Trichodoxa
Trichodoxa Sirgel, 1983 (ref. ID; 4059 original paper)
[ref. ID; 4059]
Diagnosis; Member of family Trichodinidae Claus, 1874 with coronal denticles consisting of central cone, blade, and ray, interlocked only by the central cones. Adhesive disc surrounded by only one wreath of cilia. Border membrane contains a skeletal ring bearing a series of spines on its circumference. Infundibulum a tapering tube of which the terminal portion is wound into a flat spiral. Adoral spire, consisting of polykinety and haplokinety, describes a counterclockwise circuit of 270 degrees, runs obliquely to the adhesive disc from the velum to the mouth of the infundibulum. Polykinety plunges directly into the infundibulum in which it is transformed into a peniculus that follows the shortest course to the termination of the infundibulum. The haplokinety runs along the edge of the mouth of the infundibulum for a short distance before plunging into it and then takes a reversed S-shaped course of which the last section is continued along the outer wall of the spirally coiled portion of the infundibulum. A row of germinal kinetosomes accompanies the haplokinety in the straight portion of the infundibulum. There is no trace of a third kinety. (ref. ID; 4059)
Remarks; Corliss (1979) recognizes the genera Dipartiella G. Stein, 1961; Paratrichodina Lom, 1963; Semitrichodina Kazubski, 1958; Trichodina Ehrenberg, 1830; Trichodinella Sramek-Husek, 1953; Tripartiella Lom, 1959, and Vauchomia Mueller, 1938 as members of the family Trichodinidae Claus, 1874. Trichodoxa n. g. differs from all these genera by the possession of a spine-bearing skeletal ring in the border membrane. The occurrence of a single wreath of aboral cilia also differs from the condition normally described for other genera of the family. Trichodina indica Tripathi, 1956, however, has been described as having one aboral ciliary wreath (Tripathi 1956). The above-mentioned genera further differ from Trichodoxa in other aspects. Dipartiella differs from it by the central conical parts of the coronal denticles being reduced as well as by the absence of rays on the denticles (Raabe 1963). Lom & Halder (1977), however, point out that Stein's (1961) Dipartiella is an enigmatic genus. Semitrichodina differs by the possession of a third kinety forming part of the much reduced adoral spiral (Lom 1963; Raabe 1961). In Trichodina, the adoral spiral is longer and describes a course of 360 degrees and more. In Tripartiella and Trichodinella, the coronal denticles are linked by their central conical parts as well as by spikes and corresponding incisions on the blades. Such spikes and incisions are absent in Trichodoxa. The Tricodinella-Tripartiella-Paratrichodina group (Lom & Haldar 1977) also differ from Trichodoxa by having marginal cilia. Vauchomia Mueller, 1938 differs by its adoral spiral performing 2-3 full turns as well as by the spiral following a descending course towards the mouth of the infundibulum. The course followed by the infundibulum ciliature of Trichodoxa differs from that described for Trichodina and Semitrichodina by not performing a well-defined spiralling course. It differs from the condition in Trichodinella, Tripartiella, and Paratrichodina where the course followed by both haplokinety and peniculus consist merely of a half turn (180 degrees) on the infundibulum walls. The course of followed by the infundibular ciliature of Trichodoxa is reminiscent of the pattern followed by the two parts of the pharyngeal fibers in Trichodinopsis paradoxa. The main difference, however, is that in T. paradoxa this structure starts at what is considered as the bottom of the infundibulum and runs towards the apical end of the body. In Trichodoxa it starts at the mouth of the infundibulum and runs towards the bottom of the infundibulum near the center of the body. Other characteristics of Trichodoxa also clearly distinguish it as a genus not belonging to the family Trichodiopsidae Kent, 1881. (ref. ID; 4059)
Type species; Trichodoxa genitalis n. g., n. sp. (ref. ID; 4059)
- Trichodoxa genitalis Sirgel, 1983 (ref. ID; 4059 original paper)
See; Semitrichodina genitalis (ref. ID; 4764)
- Trichodoxa phalli Sirgel, 1983 (ref. ID; 4059 original paper)
See; Semitrichodina genitalis (ref. ID; 4764)
Trichodoxa genitalis Sirgel, 1983 (ref. ID; 4059 original paper)
See
Semitrichodina genitalis (ref. ID; 4764)
Descriptions
