Malaysia Harmful Algae Research Group


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2015 © Malaysia Harmful Algae Research Group. | designed by Chui Pin

This interactive key is designed to aid researchers in the field to identify the species of Pseudo-nitzschia.
Each character is illustrated to ease Pseudo-nitzschia identification. Each taxon has hyperlinks to the taxa descriptions on
morphology, distributions and relevant references.

The key was created in 3i (Internet-accessible Interactive Identification) Interactive Key and Taxonomic Database software
package (

How to Use the interactive Key

The main window presents the list of characters, with a drop-down box of a set of states. Some characters may have
no state, numeric value should be entered (The range of valid values is indicated in parentheses).

As for Character List Sorting, the program allow sorting the characters in three ways,
By Rank - which will be sorted based on the best characters for ID (we set that in the database), the rank of the character is
specified in parentheses, e.g. "poroid structure (, I=18)".
By Separating Power - with this option, the rank are disregarded, and the program will calculate which characters better split
taxa (and according to the program, this is recalculated after each step of ID).
By Morphology - as this option will sort characters based on groupings. The characters can be sorted according to “Valve”,
“Poroid Structure”, “Fibulae and Striae”, and “Cingular Band”.

The character list can be sorted by modifying the interface from the Preferences button.
You may need to refresh the window, or press the Proceed button to refresh the screen with new options.
Your preferences are saved after the end of your work session.

You may start species ID with any character by choosing a state from the drop-down box. Each character has a hyperlink to
illustrative images. Press the Proceed button after the states of one or several characters have been chosen. This will refresh
the list of taxa fitting the search criteria, the list of eliminated taxa, and list of characters useful/no longer relevant for
further identification.

If a character has multiple states and there is uncertainty which one to chose, the NOT option can be helpful; the taxa not
having this state will remain in the list.
Some characters may have no state, then exact numeric value should be entered to the field (the range of valid values is
shown in parentheses after the character name).

The button Clear all is used to return the character set to the original list and to start identification from the beginning.

This interactive key is at the beta-test stage, so a form is provided below for your comments.

Interactive Key to species of Pseudo-nitzschia
Teng, S.T., Dmitriev, D, Lim, H.C., Lim, P.T., Leaw, C.P. (In prep). An interactive identification key to species of Pseudo-nitzschia (Bacillariophyceae).   
List of Character used to identify
Feel free to comment. Your feedback is highly appreciated.