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FILINIIDAE, HARRING AND MEYERS, 1926 (family)

     Without foot. Cuticle thin, transparent, 
not usually retaining its shape well after 
preservation. Body with long spines, 2 anterior 
and 1 (Filinia) or 2 (Tetramastix) posterior 
spines. Planktonic.
The separation in two genera (Filinia and 
Tetramastix) based on the number of posterior 
spines might not be valid since intermediates 
are found (Ruttner­Kolisko 1972).

FILINIA, BORY ST. VINCENT 1824.
The genus is abundance among the plankton in polluted
biotopes like Pasig River (2009a). Prefer alkaline
waters (Sládeček 1983).

TETRAMASTIX GROUP

71 a. Two posterior spines developed. One well 
developed (200 μm)one more or less reduced 
(= spine). Lateral spines broad-based,
club-like, and only slightly longer the body. 
Body spindle-shaped. Size 150-200 μm. 
Shows affinity for Cryptomonads,
Bluegreens and Dinoflagellates in 
Lake Lanao (Lewis 1979). Warm stenotherm, 
planktonic in lakes and ponds. Indicator of
oligotrofic waters (Sládeček 1983).
Stenohaline, cannot handle a wide fluctuation
in the salt content of water.
Common.
- Laguna de Bay, La Mesa Dam, Calibato Lake, 
  Lake Lanao, Paoay Lake.
   Filinia opoliensis, (ZACHARIAS, 1898)
    (syn. Tetramastix opoliensis)
                   [1941a, 1974, 1977, 1978a+b, 1979b, 
             1980, 1984a, 1986a, 2008b, 2011b+c]

F. opoliensis from Laguna de Bay	F. opoliensis  (Photo Rey Donne S. Papa, 2007)

 

 

71 b Only one posterior spine........................72

FILINIA-TERMINALIS GROUP

72 a. Only one posterior spine, arising from the 
ventral surface. Spines not thickened at 
the base. Lateral spines much longer than body. 
Inserted more than 10 μm from terminal end of 
body. Size of body 150-250 μm, spines 510 μm. 
Lake form usually with longer spines than pond 
form. Form limnetica if spines 4 times longer 
than body or more. Feed on detritus and bacteria, 
with a particle size less than 10 μm.
Warm stenotherm 23-31^oC, pH 7.4-8.1, and conductivity
180-1,600 μS cm^-1, salinity 0-0.5⁰/₀₀
but stenohaline, so it cannot handle
a wide fluctuation in the salt content of water.
In shallow, eutrophic lakes, fishponds,
village ponds. May dominate the rotifer community.
Indicator of eutrophic and polytrophic waters
(Sládeček (1983). Abundance was higher in the
Northern basin of Taal Lake, than the Southern basin,
probably caused by the eutrophication effect of
the fish gages in the area (Papa et al. 2011b).
- Laguna de Bay, Sampaloc Lake, Taal Lake.
   Filinia longiseta (EHRENBERG, 1834)
    (syn. Triarthra longiseta)
             [1941a, 1974, 1980, 1984a, 1999, 2011b+c]

F. longiseta from Laguna de Bay

72 b. Small, cylindrical-oviform body, posterily rounded 
but may be fusiform in contracted individuals. 
Posterior spine inserted 4-10 μm from terminal 
end of body, slightly thickened at base. Like 
F. terminalis. Body length 120-140 μm. Lateral 
spines 265-350 μm. Terminal spine 180-290 μm. 
In eutrophic lakes and rice fields (Shiel and 
Sanoamuang, 1993, Tuyor and Segers, 1999)
- IRRI rice field.
   Filinia novaezealandiae, SHIEL AND SANOAMUANG, 1993
              [1999]

Other pantropic species of Filinia from the neighbourhoods
(se Sanoamuang, 2002):

Lateral setae inserted at the point near middle part of body.
 - Not recorded from the Philippines.
   Filinia camasecla MEYERS, 1938

Lateral setae short.
- Not recorded from the Philippines
   Filinia brachiata (ROUSSELET, 1901)

 

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