Hartmannella

Hartmannella Alexeieff, 1912 (ref. ID; 3687) or (Alexieff, 1912) Page, 1974 (ref. ID; 4891)

Class Tubulinea: Order Tubulinida (ref. ID; 6789)
Family Hartmannellidae (ref. ID; 7755)

See Acanthamoeba (ref. ID; 1618)

[ref. ID; 1618]
Small amoebae, with moderately or well-developed ectoplasm; vesicular nucleus with a large endosome; mitotic figure ellipsoidal or cylindrical, without polar caps. Cysts rounded; wall smooth or slightly wrinkled in one species. Several species. (ref. ID; 1618)

[ref. ID; 3991]
Type species; Hartmannella hyalina (Dangeard, 1900) (ref. ID; 3991)

  1. Hartmannella abertawensis Page, 1980 (ref. ID; 7393, 7755) reported author and year? (ref. ID; 4891)
  2. Hartmannella agricola Goodey, 1916 (ref. ID; 3687)
  3. Hartmannella aquarum Jollos, 1917 (ref. ID; 3687)
  4. Hartmannella astromyxis Ray & Hayes (ref. ID; 1618)
  5. Hartmannella cantabrigiensis Page, 1974 (ref. ID; 4891, 7126, 7393, 7755) reported author and year? (ref. ID; 6789)
    See; Copromyxa cantabrigiensis (ref. ID; 7126)
  6. Hartmannella fecalis Walker, 1908 (ref. ID; 3687)
  7. Hartmannella fluvialis Dobell, 1914 (ref. ID; 3687)
  8. Hartmannella glebae Dobell, 1914 (ref. ID; 3687)
  9. Hartmannella hibernica
    See; Nolandella hibernica (ref. ID; 7393)
  10. Hartmannella horticola (Naegler, 1909) (ref. ID; 3687)
  11. Hartmannella hyalina (Dangeard, 1900) (ref. ID; 3687) reported year? (ref. ID; 1618)
  12. Hartmannella klitzkei Arndt, 1924 (ref. ID; 3687) reported year? (ref. ID; 5624)
  13. Hartmannella lamellipodia Glaeser, 1912 (ref. ID; 3687)
  14. Hartmannella limacoides
    See; Cashia limacoides (ref. ID; 7755)
  15. Hartmannella lobifera Smirnov, 1996/97 (ref. ID; 4891 original paper)
  16. Hartmannella (Amoeba) mira (Glaeser, 1912) (ref. ID; 3687)
  17. Hartmannella motonucleata Lepsi, 1960 (ref. ID; 3687 original paper)
  18. Hartmannella polyphaga Puschk., 1913 (ref. ID; 3687)
  19. Hartmannella rhysodes Singh (ref. ID; 4173) reported author and year? (ref. ID; 4658)
    See; Acanthamoeba castellanii, strain HR (ref. ID; 4158, 4173)
  20. Hartmannella vacuolata Anderson, Rogerson & Hannah, 1997 (ref. ID; 7393 original paper)
  21. Hartmannella vermiformis Page, 1967 (ref. ID; 7393, 7755) reported year? (ref. ID; 1543) reported author and year? (ref. ID; 6789)

Hartmannella abertawensis Page, 1980 (ref. ID; 7393, 7755) reported author and year? (ref. ID; 4891)

Notes

This marine amoeba, described from the shore of the Bristol Channel (Page 1980), had a mean length in locomotion of 11.5 um. New observations showed no optically active inclusions. The original description included fine structure, but Fig.17 is presented here to illustrate the presence of the same sort of sucker-like or cup-like, sometimes slightly pyramidal, surface structures found in other hartmannelids. Their diameter was approximately 17-21 nm. These were previously interpreted as 'wicket- or hoop-like' (Page 1980). That report also called attention to the similarity of the nuclei of H. abertawensis and H. vermiformis. Besides differing in habitat, H. abertawensis was much smaller than H. vermiformis, has never been observed to produce cysts, and did not have extensive tracts of flattened rough endoplasmic reticulum. Its Golgi bodies (dictyosomes) were larger and more numerous than those of H. vermiformis. (ref. ID; 7755)

Examined materials

CCAP 1534/9, salt water, Wales (strain 187 of Page, 1980). (ref. ID; 7755)

Hartmannella astromyxis Ray & Hayes (ref. ID; 1618)

