Search key for Dutch freshwater bryozoans for field use

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This search key is, contrary to all available bryozoa search keys, intended for field use and for determination of species by using marco pictures made during field (scuba diving) expeditions. For this reason the common approach to include statoblast form is ignored. If statoblasts can be seen om a macro photo they are generally too low in detail to be usable.
For labratory determination of bryozoa species based on statoblasts [Wood] is recommended.
This search key has a known weakness that it may well not lead to a 100% scientific species identification. Additional microscopic research might well be needed to achieve that.
At the other hand this is, as far as known, the first search key intended for field research. It might well be that such a search key is more valuable than expected when used in practise.

Besides the search / determination key there is also an overview of each species and its key aspects. Both the search key and the overview are based on a set of well defined aspects.

What also may help is a polyp compare page of the different species

Also presented are several examples of non bryozoans species that are easily confused with bryozoa.

The search key

Red fields signal, in combination, a species unique aspects.

Grey fields signal that an aspect is not applicable to that particular species.

Purple fields signal that there is work to do.

Species -> P. articulata V. pavida C. mucedo F. sultana L. crystallinus P. magnifica H. punctata P. casmiana P. emarginata P. fruticosa P. fungosa P. geimermassardi P. repens
Description \/
Colony shape   Tree shaped - - + - - + + - - -
Crawling + + - + + + + + + +
Hanging - - + - - - - - - +
Encrusting - - - - - + - + + - + + +
Knoll shaped - - - - - + - - + - + - +
Caterpillar shaped - - + - - - - - - - - - -
Sack shaped - - - - + - - - - - - - -
Bushy + - - - - - - - - -
Branching pattern of the zooids
- the way the colony branches (multiple approaches)
  Regular + + + + ? ? + - ? -
Irregular - + - - ? ? - + ? +
Not branching - - + - + + - - - - - - -
  Open structure + + + + + + + - + +
Closed structure + - + - + - - + + +
  Adhering tubes - - - + ? + - - + -
Non-adhering tubes + + + - ? - + + - +
Appearance of a polypid or the colony
- the way a zooid appears
  Encrusted - - - + - - - ? + + - - ?
Smooth + + + + + + ? - - + + ?
Gelatinous - - + - + + - - - - - - -
  Chitin shine + - - - - - - - - - - - -
Rimpled - - - - - - + - - - - - -
Spotted - - - - - - + - - - - - -
  Transparent - - + - + + + ? - ? ? + ?
Opaque + + - + - - - ? + ? ? - ?
  Sturdy - - + + ? + - - ?
Brittle - slender + + - - ? - + + ? ?
Form
- of the polypide
  Round + + - + - - - - - - - - -
Horseshoe shaped - - + - + + + + + + + + +
Position of the polypid
- the way the polypide aperture is located in the zooid
  Terminal - + - + - - - ? + + ? ? -
Sideways + - - - - - - ? - - ? ? -
Somewhere - - - - - - + ? - - ? ? +
Anywhere - - + - + + - - - - - - -
Number of tentacles per polypide   Low - + - - - - - - - - - - -
Average + - - + - - - + + + - + -
High - - + - + + + - - - + - +
Habitat   Fresh water + - + + + + + + + + + + +
Clean fresh water - - - - ? - ? - - - - - -
Brackish water - + - - - - - - - - - - -
Additional remarks   Crawling stolon Polypids rosettes.
Typical pink spots
Small polyps
Closely packed
Greyish