Digital Keys to the Calanoid Copepods


Introduction to the digital ID Keys

These digital keys were designed based on the features from adult specimens (males and/or females) of calanoid copepods therefore, the users of these keys should be familiar to the anatomy of this group (order) of copepods.

These keys are looking to facilitate the identification of calanoid copepods to the level of family in the first instance and to the level of genera for the group of copepods known as the ‘Bradfordians’ and the families Centropagidae, Calanidae and Megacalanidae. In addition, the users will find keys to the species of the Genera Eucalanus and Calocalanus.

Each one of the digital keys has a short introduction to the group of calanoid copepods that it deals with, which is worth reading before playing with the key.

Hints to Play the ID keys:

  • Select the key from the home page
  • Read introduction (recommended)
  • Launch key
  • On the top left panel, have a look to the morphological features and select any you are familiar with. We recommend starting from the top ones and descending following the body plan of an adult copepod (front of Prosome towards Urosome and mouth parts towards natatory appendages).
  • Each feature might have two or more options. Each option might have a small vignette with useful information that might help you to select the right option (click in the vignette to enlarge it). Whenever you select a particular option then, the entities not conforming with your choice will move to the bottom right panel.
  • You don’t need to select options from all morphological features listed in the proposed order. You can skip those features that you are not familiar with or those that are not related to the specimen you are identifying.
  • Remember that the more options that you select, the less possible candidates you will have to choose from.
  • Options from the top tool bar such as: Best, Prune, Differences or Shortcuts; might help you to decide on the identification of your specimen.

For further information on how to use the Lucid player environment, please visit the Lucid player Help website:

If you find errors or issues while using the ID keys, please direct your comments and suggestions to [email protected]

Please cite the use of the key as:


To Dr Janet Bradford-Grieve for her hard work building each one of the keys while working at NIWA, during her free time and post retirement. To the CSIRO plankton team (Anthony, Frank, Ruth, Felicity, Claire, Mark, Anita and Julian) for creating the right environment to build the capability to keep available these valuable resources for everyone. To Matt Taylor for his collaboration during the process of reformatting the ID keys from their original source. Finally, to the community of scientists, researchers, students, amateurs and people who have found interest in copepods.

Software Used:

Lucid Player v4.0

Additional resources for the identification of marine copepods have been produced by the CSIRO plankton team and they are available at: