Essential
anatomical terminology must be learned in order to positively identify an
organism.
General
elements that need to be assessed for all zooplankton groups are:
1.
body shape and size
2.
relative length of various appendages, including antennae, legs, and setae
3.
presence and relative sizes of spines
Although
several anatomical features used to differentiate species are listed in the
literature, this Guide only makes mention of the key details which taxonomists
use for rapid identifications. The attempt was to keep the list of features to
a minimum while ensuring accurate species assignments. Although some dissection
may be required, this Guide generally only depicts anatomical details that can
be viewed under a dissection microscope. For more detailed information on
certain features (ex. cyclopoid 5th legs), refer to the sources listed in
Section 4.
After
gaining some experience, you will develop a mental picture of what a typical
specimen of each common species looks like. Therefore, although first
identifications will take time in order to consult the literature and keys,
this will not always be a necessary step. Each zooplankton group has a series
of major characteristics used for positive identification. Once you memorize
what to look for the speed of processing will dramatically increase. If ever in
doubt, always refer to the keys.
If
an identification is still uncertain after following these steps, it is always
best to adopt a more general designation rather than take a “guess”. For
example, the taxonomy of Bosmina is notoriously complicated by the elements
mentioned in the introduction to this Guide. Very fine distinctions separate
members of the 5 species found within the Sudbury Region. Therefore, if in doubt,
assign a member of this family to the proper genus (i.e. Eubosmina or Bosmina)
rather than attempting a tentative
species designation.
Identification
to the family (for Cladocera) or order (for Copepoda) level is fairly easy.
From there you must refer to the main identification characteristics for each
group, outlined in the following Sections.
Writer
Jessintya
Palupi
Fisheries
Tech Brawijaya University 2014
Editor
Gery
Purnomo Aji Sutrisno
Fisheries Tech Brawijaya University 2015
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