Plankton Portal Talk

Marking larvaceans and larvacean houses

  • kirstenr by kirstenr

    In the discussion thread about marking sipho and doliolid buds here:, a discussion was started about marking larvaceans and larvacean houses. After reading this discussion, I am unclear how to mark a house with a larvacean in it. I know we only mark one or the other, but which one is it?

    Given the different ecological roles you mention in the discussion, I would be inclined to mark an inhabited larvacean house or a larvacean without a house as "larvacean," and only mark an empty house as a "house." But I think we have been marking all larvacean houses (inhabited or uninhabited) as "houses," and only the free larvaceans as larvaceans.

    At first, I was marking both the house and the larvacean separately when a house was inhabited, until a moderator told me not to.

    Since these organisms are so common in both the CAL and MED data sets, this information should be included in the field guide (with examples) so that all classifiers mark them consistently. Also, some examples of when you would and wouldn't mark a "disintegrating larvacean house" should be included. I mark them as houses when I can still see the filters and some external structure.


  • yshish by yshish moderator, translator in response to Kirsten A. Rohrbach's comment.

    It's a very good question. If I understand it well we should do the following steps:

    Let's wait for a confirmation by a scientists or a correction of my reply 😃



  • yshish by yshish moderator, translator in response to yshish's comment.

    Here is a source to my opinion:

    But, Kirsten, you're right that it would make sense to mark it the other way according what @jo.irisson said in that thread!


  • kirstenr by kirstenr

    In the thread you listed as a source for your opinion, it talked about measuring just the house if there is a larvacean inside. I wonder if that is because the measurements are really a volume thing? It seems like you would want the volume of the organism as well as the volume of the house (which would correlate to the amount of water filtered?). But according to the ecological roles (as you agreed), it makes more sense to mark the larvaceans if they are in the house, rather than the house itself. Let's wait and see what the scientists say. It would be good to get this in the field guide, don't you think?


  • jo.irisson by jo.irisson translator, scientist

    Ecologically, what would make the most sense would be:

    • empty house = house
    • organism alone = larvacean
    • organism + house = larvacean

    however, making the difference between and empty or a inhabited house is difficult. Plus the houses themselves stay intact for only a short period of time and the larvacean never stays long without a house either. So it does not make a lot of difference.

    So in the end, yshish way is correct (and is what is suggested by the field guide: the houses in the larvacean house category has larvacean in them). This is the way you have been doing things right?


  • kirstenr by kirstenr in response to jo.irisson's comment.

    The protocol yshish outlined above is the way we have been marking them so far, yes.


  • yshish by yshish moderator, translator in response to jo.irisson's comment.

    Yes, we have been classifying full houses as houses since the beginning.