Diophrys
Diophrys Dujardin, 1840 (ref. ID; 7354) or 1841 (ref. ID; 4007, 4408)
Order Euplotida: Family Uronychiidae (ref. ID; 7354) [ref. ID; 4007]
This genus is important of benthic communities in estuarine and tidal marshes. Ciliary components of the ventral surface are the AZM, frontoventral cirri, endoral and paroral membranes, transverse and caudal cirri. The AZM extends from the cytostome along two-thirds of the left side, arching at the anterior end to the dorsal surface and back toward the ventral surface extending one-fourth of the way down the right side of the cell. The AZM is composed of both anterior and buccal membranelles. Two undulating membranes lie to the right of the AZM. The one topographically nearest to the AZM is the endoral membrane; the other is the paroral membrane. The membranes extend anteriorly from the cytostome along the edge of the right buccal overture. Cirri make up the remaining ventral ciliature and are numbered according to a system based upon the developmental characteristic that there are seven different ciliary primordia needed to form the ciliary structures to the right of the buccal cavity. The endoral membrane develops from row I, the paroral membrane and paroral cirrus (II/1) from row II, the six other frontoventral cirri (III/2, III/3, IV/2, V/2, VI/2 and VI/3) and the five transverse cirri (III/1, IV/1, V/1, VI/1 and VII/1) from rows III-VII. The three caudal cirri are numbered C1, C2 and C3 and the two left marginal cirri LM1 and LM2. Number of cirri is variable (frontoventral 7-9, transverse 5-6, caudal 3-4, and left marginal 1-3). The first dorsolateral row (kinety) of cilia is on the right side of the ventral surface while the other rows are on the dorsal surface. There are usually five kineties in D. scutum, five in D. appendiculata and four in D. oligothrix; however, this number is variable with an additional one or more rows. Each ciliary organelle has a complex ultrastructure that has already been described in other hypotrichs. Thus, the cortical surface in Diophrys is regular, with some variability in the number of ciliary structures. The "C-shaped" macronucleus is comprised of two lobes that are connected by a thin strand of nuclear membrane. In Borror's (1972) taxonomic review of Hypotrichida, there were 11 species in the genus Diophrys. Since then D. kasymovi Agamaliev, 1971, D. multinucleatus Hartwig, 1973, and D. tetramacronucleata Kattar, 1970 have been added. These 14 species of Diophrys form two morphologically different groups as originally put forth by Faure-Fremiet (1964) and more fully expanded by Hartwig (1973, 1974). The first group, represented by D. scutum, has a "typical" shape of Diophrys; a large, unified AZM, a two-part macronucleus arranged in a C-shape and a "typical" arrangement and position of the seven frontal, five transverse, two small left marginal and three large dorsal caudal cirri. (The caudal cirri were originally believed to be right marginal cirri (Faure-Fremiet 1964; Hartwig 1974), but development data show that they should be considered caudal cirri.) Included in this assemblage are D. scutum, D. appendiculata, D. magnus, D. oligothrix, and D. peloetes. Also included in the group are four species whose features differ from the above only in minor ways. D. scutiodes has only five frontal cirri (probably missing the frontal cirri that develop from the third streak); D. kasymovi has eight frontal and six transverse cirri (probably has an additional CP); D. quadricaudatus has three left marginal and four caudal cirri (both cirral groups are know to be variable) and D. tetramacronucleata has a four-part macronucleus. In the second assemblage, represented by D. irmgard, ciliates have a disc-shaped body, an AZM with a more developed collar region, two to many oval macronuclei, and a similar arrangement of the several frontal, four transverse, three left marginal and three caudal cirri (caudal and left marginal cirri are of equal size). This group includes D. irmgard, D. kahli, and D. multinucleatus. The number of cirri in each cirral group is variable. Although briefly described, two species, D. histrix and D. salina, do not conform to either group. The eight species in the first group have been separated and assigned species status on the basis of size, number of dorso-lateral rows of cilia, number of cilia