What is the ICTV Master Species List (MSL)?

Video Transcript

Prepared and narrated by Steve Powell, May 2023

• The Master Species List or MSL, provides a list of all virus species approved by the International Committee on Taxonomy of Viruses, ICTV.
• Along with many other resources, the MSL is available for everyone to access on the ICTV website at ictv.global.
• Please note that the News items  that you see on the homepage of the ICTV website change from month to month and, consequently so will the appearance of the homepage.
• To access the Master Species List, go to the Taxonomy drop down list and select “Master Species Lists”.
• Next, you will see a table which contains links to the Master Species Lists for all previous releases, starting with the year 2005 and ending with the current year.
• An updated MSL is released every year.  Each new release contains taxonomic changes approved by the ICTV Executive Committee in the fall of the previous year and ratified by the ICTV Membership in the spring of the current year.
• The Master Species Lists are saved as Microsoft Excel spreadsheets.  To download the current MSL, click the “Download Current Master Species List (MSL)” button, at the top of the screen.  Alternatively, you may also download the current MSL by clicking on the first link at the top of the table.  To download an MSL from a previous year, click the link for that year.
• You can also download an archive of selected lists from previous years by clicking in the checkboxes next to those years and then clicking the “Download archive” button.  The lists will then be downloaded into a zip folder.
• To download all the lists from the year 2005 through the current year, click in the first checkbox at the top of the table, and then click the “Download archive” button.  This will download all the lists in the table into a zip folder.
• Let us now download the current MSL, which at the time of this recording is MSL38.v1.
• You can use the Zoom to enlarge the text.
• You will note that the MSL consists of five sheets:  Version, MSL, Column Definitions, Taxa Renamed in MSL38, and Taxon Counts.  
• Returning to the Version sheet, this says that the 2022 release of the Master Species List is MSL38.  If a version is submitted as Version 2, the change will be listed on this page.
• Next, we have the MSL sheet which lists the names of every species recognized by the ICTV at the time of the release, along with the complete taxonomic classification for each species.
• In addition, the MSL sheet includes the species genomic composition, the most recent change for the species, the release number of the MSL in which the last change occurred, and the name of the proposal file for this change, which can be found on the ICTV website.  
• Finally, the last column contains the links for the complete taxonomic history of each species.
• Next, there is the Column Definitions sheet which defines the terms in the column headings in the MSL sheet.
• The Taxa Renamed in MSL38 sheet, lists the taxa that were renamed since the previous MSL.  Included is a column of the old names from the previous MSL, along with a column of the new names for the current MSL.  Also included is a column that lists the filenames of the corresponding proposals in which the taxa were renamed, and the location of those proposals on the ICTV website.
• Finally, the Taxon Counts sheet provides a count of the total number of each taxon among all virus species, as well as a count of specific changes that occurred at each rank since the previous MSL.
• In summary, the Master Species List provides a complete listing and current taxonomic classification of all virus species recognized by the ICTV, making it an indispensable resource that is available to everyone.

Thank you