Kraken
Cellular features of Kraken carinae. The filopodium might branch (br) or anastomose (an). The origin of the filopodium is usually located under the cell body and branches directly at least once (indicated by arrows). Cells contain one contractile vacuole (cv), one food vacuole with several particles (fv) and one round nucleus (nu) with one roundish nucleolus (no). Granules (g) are often observed but their number differs tremendously. Measure bar indicates 10 µm.
 
 

Kraken Dumack, Schuster, Bass et Bonkowski, 2016

 

Diagnosis: Very slow moving filose amoeba. Cell body roundish in shape. Usually a single highly branched filopodium originating between the cell body and the substrate through a ring-like structure sometimes visible by light microscopy. The filopodium branches and anastomoses, forming a network. Division longitudinal. Bacterivorous, prey is being transported through the filopodium to the cell body. Cells contain one, rarely two nuclei with one round nucleolus, one contractile vacuole, and usually one food vacuole.

 

Etymology: krakonan, n [Proto-Germanic] similar words present in several old nordic languages, Kraken refers to the monster Hafgufa (the Kraken) in norse mythology that catches its prey (ships, men, whales and everything else) with its plentiful arms. Like the Kraken of the legend our isolates are characterized by a huge network of filopodia preying on bacteria that are then transported to the cell body for digestion.

 

Type species: Kraken carinae

 

 

Kraken carinae Dumack, Schuster, Bass et Bonkowski, 2016

 

Diagnosis: Kraken as defined above. Cell body (longest axis) 5.5-11.5 µm.

Type location: Surface soil, agricultural field in northern Germany

Etymology: carina [Latin], noun = ship, nutshell; referring to the prey of the mythical Kraken. Additionally, this species is dedicated to Carina Platten in recognition of her support and encouragement.