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HEXARTHRIDAE, (BARTOS, 1959) (family)

Without foot. Jaws mallepramate. Fulcrum short,
rami more or less triangular, flat; unci teeth
numerous.
Cuticle thin, transparent, not usually
retaining its shape well after preservation.
Body with 6 arms with setae. Nauplius-like.
Planktonic.

 

HEXARTHRA, (SCHMARDA 1854)

Feeds on particles less than 10 μm (Sládeček 1983).

73 a. In freshwater. Ventral arm with 3 spines 
on each side. Size 210
μm. Shows affinity 
for Cryptomo­nads and Dinoflagellates in 
Lake Lanao (Lewis 1979b).  Feed mostly
on particles < 6
μm (Pagano et al, 1999).
Planktonic in  freshwater and in weak 
brackish water.
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).
  Common.
- Laguna de Bay, Pasig River, La Mesa Dam.
  
Hexarthra intermedia, (WISZNIEWSKI, 1929)
             [1978a+b, 1979b, 1980, 1984a,
              1986a, 1994b, 2001a, 2009a, 2011a]

 

H. intermedia from Laguna de Bay

73 b. In sea and salt water. Ventral arm with 
4 spines on each side and 8 setae in 4 
pairs terminally.

- Manila de Bay (1980, 1984), Taal lake.
   Hexarthra fennica (REMANE, 1933)
      [1941a (Pedalia),1941b, 1980, 1984a, 2001a, 2011a]

 

H. fennica from Manila Bay water culture

 

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