Testudinella patina (Hermann, 1783)

Most likely ID: n.a.


Synonym: Testudinella trilobata triangularis, Testudinella pseudoelliptica, Pterodina trilobata, Pterodina intermedia, Testudinella trilobata haterumensis, Testudinella sculpturata, Pterodina valvata


Sampling location: Bussenried, Ulmisried, Simmelried


Phylogenetic tree: Testudinella patina



  • lorica almost circular, dorso-ventral flattened
  • body transparent, length 120–350 µm, width 100–236 µm
  • foot opening ventral, circular, almost in the middle
  • foot annulated, retractile, distal end with cilia
  • corona is a band of cilia
  • two conspicuous retractor muscles
  • two eyespots
Testudinella patina

Testudinella patina is a very common and widespread species. I was able to detect it in several of my sites in floating plant material. The species is very photogenic because of the strongly flattened and transparent lorica. Already in 1995 I took the first photos of Testudinella patina (s. fig. 1) and after that always in larger intervals. I have always been able to find the species in the summer months. Because of the dorso-ventral flattening the internal organs are not on top of each other and one can study the anatomy of this rotifer in detail (s. fig. 4).


More images and information of Testudinella patina: Michael Plewka-Freshwater life-Testudinella patina


Fig. 1: Testudinella patina. L = 200 µm. Ventral view of a slightly squashed specimen. This images was taken in July 1995. Obj. 40 X.


Fig. 2 a-b: Testudinella patina. L = 183 µm. Two focal planes of a ventral view of a slightly squashed specimen. This specimen was found in August 2008. Note the circular foot opening (FO) on the ventral side of the lorica. Obj. 40 X.


Fig. 3: Testudinella patina. L = 256 µm. Ventral view of a slightly squashed specimen. This image was taken in September 2016. Obj. 40 X.


Fig. 4: Testudinella patina. L = 226 µm. Ventral view of a slightly squashed specimen. The image is from Juli 2020. CO = corona, ES = eyespots, PN = protonephridium, RM = retractor mucles, ST = stomach, TR = trophi, VI = vitellarium. Obj. 60 X.