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Pontigulasia

Pontigulasia Rhumbler, 1895 (ref. ID; 3567, 3686), 1896 (ref. ID; 3693, 7701) or 1986 (ref. ID; 6793)

Rhizopoda: Testacea: Order Testacealobosa De Saedeleer, 1934: Eulobosa: Family Difflugiidae Awerinzew, 1906 (ref. ID; 7500)

Difflugiidae Awerinzew (ref. ID; 7501)

ref. ID; 1618

Test similar to that of Difflugia, but with a constriction of neck and internally a diaphragm made of the same substances as those of the test. (ref. ID; 1618)

ref. ID; 1923

Shell with internal partition or diaphragm, with deeply constricted neck and transverse perforated partition at the point of constriction. A widely distributed genus, comprised of about 7 species. The internal partition or diaphragm of Pontigulasia may be overlooked in living animals. It appears clearly when the shell is mounted in Canada balsam. (ref. ID; 1923)

ref. ID; 3686

Shell yellow or brown; ovoid or pyriform with a constriction to form a neck; composed of agglutinated mineral particles; aperture terminal, circular having an internal transverse diaphragm on level with neck constriction. (ref. ID; 3686)

ref. ID; 6793

Pontigulasia Rhumbler, 1986 characterized by a pyriform shell, often with a contriction of the neck, is now separated into Pontigulasia Rhumbler, 1986 (with a centrally located bridge joining the two lateral walls of the shell in the neck region), Lagenodifflugia (with a diaphragm in the neck region with a single, central, circular opening), and Zivkovicia Ogden, 1987 (with a diaphragm in the neck region with two openings). The genera Apodera and Pontigulasia/Lagenodifflugia/Zivkovicia clearly differ by at least two morphological characters: (1) One of the defining characteristics of the genera Pontigulasia, Lagenodifflugia, and Zivkovicia is the presence of a distinct internal dividing wall at the base of the neck. This characteristic clearly separates Pontigulasia, Lagenodifflugia, and Zivkovicia from Difflugia, and also from Nebela and Apodera (Ogden 1987; Rhumbler 1986) and is visible under the microscope unless hidden by an apertural plug or other debris. This wall is not straight in the case of Lagenodifflugia. (2) The two taxa also differ with respect to the cement used for test construction: Pontigulasia, Lagenodifflugia, and Zivkovicia produce a structured cement, while Apodera produces a sheet-like cement (Meisterfeld 2002). (ref. ID; 6793)

ref. ID; 7701

Diagnosis

Shell pyriform, sometimes with a distinct constriction of the neck region, either circular or compressed in transverse section; composed mainly of flattish quartz particles, diatom frustules or small siliceous shell plates, bound by a network of organic cement; aperture terminal usually circular; internally the shell is divided into two regions by a narrow bridge, made mainly of organic cement with small particles embedded in it, stretched between the lateral walls at about one third of the body length from the aperture. (ref. ID; 7701)

