Homarus Research Paper

Rene Ismail

McKenna - C

9th Grade Biology PBA

American Lobster - Homarus americanus Ecosystem/Ecology of Homarus americanus

Adult American lobsters tend to dwell in depths of below 50 meters. However, some can live at depths of about 750 meters. They can weigh up to 44 pounds and reach a length of about 25 inches, however they are typically around 2 feet long and weigh 3 pounds. The American lobster’s preferable habitat is on rocky surfaces covered with algae, because algae attract animals that the lobsters prey on. This habitat allows the lobster to hide within the cracks, where it can hide from predators in its environment such as flounder, cod, crabs and eels. They dig burrows under large stones to make usable hiding spots. Adult lobsters

1. The closest living relative of the American lobster is the European lobster, Homarus gammarus.

2. Hoploparia is the second closest genus of fossil lobsters under the family Nephropidae.

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Genetics of Homarus americanus

• 100 pairs of inverted U-shaped chromosomes, common in crustaceans.

Physiology of Homarus americanus

Nervous System: Homarus americanus have a primitive nervous system, one similar to those of insects. Lobsters lack a brain and only contain about 100,000 neurons, a figure a million times less than the 100 billion found in humans. Ultimately, the American lobster has a bilaterally symmetrical nervous system. There are ganglia on each segment of the body, each made up of a paired hemi-ganglia. The ganglia of neighboring segments are linked by connectives, while the hemi-ganglia are connected by commissures. Overall, the structure of this nervous system appears as a ladder-like chain consisting of a brain, two connectives, and a ventral nerve cord. Because lobsters lack a cerebral cortex, they rely on this complex nervous system to translate pain impulses into the sensation of pain