Vexillifera

Vexillifera Schaeffer, 1926 (ref. ID; 2092, 4667, 4688, 7540, 7757)

Phylum Sarcomastigophora: Subphylum Sarcodina: Superclass Rhizopoda: Class Lobosea: Subclass Gymnamoebia: Order Amoebida: Suborder Conopodina: Family Paramoebidae (ref. ID; 2092)
Class Lobosea: Subclass Gymnamoebia: Order Amoebida: Family Paramoebidae Poche 1913 (= Mayorellidae Schaeffer 1926; cf. Page 1972) (ref. ID; 4667)
Class Flabellinea: Order Dactylopodida (ref. ID; 6789)
Gymnoamoebia: Paramoebidae (ref. ID; 7757)

[ref. ID; 2092]
This genus is composed of small amoebae which produce elongated, linear, or narrowly conical sub-pseudopodia from an anterior hyaline lobe. Since the sub-pseudopodia are often carried to the posterior end, amoebae of the genus have a spiny appearance somewhat similar to that of Acanthamoeba. Two freshwater species and five marine species have been described. (ref. ID; 2092)

[ref. ID; 4688]
The genus Vexillifera was established by Schaeffer (1926) for naked, lobose amebas that, like the genus Mayorella Schaeffer, 1926, form clear, conical or tapered (but round-tipped) pseudopods, but unlike Mayorella also form "long, slender pseudopods, extending from the anterior end during locomotion, which are capable of moving about in the water after the manner of tentacles." Schaeffer designated V. ambulacralis (Penard, 1890) as the type species; but Penard designated 2 apparently different organisms but that name, first one (Penard 1890) and then another, later (Penard 1902). The later organism he depicted as waving its long, slender, clear pseudopods by bending them at the bases prior to or during their retraction. Bovee (1951) proposed that those Mayorella-like amebas that form such clear, slender, tapered pseudopods and wave them by basal bending prior to retraction should be placed in the genus Vexillifera. Other amebas that form pseudopods that are indeterminate in length, partly granule-filled with clear, conical tips, and which are waved actively without then being retracted, he (Bovee 1953, 1970) placed in the genus Oscillosignum. Those otherwise like Oscillosignum that form an awl-shaped, rapid, locomotive state with a clear, conical, pseudopodial tip, Bovee (1953, 1970) placed in the genus Subulamoeba. These generic distinctions, although arbitrary, are clearly visible and are useful to distinguish such amebas, and are in keeping with the general trend of classifying naked, lobose amebas on the form and movement of their pseudopods, as expressed in the more or recent systematics of amebas. (ref. ID; 4688)

[ref. ID; 7757]
The genus Vexillifera Schaeffer, 1926 includes fresh and salt water amoebae, which according to Page (Page 1969; Page 1979), produce differently shaped pseudopods from an anterior hyaline zone. Up to now, seventeen species have been described in this genus. Eleven of them, V. bacillipedes (Page, 1969), V. lemani (Page, 1976), and the nine new species recently described by Bovee (1985), are freshwater species, V. telmathalassa (Bovee, 1956), V. armata (Page, 1979), V. browni (Sawyer, 1975), V. minutissima (Bovee and Sawyer, 1979), and V. pagei (Sawyer, 1975), inhabit sea waters. V. pagei was redescribes by Page (Page 1979) as Pseudoparamoeba pagei. Of all these species, only V. bacillipedes is considered as amphizonic according to the reports of Ghitino et al. (1977) and Sawyer et al. (1978). Page (1979) has emphasized the importance that cell surface ultrastructure may have in the taxonomical ordering of the different genera and species of Gymnamoebia. (ref. ID; 7757)