Notes

The genus Pontigulasia was erected by Rhumbler (1896) to accommodate the three new species, P. compressa, P. incisa and P. spiralis. The shell of this new genus was considered to differ from that of the genus Difflugia with which it shares a similar structural design and material, in two features. Firstly, if often has a constriction of the neck situated posterior to the aperture at about the position where the body swells to form its pyriform shape, and secondly, it was described as having an internal 'schundbruche' (throat bridge) which has subsequently been referred to as an internal diaphragm. This diaphragm has either one or two openings for the movement of cytoplasm into the anterior region of the shell, so that pseudopodia may be extended through the aperture. In addition to redescribing the original three species, Penard (1902) described three new species, P. spectabilis, P. bigibossa and P. bryophila. He noted that there appeared to be at least two types of construction associated with this internal division and proposed a modification of Rhumbler's diagnosis, reffering to this structure as either a bridge or a patition. Furthermore, Penard was doubtful of the value of such differences because of the difficulties he had encountered in trying to examine these particular structures from specimens mounted in balsam. Of the six species described (Penard 1902), all, with the exception of P. bryophila, have an internal structure with two openings usually situated laterally, so that a direct view into the aperture often only shows the edge of the openings, and each opening can only be seen in its entirety by viewing the aperture from either lateral angle. Whereas, in P. bryophila the single internal opening is directly opposite the apertural opening. The internal division was described by Penard (1902) as being composed of a thin sheet of chitin with small quartz particles embeded in it. He further considered that Difflugia elisa Penard, 1893 was a synonym of Rhumbler's species P. incisa, and the new species P. bigibossa was erected for his earlier description of Difflugia pyriformis var. vas sous-var. bigibossa. Four species and one variety of Pontigulasia were described by Cash & Hopkinson (1909) and another species was added later (Cash et al. 1919). This work was important because it corrected some systematic errors introduced by Penard who designated new specific names when names already existed. Thus, P. spectabilis Penard, 1902 is a synonym of P. vas (Leidy, 1874), P. bigibossa (Penard, 1902) a synonym of P. compressa (Carter, 1864), P. incisa Rhumbler, 1896 a synonym of P. elisa (Penard, 1893), and to complete these corrections a new name P. rhumbleri was proposed by Hopkinson (in Cash et al. 1919) for P. compressa Rhumbler, 1896. In their work Cash & Hopkinson (1909) credit the changes suggested for P. elisa and P. vas to Schouteden (1906) as they were initially proposed as footnotes (p.338 and p.339) in a translation of Awerintzew's (1906) monograph. Since Cash & Hopkinson (1919), nine further species have been attributed to the genus. Most of these descriptions suffer from the difficulties experienced in trying to interpret the structure of the internal division, and because of this many are inadequate with either insufficient or absence of such detail. The present account is concerned manily with the structure of the internal partition and its significance in the systematic diagnosis. (ref. ID; 7701)
  1. Pontigulasia aerophila Decloitre (ref. ID; 5112 original paper)
  2. Pontigulasia bigibbosa Penard, 1902 (ref. ID; 2109, 2234, 3693 original paper, 7500)
  3. Pontigulasia bigibossa Penard, 1902 (ref. ID; 7701, 7880, 7882)
    See; Zivkovicia compressa (ref. ID; 7701)
  4. Pontigulasia bigibbosa var. minor Varga, 1963 (ref. ID; 7701) reported year? (ref. ID; 5034 original paper)
  5. Pontigulasia bigibossa Penard, 1902
    See; Zivkovicia compressa (ref. ID; 7701)
  6. Pontigulasia bryophila Penard, 1902 (ref. ID; 2160, 2441, 3693 original paper) reported year? (ref. ID; 3501, 4643)
    See; Zivkovicia bryophila (ref. ID; 7701)
  7. Pontigulasia bryophila var. elachys Jung, 1942
    See; Zivkovicia bryophila (ref. ID; 7701)
  8. Pontigulasia compressa Carter, 1864 (ref. ID; 1316, 2022, 2147, 2456, 3686, 7850) reported year? (ref. ID; 3501)
    Syn; Difflugia compressa Carter, 1864 (ref. ID; 1316)
  9. Pontigulasia compressa Rhumbler, 1896 (ref. ID; 7701) reported year? (ref. ID; 3693)
  10. Pontigulasia compressa var. flexa Cash & Hopkinson, 1909
    See; Zivkovicia flexa (ref. ID; 2151, 7701)
  11. Pontigulasia compressoidea Jung, 1942 (ref. ID; 7701) reported year? (ref. ID; 2456)
  12. Pontigulasia contusa Jung, 1942 (ref. ID; 7701) reported year? (ref. ID; 2152)
  13. Pontigulasia elisa Penard, 1893 (ref. ID; 3686, 7701) reported year? (ref. ID; 1316)
    Syn; Difflugia elisa Penard, 1893 (ref. ID; 1316); Pontigulasia incisa Rhumbler, 1896 (ref. ID; 7701)
  14. Pontigulasia epiouxi Chardez, 1983
    See; Zivkovicia epiouxi Chardez, 1984 (ref. ID; 2151)
  15. Pontigulasia gessneri Van Oye, 1956 (ref. ID; 7701) reported year? (ref. ID; 2564 original paper)
  16. Pontigulasia incisa Rhumbler, 1896 (ref. ID; 2109, 2147, 2441, 7701) reported year? (ref. ID; 3501, 3693)
    See; Pontigulasia elisa Penard, 1893 (ref. ID; 7701)
    Syn; Difflugia elisa Penard (ref. ID; 3693)
  17. Pontigulasia irregularis Decloitre, 1969 (ref. ID; 7701)
  18. Pontigulasia rhumbleri Hopkinson, 1919 (ref. ID; 7701) reported year? (ref. ID; 2152)
    Syn; Pontigulasia compressa Rhumbler, 1896 (non Pontigulasia compressa (Carter, 1864)) (ref. ID; 7701)
  19. Pontigulasia sarrazinensis Chardez, 1984 (ref. ID; 2151 original paper, 2152)
  20. Pontigulasia spectabilis Penard, 1902 (ref. ID; 2109, 2147, 3693 original paper, 7500) reported year? (ref. ID; 3501, 3595)
    See; Zivkovicia vas (ref. ID; 7701)
  21. Pontigulasia sphaeroideus Tarnogradsky, 1961 (ref. ID; 3501 original paper, 7701)
  22. Pontigulasia spiralis Rhumbler, 1896 (ref. ID; 7701) reported year? (ref. ID; 3693)
  23. Pontigulasia varadi Godeanu, 1972
    See; Zivkovicia bryophila (ref. ID; 7701)
  24. Pontigulasia vas Leidy (ref. ID; 1316, 1618, 1923) or (Leidy) Schouteden, 1906 (ref. ID; 7701) reported year? (ref. ID; 4643)
    See; Zivkovicia vas (ref. ID; 7701)
    Syn; Pontigulasia spectabilis Penard (ref. ID; 4643) reported author and year? (ref. ID; 1923); Difflugia vas Leidy, 1874 (ref. ID; 1316)

