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Silica-scaled Chrysophytes and Synurophytes from east Texas.

Abstract.--A total of 27 scale-bearing species of the algal classes Chrysophyceae and Synurophyceae, referred to herein as scaled chrysophytes, were recorded in 35 water bodies from 11 eastern Texas counties using transmission electron microscopy. These were distributed between the Chrysophyceae (one Chrysosphaerella sp., one Paraphysomonas sp. and two Spiniferomonas sp.) and Synurophyceae (14 Mallomonas sp. and nine Synura sp.). The number of taxa per collection varied from zero to six. Twenty-three taxa are new records for Texas. Mallomonas multisetigera is reported for the first time from North America. Scales of the colorless free-living flagellate Gyrornitus disomatus, an organism of uncertain taxonomic affinity, were also observed.

Surveys of the freshwater algal flora of Texas were initiated through a series of investigations by H. C. Bold and his students (Deason & Bold 1960; Chantanachat & Bold 1962; Bisehoff & Bold 1963; Brown & Bold 1964; Cox & Bold 1966; Smith & Bold 1966; Groover & Bold 1969; Archibold & Bold 1970; Baker & Bold 1970. Other studies have included Texas collections, but were not directed specifically on the Texas flora (Flint 1955; Nicholls 1964; Hoffman 1967; Ott 1976; Carty 1989; Carty & Cox 1985; 1986; Sheath et al. 1993a; 1993b; Swamikannu & Hoagland 1990; Vis & Sheath 1996). All of these reports are based on light microscopy.

Silica-scaled chrysophytes are taxonomically placed in the division Chrysophyta, classes Chrysophyceae and Synurophyceae, based on ultrastructural and biochemical characteristics (Andersen 1987). The majority of chrysophyte genera lack a covering of siliceous scales and exhibit a great plasticity in regard to both morphology and nutrition (Hoek et al. 1995). Most of the common chrysophytes are flagellated, occurring as single cells or are colonial.

The first electron micrographs of silica-scaled chrysophytes from Texas are in the unpublished report of Marquis (1977) based on collections made in the Edwards Plateau located at the southern most end of the High Plains province (Cole 1966). The chrysophyte flora of neighboring Louisiana (Wee et al. 1993), the nearby state of Arizona (Gretz et al. 1979; 1983; 1985), and the country of Mexico (Kristiansen & Tong 1995) also have been studied previously using electron microscopy. Adjacent states, such as New Mexico and Oklahoma remain to be investigated.

In this study, the silica-scaled algal flora from 11 counties representing 35 eastern Texas locations in the western Coastal Plain physio-graphic province (Cole 1966) were examined using transmission electron microscopy (TEM).


Phytoplankton samples were collected with a plankton net (10[mu]m mesh size) in mid-March of 1996 from 35 ponds and lakes in 11 Texas counties (Table 1). Samples were fixed in acid Lugol's (Wee 1983). For TEM, subsamples were placed on Formvar-coated, carbon-stabilized grids, air dried and examined with a Philips 300 transmission electron microscope. All identifications were based on TEM. Percentages were based on the number of samples in which a taxon was observed divided by the total number of samples. Physical/chemical parameters taken in the field were surface water temperature, pH (Markson model 85), and specific conductance (Oakton WD-60). In an attempt to identify coordinated variation between physical/chemical parameters and species composition of the samples, the data were subject to multivariate analyses, including Detrended Correspondence Analysis (DCA, Hill 1979) and Canonical Correspondence Analysis, (CCA, ter Braak 1992). Species occurring in only one sample were eliminated prior to analysis, re sulting in a data set of 17 samples and 31 taxa. All micrographs documenting this study are on deposit in the herbarium of Central Michigan University.


The taxa identified, and the collection sites for each taxon are listed in Table 2. Twenty-seven silica-scaled synurophycean and chrysophycean taxa from five genera, Mallomonas (14 taxa), Synura (10 taxa), Spiniferomonas (two taxa), Paraphysomonas and Chrysosphaerella (one taxon each) were observed from the 35 samples. All scale morphologies were similar to those in the published literature.

The number of scale-bearing chrysophyte taxa observed per sample varied from zero to six (Table 1). Species richness was greatest at three sites, Doc Young Pond, Lake Cherokee and South Twin Lake, where some of the lowest water temperatures, ranging from 14.8-15.7[degrees]C, were observed (Table 1). The most frequent Mallomonas species were M. tonsurata (20%), M. caudata (17%) and M. crassisquama and M. hamata (11% each). Common species from other genera were Synura uvella (34%), S. echinulata and S. petersenii f. petersenii (both 20%), S. australiensis (14%) and Spiniferomonas trioralis (23%). Species observed from only one collection site included Mallomonas annulata, M. doignonii, M. elongata, M. heterospina, M. mangofera, M. papillosa, Synura curtispina, S. mollispina, Spiniferomonas crucigera and Chrysosphaerella coronacircumspina. Additionally, Mallomonas multisetigera is newly reported for North America (Fig. 1 a).

