Filinia longiseta (Ehrenberg, 1834)

Most likely ID: n.a.

 

Synonym: n. a.

 

Sampling location: Pond of waste disposal company Constance,  Lake Constance,  Mühlhalden pond, Hagstaffel pond

 

Phylogenetic tree: Filinia longiseta

 

Diagnosis: 

  • body sac-shaped, plump, anteriorly transversely truncated, without foot
  • two long lateral setae situated near head
  • one long ventral seta situated at posterior third
  • length of body (without setae) 130–252 µm
  • two eyespots with lenses
  • vitelarium with 8 nuclei
  • circumapical ring of cilia
  • two unci with about 26 theeth
  • resting egg with bubble shaped surface
  • planktonic lifestyle
Filinia-longiseta
Filinia longiseta

Filinia longiseta is one of the most common rotifers in the plankton. The species can be identified very easily by the three long setae, which can be moved very fast by strong muscles, enabling Filinia longiseta to jump quickly. This species occurs only in spring and summer. In autum, restings eggs are formed, which remain in the mother’s body and sink to the bottom of the water when it dies. The next generation hatches from these eggs the following year. Filinia longiseta has two eyespots, which are equipped with two small lenses (s. fig. 5).

 

More images and information of Filinia longiseta: Michael Plewka-Freshwater life-Filinia longiseta

Filinia-longiseta

Fig. 1 a-c: Filinia longiseta. L = 172 µm (without setae). Three focal planes from right of a freely swimming specimen. Obj. 40 X.

Filinia-longiseta

Fig. 2 a-c: Filinia longiseta. L = 181 µm (without setae). Lateral view from right (a, b) and left (c) of a second, freely swimming specimen. Obj. 40 X.

Filinia-longiseta

Fig. 3: Filinia longiseta. Dorsal view of a slightly squashed specimenLateral view from right (a, b) and left (c) of a second freely swimming specimen. CC = circumapical ring of cilia, DA = dorsal antenna, LA = lateral antenna, RM = retractor muscle for lateral seta. Obj. 60 X.

Filinia-longiseta

Fig. 4: Filinia longiseta. The trophy (Tr) in a strongly squashed specimen. LA = lateral antenna, St = stomach, Vi = vitelarium. Obj. 60 X.

Filinia-longiseta

Fig. 5: Filinia longiseta. The pair of eyespots (ES) with lenses (LE) in a strongly squashed specimen. Obj. 60 X.

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