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Jaws virgate. Mostly littoral and only a few planktonic species.  


TRICHOCERCA, LAMARCK 1801, (syn. Diurella, Mastigocerca, Rattulus)
Lorica not flattened, asymmetrical, more or less cylindrical.
Foot short with toes of unequal length (subgenus Diurella),
often with one toe almost reduced or absent
(s. str.)).
Most species are littoral. Prefer
oligotrophic and acid waters (
Sládeček 1983).
Trichocerca disappeared from Laguna de Bay in periods
with increase in salinity showing sensitivity to the
increased salinity. A decrease in mean density from
1.4 to 0.6 individuals m-3 was found in Pasig River
from the outlet from the brackish water Laguna de Bay
to the saline Manila Bay by
Papa and his team (2009a).


Diurella, Subgenus


60 a. With hood or plate-like projection on anterior margin of
lorica. Two toes, right toe very short. Body long, slender,
cylindrical. Size < 300
μm, left toe 125 μm. Sucks out the
yolk of other rotifers eggs, especially Keratella, and
attaches its eggs to other rotifers. Planktonic. Usually
sporadic, rarely numerous.
- Laguna de Bay, La Mesa Dam, Paoay Lake, Taal lake.
   Trichocerca capucina, (WIERZ, 1893),
    (syn. Diurella capucina).
      [1941a, 1974, (T. longiseta),  
      1978a+b, 1980, 1984a, 1986a, 2008b, 2011b+c]

T. capucina from Laguna de Bay


60 b. Without this. Body short  compact....................61

Trichocerca (s.str.), Subgenus


61 a. Single dorsal ridge or wide keel at the anterior end. 
Keel usually striated. One long toe
. Size 170 μm.
- Lake Lanao, ponds in Lanao del sur.
   Trichocerca rattus, (MULLER, 1776)
      [1978a+b, 1986a]


61 b. Without dorsal ridge..............................................62  

62 a. Right toe absent, or extremely small. Size 70-­110 my, 
left toe 40-60 um. Eggs attached to other rotifers like 
Brachionus angularis. Planktonic in lakes and ponds, 
also in brackish water. Usually sporadic.

- Bunot Lake, Laguna Lake
   Trichocerca pusilla, (LAUTERBORN, 1898)
      [1941, 1980, 1984, 1999]  

T. pusilla  from Laguna d Bay


62 b. Right toe present but much reduced. Left toe less
than half the body length. Anterior border of lorica 
with undulations. Size of body 120
Planktonic in tropical waters.
- Lake Danao (Leyte/Cebu?), Tadlac Lake, Taal Lake.
Trichocerca dixon-nuttalli (JENNINGS, 1903)
   (syn. Trichocerca ruttneri (DONNER, 1953))
Trichocerca inermis (LINDER 1904))
       [1941, 1999, 2001a, 2011a]   


62 c.  Right toe present. Kidney-shaped lorica, body is short,
thick, and strongly curved, so that the back forms an
arc. The head sheath is marked off from the body and is
composed of eight longitudinal folds. Lacks anterior
spines and protuberances. The toes from almost equal
length to left toe larger than the right. Body
(excluding the toes) 100 μm. Width up to 40 μm.
Length of longest toes 25-40 μm. The species were
correlated with abundance of cyanobacteria (blue
green algae) in occurrence (Lewis 1979b)
- Lake Lanao (in 1970-71)
Trichocerca brachyura  (GOSSE, 1851)
Diurella brachyura)


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