  1. Vexillifera ambulacralis (Penard, 1890) (ref. ID; 3687) reported year? (ref. ID; 3497, 5624)
  2. Vexillifera anapes Bovee, 1985 (ref. ID; 4688 original paper)
  3. Vexillifera arionoides Bovee, 1985 (ref. ID; 4688 original paper)
  4. Vexillifera armata Page, 1979 (ref. ID; 2092 original paper, 2093, 3719) reported author and year? (ref. ID; 7305)
  5. Vexillifera aurea Schaeffer, 1926 (ref. ID; 3687) reported author and year? (ref. ID; 7305)
  6. Vexillifera bacillipedes Page, 1969 (ref. ID; 2092, 2093, 3719, 4667, 6789, 7540)
  7. Vexillifera browni Sawyer, 1975 (ref. ID; 2093, 7757) reported year? (ref. ID; 3847) reported author and year? (ref. ID; 7305)
  8. Vexillifera dadayi Lepsi, 1960 (ref. ID; 3687 original paper)
  9. Vexillifera displacata Bovee, 1985 (ref. ID; 4688 original paper)
  10. Vexillifera filopodia Bovee, 1985 (ref. ID; 4688 original paper)
  11. Vexillifera granatensis M.L. Mascaro, Osuna & C. Mascaro, 1985 (ref. ID; 7757 original paper)
  12. Vexillifera lemani Page, 1976 (ref. ID; 7540, 7757)
    Syn; Amoeba ambulacralis Penard, 1920 (ref. ID; 7540)
  13. Vexillifera minuta Bovee, 1985 (ref. ID; 4688 original paper)
  14. Vexillifera minutissima Bovee & Sawyer, 1979 (ref. ID; 7710, 7757) reported year? (ref. ID; 3847) reported author and year? (ref. ID; 6789, 7305)
  15. Vexillifera ottoi Sawyer (ref. ID; 3847) reported author and year? (ref. ID; 2093, 7305)
  16. Vexillifera pagei Sawyer, 1975 (ref. ID; 2093, 7757)
    See; Pseudoparamoeba pagei (ref. ID; 7757)
  17. Vexillifera spinoa Bovee, 1985 (ref. ID; 4688 original paper)
  18. Vexillifera subula Bovee, 1985 (ref. ID; 4688 original paper)
  19. Vexillifera telma Bovee, 1985 (ref. ID; 4688 original paper)
  20. Vexillifera telmathalassa (ref. ID; 7305)
  21. Vexillifera telmathalassa Bovee, 1956 (ref. ID; 2092, 7757)
  22. Vexillifera telmathalassa Page, 1972 (ref. ID; 2093)
  23. Vexillifera variabilis Bovee, 1985 (ref. ID; 4688 original paper)

Vexillifera ambulacralis (Penard, 1890) (ref. ID; 3687) reported year? (ref. ID; 3497, 5624)

Descriptions

The granular body possesses several slender pseudopodia stretching forwards and typically few uroids. The nucleus is rather small and contractile vacuoles often appear. (ref. ID; 3497)

Measurements

Length without pseudopodia 10-38 um. (ref. ID; 3497)

Vexillifera anapes Bovee, 1985 (ref. ID; 4688 original paper)

Descriptions

Etymology

It is named for its appearance in moderate locomotion, when it resembles the splayed, webbed foot of a duck. (ref. ID; 4688)

Habitat

Slow-flowing, cool, freshwater streams at muddy bottom. (ref. ID; 4688)

Type locality

; This vexilliferan was first found in a collection taken in October 1961, from the muddy bottom, at a water temperature of 21 degrees C, of a creek at the crossing of state highway 235, 2.5 mi S of state highway 100, 7.2 mi N of the town of Brooker, Florida, U.S.A. It appears to be widely distributed in small streams on muddy bottom. (ref. ID; 4688)

Vexillifera arionoides Bovee, 1985 (ref. ID; 4688 original paper)

Descriptions

Habitat

Backwaters of organically laden cool streams, with much decaying vegetal detritus. (ref. ID; 4688)

Type locality

In collections at 19 degrees a quiet backwater of the Suwanee River 1/4 mi above the influx of the White Sulfur Spring into that river near the town of Fort White, Florida, U.S.A. in March 1958. (ref. ID; 4688)

Vexillifera ambulacralis (Penard, 1890) (ref. ID; 3687) reported year? (ref. ID; 3497)

Descriptions

The granular body possesses several slender pseudopodia stretching forwards and typically few uroids. The nucleus is rather small and contractile vacuoles often appear. (ref. ID; 3497)

Measurements

Length without pseudopodia 10-38 um. (ref. ID; 3497)

Vexillifera armata Page, 1979 (ref. ID; 2092 original paper, 2093, 3719) reported author and year? (ref. ID; 7305)

Diagnosis

Locomotive form longer than broad, producing linear or finely conical pseudopodia characteristic of genus from anterior hyaloplasm; length not including long pseudopodia approximately 10 to 23 um, mean 15.5 um; length : breadth ratio 1.0 to 2.2, mean 1.6. The hyaline zone usually occupied about one quarter of the total length. Floating form usually irregularly rounded, with hyaline pseudopodia, if any, usually unevenly distributed. Nucleus 2.8 to 4.2 um, with central nucleolus 1.9 to 2.8 um; nuclear division with dissolution of nuclear membrane by metaphase. Surface covered with flexible hexagonal cylinders (glycostyles), approximately 60-70 nm tall and 50 nm in diameter, unique to genus but not to species. Several trichocyst-like bodies, approximately 5 um long and 0.2 um in diameter, with quadrilateral transverse section, present in each cell; no fixed position; ejection not known to occur. (ref. ID; 2092)

