the antennae in the form of ganglia lies the brain.
Crustaceans have three main ways to reproduce. Most species are made up of males and females and reproduce sexually. A small percentage are hermaphrodites, which means they have both male and female reproductive systems. In the crustacean's world, it is not unusual for a male to change into a female or a female to change into a male; this usually happens when there is a shortage or lack of a certain sex. Many crustaceans reproduce through parthenogenesis, by which viable eggs are produced by a female without fertilization.
Next time you dip that delicious piece of crab meat in garlic butter, take a moment to ponder that you are filling your belly with one of the oldest and numerous animals on Earth.
Christopher spends his time on freelance writing, writing for change, seminars and private sessions to help people manifest the life they want to live. For weekly tips and information about upcoming events, subscribe to his periodic email list. http://quantumworthhealing.com