Descriptions

Pseudopods variable; one to several contractile vacuoles; cyst, circular and biconvex; the inner wall stellate with 3-9 (5-7) drown-out points; during encystment, endosomic materials are extruded into the cytoplasm; fresh water. (ref. ID; 1618)

Measurements

18-42 um in diameter; cyst 14-32 um in diameter. (ref. ID; 1618)

Hartmannella cantabrigiensis Page, 1974 (ref. ID; 4891, 7126, 7393, 7755) reported author and year? (ref. ID; 6789)

See

Copromyxa cantabrigiensis (ref. ID; 7126)

Descriptions

This species was described (Page 1974) from two freshwater sources in Cambridge. Its locomotive form had a mean length of approximately 23 um, the cyst a mean diameter of 8.8 um. New obsevations with crossed polarisers showed that the small inclusions previously recognised as crystalline were optically active. In the longitudinal section an anterior hyaline zone is difficult to distinguish. Some cytoplasmic filaments can be seen near either end. The nucleus had an irregular outline, with no inner fibrous lamina. The central nucleolus occasionally contained a smallish lacuna and was accompaned by a paranucleolar body, present also in cysts. The surface appeared smoother than that of any other hartmannellids, but indications of cup-like structures with a hexagonal cross-section could be faintly perceived in favourable tangential sections. The diameter of such structures at the point of sectioning was about 15-20 nm. The mitochondria were oval to elongate in profile, up to 1.5 um long, with tubular cristae about 50 nm in diameter, rather infrequently branching. Although the Goldi body was near the nucleus, these bodies (two or more in some sections) could also be elsewhere. Each consisted of three to five, often four, flattish sacs, and the maximum width of the body was 0.8 um, often less. Much of the rough endoplasmic reticulum was in longish, rather open tracts. These amoebae contained no endocytic bacteria. Sections of cysts fixed by different methods were very similar. Both nuclei and cytoplasmic organelles were better preserved than is usual in cysts. Although a thin outer layer (exocyst) was described from light microscopic observations (Page 1974), the electron microscope always showed a single wall composed of fibrous material of uniform appearance, about 0.2 um thick. The cell was always separated from the wall and had a wrinkled surface not present in the contour of the wall, suggesting a further reduction in cell volume after hardening of the wall. (ref. ID; 7755)

Examined materials

CCAP 1534/8, freshwater, England (strain 123 of Page, 1974). (ref. ID; 7755)

Hartmannella hyalina (Dangeard, 1900) (ref. ID; 3687) reported year? (ref. ID; 1618)

Descriptions

Ectoplasm well developed; endoplasm vacuolated; slender pseudopodia extend in different directions; Hartmann and Chagas observed a centriole in the endosome. (ref. ID; 1618)

Measurements

20-25 um in diameter. (ref. ID; 1618)

Hartmannella lobifera Smirnov, 1996/97 (ref. ID; 4891 original paper)

Diagnosis

Hyaline cap sometimes obliterated by the intruding granuloplasm. Posterior hyaline lobes common, sometimes a morulate-like uroid is present. Length of the locomotive form varies from 28 to 42 um (mean 35.2 um); breadth varies from 5 to 8 um (mean 6.8 um). Length/breadth ratio (L/B) varies from 4 to 7 (mean 5.1). Nucleus 3.5-6 um in diameter, nucleolus 1-2 um. Contractile vacuoles present when amoebae are cultivated in 20 o/oo seawater. Capable of living and multiplying in 35 0/00 seawater and does not survive in freshwater. No cytoplasmic crystals. Cysts 10-12 um in diameter. Endocyst always situated eccentrically, being attached to the ectocyst at one side and separated from the latter by a distinct empty space at the opposite side. Inner cyst wall consists of three amorphous layers; its thickness is about 170 nm. Outer wall appears to have a fibrous nature; its thickness is about 160 nm. (ref. ID; 4891)

Differential diagnosis

The present species is three times larger then the only known marine species of Hartmannella, H. abertawensis; it has a different uroid and a different cyst structure. The latter feature also differentiates it from any described freshwater member of this genus. (ref. ID; 4891)