This species, from the penis of pulmonates Trachycystis leucocarina and T. genitalis, has a circular shape when viewed adorally. Seen from the side, the shape of the body grades from that of a high cone in smaller specimens to that of a dome in the larger individuals. The aboral/adoral axis may reach a length of 90 um. The diameter as well as the number of denticles in the corona of the larger dome-shaped individuals are about twice that of the smaller cone-shaped ones. This as well as the fact that there is a grading from cone to dome-shaped, which can be correlated with diameter, indicates that those individuals with the shape of a cone are merely young specimens while the dome-shaped ones are mature. This seems evident when it is borne in mind that Davis (1947) indicated that the plane of binary fission runs along the aboral/adoral axis. In accordance with the authoritative descriptions given for trichodinids in general (Lom 1958, 1973), the circular adhesive disc is reinforced by a skeletal complex of three elements consisting of the corona, the striated membrane, and the border membrane surrounding the other two. The corona consists of a series of denticles varying in number from 12 in the smallest cone-shaped individuals to 31 in the dome-shaped ones. Each denticle consists of a hollow cone-shaped central part bearing a radially extending blade as well as a ray which extends towards the center of the corona. The posterior margin of the blade is straight and slightly directed posteriorly while anterior margin is convex. The ray is slightly curved. The denticles are wedged together only by their central conical parts, similar to the condition in the genus Paratrichodina Lom, 1963 (Lom & Haldar 1977). The striated membrane carries a series of radial pins or striae stretching from just adorally of the central parts of the coronal denticles to just medially of the border membrane. The striae taper from their distal towards their proximal ends. The distal end of each possess a slight swelling thus corresponding with the condition in Semitrichodina sphaeronuclea (Haider 1964). I could not find undulated extensions of the middle part of the striae similar to those described for Trichodinella epizootica (Lom 1973). There are 8-9 striae to each denticle of the corona. The outer edge of the striated membrane is separated from the border membrane by a distinct line. The border membrane contains a continuous proteinaceous skeletal ring bearing a series of strong spines on its circumference. These spines occur more or less opposite each third striae of the striated membrane. According to previous descriptions, the border membrane of other genera in the family Trichodinidae contains fine striae instead of such a ring with spines (Corliss 1953). Photographs of the species described by Lom & Laird (1969) clearly show the absence of such a ring with spines. The species described as new in the present paper, Trichodoxa genitalis, can move its flexible border membrane in such a way that the spines are directed parallel to the aboral/adoral axis or perpendicular to it in a radial direction. A marginal pellicular fold, the velum, surrounds the body just to the adoral side of the border membrane. A ciliary girdle presenting the locomotory cilia or aboral ciliary wreath No. II of Trichodina (Lom 1973) is present in the groove formed on the aboral side of the velum. Similar to the condition described Lom (1959, 1973) for Trichodinella epizootica (Raabe, 1950), this wreath is composed of short, obliquely arranged rows of cilia. No cilia corresponding to the ciliary wreath Nos. I & III of Trichodina (Lom, 1973) are present in Trichodoxa genitalis. Lom (1958) points out that the marginal cilia (ciliary wreath No. I) are not found in endoparasitic trichodines of amphibians nor in the ectozoic Trichodinella epizootica. The adoral ciliary spire runs obliquely to the basal disc. It consists of a row of cilia borne on either side of a shallow groove. The spire starts at the velum and ascends to the mouth of the infundibulum which is situated excentrally, near the adoral pole, by performing a counterclockwise circuit of 270 degrees. The infundibulum extends obliquely towards the middle of the body. It consists of a tapering tube of which the terminal part is wound into a flat spiral. The infraciliature of the adoral ciliary spiral consists of a polykinety and haplokinety (Lom 1964). The haplokinety consists of a single row of kinetosomes and the polykinety of a row of elongated ones. No trace of a third kinety -described for Semitrichodina sphaeronuclea- is found in T. genitalis. On reaching the infundibulum, the polykinety directly plunges into it and follows the shortest route to its terminal point. This implies that it follows a more or less straight course towards the inner wall of the spirally coiled part of the infundibulum, along which it is then continued right to its termination. Just after entering the infundibulum, the polykinety is transformed into a peniculus consisting