A Study of Octopus Behavior

Purpose

The purpose of this study is to investigate behavior in the common octopus.

 

Hypothesis

The octopus will be more active during the night than during the day.

 

Background

Octopus are mollusks. That means they are invertebrates and do not have backbones. They belong to a group of invertebrates known as cephalopods. Cephalopods include squid, cuttlefish, and nautilus. They evolved from limpets. Limpets are like clams. Eventually limpets grew separate chambers of their body and started looking like there relative the nautilus and started swimming. Later they took many new and amazing shapes and sizes. They are nocturnal. The octopus used is Octopus vulgaris or the common octopus.

Octopus mostly prey on crustaceans such as crabs, shrimp, and lobster. They will also feed on fish and clams. Some octopus even eat other octopus. Some octopus use poison to kill there prey. They will wait long periods of time for prey. Then will come from behind and attack the prey.

Octopus require large volumes of very clean oxygenated seawater. They like lots of room with a shelter such as a flower pot. Ratio of water recommended is 100 liters per 500 grams of octopus body mass. Temperature 10-20 C is tolerated, 15 C for some octopus. For octopus sharing tanks both require a separate shelter. Food being given depends on the size of octopus. Recommended pH of 8.0. Salinity approximately 30 ppt.

Salinity is a measure of the salt in a certain amount of water. The pH scale indicates how acidic or basic a liquid is. The pH scale ranges from one to fourteen. Seven is neutral. Numbers under seven are acidic. Numbers over seven are base. Temperature is the measure of how much kinetic energy is in something. Salinity is measured in parts per thousand (ppt). Temperature is measured in Fahrenheit ( F ), Celsius ( C ), and Kelvin ( K ). 32 F, 0 C, and 273 K are freezing points. 270 F, 100 C, 373 K are boiling points.

Related Links

The Cephalopod Page



Procedure

Culturing Octopus

Step#1) Get tanks that are 18 6/8 in. high, 29 3/8 in. long, and 12 1/8 in. wide
Step#2) Build fame made up of 2 by 4 s, cinder blocks, and screws
Step#3) Set four tanks up on frame and a single filter for the tanks
Step#4) Fill each tank with about 29 gallons of water
Step#5) Make the water about 24 C, a pH of 8, and a salinity of 31 ppt
Step#6) Get lids that are 12 1/8 in. by 29 3/8 in.
Step#7) Put half flower pot in each tank
Step#8) Put octopus in tanks
Step#9) Feed or test them twice daily ( Depending on the group)

Results

 

Conclusion

 

The data supported the hypothesis and the hypothesis was accepted . Octopuses are more active at night than during day .

Data
Bibliography

Forsythe, J.W.(1980). A Closed Marine Culture System For Rearing Octopus joubini And Other Large-Egged Benthic Octopods. World Mariculture Society Proceedings, 11 202-210

Hinegardner, R.T. et al (1981). Marine Invertebrates .Washington D.C.:National Academy Press.

Mowka , E .J .(1981) The Seawater Manual . Aquarium Systems Inc.

Rathjen, W.F. and G.L Voss(1969) The Cephalopod fisheries Review. Cephalopod Life Cycles 2 (12) 235-274

Voss, G.L.(1971). Shy Monster, The Octopus. National Geographic. 140 (6) 776-799

Wood, J.B.(1995-2000) The Cephalopod Page. Available at: http://is.dal.ca/śceph/TCP/index.html

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