Pontigulasia bigibbosa var. minor Varga, 1963 (ref. ID; 7701) reported year? (ref. ID; 5034 original paper)

Descriptions

A species similar to Z. compressa differentiated from it only by size, body length 76-87 µm, breadth 58-62 µm. The only information given for the internal structure is a figure showing it to be u-shaped in lateral view. (ref. ID; 7701)

Pontigulasia compressa Carter, 1864 (ref. ID; 1316, 2022, 2147, 2456, 3686, 7850) reported year? (ref. ID; 3501)

Synonym

Difflugia compressa Carter, 1864 (ref. ID; 1316)

Descriptions

See Difflugia sphincta.

The shell is brown, ovoid or pyriform, with a short neck that joins the body in a V-shaped wedge. Convex protruberances arise from each arm of the V-shaped wedge to give this species its characteristic shape. In lateral view it is compressed. It has a rough surface composed of different sizes of sand- or quartz-grains arranged on an organic matrix. The aperture is circular or ovoid, and internally at the junction of the neck is a perforated diaphragm. This species varies considerably in size and in the composition of the shell, often large particles are used to construct the shell and mask the characteristic outline of the convex protruberances. (ref. ID; 3686)

Measurements

Length of shell 196-289; breadth of shell 166-222; depth of shell 107-179; diameter of aperture 45-75 µm (n=17). (ref. ID; 3686)

Pontigulasia compressoidea Jung, 1942 (ref. ID; 7701) reported year? (ref. ID; 2456)

Descriptions

This species have not been clearly differentiated from Z. compressa and are probable synonyms, but as neither description contains reference to the structure of the diaphragm this combination cannot be made. (ref. ID; 7701)

Pontigulasia contusa Jung, 1942 (ref. ID; 7701) reported year? (ref. ID; 2152)

Descriptions

This species have not been clearly differentiated from Z. compressa and are probable synonyms, but as neither description contains reference to the structure of the diaphragm this combination cannot be made. (ref. ID; 7701)

Pontigulasia elisa Penard, 1893 (ref. ID; 3686) reported year? (ref. ID; 1316)

Synonym

Difflugia elisa Penard, 1893 (ref. ID; 1316); Pontigulasia incisa Rhumbler, 1896 (ref. ID; 7701)

Descriptions

The shell is brown, pyriform with a distinct constriction to form a neck region, and it is oval circular in transverse section. It has a rough surface which is composed mainly of small grains. The aperture is circular, and surrounded by an irregular arrangement of small sand particles. An internal, perforated, diaphragm is present across the neck, at the junction of the neck with the main body. (ref. ID; 3686)

The shell is pyriform, circular in cross section and has a distinct constriction of the neck region and internal bridge divider is present. (ref. ID; 7701)

Remarks

Penard (1902) describes four species with distinct necks: P. incisa (= P. elisa); P. bryophila; P. spectabilis (= P. vas) and P. spiralis, all having the same range of size, but differing in structure and also the form of the internal diaphragm. (ref. ID; 3686)

Using the rule of priority Penard's name elisa is correct for this species, in addition, his figures and descriptions (Penard 1902) are excellent clearly showing the distinctive features. (ref. ID; 7701)

Geographical distribution

Austria (Laminger 1972), Belgium (Chardez 1980; Chardez & Hellebaut 1978), Germany (Schonborn 1965), Poland (Moraczewski 1965), Russia (Tarnogradskij 1961), Switzerland (Penard 1902). (ref. ID; 7701)

Measurements

Length of shell 118-144; breadth of shell 80-92; depth of shell 74-84; diameter of aperture 29-35 µm (n=3). (ref. ID; 3686)

Body length 85-100 µm (Penard 1902), 120-150 µm (Rhumbler 1896), 100-120 (Penard 1893): breadth 80-90 µm (Rhumbler 1896). (ref. ID; 7701)

Pontigulasia gessneri Van Oye, 1956 (ref. ID; 7701) reported year? (ref. ID; 2564 original paper)

Descriptions

A poorly described species containing no mention of an internal division body length 90 µm, breadth 63 µm and diameter of aperture 32 µm. (ref. ID; 7701)

Pontigulasia irregularis Decloitre, 1969 (ref. ID; 7701)

Descriptions

A species described with a distinct collar and unsymmetrical shell, but with no mention of an internal division, body length 80 µm and breadth 55 µm. (ref. ID; 7701)

