By Addison, Sarai, and Marisa

Model Organisms The Cephalopods:A Neurological comparison between Octopuses and Cuttlefish.

Presentation Overview

Overview

Getting to know the Octopus

Exploring the Cuttlefish

How are they alike and different

References

What is A Model Organism

A model organism is an organism that is studied to understand particular biological phenomena.

Model organisms are typically easy to take care of and can be easily manipulated and studied in a laboratory setting

Model organisms are well known anatomically and behaviorally.

Octopus Vulgaris

1 History in Research

The common octopus is the most widely researched octopus.

They are easily accessible to researchers.

Do well in captivity.

2 Range and Habitat

Biogeographical regions in the Indian, eastern Atlantic, and Pacific oceans. Along with the Mediterranean sea.

Mainly found in the coastal waters near coral reefs.

Lives at depths of 100 - 150 meters.

3 Lifestyle and Diet

Octopuses like to live a secluded lifestyle.

Life spans extend from 1-2 years.

Known to eat crustaceans, and small bony fish.

Central Nervous System of O. vulgaris

● The Optic lobes, the nervous system of the arms and the central brain make up the nervous system.

● The central brain is located in the brain capsule that surrounds the esophagus.

● The optic lobes has three layers which show similarities to the vertebrate retina.

● The Peduncle lobe granule cells make parallel fibers. These fibers are similar to the folia in vertebrate cerebellum

● The VL is the highest functional lobe in the central brain. It is similar to hippocampus of the vertebrates.

<http://tolweb.org/accessory/Ventral_View_of_Cephalopod_Brain?acc_id=2128>.

Importance to Neurological Research

Evolutionary biologist and neurologist study the nervous systems of octopuses to understand how our own nervous system evolved.

Memory and learning are popular subjects to study in these model organisms.

It was found that octopuses MSF-VL system is similar to the hippocampus in mammals.

High numbers of interneurons found in the MSF-VL in areas of learning and memory show high redundancy of connections.

The communication between neurons could possibly be species specific.

Sepia Officinalis

1 History in Research

This species of cuttlefish has mainly been used for researching the connections between color display and communication between organisms, the area of the brain that processes sight is extremely large.

2 Range and Habitat

Mediterranean sea to as far as South Africa.

This species of cuttlefish live on sandy seabeds around 200m deep.

3 Lifestyle and Diet

Cuttlefish typically eat small fish and crustaceans, they are social animals and often travel in groups interacting with one another.

Importance to Neurological Research

The cuttlefish has complex communication methods using only color.

This can help us understand how animals communicate without the use of sound or facial expressions, unlike other animals such as mammals and birds which use vocalization and body movement to communicate.

Cephalopods are one of the most intelligent classes of animals on the planet, and understanding how they communicate using color can help us better understand them as a species and help us better understand communication between other animals.

The cuttlefish is a great model to use for this type of research because it uses exclusively color patterns and signals to communicate, this is one of the only species that displays this behavior. Since the cuttlefish is unique it can be used to compare with other species that might show changing color displays and movement behavior, like chameleons.

Central Nervous System of cuttlefish sp

The nervous system of S. officinalis shows very large development of the optical lobe.

What the Scientific Community Gained

Cuttlefish were used as a model organism to study imprinting, specifically food imprinting.

An article published by the royal society stated that when the cuttlefish were young, they were shown only a specific food source, and ate only that food source

As they grew they were provided with alternate food sources but refused to eat anything else except for the food source they had imprinted on.

Comparisons of Cuttlefish and Octopuses

Lack of shell- Octopuses do not have a shell, and a cuttlefish has an internal shell called the cuttlebone.

Cuttlefish fish use Hemocyanin for oxygen transport (blue-green pigment), Octopuses use Hemoglobin.

Both have eight arms, but cuttlefish have two tentacles and they have a shorter arm to body length

Comparing the nervous systems

The octopus brain is closer to a vertebrate brain than to its close relatives

They have 500 million neurons compared to lower molluscs which have 20,000

Cuttlefish can transform from one color to another in 1 second, and in a few seconds turn a wide range of colors all controlled by the nervous system

Picture References

Slide1-http://files.tripstodiscover.com/files/204/07/Red-Sea-Coral-Reef.jpg

Slide 2- http://alphasouthsarl.com/fish/octopus-vulgaris/index.htm

Slide 5- Young, Richard E., and Michael Vecchione. "Ventral View of Cephalopod Brain." Tree of Life Web Project. Web. 27 Nov. 2011. <http://tolweb.org/accessory/Ventral_View_of_Cephalopod_Brain?acc_id=2128>.

Slide 9- https://www.researchgate.net/figure/5963492_fig4_Figure-1-Sepia-brain-with-right-optic-lobe-cut-away-A-Lateral-aspect-with-nerve

Article References Case, Robin J.” Octopus Vulgaris.”Animal Diversity Web. University

of MIchigan Museum of Zoology,1999 http://animaldiversity.org/accounts/Octopus_vulgaris/#food_habits. Web.07 Sept.2016.

http://www.biolbull.org/content/210/3/308.full

Hochner Binyamin, Shomrat Tal, Fiorito Graziano.” The Octopus: A model for a Comparative Analysis of the Evolution of Learning and Memory Mechanisms”.The Biological Bulletin.210.6(2006):308-317.web.2016.

http://rsbl.royalsocietypublishing.org/content/2/3/345.short