per row, length of the terminal portion of the AZM on the right side of the body, and number of cirri within each cirral group; these characteristic are now known to be highly variable and overlapping. Similar variable and overlapping characteristics have been used in the past to describe 51 species in the genus Euplotes. Gates (1977, 1978), using multivariate analyses of selected cortical structures, characterized six different evolutionary groups within the genus Euplotes and concluded that many characteristics previously used to described species of Euplotes no longer could be considered valid. Similarly, in view of the identical morphogenetic process of division in D. scutum, D. oligothrix, and D. appendiculata, members other first groups of Diophrys may represent a single evolutionary grouping of morphologically inseparable populations. There may exist adequate stocks for breeding test are established and appropriate multivariate morphometric analyses made to set the limits of each species, the assemblage should be regarded as the D. scutum complex. The genus Diophrys, along with several other closely related genera (Euplotes, Aspidisca, Certesia), exhibits morphogenetic characteristics during cell division not seen in this combination among other hypotrichs. (1) Opisthe oral primordium develops de nova just posterior to the parental AZM with continuing development occurring in a subsurface pouch, (2) parental AZM becomes proter AZM, (3) OP does not donate kinetosomes to any developing cirral primordia, (4) cirral primordia for development of the frontal and transverse cirri form separately from other primordia or parental structures, (5) left marginal cirral primordia develop lateral to the parental left marginal row, and (6) parental kinetosomes do not appear to participate in development of ciliary structure of daughter cells. The above morphogenetic characteristics as seen in Euplotes, Aspidisca, Certesia, Uronychia, and Diophrys appear to unify the family Euplotidae. Because of the diverse cortical morphology of other genera (Gastrocirrhus, Swedmarkia, Paraeuplotes) now included in this family, the cortical division process must be used in the future to determine the justification for taxonomic inclusion of these in the same family. (ref. ID; 4007) [ref. ID; 4408]
Taxonomy; In 1838, Ehrenberg described Stylonychia appendiculata, but not as the type species of that genus. In 1841, Dujardin set up the genus Diophrys for one species, D. marina Dujardin, 1841. Later in the same publication, Dujardin erected Ploesconia for 10 species. The first was P. patella Dujardin, 1841, so Ploesconia became a junior synonym of Euplotes. A later species P. scutum Dujardin, 1841 was described as having an adoral zone membranelle (AZM) extending along the right side of the organism. The term adoral zone of oral polykinetids (AZOPK) is now used (Hill, 1990). In 1858, Claparede & Lachmann described Schizopus norvegicus. Most subsequent authors, including Quennerstedt, Stein, Kent, Kahl and Borror, have synonymized this organisms with Ehrenberg's Stylonychia appendiculata (see Borror (1972) and references therein). In 1859, Stein revised Stylonychia, erecting the genus Styloplotes, which included Stylonychia appendiculata, and indicating that Diophrys marina and Schizopus norgvegicus were junior synonyms (Borror, 1972). In an 1867 revision, Quennerstedt reevaluated Claparede & Lachmann's ciliate, Schizopus norvegicus, and believed it to be congeneric with, but not conspecific with, Styloplotes appendiculata (Ehrenberg, 1838), and then renamed it Styloplotes norvegicus. However, Schizopus Claparede & Lachmann, 1858 has priority over Styloplotes Stein, 1859, hence Quennerstedt's name became a junior synonym. It was Levander, in 1894, that sorted out the priorities in nomenclature and a named the species Diophrys appendiculata (Ehrenberg, 1838). In this century this name has been used by many protozoologists to report on the same and similar species. (ref. ID; 4408)