Descriptions

Locomotive amoebae were always monopodial, with an anterior hyaline cap which from time to time was obliterated by intruding granules. When the amoeba starts move the cap may be somewhat narrower than the rest of the cell. The body of the locomotive form was usually equally wide at its anterior, posterior and middle parts. Amoebae moved by steady flowing of the cytoplasm; no evidence of eruption was seen. The presence of 1-3 small posterior hyaline lobes was very common. The formation of these lobes was a very characteristic process connected with the changing of the direction of movement. Some specimens in locomotion had no lobes, but instead they had a broad, not very well differentiated morulate uroid and some had no differentiated uroid at all. Villous uroid or trailing uroidal filaments were never observed. The amoebae frequently changed direction of locomotion. In fact it was difficult to find a monopodial locomotive form, because most amoebae produced pseudopodia, often in two or three different directions simultaneously. The amoeba can change the direction of locomotion by turning its anterior end, but more often it produces a lateral pseudopodium. This pseudopodium becomes the leading one and the amoebae starts to move in new direction. While the major part of the amoebae body progresses in the new direction the remnants of the previous hyaline can remain at the same place. Thus it moves along the amoebae body towards its posterior end. When it reaches the end of the cell it separates from the glass and forms a posterior hyaline lobe. When not moving ("resting") the amoebae were generally rounded, often with 3-5 distinct hyaline lobes. The amoebae did not produce a differentiated floating form; floating amoebae were often irregular and produced pseudopodia in all directions. A vesicular nucleus was discernibe in both live and in stained specimens. Its diameter as measured in stained preparations, was 3.5-6 um and the diameter of the nucleus was 1-2 um. A small contractile vacuole was usually situated in the posterior part of the body, but sometimes it was observed moving within the cell. Prior to systole it was always situated near the surface at the posterior part of the cell. The refractile spheres, about 1 um in diameter, were the most characteristic cytoplasmic inclusions. Their number varied from 3 to 42 per cell. The cytoplasm also contained many small opaque granules and some food vacuoles. After 3-4 weeks of cultivation on medium the amoebae produced cysts. The cysts had two distinct walls: a thin outer wall and a thicker inner one. The cell was sealed to the inner wall of the cyst. The slightly ovoid endocyst was always situated eccentrically inside the spherical ectocyst, being attached to the outer wall from one side and leaving a distinct empty space on the other side. No cyst pores were detected. The diameter of the ectocyst was 10-12 um and the maximum dimension of the endocyst was 8-11 um. All observed cysts were uninucleate. The nucleus was spherical, with a central and slightly heterogeneous nucleolus and without any differentiated inner nuclear lamina. The cell surface coat consisted of a thin (about 20 nm) glycocalyx without any visible differentiation. The mitochondria were rounded or elongate, with tubular cristae. Dictysomes were few and consisted of 3-6 flattened cisternae. Some membrane-bounded inclusions with a rounded or irregular form, were present in sections. The contractile vacuole was situated in the posterior part of the body, near the cell surface. It was surrounded by regularly arranged microfilaments and by small vesicles; several mitochondria were always situated around it. In all studied cells the granuloplasm was separated from the hyaloplasm by a layer of microfilaments. Microfilaments weer also abundant in th granuloplasm and sometimes they were arranged in short cores, but careful searching did not indicate the presence of cytoplasmic microtubules. A study of the cysts indicated the presence of three amorphous distinct layers in the endocyst. The total thickness of the endocyst wall was about 170 nm. The ectocyst was finer and its wall appeared to have a filamentous nature. Its thickness was about 160 nm. The endocyst was always situated eccentrically within the ectocyst and a distinct eccentric empty space between them was always observed. Within the agar, ectocysts of neighbouring cysts may be closely adjacent one to another. The surface of the cell within the cyst had channels which formed invaginations of the cell surface. These channels were approximately parallel at neighbouring sites on the surface, but could have different orientations in different region of the surface. The material of the inner cyst wall penetrated some of these channels, while the others were empty in sections. There functional significance remains unknown. (ref. ID; 4891)

Remarks

The species is similar to the known representatives of this genus with respect to locomotive morphology, formation of the lateral pseudopodia while changing direction of movement and absence of a villous-bulbous uroid. The posterior hyaline lobes which are common for this species were also noted for H. cantabrigiensis (Page, 1974). The fine structure of the present species corresponds well to that known from studied freshwater and marine species of Hartmannella (Page 1980, 1986). Cup-like structures or any other discrete elements in the glycocalyx of the present species were not found, but they were possibly destroyed during fixation. In the marine H. abertawensis, differentiated elements in the glycocalyx, were also not observed with certainty (Page 1980). The present species differs from all known species of Hartmannella due to its locomotive morphology and the cyst structure. These features warrant a description of a new species - Hartmannella lobifera. (ref. ID; 4891)