Scaled chrysophytes were observed in every collection except Lake Palestine (sample 22). The reason(s) for this is unknown.

In the scanning electron microscope examination of samples from the Edward's plateau through central and northeastern Texas, Marquis (1977) observed nine Mallomonas taxa. This current study observed four of Marquis' (1977) taxa: Mallomonas caudata, M. doignonii, M. mangofera (as M. texensis) and M. transsylvanica. Mallomonas asmundiae, M. corymbosa, M. lychenensis, M. pseudocoronata and M. teilingii var. papillosa nomen nudum were not observed during this current study.

Scales of Gyromitus disomatus Skuja (Fig. 1b), a colorless free-living flagellate of unknown taxonomic affinity, were observed in the Lake Tyler sample. This organism has no obvious affinities with any taxonomic group (Swale & Belcher 1974). Nicholls (1979), using X-ray emission spectra, has shown that the scales are composed of silica, but not calcified, and hence do not represent coccoliths.

Specific conductance across all collections ranged from 47.4 to 619.0 [mu]S/M. For the ten most frequently observed species, Synura echinulata and Mallomonas crassisquama had the narrowest ranges, 89.8 to 128.7 and 49.4 to 109.3 [mu]S/M, respectively. The largest ranges were observed in Synura uvella (47.4 - 371.0 [mu]S/M) and Spiniferomonas trioralis (84.7 - 371.0 [mu]S/M). These are very close to the ranges reported by Wujek & Menapace (1998). As Siver (1993) reported, until more conductivity studies are published, it is unknown "at this time whether individual taxa are responding to specific anions and cations or some combination thereof."

The range in water temperatures (12.0 to 24.3 [degrees]C) and the time of year may indicate that the collections contained elements of both late spring and summer floras. Species observed, such as Mallomonas akrokomos and M. transsylvanica, have been observed under the ice in more northern regions (Cronberg & Kristiansen 1980; Siver 1991). Taxa such as M. crassisquama, M. tonsurata and Synura curtispina, are more commonly observed during the summer (Siver 1991), supporting the hypothesis that collections made during this current study contain some taxa common in summer and others more common in the spring or winter. With additional sampling, especially in colder waters, given that collections were taken during mid March when the surface water had begun to warm (Table 1), it is suspected that additional warm water species and cooler water taxa known to occur in the southeastern U.S. will be found to occur in Texas.

The pH of the collections ranged from 6.4 to 8.3. Many of the species observed in localities with low pH values, including Mallomonas hamata, M. transsylvanica, Synura echinulata and S. sphagnicola, have been reported previously as common in acidic habitats (Siver 1988; 1989; 1991; Wujek & Menapace 1998). Observations made during this study clearly support these earlier findings.

Synura petersenii f. petersenii occurred in the largest pH range, 6.5 to 7.1, for the most prevalent taxa followed by S. australiensis, S. uvella and Mallomonas caudata, 6.4 to 6.9 and then M. tonsurata with 6.6 to 7.0. Both Mallomonas crassisquama and Synura echinulata had the narrowest ranges (Table 1). The data for all nine species are within the values reported in the literature.

Multivariate analysis did not demonstrate clear relationships between the measured physical/chemical parameters and the scaled chrysophyte and synurophyte species composition of the samples. The first, second and third axes of a DCA ordination of the samples, which was based on the presence of scaled chrysophyte and synurophyte taxa, were not significantly correlated with any of the measured parameters. Likewise, a Canonical Correspondence Analysis showed low species-environment correlations. A Monte Carlo test of the CCA model using 100 random iterations failed to reject the hypothesis that no relationship existed between the species-samples matrix and the matrix of physical/chemical parameters.

Several explanations exist for the apparent lack of correspondence between the species composition of the samples and the environmental parameters. First, the relatively small number of samples taken at each lake may have resulted in taxa being missed. The sparse species-samples matrix and the large number of samples with only two or three taxa may have skewed ordination results. Additionally, collecting data that included an abundance measurement for taxa might result in more sensitive ordinations than the current data which were based on species presence or absence. Moreover, sampling during the period of turnover from the winter flora to the summer flora may have obscured species-environment patterns that would otherwise exist. It also is possible that the limiting environmental factor(s) structuring the scaled chrysophyte and synurophyte community were not measured or that scaled chrysophytes and synurophytes are not strong indicators of environment in eastern Texas lakes within the measured ranges of the environmental parameters.

