Which phylum do lobsters belong to

Unlike the American lobster they lack large claws, have spines all over their bodies, and live in subtropical and tropical oceans. A Spiny Lobster. Anatomy and Biology of an Adult Lobster. Like all Arthropods Homarus americanus, is bilateral. This means that if you were to cut a lobster from head to tail or more correctly cephalon to abdomen! The organs are arranged in such a way that each half would be identical. They would be mirror images of one another.

Body Plan:. A lobster consists of two main parts. The first part, the cephalothorax, which is made up of the cephalon the head and the thorax the mid-section , is often called the body of the lobster and is covered by a hard shell called the carapace.

The second part that makes up the lobster is the abdomen, which is commonly called the tail. The 14 segments that are fused together to make up the cephalothorax are called somites and each somite bears a pair of appendages that are located on different areas of the lobster, usually on either side of the body or on the underside of the body.

The eyes of the lobster are found on the first segment, and are housed at the end of two individual, movable stalks found on either side of the rostrum the very tip of the cephalon. Each eye is actually made up of thousands of little lenses joined together, which is why they are called compound eyes.

In fact, in bright light a lobster is practically blind. Lobsters cannot really see specific images but they can detect motion in dim light. The second segment of the cephalothorax bears the antennules, which are carried on a three-segmented peduncle foot and contain the chemosensory organs. The chemoreceptors found in these short antennae detect distant odors or chemical signals that are carried by the seawater.

These messages received by the antennules help a lobster find food, choose a mate and decide if danger is near. The more then different types of receptors found on the delicate hairs of the antennules are sensitive enough to allow a lobster to distinguish between particular species of mussels.

Imagine having a nose that sensitive! The antennae, which consist of a five-segmented peduncle and a single flagellum, are located on the third segment.

These antennae are much longer then the antennules and are used as sense organs as well. The last three segments of the cephalon and the first three segments of the thorax are where the mouthparts are located.

The many mouths of the lobster have a variety of functions and are found on the underside of the lobster. Some are used to grip food such as the second and third maxillipeds. Others, such as the first and second maxillae and the first maxillipeds are used to pass this food along to the jaws, also called the mandibles, for crushing and ingestion.

The Jaws are located on the fourth segment of the cephalothorax, and the other mouths are located on segments The remaining segments of the cephalothorax are where one finds the walking legs of the lobster and what are commonly called the claws.

These five legs including the claws are located on segments , and are joined to the lobster on either side of the body. Why is lobster called an invertebrate? What animal classification is a lobster? Are shrimp and lobsters bugs? Are lobsters Just sea bugs?

Do scorpions taste like lobster? What happens if I eat a scorpion? Is it safe to eat a dead scorpion? As invertebrate crustaceans, lobsters also have a hard outer shell or exoskeleton, and no inner skeleton or bones. See the full taxonomy here. Nervous System The lobsters nervous system is very primitive.

In fact it is most similar to the nervous system of an insect. Antennae and stiff body hairs assist greatly in the sense of touch. As divers, we think of lobsters in a variety of ways. Many photographers consider lobsters wonderful subject matter, and almost any diver enjoys seeing them on a reef.

During the day, it is common for many lobsters to seek cover under ledges and overhangs and in cracks, crevices and caves. Often, when they have taken cover, you can spot lobsters by seeing their long antennae sticking out into the open. At night, many species are more active and they readily leave their hiding places to forage for food. Their food generally consists of dead organic matter and a variety of snail, worms, mollusks, other crustaceans and other animals that they can crush with their powerful mandibles.

Despite their stiff bodies and robot-like appearance, lobsters can move rapidly over short distances by swimming backwards when they so desire. Rapidly tucking their tail provides backward thrust, and when swimming, as opposed to walking across the sea floor, that is the direction they tend to go.

A variety of species of lobsters are known as spiny lobsters. These species lack claws but their exoskeletons are often covered with numerous sharp spines at the base of their antennae and on their shells. These barbs provide some defense against natural predators and divers. In addition, their heavily armored antennae can inflict a tearing wound when they thrash them about in a whip-like fashion. Spiny lobsters are social animals and often gather in groups of a dozen or more.

In some instances they are believed to warn other lobsters of danger with loud rasping sounds made by rubbing the base of their antennae against the ridges below their eyes.

Why they march remains a mystery. Whether spiny lobsters are really lobsters or crayfish is a point of debate among some specialists. Unlike their counterparts in New England, the various species of spiny lobsters found in the Caribbean, California and many other parts of the world lack the large pinching claw found in Maine lobster, although females possess a small pincer on the last pair of walking legs.

As strange as it sounds, many people refer to spiny lobsters as crayfish because they lack claws, but the real fly in the ointment here is that freshwater crayfish possess claws. Go figure. Also known as the American lobster, the Maine lobster Homarus americanus occurs from the Canadian Maritimes southward to North Carolina, but it tends to be most abundant in Maine waters.

This well-known crustacean possesses two strong claws: a big-toothed crusher claw for pulverizing shells and a finer-edged serrated claw used for tearing soft flesh. Far more solitary than spiny lobsters, the American lobster is one of about 30 clawed species worldwide. A variety of species are known as slipper lobsters. Some claim that these lobsters look like a flattened marine armadillo.

Whether you have that much imagination is a personal matter, but the bodies of slipper lobsters are more flattened from top to bottom and more heavily armored than their spiny cousins. Upon first sighting, it is sometimes hard to tell the front from the rear in slipper lobsters because of their broad, flat body and very short antennae.

Although they are edible, slipper lobsters are not as heavily pursued by commercial fishermen as spiny lobsters and Maine lobster. Exactly where the best places to find lobsters of legal size is an issue that is hotly debated by hunters. At different times legal-sized individuals can be found in rocky reef and coral reef communities in depths ranging from the tide pools to well below sport diving limits. Worldwide there are more than 2, species of shrimps.

Shrimps play important roles in almost every known marine niche from the tidal zones to the deep sea and from the tropics to the poles. With so many different species occurring in such a range of diverse habitats, it only makes sense that shrimps are a very diverse group of animals. Most species are scavengers, but others play vital roles as cleaners and many species are important sources of food for many marine creatures, especially a variety of predatory fishes.

Shrimps have elongated bodies typically divided into two major parts. One section, the cephalothorax, is composed of the head and thorax, which are fused. The other major section is the abdomen, which is segmented. The abdomen and tails of shrimps are proportionally longer than those of crabs and lobsters.

Shrimps use their tails and abdomens to create thrust when they swim. By quickly flexing muscles in their abdomen and tail, shrimps can propel themselves backwards at surprisingly fast speeds over short distances. This sudden burst of speed provides them with a valuable means of avoiding predators. The underside of the tail of shrimps is equipped with several wide, well-developed appendages known as pleopods, structures which enable many species to swim slowly forward while maintaining control of their attitude.

Most shrimps are superb swimmers, but as divers we spot the majority of species as they rest or walk about the reef.