Dinobryon stipitatum Stein, 1878
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Lake Constance
Phylogenetic tree: Dinobryon stipitatum
Diagnosis:
- cells spindle-shaped
- lorica vase-shaped, long and straight with long tapering portion
- cells attached with a tapered stalk of cytoplasm to the posterior part of the lorica
- two golden brown colored chloroplasts
- the anterior chloroplast with an eyespot
- two flagella of different lengths
- one spherical nucleus between chloroplasts
- two contractile vacuoles in midbody
- length of lorica 35–70 µm
- cells forming a branched colony, branches long and straight
- colony up to 500 µm long
I have found Dinobryon stipitatum only very rarely and exclusively in the plankton of Lake Constance. The lorica of this species is very slender with a long, tapered end. The anterior third is only slightly bulbous or parallel sided and the opening of the lorica is somewhat widened. Due to the slender shape of the loricae, the branches of the colonies also appear slender and straight. The colonies can grow up to 500 µm long. The cells are typical of the genus Dinobryon and do not differ from Dinobryon sertularia or Dinobryon divergens.
Fig. 1: Dinobryon stipitatum. L = 420 µm (of colony). A freely floating colony. Obj. 40 X.
Fig. 2: Dinobryon stipitatum. L = 490 µm (of colony). A second freely floating colony. Obj. 40 X.
Fig. 3: Dinobryon stipitatum. L = 47 µm (of lorica). The loricae are straight and slender with a tapered end. The distal end is slightly widended. The cells are about 20 µm long. CHl 1-2 = chloroplasts, CV = contractile vacuole, ES = eyespot, Nu = nucleus. Obj. 100 X.