In conclusion, as has been demonstrated in other regions of the U.S., Texas contains a diverse flora of scaled chrysophytes. This investigation is by no means exhaustive, and it is believed that further collections and observations from eastern Texas and other Texas physiographic provinces will yield additional species and possibly clarify species-environment relationships. Including this paper, the silica-scaled chrysophytes known from Texas, based on electron microscopy, now comprise 33 taxa.


The authors wish to thank M. Wujek for all aspects of the field collections, Alexandra Van Kley for her assistance in some of the field collections, P. Elsner for grid coating, K. Jeisel for some of the TEM observations, and CMU MultiMedia Production in helping with the preparation of the illustrations. The senior author thanks the FRCE Committee of Central Michigan University for partial funding of this study. We thank Sara Marquis Burgin for making available her unpublished observations.
Table 1

Eastern Texas plankton collection sites containing silica-scaled
chrysophytes and synurophytes, plus physical/chemical data and number of
taxa observed for each site, 17 March to 20 March, 1996.

 No. Location pH

Shelby County - 17 March, 1996

 1 Toledo Bend Reservoir 6.8
 Just southwest of County 139
 bridge across arm of the

 2 William Roberts Pond 6.7
 At Shelbyville - spring fed

 3 Center City Reservoir 7.1
 1/2 mile east of US 96, 3
 miles south of Center

 4 Pinkston Reservoir 7.7
 Near Aiken, southwest corner
 of county

Nacogdoches County - 17
March, 1996

 5 Sam Rayburn Reservoir 6.8

Jasper County - 17 March, 1996

 6 BA Steinhagen Lake 6.5
 Martin Dies Jr. State
 Park, south of US 190

Nacogdoches County - 17
March, 1996

 7 Lake Nacogdoches 6.5

Rusk County - 17 March, 1996

 8 Lake Striker 6.7

 9 Craig's Pond 6.7

 10 Willow Lake 6.6
 In Henderson

 11 Martin Lake 6.7
 Martin Lake State Park

Panola County - 17 March, 1996

 12 Lake Murvaul 6.7

Rusk County - 19 March, 1996

 13 Doc Young Pond 6.6
 Impoundment, about 2+ miles
 west of Tabem on north side
 of Texas Hwy 43 (1 1/4 miles
 east of Road 1716)

 14 Pond 6.7
 Northeast side of Road 1716,
 1 1/2 miles northwest of
 Texas Hwy 43

 15 Lake Cherokee 6.7
 Small arm crossing Farm
 Road 1716

 16 Long Glade Lake 6.7
 Boat launch, west side of
 Road 2127, 2 miles south of
 Lake Cherokee

 17 J.W. Walters Pond 6.7
 East side of Road 2127, 2
 miles north of Road 1727

 18 Lake Forest Park 6.6
 In west Hendersonville,
 south side of Texas Hwy 64

Smith County - 19 March, 1996

 19 Pleasure Acres Lake 6.7
 Lake at subdivision, north
 of Texas 64, northwest of
 New Chapel Hill
 20 Pond 7.8
 West of Pleasure Acres Lake
 entry road

 21 Lake Tyler 6.7
 Near Southeast side of Farm
 Road 848

Henderson County - 19 March,

 22 Lake Palestine 6.5
 West side of main lake,
 southeast side of Texas 155

Cherokee County - 19 March,

 23 Lake Jacksonville 6.5
 Northwest part just east of
 Farm Road 747

Nacogdoches County - 19 March,

 24 Whisper Oaks Pond 8.3

Harrison County - 20 March,

 25 Lake 7.0
 On south side of access road
 that parallels I 20, just
 east of US 259, exit at

 26 Privately owned lake 6.8
 Between I 20 and US 80 east
 of Longview, west of Ring
 Road [281] just south of
 County 3417

 27 Highway Lake 6.9
 In small subdivision, east of
 Longview, south side of
 Highway 80, accessed via
 County 3427, composite sample
 from both sides of dam
 between 2 biggest ponds

 28 Big Rock Lake 6.9
 East of Farm Road 450, east
 of Longview, between US 80
 and Farm Road 449

Marion County - 20 March, 1996

 29 Lake of the Pines 6.5
 At Island View boat ramp,
 south side of lake

Upshur County - 20 March, 1996

 30 Barton Lake 6.5
 East of Gilmer on south side
 of Texas 154 bridge

 31 Beaver Pond 6.8
 South of Gilmore, north side
 Bluebird Road between US 271
 and Texas 300

 32 South Twin Lake 6.4

 33 North Twin Lake 6.6

 34 Spencer's Pond 7.5
 West side of US 217, south
 of Gilmore, 1 mile north of
 Eagle and Evergreen Roads

 35 Big Sandy Lake 6.6

 Sample Temperature Conductivity #taxa
 No. [degrees]C [micro]S/M obs.

