Vahlkampfia Chatton & Lalung-Bonnaire, 1912 (ref. ID; 4882, 7755) reported year? (ref. ID; 1618) or Chatton & Lalung-Bonnaire 1912 emend. Calkins, 1913 (ref. ID; 3687)
Class Heterolobosea Page & Blanton, 1985: Order Schizopyrenida Singh, 1952: Family Vahlkampfiidae Jollos, 1917 (ref. ID; 4882)

[ref. ID; 1618]
Small amoebae; vesicular nucleus with a large endosome and peripheral chromatin; with polar caps during nuclear division; snail-like movement with one broad pseudopodium; cyst with a perforated wall; fresh water or parasitic. (ref. ID; 1618)

[ref. ID; 1923]
Amoeba slug-like, producing flagellate forms with 2 flagella. Numerous forms, commonly called "Limaxamoebae" occurring in water, soil, dung, and giving very easily abundant cultures in which the flagellate stage can be observed. (ref. ID; 1923)

Vahlkampfia aberdonica Page, 1974 (ref. ID; 7755) reported author and year? (ref. ID; 42, 5753)
Description; The cyst wall consisted of two layers markedly different in final appearance, the inner one very finely fibrous, the outer more darkly staining but somewhat coarser in texture. Walls without this outer layer were also found (Page 1974). (ref. ID; 7755)
Vahlkampfia anaerobica Smirnov & Fenchel, 1996 (ref. ID; 4882 original paper)
Diagnosis; The frontal hyaloplasm occupies up to 1/3 of the total body length. Long, trailing, sometimes brached uroidal filaments common. Length of the amoebae varying between 11 and 34 um with an average of 22-24 um; breadth varying between 3 and 11 um (average: 6-7 um). The L/B ratio varies between 2 and 5.2 with an average of 2.8-3.8. No mitochondria with cristae, but organelles bounded by a double membrane are present. The cell has endocytic bacteria in the cytoplasm. Single nucleus about 3 um in diameter with a thin peripheral layer of nucleolar material adjacent to the nuclear membrane. The nucleus is enveloped with flattened saccules of RER originating from the external nuclear membrane. Anaerobic. (ref. ID; 4882)
Comments; This limax amoebae has many similarities (locomotive morphology, eruptive movement the absence of the alternate flattened form and of dictyosomes) in common with members of the class Heterolobosea Page & Blanton, 1985; order Schizopyrenida Singh, 1952. The absence of mitochondria with cristae is probably secondary and a result of adaptation to anaerobic habitats. Many anaerobic protozoa do not have typical cristate mitochondria (Finlay & Fenchel 1989; Goodkov & Seravin 1991; Fenchel & Finlay 1995), although organelles bounded by a double membrane occur in most groups. The absence of mitochondria with cristae is not considered to warrant the establishment of a new taxon for this amoeba. Due to difficulties of cultivating and cloning, the entire life cycle of V. anaerobica is not known with certainty. Within in the class Heterolobosea presence/absence of flagellated stages, cyst structure and the type of the nuclear division are very important for classification. Thus, the proposed systematic position of the species can be considered only as provisional and more or less formal. At this time it is assumed that this heterolobosean does not have a flagellated stage and that it does not form cysts. The locomotive morphology, the presence of uroidal filaments or a villous-bulbous uroid and the absence of a flagellated form all indicate that the species belongs to the genus Vahlkampfia Chatton & Lalung-Bonnariew, 1912 within the family Vahlkampfiidae Jollos, 1917. The nuclear structure and the uroid of the present species are both rather different from that of any other Vahlkampfia spp. Also, no anaerobic and amitochondrial species are known within the genus. These features together warrant the description of a new species within the genus. (ref. ID; 4882)
Known habitat; Marine, upper layer of ananerobic sediments, in or bellow mats of colorless sulphur bacteria. Niva Bay, the Sound (15 km South from Helsingor), Denmark. (ref. ID; 4882)
Type slides; Deposited at the British Museum of Natural History (holotype 1995:9:6:1; paratype 1995:9:6:2). (ref. ID; 4882)
Vahlkampfia avara Page, 1967 (ref. ID; 7755) reported author and year? (ref. ID; 42, 5753, 7050)
Description; The internal transcribed spacer (ITS) sequences. (ref. ID; 7050)
