Copepods: Life Cycle

Life cycle

Copepods are the largest class of crustaceans.  They are the path of energy transfer between PHYTOPLANKTON and ANIMALS in most aquatic ecosystems. 

The body of a copepod is usually between 1-5mm, and is generally made up of three parts:

1. Cephalosome (cephalo- head)
2. Metasome
3. Urosome

Vision is carried out with a central naupliar eye.   Chemical and motion sensing is performed using multiple sets of antenna.  

Copepods are generally planktonic, meaning that they live in the water column  and drift with the current.  They feed on suspended material in the water, thus they are suspension feeders.  They use a body part called a maxillae to capture food particles and move them to their mouth.  

Sexes:

Generally speaking the female copepods are larger than male.  The easiest way to tell them apart is when the female has a egg sack attached.  

The male will grab hold of the female as they exchange genetic material for reproduction.  She will hold eggs that will mature until she releases them into the water.  

The eggs will hatch into a larva called nauplii.  They will go through several stages before becoming adults.

Once the adult phase has reached the copepod will not molt anymore.

The cycle may take a little as one week or up to months or years depending on the species of copepod.