Descriptions

This strain have a spiny appearance, usually longer than broad, with the anterior hyaline region more or less flattened and the posterior mass granular and often conical toward the tail. The pseudopodia start as blunt projections of the hyaline zone, elongate rapidly and become thinner and more or less linear, with a more or less constant diameter along much of the length. After the initial blunt, conical projection has lengthened, the pseudopodium has a basal diameter of less than 0.5 um. When it has reached its full length, often greater than the length of the main cell mass, the pseudopodium may bend, rarely may become helical, and usually is carried back along the sides to be resorbed posteriorly; this accounts for the spiny appearance of the amoeba. The cell moves by advance of the broad hyaline lobe from which the sub-pseudopodia are produced. This lobe may narrow as it is pushed forward, so that the cell as a whole sometimes is urn-shaped, but generally the hyaline is more flattened than the posterior mass. Surface covered with flexible hexagonal cylinders (glycostyles), approximately 60-70 nm tall and 50 nm in diameter, unique to genus but not to species. The amoebae often fed by ingesting one or more bacteria toward the posterior end; ingestion of single bacteria by the hyaline anterior edge was also observed. Large numbers of bacteria are not ingested in a single food vacuole. Ten amoebae bore from four to 12 sub-pseudopodia, including those along the sides and at the posterior end, with a mean count of more than seven. Again, this maximum probably can be surpassed. The locomotive rates of 10 amoebae at 19 degrees were 8.4 to 17 um per minute, that is, from 0.6 to 1.1 times their lengths. No crystalline or other dense granules were observed, and no contractile vacuole was present. Nuclear division with dissolution of nuclear membrane by metaphase. Several rod-shaped trichocyst-like bodies (TLB's), approximately 5 um long and 0.2 um in diameter, were recognized with the light microscope only after having been discovered in sections. They could be observed in living cells even with bright-field optics, more distinctly in somewhat flattened cells with phase contrast. They were also seen in wet mounts fixed by addition of saturated mercuric chloride solution and in hematoxyin preparations. (ref. ID; 2092)
  • Cyst: No cysts were ever seen. (ref. ID; 2092)

    Marine species. (ref. ID; 2093)
    V. armata was observed to have a surface coat only 70 nm thick, including a layer of hexagonal cylinders (glycostyles). (ref. ID; 3719)

    Type locality

    Kingsbridge Estuary, South Devon, England. (ref. ID; 2092)

    Type material

    Type slides have been deposited in the British Museum (Natural History) and given the numbers 1978:6:28:1 (holotype) and 1978:6:28:2 (paratype). (ref. ID; 2092)

    Measurements

    In locomotion on the under side of a coverslip, 100 amoebae were from 10 to 23 um long, with a mean of 15.5 um (these lengths do not include the long pseudopodia). The length : breadth ratio was from 1.0 to 2.2, with a mean 1.6. The hyaline zone usually occupied ?about one water of the total length. In 20 amoebae, the length of the longest pseudopodium ranged from 0.2 to 1.1 times of the main cell mass, though it undoubtedly can become greater. Floating form usually irregularly rounded, with hyaline pseudopodia, if any, usually unevenly distributed. Nucleus 2.8 to 4.2 um, with central nucleolus 1.9 to 2.8 um. (ref. ID; 2092)

    Vexillifera bacillipedes Page, 1969 (ref. ID; 2092, 2093, 3719, 4667, 6789, 7540)

    Descriptions

    This species has only a thin, amorphous glycocalyx with no glycostyles. (ref. ID; 2092)
    Freshwater species. (ref. ID; 2093)
    V. bacillipedes possesses irregular tufts extending from the glycocalyx. (ref. ID; 3719)

    Vexillifera browni Sawyer, 1975 (ref. ID; 2093, 7757) reported year? (ref. ID; 3847) reported author and year? (ref. ID; 7305)

    Descriptions

    Marine amoebae. (ref. ID; 3847)

    Vexillifera displacata Bovee, 1985 (ref. ID; 4688 original paper)

    Descriptions

    Comments

    V. displacata somewhat superficially resembles V. browni Sawyer, 1975, but the latter is clearly marine and unable to survive in freshwater (Sawyer 1975) whereas V. displacata is a freshwater species and its pseudopods are more nearly filose than those of V. browni as the latter appear in Sawyer (l.c.) photomicrographs. (ref. ID; 4688)

    Habitat

    Slow-flowing streams on muddy bottom. (ref. ID; 4688)

