flagflag
Invertebrate Brain Gallery

Many invertebrate animals have evolved a rich variety of brains (head ganglia). Unusually large brains of squids and octopuses and small but sophisticated brains of arthropods, especially those of insects, are among the most fascinating brains created on earth by natural selection. Here, photographs of invertebrates of 6 phyla, 35 orders and 47 species and those of their central nervous systems are presented, with brief explanations of their characteristics. Enjoy seeing the pictures and consider evolution of brains in invertebrates. These images can be only used for research and education freely. Providers (Dr. Makoto Mizunami) have copyright for images and documents.

Common Octopus Back to the top page of brain gallery
tako.jpg
tako_nou.jpg
tako_zen.jpg
Author Comment
Kuramochi
2006-04-12
18:16
Common octopus/ Octopus vulgaris
Body length: 50-60 cm.
Octopuses are characterized by their eight arms (not tentacles), usually bearing suction cups. Three defensive mechanisms are typical of octopuses: ink sacs, camouflage, and autotomising limbs. Most octopuses can eject a thick blackish ink in a large cloud to aid in escaping from predators.
Octopuses are highly intelligent, probably the most intelligent of any of the invertebrates, with their intelligence supposedly comparable to that of the average housecat. Maze and problem-solving experiments show that they have both short- and long-term memory. In laboratory experiments, octopuses can be readily trained to distinguish between different shapes and patterns. They are able to open jars after learning from observation.
Octopus arms show a wide variety of complex reflex actions arising on at least three different levels of the nervous system. Some octopuses, such as the mimic octopus, will move their arms in ways that emulate the movements of other sea creatures.
An octopus has a highly complex nervous system, only part of which is localized in its brain. Two-thirds of an octopus's neurons are found in the nerve cords of its arms, which have a remarkable amount of autonomy.

Infomation

ID38
AuthorKuramochi
Date2006-04-12
SeqF04
Views4315
Keyword

Mollusca
  • Cephalopoda
Links

Relative URL
JSCPBikeno
Wikipediaikeno
Brain Gallery
Phylum
updating of the site
Copyright (C) 2018 Neuroinformatics Unit, RIKEN Center for Brain Science