Type locality

The Sound, Niva Bay (brackish-water, salinity about 15 0/00), Denmark. (ref. ID; 4891)

Type slide

Type slides are deposited at the British Natural History Museum (London, U.K.). Holotype: 1995:9:6:5; Paratype: 1995:9:6:6. (ref. ID; 4891)

Measurements

Seventy specimens were measured on the glass surface. The length of the locomotive form varied form 28 to 42 um (mean 35.2 um) and the breadth from 5 to 8 um (mean 6.8 um). Length/breadth ratio (L/B) varied between 4 and 7 (mean 5.1). (ref. ID; 4891)

Hartmanella rhysodes Singh (ref. ID; 4173) reported author and year? (ref. ID; 4658)

See

Acanthamoeba castellanii, strain HR (ref. ID; 4158, 4173)

Descriptions

Soil amoebae. (ref. ID; 4658)

Hartmannella vacuolata Anderson, Rogerson & Hannah, 1997 (ref. ID; 7393 original paper)

Descriptions

Highly vacuolated, limax amoeba with rather constant monopodial form (mean length 32.8+/-6.8 um and mean breadth 8.5+/-1.8 um) with steady, nonerputive locomotion (mean rate of 0.82+/-0.3 um/s), anterior end with broad hyaline zone, and posterior without a uroid, though occasionally with trailing strands of cytoplasm. Cells range in size from 23 to 45 um. The length to breadth ratio is 3.9. Anterior of cell may bifurcate with two emergent pseudopodia with hyaline caps or occasionally becoming angular and somewhat branched when changing motion. Floating form with several bent arms which may be slightly enlarged at the distal ends. Cytoplasm with numerous vacuoles, sometimes filled with debris, and some large enough to occupy one half the breadth of the cell. The nucleus (2.0 um) with undulating margin contains a central somewhat denser nucleolus (0.7 um) suspended within a coarsely granular nucleoplasm. The nucleus is surrounded by mitochondria, small vesicles, and Golgi bodies. The mitochondria have tubular cristae and are interspersed among vacuoles. The plasm membrane is coated with a glycocalyx with occasional cup-shaped structures. The arms of the floating form contain a finely fibrillar hyaloplasm and the surface of the cell is coated with a somewhat osmiophilic glycocalyx. Prey includes mainly bacteria. (ref. ID; 7393)

Remarks

The steady, noneruptive form of locomotion, glycocalyx with occasional circular to polygonal glycostyles, and the presece of the trailing thickened strands of cytoplasm are characteristic of the genus Hartmannella. The fine structural features are also consistent with those reported for other members of this genus (Page 1980, 1983) including the nucleus with undulating margin and central nucleolus, perinuclear Golgi, and features of the glycocalyx. Only one other marine species (Hartmannella abertawensis Page, 1980) has been reported, although more recently a marine isolate identified as Hartmannella has been identified which is approximately the same size as our species, but differs markedly in shape and locomotion (Smirnoff, A., pers. commun.). It also produces cysts which have not been observed in our isolate. Hartmannella abertawensis is a relatively small limax amoeba with length of 7.5-19.0 um (mean 11.5 um) and contains a glycocalyx consisting of units shaped like truncate pyramids, each with basal diameter c. 15 nm. The larger size our isolate (32.8 um), its numerous vacuoles, and the lack of pyramidal units in the glycocalyx, indicates this is not H. abertawensis. The floating form with extended arms is not common for limax amoebae and is more characteristic of members of the family Amoebidae; however, at least one other limax species Nolandella (Hartmannella) hibernica also has a floating form with radiating arms (Page 1980), and this is not considered to be an unusual feature of a Hartmannella sp. (Page, F.C., pers. commun.). Nolandella hibernica, originally described as Hartmannella hibernica, was assigned to the genus Nolandella by Page (1980, 1983) who noted differences from the genus Hartmannella; i.e. shape more like the Vahlkampfiidae, from which it differs in both mitotic pattern and presence of a dictyosome, and cell surface structures that resemble those of Platyamoeba (q.v.). (ref. ID; 7393)

Etymology

Hartmannella vacuolata is named to denote the highly vacuolated form of the cytoplasm. This condition has been observed consistently in laboratory cultures throughout repeated transfers and appears to be a characteristics feature of this new species. (ref. ID; 7393)

Habitat

Marine, fine sandy, surface sediments, low in organic content 0.3% (w/v) with salinity of ca. 32 ppt. (ref. ID; 7393)

