Nusuttodinium aeruginosum

(Stein) Takano & Horiguchi, 2014

Most likely ID: n.a.

 

Synonym: Gymnodinium aeruginosum

 

Sampling location: Simmelried, Ulmisried

 

Phylogenetic tree: Nusuttodinium aeruginosum

 

Diagnosis: 

  • length 13–44 µm
  • body ovoid, tear-shaped or squarish
  • epicone (anterior half) longer than hypocone (posterior half)
  • eyespot sometimes present
  • chloroplasts (= kleptoplasts) numerous, blue-green
Nusuttodinium-aeruginosum
Nusuttodinium aeruginosum

I found Nusuttodinium aeruginosum (previously Gymnodinium aeruginosum) up to now in the Ulmisried and in the Simmelried. The species can be identified easily by the blue-green color. In fact, Nusuttodinium aeroginosum is a colorless species. The chloroplasts, which give the cell its blue-green coloration, were “stolen” from photosynthetic prey organisms. Such stolen chloroplasts are also called cleptoplasts. It could be proved that Nussuttodinium aeroginosum obtains these kleptoplasts from Chroomonas. The cells of the prey organisms are completely digested except for the chloroplasts. These are then incorporated into the peripheral cell layer and kept alive.

 

In the literature, the species is described without an eyespot. However, I could detect an eyespot in some specimens but not in all (s. figs. 2 a-e and 4 a-c). Furthermore I found specimens with a rounded epicone and hypocone (s. fig. 3 a-c) and a length of up to 42 µm. Thus, the species seems to be quite variable. 

Nusuttodinium-aeruginosum

Fig. 1: Nusuttodinium aeruginosum. L = 31-42 µm. Overview of a mass occurrence. Obj. 40 X.

Nusuttodinium-aeroginosum

Fig. 2 a-e: Nusuttodinium aeruginosum. L = 36 µm. A freely swimming specimen from ventral (a-d) and from dorsal (e). Obj. 100 X.

Nusuttodinium-aeroginosum

Fig. 3 a-d: Nusuttodinium aeruginosum. L = 37 µm. Different focal planes of a second freely swimming specimen from ventral. Obj. 60 X.

Nusuttodinium-aeroginosum

Fig. 3 a-c: Nusuttodinium aeruginosum. L = 38 µm. A slightly squashed specimen from dorsal. CL = cleptoplasts, NU = nucleus, TF = transversal flagellum. Obj. 100 X.

Nusuttodinium-aeroginosum

Fig. 4 a-c: Nusuttodinium aeruginosum. L = 36 µm. A slightly squashed specimen from ventral. ES = eyespot, LF = longitudinal flagellum. Obj. 100 X.