of several rows of kinetosomes. These rows could be six in number, as in Trichodina generally (Lom 1964), but the granular nature of the cytoplasm makes it difficult to determine the exact number beyond doubt. In protargol-impregnated specimens, a continuous band-like structure is demonstrated accompanying the polykinety over its entire course including the penicular part. The impression is gained that the kinetosomes are embedded in this band which is slightly more intensely impregnated than the surrounding cytoplasm. The haplokinety follows the circumference of the mouth of the infundibulum for a distance and then pluges into it, taking a reversed "S"-shaped course. Although it runs parallel to the polykinety along its extra-infundibular part, the haplokinety thus becomes out of phase with the peniculus in the infundibulum. The terminal part of the haplokinety runs along the outer wall of the spiral part of the infundibulum. Similar to the condition in the polykinety, the haplokinety also appears embedded in a band-like structure. As the terminally coiled part of the infundibulum narrows, the two bands containing the kinetosomes of the haplo- and polykinety gradually converge, and it appears as if they are fused along the terminal half whorl of the spirally coiled part. A row of kinetosomes corresponding to the germinal row described for various peritrich ciliates (Lom 1964) accompanies the haplokinety from the mouth of the infundibulum almost to a point where the spiral portion begins. Just beyond the point where the straight portion of the infundibulum passes over into the spiral portion, a single row of kinetosomes diverges from the peniculus and stretches to a point next to the haplokinety at a distance of about one full whorl from the termination of the infundibulum. From this point the row of kinetosomes runs parallel to the haplokinety and can be followed up to that part of the infundibulum where the haplo- and polykinety appear to fuse. In the terminal whorl of the infundibulum the haplokinety is also accompanied by a belt-like structure which takes on a black color in protargol-impregnated specimens. Although much shorter, this structure seems to represent the impregable belt-shaped formation described for peritrich ciliates by Lom (1963). At the termination of the infundibulum, a small, horse-shoe shaped body, oriented perpendicular to the course of the peniculus and haplokinety, occurs. Although it cannot be clearly discerned with the aid of the light microscope, the impression is gained that this body consists of a series of elongated granules. Lom (1964) describes a similar structure for Trichodina pediculus (O.F. Muller, 1786). He regards it as part of the peniculus and refers to it as P3. The macronucleus is spherical and located excentrally and to the aboral side of the infundibulum. The micronucleus is situated closely against it in a small indentation, with the result that it is not easily seen. Semitrichodina spaheronulcear (Lom, 1956), Trichodina ovonucleate Raabe, 1958 and T. spongillae (Jackson, 1875) resemble Trichodoxa genitalis in possessing a more or less spherical macronucleus. Laid questions he status of T. ovonucleata, pointing out that the macronucleus is round in young specimens of species in which it is C-shaped by maturity. He agues that this trichodine may be only a young specimens of T. retuncinata Raabe, 1958, which has a C-shaped macronucleus. As far as the new species Trichodoxa genitalis is concerned, all the specimens I examined had round macronuclei. Form the variation in size, as well as form the number of denticles in the corona, it can be concluded that have observed a wide spectrum of stages of maturity. A contractile vacuole occur sin a central position between the infundibulum and macronucleus. A slender duct leading form the vacuole opens into the straight portion of the infundibulum. The relationship between T. genitalis and its host is not clear. In sections of the penis of the host, the lining epithelium appeared damaged. This could, however, be the result of the epithelium having been in a secretory phase during fixation. (ref. ID; 4059)
Type specimens
Syntypes of T. genitalis have been deposited in the Natural Museum, Pietermaritzburg, South Africa. (ref. ID; 4059)
Measurements
Measured according to the system followed by Lom (1958), the denticle has the following dimensions: length 7.65 um, width of central part 3 um, length of ray 5 um, length of blade 7 um. (ref. ID; 4059)
Trichodoxa phalli Sirgel, 1983 (ref. ID; 4059 original paper)
See
Semitrichodina genitalis (ref. ID; 4764)
Descriptions