Notes; In the fixation which gave the best preservation of internal structure, the cyst wall of this species appeared thicker (to 0.7 um, usually 0.4 um or less) and less dense than that of V. inornata. The cyst walls of both strains of V. avara had the same appearance. It was evident that the substance of this less rigid wall often penetrated into the surface irregularities of the cell and tended to break up on the outside of the wall. The wall appeared somewhat more dense in cysts fixed by a slightly different procedure, but the entire wall was of a uniform texture even after thickening. Possibly the 'outer gelatinous layer' (Page 1967) corresponds to the wall seen with the electron microscopic and the thin inner layer described from light microscpic observations is simply the interface with the cell proper. The ragged appearance of the exposed surface of the wall can be correlated with the marked tendency to collect bacteria and detritus which gave this species its name. As in V. inornata, major splitting of the wall was ever observed. (ref. ID; 7755)
Vahlkampfia caledonica Anderson, Rogerson & Hannah, 1997 (ref. ID; 7393 original paper)
Description; Limax amoebae (mean length 47.4 +/- 16.0 um and mean breadth 12.1 +/- 3.2 um) with eruptive locomotion, rapid (2.8 +/- 0.8 um/s) changing direction frequently; hyaline cap slight and distinct, finely granular emerging from a more granular endoplasm. Cells range in size from 25 to 75 um, infrequently reaching lengths of 100 um. The length to breadth ratio is c. 4.0. Nucleus (4.0 um), spherical, located near posterior of cell, sometimes surrounded by distinct granules, containing a central nucleolus (1.5 um). Most cells are uninucleate, but some contain two or three nuclei. Cell body tapered at the posterior with an occasional filamentous uroid, but lacking a collopodium or bulbous posterior end. Sedentary cells may be somewhat contracted, and sometimes have fine, flamentous, cytplasmic attachments to the substratum. In older cultures, some cells may become fully contracted into spherical bodies lacking a wall. No cysts were observed. Fine structural features are characteristic of the genus including mitochondria with sparse, flattened cristae surrounded by endoplasmic reticulum. Scattered, somewhat ellipsoidal, electron-dense reserve bodies (c. 0.2 um) are especially prominent near the periphery of the cell. The glycocalyx is composed of a thin flamentous layer immediately coating the plasma membrane; there are no distinctive glycostyles. Digestive vacuoles are scattered throughout the cytoplasm and contain bacteria, filamentous cyanobacteria, diatoms, and sometimes flagellates. No Golgi bodies were observed. (ref. ID; 7393)
Remarks; The light microscopic morphology of V. caledonica is characteristic of the genus Vahlkampfia with eruptive locomotion, thin hyaline anterior cap of cytoplasm, and posteriorly-tapered cell body. The fine structure, especially the mitochondria with sparse flattened cristae and the scattered dense reserve bodies, resembles Pernina, Kadiri et al., 1992, a genus of vahlkampfiid-like marine amoebae isolated initially from decaying seaweed. However, the most distinctive feature of Pernina, separating it from our vahlkampfiid amoeba, is the cyst with an organic wall bearing plugged pores. We have never observed cysts in our cultures. The cultures have been observed repeatedly, including aging cultures, and were successively transferred and maintained in the laboratory for several months. The spherical bodies frequently observed in older cultures lack a cell wall, and the fine structure is not distinctly different from the trophic stage, with the exception that the cytoplasm sometimes contains regions with clumps of glycogen. Thus, we have assigned this new species to the genus Vahlkampfia. Vahlkampfia caledonica is a relatively large species of Vahlkampfia. It is closest in size to the freshwater species Vahlkampfia ustiana Page, 1974 with a length of 30-65 um, which also can be multinucleate. However, V. ustiana has a prominent collopodium or bulbous posterior end and forms cysts (Page 1974). Its length to breadth ratio is 3.5 while that of our new species is 4.0. Hence, we conclude that our species is not V. ustiana that has invaded a marine habitat. Other known marine species of Vahlkampfia are smaller that V. caledonica (Page 1983). (ref. ID; 7393)
Etymology; Vahlkampfia caledonica is named for the geographic location where it was collected in Kames Bay, Isle of Cumbrae, Scotland. (ref. ID; 7393)
