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KERATELLA, (BORY ST. VINCENT 1822) (syn. Anuraea)

Foot absent. Cuticle thickened to form a stiff shell

(lorica) retaining its shape well after preservation. Often

ornamented with ridges or striations. Body with anterior and

usually 1 or 2 posterior spines. Feeds on particles less

than 10 μm (Sládeček 1983).

The genus is abundance among the plankton in polluted

biotopes like Pasig River (2009a).

Planktonic.

49 a. Insertion of the posterior spine terminal.

COCHLEARIS GROUP.

Lorica dorsal with median line. Size 150-300 μm.
Polymorphic:

§ Central line of lorica straight (form tecta)
with long-spined (form macracantha),
medium spined (form typica)
and spineless (form tecta) forms.
The reduction of the spine is corre­lated
with increasing eutrophy.

§§ Central line of lorica with a definite kink,
field pattern irregular (form irregularis),
with longspined to spineless forms.
The irregular field pattern is correlated
with high temperature and is
common in tropic waters (var. javana).

§§§ Lorica covered with small spines (form hispida),
     correlated with turbulent water.

An affinity for diatoms and blue-greens (cyanobacteria)
as food has been found in Lake Lanao (Lewis 1979).
Planktonic in large and small waters,
also in brackish and saline water.

Indicator of mesotrophic waters (Sládeček 1983).
Rare.

- Laguna de Bay, La Mesa Dam, Lake Lanao, Lake Danao, Paoay Lake.

Keratella cochlearis {GOSSE, 1851)
[1941a, 1974, 1978a+b, 1979b, 1980, 1984a, 1986a, 1999,
 2008b, 2009a, 2012a]

      With small spines on lorica.
      - Laguna de Bay, Lake Danao (Leyte/Cebu?).

Keratella cochlearis var. hispida (LAUTERBORN)
                     [1980, 1999] 

49 b. Insertion of posterior spines at the posterior corners.

      QUADRATA GROUP..................................................50

Keratella sp, Taal Lake (Photo: Rey Donne S. Papa, 2007)

 

To 50 a.