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ROTIFERA, Rotifers or Wheel animacules (phylum)

Wormlike animals with anterior wheel organ, which bears 
a usually double ciliated ring, the "cingulum" 
and the "trochus". This serves both for 
progression and for bringing up food.  
This serves both for progression and for bringing up food.

 

The jaw (trophi) are situated in the mastax and consists of five sets of elements: 
An unpaired median fulcrum (yellow) connects two rami (green) at their joint.  The rami are hollow, more or less triangular structures.  Fulcrum and rami are joined in a functional unit, the incus. The unci (blue) are plates formed by connection of a variable number of teeth into one rigid structure. The teeth are mostly unequal, with the ventral ones the largest. The manubria (red) are crescent-shaped and compartmented supports of the unci with (Ploima) or without (Flosculariaceae) an elongate shaft. Unci and manubria together form the malleus of the trophi (Fontaneto, 2007)Monogononts have seven different trophi types: 
Malleate, malleoramate, virgate, forcipate, incudate, uncinate. Se Fontaneto (2007)for further desciptions. 
Lorica present, i.e. cuticle thickened to form a stiff shell, which retain its well after preservation can be present or absent i. e.  cuticle thin and flexible, not retaining its shape well after preservation. No legs present, with or without tail like foot.
Food: Bacteria, algae, detritus, or small zooplankton organism. Planktonic or bentic.
A positive correlation between dissolved oxygen and population size of rotifers has been found in Pasig River [2009a]. See Wallace et al. (2006) further details about biology and ecology of rotifers.

 

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ROTIFERA, Rotifers. Key to the families of Philippine rotifers.

      (Key to genera and speciesà15)

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 7 a.  Wheel organ (Corona) of Conochilus or Hexarthra type
           FLOSCULARIACEA (order)......................................14

 

 7 b. Wheel organ (Corona) not of Conochilus or Hexarthra type..........8

            

 8 a. Jaws (trophi) uncinate. Fulcrum short, rami more or less
triangular, flat, all trophi elements except the unci
strongly reduced. Not important since the food is already pre-digested.

           COLLOTHECACEA (order),COLLOTHECIDAE (family à Collotheca)..77

 8 b. Jaws (trophi) not uncinated

           PLIOMA (order)...............................................9

 

 9 a. Wheel organ (corona) of Asplanchna type..........................10

 9 b. Wheel organ (corona) not of Asplanchna type......................12

 

10 a. Jaws (trophi) symmetrical........................................11

 

10 b. Jaws (trophi) asymmetrical

           TRICHOCERCIDAE (family à Trichocerca)......................60

11 a. Jaws virgate. All four parts present, fulcrum is long,
asymmetric and the rami pointed bent towards dorsally.
Piercing and sucking. Here it consists of thin, hence
hardly discernable elements.

           SYNCHAETIDAE (family à Polyarthra).........................66

 

11 b. Jaws incudate. Curved, sharp-pointed rami like pincers.
      Seizing type (Asplanchna).
           ASPLANCHNIDAE (family à Asplanchna, Asplanhnopus)..........64

 

12 a. Wheel organ (corona) of typical Euchlanis–Brachionus type........13

 

 

 

12 b. Wheel organ (corona) simple, not Euchlanis–Brachionus type

           LECANIDAE (family à Lecana)................................59

 

 

 

13 a. Anterior and/or posterior end with spines

           BRACHIONIDAE (super-family à Brachionus, Plationus, Platyias, 
            Keratella, Anuraeopsis, Euchlanis, Dipleuchlanis, Mytilina,

           Lepadella, Colurella, Trichotria)......................35

 

13 b. Anterior and posterior end without spines 

           GASTROPODIDAE (family à Ascomorpha)........................63

 

14 a. Wheel organ (corona) of Conochilus type

           CONOCHILIDAE (family à Conochilus).........................74
 

 

14 b. Wheel organ (corona) of Hexarthra type

          TESTUDINELLIDAE (incl. HEXARTHRIDAE) (family à 
           Testudinella, Pompholyx, Trochosphaera, Filinia,
          Hexarthra)............................................68

 

(Key to genera and speciesà15)

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