Habitat; Marine, fine sandy, surface sediments, low in organic content 0.3% (w/v) with salinity of c. 32 ppt. (ref. ID; 7393)
Type locality; Isolated from sediment in Kames Bay in the Firth of Cylde. (ref. ID; 7393)
Type specimen; A holotype specimen (Kernechtrot stained permanent slide, registration number 1996:5:28:2) has been deposited with the British Museum of Natural History, London. (ref. ID; 7393)
Vahlkampfia enterica Page, 1974 (ref. ID; 7755) reported author and year? (ref. ID; 5753)
Notes; This finely fibrous wall sometimes showed splitting, as reported from light microscopic observations (Page 1974). The inner and outer walls sometimes appeared of similar density with one fixation method and different with another, but the outer layer usually appeared somewhat darker with both methods, even when no splitting occurred, suggesting some change in the exposed material. (ref. ID; 7755)
Vahlkampfia guttula Dujardin (ref. ID; 3497)
Description; The flat body without definite pseudopodia is elongate elliptical, and made of a wide well-developed ectoplasm and an endoplasm having posterior projections and reflexible granules. The nucleus is large and has an endosome provided with central clear area. Short uroids always seen at the posterior end. (ref. ID; 3497)
Comments; It is easily distinguished from the allied form, V. limicola Rhumbler, in presence of uroids. (ref. ID; 3497)
Measurements; Length 30-62 um; breadth 22-42 um; diameter of a nucleus 7-10 um. (ref. ID; 3497)
Vahlkampfia inornata Page, 1967 (ref. ID; 7755) reported year? (ref. ID; 1543) reported author and year? (ref. ID; 5753, 7050)
Description; The internal transcribed spacer (ITS) sequences. (ref. ID; 7050)
The simple, smooth cyst wall seen with the light microscope was shown by the electron microscope to consist of a uniform layer of very finely fibrous material, which became rigid early enough not to follow the folds in the cell surface. The wall is about 0.2 um thick. No major splitting of the wall was ever seen. An interisting difference between encysted and trophic stages was the greater elongation of the mitochondria in the former. (ref. ID; 7755)
Vahlkampfia limax (Dujardin) (ref. ID; 1618, 1923, 3342, 5624) or (Vahlkampf, 1905) (ref. ID; 3497)
Description; In fresh water. (ref. ID; 1618)
The oblong body usually produces a single broad forward pseudopodia, and typically has posterior uroids. Discrimination of the ecto- and endoplasm is not always distinguishable, and protoplasmic current is generally active in moving. Contractile vacuoles are typically present. The commonest amoeba in fresh water is also common in brackish and sea water. (ref. ID; 3497)
Measurements; 30-40 um long. (ref. ID; 1618)
13-27 um. (ref. ID; 3342)
Length 22-37 um. Marine specimens are generally smaller than fresh water ones. (ref. ID; 3497)
Vahlkampfia limicola Rhumbler (ref. ID; 3497, 5624)
Description; The body is flat and ovate, and contains a wide clear ectoplasm which make a broad pseudopodium. The nucleus is rather large and characteristic in chromatic granules arranged along the nuclear membrane instead of an endosome. Contractile vacuoles are usually present. (ref. ID; 3497)
Measurements; Length 13-20 um. (ref. ID; 3497)
Vahlkampfia lobospinosa Craig, 1912 (ref. ID; 3807) reported author and year? (ref. ID; 3680, 4060, 7289)
Description; The 16S-like ribosomal RNA sequences, length and % G + C content. (ATCC# 30298, GenBank M98052). (ref. ID; 7289)
Vahlkampfia patuxent Hogue (ref. ID; 1618)
Description; In the alimentary canal of the oyster; ordinarily one large broad fan-shaped pseudopodium composed of the ectoplasm; in culture, pseudopodium-formation eruptive; holozoic on bacteria; multiplication by fission or budding; encystment rare; cysts uninucleate. (ref. ID; 1618)
Measurements; About 20 um long during the first few days of artificial cultivation, but later reaching as long as 140 um in diameter. (ref. ID; 1618)
Vahlkampfia ustiana Page, 1974 (ref. ID; 7393, 7755) reported author and year? (ref. ID; 42, 5753)
Notes; The cyst wall of this species was distinctly two-layered, and the two layers could be either tightly pressed together or separated. The inner layer was much denser than the outer and sometimes difficult to distinguish from the cell proper, from which it was, however, delimited by the plasma membrane, which was preseved at some points. (ref. ID; 7755)