This new species is named after its location in the penis of pulmonate Trachycystis menkeana. The aboral/adoral axis may reach a length of 60 um. The body is dome-shaped and presents a circular outline when seen in an aboral aspect. The adhesive disc is reinforced by the aboral skeletal complex consisting of the corona, striated membrane, and border membrane. The corona is made up of 23-31 denticles, each consisting of a hollow cone bearing a radially extending blade and a centrally extending ray. The posterior margin of the blade is straight, while the anterior and distal margins describe a convex arch. The denticles are interlocked only by way of their cones, similar to the condition in Trichodoxa genitalis n. sp. The ray of each denticle is slightly curved. There are eight striae of the striated membrane to each coronal denticle. These striae taper from their distal ends, just medially of the border membrane, towards their proximal ends adorally of the coronal cones. The border membrane is separated from the striated membrane by a distinct line. It resembles the border membrane of T. genitalis in containing a skeletal ring bearing strong spines on its circumference. The band forming this ring is <1 um wide and a the spines are 2.5 um long. The spines are arranged in such a way that they occur more or less opposite each third striae of the striated membrane. As in T. genitalis, the living organism can tilt the border membrane in such a way that the spines are directed radially or parallel to the adoral/aboral axis. All the skeletal elements of the basal disc are covered by pellicle. A velum is present. The cilia wreath surrounding the basal disc consists of short obliquely arranged rows of cilia comparable to the aboral ciliary wreath No. II of Trichodina. But no cilia comparable to aboral ciliary wreath No. I or III occur. The adoral ciliary spire, similar to the condition in T. genitalis, starts at the velum and performs a counterclockwise circuit of 270 degrees to reach the mouth of the infundibulum. It consists of a shallow relatively wide groove bearing a row of cilia on either side. The infundibulum extends towards the middle of the body. Its terminal portion is wound into a flat spiral. On reaching the mouth of the infundibulum, the haplokinety plunges into it and is continued as a peniculus consisting of several rows of kinetosomes. It follows the shortest route to the termination of the infundibulum. The polykinety accompanies part of the edge of the mouth of the infundibulum before entering it and being continued down the infundibulum on an S-shaped route. It finally runs along the outer wall of the spirally wound part of the infundibulum. At the end of the infundibulum a horse-shoe shaped body representing the P3 occurs. A germinal row of kinetosomes accompanies the haplokinety along the straight portion of the infundibulum. Just beyond the point where this straight portion passes over into the spiral portion a row of kinetosomes gradually diverges from the peniculus and approaches the haplokinety along which it is then continued to the termination of the infundibulum. In the terminal whorl of the infundibulum, the haplokinety is accompanied by a belt-like structure which takes on a black color in the protargol-treated specimens. The infundibular kinety according to this description thus resembles that of T. genitalis. The macronucleus is C-shaped and lies in a plane parallel to and near the adhesive disc. It is oriented in such a way that the open part of the "C" is on the same side of the body as the infundibulum. The micronucleus is situated in the -y' position. The contractile vacuole is located on the aboral side of the infundibulum into which its slender duct opens. (ref. ID; 4059)
Comments
According to Fantham's (1924) description of Trichodina achatinae, that organisms seems to resemble Trichodoxa phalli n. sp. in certain aspects. He mentions that the "cytopharynx" is spirally curved and that the macronucleus is crescentic. Furthermore, his ciliate also occurs in the genital system of a terrestrial pulmonate, although it belongs to a different family than the host of T. phalli. These characteristic are, however, not sufficient to recognize the two trichodinids as belonging to the same genus or species. The description of Trichodina achatinae, incidentally, is so incomplete that its name has regularly been treated as a nomen dubium (Haider, 1964). (ref. ID; 4059)
Type specimens
Syntypes of T. phalli have been deposited in the Natural Museum, Pietermaritzburg, South Africa. (ref. ID; 4059)
Measurements
The denticles have the following dimensions: length 5.5 um, width of central part 2.25 um, length of ray 5 um, length of blade 5 um. The ray, being as long as the blade, is thus relatively longer than in T. genitalis. (ref. ID; 4059)