Apodera vas f. reticollaris Jung, 1942
Diagnosis: Test composed of two clearly distinct parts, a subspherical or ellipsoidal, compressed basal part and a neck. The two parts are separated by a deep constriction. Test brown to dark brown. Neck rather straight not swollen at the junction separating the main part of the test from the neck.
Dimensions: L=118-158 μm, B=75-97 μm
Remarks: Jung (1942) described new form of Apodera vas f. reticollaris, which differes from the type by the straighter neck and absence of bulb on the junction separating body from the neck. It is darker than type species, almost dark brown. Dimensions of the test are not differing very much from type: length 118-158um, breadth 75-97um, diameter of the aperture 28-38um. Whether this is just phenotypic plasticity or independent species need to be proven by molecular methods. Zapata and Fennandez (2008) already observed polymorphism within A. vas species. Based on morphology and morphometry they were able to separate at list 2-3 morphotypes within the species. The polymorphism of A. vas need to be proven by molecular methods (from Kosakyan).
Reference: Kosakyan, A., Gomaa, F., Lara, E. and Lahr, D.J.G. : Current and future perspectives on the systematics, taxonomy and nomenclature of testate amoebae – European Journal of Protistology, 2016