Type locality

Isolated from sediments in Kames Bay in the Firth of Clyde. (ref. ID; 7393)

Specimen deposited

A holotype specimen (Kernechtrot stained permanent slide, registration number 1996:5:28:1) has been deposited with the British Museum of Natural History, London. (ref. ID; 7393)

Hartmannella vermiformis Page, 1967 (ref. ID; 7393, 7755) reported year? (ref. ID; 1543) reported author and year? (ref. ID; 6789)

Remarks

H. vermiformis differs from the "true" Hartmannellidae by having a largely, worm-shaped form and a very well-pronounced hyaline cap which is much more stable than in other Hartmannella species. (ref. ID; 6789)
This is the most commonly reported species of Hartmannella. It was described by Page (1967) from two widely separated sites in the USA. In that study the amoebae were 12-33 um long and the mean cyst diameter was about 6 um. However, subsequent observations of isolates from other sources suggest that these sizes are often exceeded; Findings have been reported from freshwater and terrestrial sources in Czechoslovakia (Cerva 1971), Sweden (Cerva and Huldt 1974), England (Page 1976), France (Molet et al. 1976; Derr-Harf et al. 1978; Grillot and Ambroise-Thomas 1981), USA (O'Dell 1979), India (Singh and Hanumaiah 1979), Spain (Battista Diaz et al. 1982), and Australia (B. Robinson, personal communication). Cerva et al. (1973) found it in the human nasal mucosa, and Kadlec (1975, 1978) in the bronchi of a dog and the trachea and intestine of turkeys. Pathogencity tests of endozoic isolates by Kadlec (1978) were negative, as were tests of freshwater isolates by Cerva (1971) and Grillot and Ambroise-Thomas (1981). Because of this wide distribution, the opportunity was taken to compare strains from widely separated habitats: CCAP 1534/7a, from a lake in Wisconsin, USA (hereafter referred to as the American strain) and CCAP 1534/7b, from leaf litter in Wandlebury, near Cambridge (the English strain). Amoebae of the English strain were 15-37 um long (mean 26.6 um) in locomotion, and the mean diameter of cysts of that strain was 6.9 um. No optically active inclusions were found in this species. Of all the hartmannellids and vahlkampfiids studied, the strains of this species were the most difficult to fix. The most satisfactory method for both strains included 15 min in a glutaraldehyde/OsO4 mixture, 10 min in OsO4 alone, 15 min in uranyl acetate. The results obtained with each strain by a giben method were similar. The nucleus, which had no inner fibrous lamina, was characterised in all fixations of both strains by the presence of conspicuous chromatin bodies between nucleolus and nuclear membrane and also flattened against the inner surface of the nuclear membrane. H. abertawensis is the only other amoeba with a very similar nuclear structure. The presence of sucker-like, often somewhat pyramidal surface elements was readily discernible. These elements were about 12.5 nm wide, their height above the plasm membrane about 6 nm. The mitochondria were oval to elongate, with a maximum length of 1.1 um but often shorter; The cristae were tubular, about 46 nm in diameter; branching was not detected with certainty. Dictyosomes appeared rare. Much of the rough endoplasmic reticulum occurred as long, flattened tracts. These amoebae contained no endocytic bacteria. Many sections cysts of both strains were observed, and both basic structure and variations were similar in English and American strains. The wall as laid down had a very finely fibrous appearance, most dense in a thin region closest to the plasma membrane. A single wall was produced, and sometimes it did not separate at all over most of its circumference or separated so close to the outer surface in some places that the separated material would not be distingishable with the light microscope. At other times the separation extended over much the cysts's surface, and the separated material appeared as a distinct exocyst some distance from the inner part of the wall. This variation can be attributed to continuing secretion of wall material as the cell continued to decrease in volume, after the wall material secreted in early stages had begun to harden. Except for the dense layer of the endocyst nearest to the plasm membrane, there appeared to be no morphological difference in the material of the apparent exocyst and endocyst thus produced that cannot be accounted for by a greater drying of the separated outer layer. These observations agree with and explain the observations on variation reported by Page (1967) which Singh and Hanumaiah (1979) found so puzzling. If an excysting cell dissolves as wall closely applied to it but must break out of a further barrier, the apparent variation in the excystment process itself (Page 1967) is also explained. (ref. ID; 7755)

Examined materials

CCAP 1534/7a, freshwater, USA (strain 25 of Page, 1967), and CCAP 1534/7b, from leaf litter, England. (ref. ID; 7755)