Pontigulasia rhumbleri Hopkinson, 1919 (ref. ID; 7701) reported year? (ref. ID; 2152)

Synonym

Pontigulasia compressa Rhumbler, 1896 (non Pontigulasia compressa (Carter, 1864)) (ref. ID; 7701)

Descriptions

The sehll is pyriform, tapering evenly from the aperture to the rounded aboral extremity, laterally compressed. It has a fragile shell usually with a relatively smooth surface, composed equally of diatom frustules and flattened particles of quartz. These particles are packed closely together so that only small areas of organic cement are seen between them, the cement is seen as either individual rings or as a network. Each ring of cement has a wall 200 nm thick, sometimes with an inner smaller network or often only a few thin strands overlying an inner apparently smooth mesh membrane. The external aperture is curcular or oval and surrounded by small particles. In the present sample several specimens exhibit some malformation of outline, suggesting that they have a fragile construction. The inner dividing wall is an apparently delicate structure, with the central portion often being about 10 µm in width. The bridge expands evenly from the centre until it connects with the two laterally compressed walls, leaving large openings on either side. It does not form a complete barrier as it is absent along the inner lateral margins. The fragility of the bridge was demonstrated in one specimen, where the central portion of the structure had been broken and lost leaving only the wider side pieces projecting from the shell wall. (ref. ID; 7701)

Remarks

This species may be confused with compressed specimens of Difflugia, because of similarities in shell composition, although the presence of an internal bridge can usually be seen by optical microscopy as a dark bar positioned in the middle of the neck region when viewed in lateral position. Nevertheless, because of its size, this bar could easily be mistaken for a dark shell particle and so be overlooked. The present specimens agree well with the earlier descriptions given by Rhumbler (1896) and Penard (1902). (ref. ID; 7701)

Material examined

Specimens were collected from samples of Sphagnum moss gathered from a mat of vegetation which was suspended across an isolated corner of Lake Vlasina, Serbia, Yugoslavia in September, 1982. (ref. ID; 7701)

Geographical distribution

Argentina (Boltovskoy & Lena 1966, 1974), Britain (Cash et al. 1919), Germany (Grospietsch 1958), Switzerland (Penard 1902). (ref. ID; 7701)

Pontigulasia sphaeroideus Tarnogradsky, 1961 (ref. ID; 3501 original paper, 7701)

Descriptions

This species was differentiated from P. bryophila because of a constriction at the neck. However, the figures given show P. bryophila and P. sphaeroideus with a constriction, whilst P. spectabilis (= vas) a species whose diagnosis is based on such a feture is shown without a neck. Unfortunately the description is insufficient to distinguish P. sphaeroideus from either Z. bryophila or Z. montana, and it must therefore be considered doubtful. (ref. ID; 7701)

Pontigulasia spiralis Rhumbler, 1896 (ref. ID; 7701) reported year? (ref. ID; 3693)

Descriptions

The shell is pyriform, circular in cross section and has a distinct constriction of the neck region which is usually off-set at an angle from the main body, there is an internal bridge divider. (ref. ID; 7701)

Remarks

This species is probably a synonym of P. elisa as it differs only in the spiral nature of the neck, a feature that Penard (1902) suggested was difficult to distinguish in separating theste two species. Rhumbler's (1896) figures for P. spiralis do not depict a normal shell but show only joined specimens with two apertures and one specimen with an additional large portion of shell material. (ref. ID; 7701)

Geographical distribution

Argentina (Vucetich 1974), Germany (Rhumbler 1896), Switzerland (Penard 1902). (ref. ID; 7701)

Measurements

Body length 120-130 µm (Rhumbler 1896), 100-156 µm (Penard 1902). (ref. ID; 7701)

Pontigulasia vas Leidy (ref. ID; 1316, 1618, 1923) or (Leidy) Schouteden, 1906 (ref. ID; 7701) reported year? (ref. ID; 4643)

See

Zivkovicia vas (ref. ID; 7701)

Synonym

Pontigulasia spectabilis Penard (ref. ID; 4643) reported author and year? (ref. ID; 1923); Difflugia vas Leidy, 1874 (ref. ID; 1316)

Descriptions

Round or ovoid test; constriction deep and well-marked; with sand-grains and other particles; aperture terminal; fresh water ponds. Stump (1943) made a study of the nuclear division of the organism. During metaphase eight to twelve "chromosomes" form a well-defined equatorial plate; average time for completion of the division was found to be eighty minutes. (ref. ID; 1618)

Resembling Difflugia oblonga in appearance except for the deeply constricted neck. Internal partition well observed only in oral view, with 2 to 4 perforations. Sometimes with zoochlorellae. Habitat subaquatic mosses at pond sides and in wet Sphagnum. (ref. ID; 1923)

Measurements

Length 125-170 µm. (ref. ID; 1618, 1923)