Apodera vas f. recticollis Jung, 1942
Diagnosis: Test composed of two clearly distinct parts, a sub-spherical 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 Apodera vas f. recticollis (erroneously called A. vas f. reticollaris by Kosakyan et al. 2016), which differs from the type by the straighter neck and absence of a bulb on the junction separating the body from the neck. It is darker than the type species, almost dark brown. Dimensions of the test are not differing very much from the type: length 118-158 μm, breadth 75-97 μm, diameter of the aperture 28-38um. Whether this is just phenotypic plasticity or an independent species needs to be proven by molecular methods. Zapata and Fernandez (2008) already observed polymorphism within A. vas species. Based on morphology and morphometry they were able to separate at least 2-3 morphotypes within the species. The polymorphism of A. vas needs 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