Rotifer key

[lukem321]

On the old site, there is discussion about creating an identification key for rotifers. My question right now is should the key be arranged by family or by overt features like whether or not they have a lorica, foot etc? I think the key should be based on the later because, as Actinophrys pointed out, it is not always easy to differentiate between families. The key would then be comprised of distinct genera that are in morphologicaly but not necessarily phylogenicly similar groups.

[Oliver]

Hello,
Just a general comment. Having a background in bacterial systematics, I am not an expert rotifer systematics, but assume that there are similar issues/problems.
Rotifer classification into families and genera is based, I assume, mainly on morphological criteria and not so much on phylogenetic ones (DNA studies). The point of an identification key is to quickly associate a name to the specimen and therefore I would agree that overt features are better suited, regardless if these features represent phylogenetic relationships. Some flower identification books also group the plants based on flower color, for practical purposes. This does not mean that two plants with the same flower color are also closely related, of course. Ideally these "overt features" should also represent phylogenetic relationships, but I wonder if DNA studies for benchmarking these features have already been done.

The (German) book "Das Leben im Wassertropfen" (Streble, Krauter) sorts the organisms based on characteristic features. Similar appearing organisms are presented together, often they belong to different genera (or at least they were classified and named that way).

A more pressing question that I have is, to what extent the different rotifers (etc.) of one species are indeed morphologically similar. Do they change appearance based on environmental conditions? Strictly speaking, two individuals belong to the same species if they are able to (sexually) reproduce with each other. Considering the diversity of nature, I would not be surprised if two individuals with a differing appearance are able to reproduce (same species) or if two identical looking ones belong to different species. How powerful is morphology in this area? But then again, I know too little about rotifers in order to assess if these issues play a role in practice. I also wonder how often rotifers (and others) are re-classified and re-named. In the field of bacterial systematics there was a trend to "clean up" the historic classifications and to re-classify and re-name the organisms based on phylogenetic and biochemical criteria. It was very confusing and often multiple names coexisted.

Oliver.

[lukem321]

Thanks for the insightful comment

To sort of answer your question, from what little I know about rotifer taxonomy, certain morphological traits can be reliable in identifying different genera without much of a problem with variation within a genus. This is because traits such as number of toes, which are often used to differentiate between similar genera, do not usually vary while other traits such as number of spines (that are not used in identification)

[lukem321]

I started making drawings of different genera of rotifers. They aren't meant to be detailed, but they should include important characteristics for identification such as the foot and toes. Let me know what you guys think, criticism is greatly appreciated.
Drawings:
https://www.flickr.com/gp/127137378@N05/p012z2

[Cathleen]

A standard thoughts. Developing a background with microbe systematics, We are no expert rotifer systematics, nevertheless presume that we now have identical issues/problems.
Rotifer distinction into individuals and genera is reliant, I assume, mainly about morphological conditions and not really much about phylogenetic versions (DNA studies). The actual of your recognition essential is to rapidly connect a name towards the example of beauty and as a consequence I'd acknowledge that overt characteristics are usually superior best suited, whether most of these characteristics represent phylogenetic relationships. Some floral recognition publications also class the plant life depending on floral shade, with regard to functional uses. This kind of isn't going to show that 2 plant life with the similar floral shade may also be tightly associated, certainly. Ultimately most of these "overt features" should also represent phylogenetic relationships, nevertheless My spouse and i ask yourself when DNA scientific studies with regard to benchmarking most of these characteristics have been accomplished.

The (German) ebook "Das Leben i am Wassertropfen" (Streble, Krauter) varieties the microorganisms depending on feature characteristics. Identical showing up microorganisms are usually presented with each other, usually that they are part of diverse genera (or no less than we were looking at categorized and known as that way).

A far more depressing issue that we have got can be, from what scope the various rotifers (etc. ) of 1 varieties are usually really morphologically identical. Perform that they transform visual appeal depending on environment conditions? Strictly talking, 2 folks are part of the identical varieties when they will (sexually) multiply with one another. For the range connected with character, I'd not really end up being amazed when 2 those that have a different visual appeal can easily multiply (same species) or perhaps when 2 the exact same looking versions are part of diverse varieties. Precisely how highly effective can be morphology of this type? Then again all over again, I am aware too little with regards to rotifers so as to assess when most of these concerns be involved used. My spouse and i also ask yourself the way usually rotifers (and others) are usually re-classified and re-named. In the field of microbe systematics there was a pattern in order to "clean up" the cultural types in order to re-classify and re-name the microorganisms depending on phylogenetic and biochemical conditions. It was very puzzling and quite often several bands coexisted

[gekko]

As someone who is notorious for misidentifying all kinds of critters, I cannot add anything meaningful to this thread, but I'd like to say "welcome" to Cathleen for joining the forum and contributing to this discussion.

[lukem321]

Thank you to everyone for commenting. With a lot of help from Actinophrys here on the forum, I made about 30 (not very detailed) illustrations of different rotifer genera, and tried to include characteristics that are useful for identification. I would greatly appreciate constructive criticism from the forum, as there are bound to be flaws in my drawings.
Link to illustrations: https://www.flickr.com/gp/127137378@N05/Hw1M4f

Thank you to anyone that takes the time to look at these

[Crater Eddie]

I, for one, think your sketches are very good. Enough detail to be useful for comparison, not so much detail as to bog one down. I would use this.

[gekko]

Thank you to everyone for commenting. With a lot of help from Actinophrys here on the forum, I made about 30 (not very detailed) illustrations of different rotifer genera, and tried to include characteristics that are useful for identification. I would greatly appreciate constructive criticism from the forum, as there are bound to be flaws in my drawings.
Link to illustrations: https://www.flickr.com/gp/127137378@N05/Hw1M4f

Thank you to anyone that takes the time to look at these

Beautiful work! Thank you.

[Seb28]

Hi
I found some interesting websites and PDF files, which can help with the ID of rotifers.It may be useful to someone.

1.http://www.plingfactory.de/Science/Atla ... ifera.html

2.http://rotifer.acnatsci.org/rotifer.php

3.http://visualsunlimited.photoshelter.co ... =usrSearch

4.PDF file: http://www.mdfrc.org.au/bugguide/resour ... pepods.pdf

5.PDF file: https://www.ebiomedia.com/index.php?pag ... &Itemid=38

6. http://www.microscopy-uk.org.uk/mag/ind ... otidr.html

[lukem321]

Thank you all for the kind words, and I found the first link very helpful!

[lukem321]

First draft of the key: https://docs.google.com/document/d/1CBn ... sp=sharing
Sources:
Shiel, R. J., 1995. A guide to the identification of rotifers, clado-
cerans and copepods from Australian inland waters. Albury,
N.S.W., Co-operative Research Centre for Freshwater Ecology,
Murray-Darling Freshwater Research Centre
found here: http://www.mdfrc.org.au/bugguide/resour ... pepods.pdf
and this site:
http://www.nies.go.jp/chiiki1/protoz/identi-r.htm
specifically ref id 953, 1663, and 3334

[gekko]

Beautiful, professional work. Very clear and useful. I've printed it to have as a handy reference. Thank you!