Diagnosis; Both benthic and planktonic Diophrys populations are found in marine and estuarine habitats. There are no freshwater representatives. The Diophrys cell is more or less the shape of a bar of soap. Its elongated oval body has relatively parallel sides, has a flattened, circular appearance in cross-section and has a smooth arched dorsal surface with little sculpturing. The AZOPK is located in a groove around the anterior end of the cell. The ventrally located buccal cavity is anterior to the transverse cirri. The ventral surface shows some sculpturing. The large, unified AZOPK is composed of linear files of closely set rows of kinetosomes (membranelles), extending in a prominent convex curve from the cytostome along two-thirds of the left side of the ventral surface. When the AZOPK reaches the anterior end of the cell, it arches around to the dorsal surface and then back toward the ventral surface and extends about one-quarter of the way down the right side of the cell. The AZOPK is narrow as it crosses the anterior end and becomes wider half way down the left side of the cell. It then extends posteriorly in a helical manner forming a sigmoid curve that narrows to the cytostome. The membranelles of the AZOPK show little differentiation in interphase, except for a gap between the membranelles of the collar and lapel portions of the AZOPK in some populations. There are two ciliary membranes to the right of the AZOPK, which are described in other Euplotes-like ciliates as an undulating membrane, endoral cilia or oral membrane (Borror 1972; Hill 1981 & 1990). The membrane topographically nearest the AZOPK is the monokinetidal endoral ciliary row; the other is a large, conspicuous polykinetidal paroral ciliary membrane. These ciliary structures extend from the cytostome anteriorly along the right edge of the convex curved buccal overture. Cirri make up the remaining ventral ciliature. There are seven frontoventral cirri (II/1 [paroral cirrus], III/2, III/3, IV/2, V/2, VI/2, VI/3). Cirri V/2 and VI/2 are small and are located anterior to the transverse cirri. There are five transverse cirri (III/1, IV/1, V/1, VI/1, VII/1), which along with the five large frontoventral cirri are locomotory in function. There are three enlarged right postero-marginal caudal cirri which are employed in reverse, or direction-changing motion. There are two postbuccal left marginal cirri. Kinetal row number 1 is found on the left ventrolateral surface immediately to the left of the AZOPK. The remaining kinetal rows are on the dorsal surface and are numbered consecutively to the cell's right. Dorsal cilia are short bristles 2-3 um long. The two elongated pieces of the macronucleus are connected by a thin strand of nuclear membrane and are arranged in a C-shape. There are several micronuclei associated with each lobe of the macronucleus. Diophrys cysts resemble those of Euplotes. They are spherical with the cell's ciliation being retained within the membrane of the cyst wall. Observations corroborate those of Burkovski and Epshtein (1982) that D. appendiculata is a bacterivore whereas D. scutum is a grazer upon diatoms. The species in the genus Diophrys separate into two complexes. The D. appendiculata complex includes D. appendiculata (Ehrenberg, 1838) Levander, 1894; D. oligothrix Borror, 1965; and D. appendiculata var. samuchi Aliyev, 1990. The D. scutum complex includes D. scutum (Dujardin, 1841) Kahl, 1932; D. peloetes Borror, 1965; D. quadricaudatus Agamaliev, 1967; D. scutioides Agamaliev, 1967; D. magnus Raikov & Kovaleva, 1968; D. tetramacronucleata Kattar, 1970; and D. kasymovi Agamaliev. 1971 (ref. ID; 4408) [ref. ID; 7354]
Members of the genus Diophrys Dujardin, 1840 are more or less parallel-sided and flattened-circular in cross-section, with a ventral buccal cavity. The FVC are fewer and more variable in number than in Euplotes. There usually are three hypertrophied, dorsal right caudal cirri. The paroral and endoral membranes are conspicuous. There usually are two or more macronuclei. They are marine. We recognize only two species: the type species of the genus D. appendiculata (Ehrenberg, 1838) and D. scutum (Dujardin, 1841). (ref. ID; 7354)
Type species; Diophrys appendiculata (Ehrenberg, 1838) (ref. ID; 7354)
- Diophrys acutum Dujardin (ref. ID; 2117)
Diophrys appendiculata-complex
[ref. ID; 4408]