    Type locality

    This ameba was first found on muddy bottom of a drainage ditch at a water temperature of 22.5 degrees C in November, 1961, on the southern outskirts of the city of Gainesville, Florida, U.S.A. It apparently is widely distributed. (ref. ID; 4688)

    Vexillifera filopodia Bovee, 1985 (ref. ID; 4688 original paper)

    Descriptions

    It is widely distributed in quiet pools and backwaters with much organic debris. (ref. ID; 4688)

    Habitat

    Quiet, swampy backwaters of ponds, lakes, streams, at 18 to 25 degrees C. (ref. ID; 4688)

    Type locality

    This ameba was first seen in November 1949 from an old water sample that was collected on June, 116, 1948, from a stagnant freshwater canal extending from West Okoboji Lake at crescent Beach, in Dickinson Country, Iowa, U.S.A. (ref. ID; 4688)

    Vexillifera granatensis M.L. Mascaro, Osuna & C. Mascaro, 1985 (ref. ID; 7757 original paper)

    Descriptions

    Notes

    The species described may be included in the genus Vexillifera, according to the generic characters indicated by Page (1969). The light microscopical study has revealed the existence in the cytoplasm of clear crystalline inclusion, which are currently under investigation in this laboratory after isolation by lysis of the trophozoites. Although Page did not mention the existence of this type of inclusions in V. bacillipedes, their presence is suggested by the photographs is his paper (Page 1979). Eight of the nine species recently described by Bovee (1985) have crystalline inclusions, in different forms and sizes, but none are so clear and patent as the inclusions observed in this species. In Bovee's work (1985), the drawings and descriptions do not give us the possibility of securing a clear morphological similitude between his species and ours, on the other hand, having not published any ulrastructural study we cannot compare it. V. armata, the other species of this genus studied with the electron microscope lacks crystalline inclusions and any other type of dense granules. Pulsatile vacuoles are also absent in this marine species. Mitochondria of V. armata (Page 1979) are very similar to those of the species described in the present paper in both the appearance of the cristae and electrondensity. The absence of a Golgi body or some similar membrane system differentiates this species clearly from V. armata or V. bacillipedes which both have a Golgi body close to the nuclear region (Page 1979). Nevertheless, the most remarkable characteristic is the peculiar morphology of its cell surface. While V. bacillipedes presents an amorphous glycocalyx without glycostyles though with long and irregular prolongation (Page 1979), this species possesses a very characteristic glycocalyx with a special morphology and disposition. This type of glycocalyx, with glycostyles arranged in a regular manner, differs clearly from that of V. armata (Page 1979) and from those of the species of the Vannella genus previously ultrastructurally described (Page 1979). Glycostyles of Pseudoparamoeba pagei are also distinct (Page 1979). All these considerations have lead us to believe that we are describing a new species and, previously to a general reorganization of the taxons of the suborder Conopodina, which possibly will be accomplished in a few years time by experts in this subject, we include it in the genus Vexillifera Schaeffer, 1926, and propose the specific denomination of Vexillifera granatensis. (ref. ID; 7757)

    Vexillifera lemani Page, 1976 (ref. ID; 7540, 7757)

    Synonym

    Amoeba ambulacralis Penard, 1920 (ref. ID; 7540)

    Description

    Freshwater species. (ref. ID; 7757)

    Vexillifera minuta Bovee, 1985 (ref. ID; 4688 original paper)

    Descriptions

    Habitat

    In decaying vegetation in warm shallow waters at the edge of lakes with sandy bottoms. (ref. ID; 4688)

    Type locality

    This ameba was found repeatedly in collections from shallow water on the west side of Newnan's Lake on the eastern border of the city of Gainesville, Florida, U.S.A., from August 1956 through June 1962. (ref. ID; 4688)

    Vexillifera minutissima Bovee & Sawyer (ref. ID; 3847) reported author and year? (ref. ID; 6789, 7305)

    Descriptions

    Marine amoebae. (ref. ID; 3847)

    Vexillifera ottoi Sawyer, 1979 (ref. ID; 7710, 7757) reported year? (ref. ID; 3847) reported author and year? (ref. ID; 2093, 7305)

    Descriptions

    Marine amoebae. (ref. ID; 3847)

    Vexillifera spinoa Bovee, 1985 (ref. ID; 4688 original paper)

    Descriptions

    Habitat

    Brackish backwaters of the mouths of rivers at cool temperature. (ref. ID; 4688)

    Type locality

    This ameba was numerous in a collection at a water temperature of 14 degrees C from a brackish backwater of the Peace River at Punta Gorda, Florida, U.S.A., in January 1959, near the influx of the river into the Gulf of Mexico. (ref. ID; 4688)