Shelby County - 17 March, 1996

 1 24.3 371.0 3

 2 21.2 117.6 2

 3 23.8 117.2 1

 4 22.8 105.8 1

Nacogdoches County - 17
March, 1996

 5 21.9 150.0 1

Jasper County - 17 March, 1996

 6 22.3 147.0 2

Nacogdoches County - 17
March, 1996

 7 13.8 103.9 4

Rusk County - 17 March, 1996

 8 16.5 279.0 1

 9 18.3 92.2 4

 10 14.4 157.5 1

 11 17.2 172.9 3

Panola County - 17 March, 1996

 12 16.9 190.3 5

Rusk County - 19 March, 1996

 13 14.8 89.8 6

 14 18.8 73.0 3

 15 16.7 92.6 6

 16 19.6 60.2 1

 17 16.4 86.9 2

 18 16.3 103.1 2

Smith County - 19 March, 1996

 19 18.3 101.3 1

 20 16.6 128.7 1

 21 18.2 95.3 4

Henderson County - 19 March,

 22 15.0 176.9 0

Cherokee County - 19 March,

 23 15.9 84.7 2

Nacogdoches County - 19 March,

 24 16.5 88.1 1

Harrison County - 20 March,

 25 13.5 396.0 2

 26 13.8 72.1 3

 27 17.4 113.1 3

 28 13.5 47.4 4

Marion County - 20 March, 1996

 29 14.2 134.1 1

Upshur County - 20 March, 1996

 30 16.4 97.7 2

 31 16.1 136.0 1

 32 15.7 77.1 6

 33 13.6 88.1 1

 34 12.0 619.0 2

 35 13.9 93.3 1
Table 2

Species of silica-scaled chrysophytes and synurophytes from eastern
Texas. See Table 1 for description of locations. Taxa indicated with an
asterisk (*) are new reports for Texas; double asterisks (**) are new
for North America.

Taxon Collection Locations


 (*) C. coronacircumspina 11
 Wujek & Kristiansen

 (*) P. vestita (Stokes) 6, 8, 11, 34
 de Saedeleer

 (*) S. crucigera Takahashi 15
 (*) S. trioralis Takahashi 1, 5, 11, 12, 15,
 18, 21, 23, 34


 (*) M. akrokomos Ruttner in Pascher 7, 15
 (*) M. annulata (Bradley) Harris 31
 M. caudata Ivanov em. Krieger 7, 26, 27, 28, 30, 32
 (*) M. crassisquama (Asmund) Fott 7, 12, 23, 32
 M. doignonii Bourrelly em. Nicholls 16
 (*) M. elongata Reverdin 10
 (*) M. hamata Asmund 2, 17, 31, 32
 (*) M. heterospina Lund 12
 M. mangofera Harris & Bradley 25, 32
 (*) M. papillosa Harris & Bradley 18
 (**) M. multisetigera Durrschmidt 9
 (*) M. portae-ferreae Peterfi & Asmund 4, 12
 M. transsylvanica Peterfi & Momeu 3, 35
 (*) M. tonsurata Teiling 21, 25, 26, 28, 29, 32,

 (*) S. australiensis Playfair 13, 14, 27, 28, 32
 em. Croome & Tyler
 (*) S. curtispina (Petersen & 24, 32
 Hansen) Asmund
 (*) S. echinulata Korshikov 1, 2, 13, 19, 20, 21, 35
 (*) S. mollispina Korshikov 13
 (*) S. petersenii f. 1, 3, 7, 12, 13, 14, 29
 petersenii Korshikov
 (*) S. petersenii f. glabra 1, 5, 15
 (Korshikov) Siver
 (*) S. sphagnicola Korshikov 13
 (*) S. spinosa f. spinosa Korshikov 15, 21, 29
 (*) S. uvella Stein em. Korshikov 1, 13, 14, 15, 17, 26,
 27, 28, 29, 30, 32, 33

 Classis insertae
 (*) Gyromitus disomatus Skuja 21


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Author:Wujek, Daniel E.; Wee, James L.; Van Kley, James E.
Publication:The Texas Journal of Science
Article Type:Statistical Data Included
Geographic Code:1U7TX
Date:Feb 1, 2002
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