Variation in the D. appendiculata complex; Isolates measured and grouped under the name of D. appendiculata are smaller, have a relatively smaller lapel and fewer dorsal cilia than members of the D. scutum complex. Members of the two groups, however, overlap considerably in number of dorsolateral kineties and in the length of the buccal cavity relative to cell length. The collar membranelles in members of the D. scutum complex arise between ridges that are Y-shaped in cross-section. They also have an anterio-dorsal ridge that is absent in members of the D. appendiculata complex. Isolates of D. appendiculata may differ in cell shape, posterior configuration of the lapel, and the number and distribution of cirri within cirral groups. It appears that the number of dorsal cilia and relative length of the lapel scale with cell size, whereas the relative length of the buccal cavity varies independently with cell size. The following examples indicate the nature and the extent of morphological variation in cell size, the configuration of the buccal cavity, the number and the arrangement of cirri within cirral groups and difference in number of kinetal rows and the distribution of cilia within rows. An isolate of D. appendiculata taken in 1959 exhibits the most typical sort of five kinetal rows, a single left marginal cirrus, and a distinct gap between collar and lapel. An isolate collected in 1965 and named D. oligothrix by Borror (1965), shows an uneven distribution of dorsal cilia within the five kinetal rows. The AZOPK has numerous membranelles and has no gap between lapel and collar membranelles. There are two left marginal cirri. A 1970 isolate, previously reported by Hill (1981) as D. oligothrix Borror, 1965, usually has four dorsal kineties, no gap between collar and lapel, and two left marginal cirri. Nondividing cells in this population average 65-101 um (avg. 78 um) long and 48-69 um (avg. 58 um) wide (n=50). They have an average of 47-63 (avg. 55) membranelles (n=50). The number of ciliary structures with in any ciliary groups is fairly constant with less than 2% variability in frontoventrals 7-9, transverse 5-6, caudal 3-4, left marginals 1-3 and kinetal rows 4-5. Members of a 1980 isolate from Plum Island, MA, have five kinetal rows but no more than four cilia per row, broad separation between collar and lapel, and one left marginal cirrus. Of 25 cells examined, only one cell had two left marginal cirri. (ref. ID; 4408)
Type species; Diophrys appendiculata (ref. ID; 4408) - Diophrys appendiculata (Ehrenberg, 1838) (ref. ID; 3119, 4893, 7354, 7605), (Ehrenberg, 1838) Kahl, 1932 (ref. ID; 2117, 2316) or (Ehrenberg, 1838) Levander, 1894 (ref. ID; 4408) reported author and year? (ref. ID; 191, 4007)
Syn; Diophrys hystrix Buddenbrock, 1920 (ref. ID; 4893); Diophrys multicirratus Alekperov, 1984 (ref. ID; 4893); Diophrys pentacirratus Alekperov, 1984 (ref. ID; 4893); Stylonychia appendiculata Ehrenberg, 1838 (ref. ID; 4408) - Diophrys appendiculata var. samuchi Aliyev, 1990 (ref. ID; 4408)
- Diophyrys histrix (ref. ID; 4007)
See; Diophryopsis histrix (Buddenbrock, 1920) Hill & Borror, 1992 (ref. ID; 4408) - Diophrys hystrix Buddenbrock, 1920
See; Diophrys appendiculata (ref. ID; 4893) - Diophrys irmgard Mansfeld, 1923 (ref. ID; 3119) reported author and year? (ref. ID; 4007)
- Diophrys kahli Dragesco, 1963 (ref. ID; 3119) reported author and year? (ref. ID; 4007)
- Diophyrys kasymovi Agamaliev, 1971 (ref. ID; 4007, 4408)
- Diophyrys magnus Raikov & Kovaleva, 1968 (ref. ID; 4408) reported author and year? (ref. ID; 4007)
- Diophrys multicirratus Alekperov, 1984
See; Diophrys appendiculata (ref. ID; 4893) - Diophrys multinucleata Hartwig, 1973 (ref. ID; 3119, 4007)
- Diophyrys oligothrix Borror, 1965 (ref. ID; 4007, 4408, 4893) reported author and year? (ref. ID; 191)
- Diophyrys peloetes Borror, 1963 (ref. ID; 4893) or 1965 (ref. ID; 4408) reported author and year? (ref. ID; 4007)
See; Diophrys scutum (ref. ID; 4893) - Diophrys pentacirratus Alekperov, 1984
See; Diophrys appendiculata (ref. ID; 4893) - Diophyrys quadricaudatus Agamaliev, 1967 (ref. ID; 4408) reported author and year? (ref. ID; 4007)
See; Diophrys scutum (ref. ID; 4893) - Diophyrys salina (ref. ID; 4007)
- Diophyrys scutiodes (ref. ID; 4007)
- Diophyrys scutioides Agamaliev, 1967 (ref. ID; 4408)
- Diophyrys scutoides Agamaliev, 1967 (ref. ID; 4893)
See; Diophrys scutum (ref. ID; 4893)
Diophrys scutum-complex
[ref. ID; 4408]