    Vexillifera subula Bovee, 1985 (ref. ID; 4688 original paper)

    Descriptions

    Habitat

    Cool, slow-flowing streams with little detritus. (ref. ID; 4688)

    Type locality

    This organism was found in numbers of over 50 individuals in a collection in November 1957 from a freshwater creek 1+1/2 mi NW of Fairbanks, Florida, U.S.A, where State Highway 24 crosses the creek by bridge, at water temperature of 17.8 degrees C. (ref. ID; 4688)

    Vexillifera telma Bovee, 1985 (ref. ID; 4688 original paper)

    Descriptions

    It appears to be widely distributed in well-fertilized, stagnant, freshwater situations. (ref. ID; 4688)

    Comments

    V. telma somewhat resembles V. bacillipedes Page, 1969, but is somewhat larger (20 to 30 um in locomotion, compared to a mean length of 12.5 um for V. bacillipedes) and has many small distinguishable crystals, whereas V. bacillipedes has none; the water-expelling vesicle of V. telma develops from a single, small vesicle, whereas that of V. bacillipedes forms by fusion of several small vesicles; the "bacilliform" pseudopods reported for V. bacillipedes are not formed by V. telma. (ref. ID; 4688)

    Habitat

    Stagnant freshwaters with organic detritus at temperatures between 20 and 25 degrees C. (ref. ID; 4688)

    Type locality

    A waterfilled ditch near a chemical fertilizer plant at El Segundo, California, U.S.A., in February 1950. (ref. ID; 4688)

    Vexillifera telmathalassa (ref. ID; 7305)

    Descriptions

    The spherical nucleus (2-3 um diameter) contains a central nucleolus. The size of sedentary forms is 8-10 um rounded, and radiate floating forms are 6-8 um body size, with pseudopods to 45 um. Locomotive forms are 15-45 um long with pseudopods 5-30 um long, emanating from the margin or body surface. The long tapered subpseudpodia project outward or upward from the leading edge of the amoeba, and characteristically relax and collapse before retraction. The ectoplasm is clear surrounding a finely granular endoplasm. Large vacuoles known as "glanzkorper" occur in the cytoplasm in cultured specimens, and especially visible in the afternoon. Floating forms produce long tapered subpseudopodia that may be bent irregularly. Upon settling, the floating form produces a trident of three pseudopodia attached to the substrate (Bovee 1956; Bovee and Sawyer 1979; Page 1983). (ref. ID; 7305)

    Remarks

    The glycostyles projecting from the plasma membrane are somewhat unique for a species of Vexillifera. They are more stubby and compactly arranged than in other species (Page 1983). However, they sometimes have a fine filamentous projection extending from the tip as occurs in other species of Vexillifera (Page 1983). The filamentous projections appear to cross-link glycostyles on opposing surfaces of cell, such as between closely spaced pseudopodia. Similar fine filaments cross-linking glycostyles on the inner surface of secretory vesicles. While somewhat unique, the general arrangement and shape of the glycostyles is closer to that of Vexillifera spp. than to other glycocalyx-bearing genera (Page 1983). Since the fine structure data reported here expands the taxonomic indicators for V. telmathalassa, and provides a broader context for identifying it, some key features are summarized in comparison to related species in Table 1. This table provides a concise summary of fine structural and light microscopic features that are presently scattered in the literature. The similarity of the glycocalyx on the plasm membrane and the inner lining of the Golgi vesicles within the cytoplasm suggests that these secretory vesicles supply additional membrane to the surface of the cell by fusion with the plasma membrane and evagination as has been reported for other amoebae, including scale-bearing species (Anderson 1977; Page 1983). Evagination of vesicular membranes after fusion with the plasm membrane of cell typically projects the glycostyles outward. The role of the filamentous observed on the surface of V. telmathalassa requires further investigation. They may provide a surface coat of adhesive webs to better entangle and capture prey particles, and/or by cross-linking closely apposed membrane surface may help to strengthen the interface of the cell with the environment. It is not possible to fully characterize the glycocalyx by routine stained techniques for transmission electron microsopy. (ref. ID; 7305)

    Habitats

    Marine. (ref. ID; 7305)

    Vexillifera variabilis Bovee, 1985 (ref. ID; 4688 original paper)

    Descriptions

    Habitat

    Clear, quiet freshwater pools with little organic debris, at 20 to 25 degrees C. (ref. ID; 4688)

    Type locality

    This organism was found first in August 1959, in a rain-water filled pool at 21.5 degrees C on a granite outcrop ("Bald Knob") at the summit of Salt Pond Mountain (altitude 4,250 ft.) in Giles County, Virginia, U.S.A. (ref. ID; 4688)