Variation in the D. scutum complex; In D. scutum there are usually five dorsal kinetal rows. However, organisms with 6-10 rows occur in some isolates. The total number of dorsal cilia in organisms with five kineties regresses closely with cell length. Considerable variability occurs between isolates of otherwise similar ciliates in the number and arrangement of frontoventral and transverse cirri. The number of frontoventral cirri may vary from as few as six to as many as 11. Isolates with only four transverse cirri have been found. Thus, species such as D. quadricaudatus and D. scutioides described by Agamaliev (1971) are included in the D. scutum complex. In D. scutum, the C-shaped macronucleus is composed of two lobes that are connected by a thin strand of nuclear membrane. However, in some isolates the lobes may nearly be fused into a single unit, or as seen in other isolates there may be three lobes. In some extreme instances the macronuclear material has been split up among 12-26 irregular fragments. Diophrys tetramacronucleata Kattar, 1970 (1970) appears to be an example of an organism with a highly lobed macronucleus. If isolates of the D. scutum group are arranged by ascending size, neither the relative length of the buccal cavity nor the lapel length appear to scale with size. Because of this, it became necessary to reexamine the premise that D. peloetes Borror, 1965 is morphologically distinguishable from other members of the D. scutum group on the basis of the number of dorsolateral kineties and length of the lapel (Borror, 1965). It suggests considerable overlap in relative length of the lapel between D. peloetes and of the D. scutum complex with five kineties. Further, there is greater within-isolate variability in the number of dorsolateral kineties than realized in 1965. In view of these overlaps, it is suggested that D. peloetes Borror, 1965 should fall as a junior synonym of D. scutum. (ref. ID; 4408)
Morphogenesis: The process of cortical morphogenesis within the genus Diophrys begins with the subcortical appearance of the anlage of the new opisthe AZOPK to the left and posterior to the parental AZOPK. The subcortical pouch opens as the new opisthe AZOPK develops by the rapid proliferation of kinetosomes and their alignment into membranelles. As the AZOPK is forming, it migrates along the division furrow around the anterior portion of the developing opisthe. The parental AZOPK becomes the AZOPK of the proter. Concomitantly with the development of the AZOPK five cirral primordia streaks of the frontoventral and transverse cirri appear to the right of the buccal cavity and anterior to the parental transverse cirri. As kinetosome proliferation continues within the cirral primordia, they divide to form the proter and opisthe cirral primordia fields. The number of kinetosomes continues to increase as the cirral primordia in both fields enlarge, begin to form lobes, and then break apart to become distinct cirri. Within each field, five transverse cirri (III/1-VII/1) and six frontoventral cirri (III/2, III/3, IV/2, V/2, VI/2 and VI/3) develop. The proter paroral primordium forms to the right of the posterior end of the parental AZOPK. In contrast, the opisthe paroral primordium develops near the posterior end of the developing opisthe AZOPK. Both paroral primordia elongate due to the proliferation of kinetosomes to form a lobe, the anterior end of which becomes the paroral cirrus (II/1). The posterior portion of the primordium becomes the paroral membrane. The two left marginal primordia begin on the ventral surface between the AZOPKs of the proter and opisthe and the cell's left margin. Kinetosomes proliferate rapidly into lobes that separate into the two left marginal cirri in each daughter cell. Caudal cirri develop within the two right-hand kinetal rows. The proter caudal primordia develop anterior to the fission line whereas the caudal primordia of the opisthe develop at the posterior end of the cell. The developing primordium in the right-most kinetal row separates into two lobes that form two of the caudal cirri. The inner kinetal row forms a single caudal cirrus. (ref. ID; 4408) - Diophrys scutum Dujardin, 1841 (ref. ID; 4007, 4893, 7354) or 1842 (ref. ID; 3119, 3498) reported year? (ref. ID; 3771, 4111), (Dujardin, 1841) Kahl, 1932 (ref. ID; 4408) reported author and year? (ref. ID; 191, 7571)
Syn; Diophrys peloetes Borror, 1963 (ref. ID; 4893); Diophrys quadricaudatus Agamaliev, 1967 (ref. ID; 4893); Diophrys scutoides Agamaliev, 1967 (ref. ID; 4893)
- Diophrys tetramacronucleata Kattar, 1970 (ref. ID; 4007, 4408)