Taxonomical Research

We examined about 200 samples of Pleisocene and Holocene deposits, which were collected from 29 boreholes at a depth of 0.5-47 m, as well as from buried soils and the material of cryopedolith-located fossil rodent burrows. In the ice-complex sediments, viable protozoa were found in 25 of 125 samples (20% of total samples examined). Occurrence of viable protozoa was considerably higher in the buried soils (80%; 14 samples) and fossil burrows (100%; 12 samples) (Table 8.1).

The protozoological analysis of the samples revealed specimens of major protozoa macrotaxons: naked amoebas, heterotrophic flagellates, ciliates and heliozoa (Table 8.2, Fig. 8.3).

Twelve cultures of cyst-forming species of ancient ciliates were obtained from the samples of permafrost sediments, buried soils and burrows. They were represented, in their major part, by specimens of polyzonal species. Apart from ten strains of specimens of the taxonomical group Colpodea — Colpoda steinii, C. inflata, C. aff. aspera, C. aff. augustini, Colpoda sp., Platyophrya aff. vorax—the ciliates Vorticella sp. (Oligohimenophorea) and Oxytricha sp. (Spirotrichea) were isolated.

It turned out that the occurrence of viable amoeboid organisms (49%) in the permafrost sediments was higher than that of ciliates (9%). Naked amoebas were found both in the samples of permafrost sediments and in buried soils. We identified specimens of lobose (Leptomyxida, Acanthamoebidae) and heterolobose (Vahlkampfiidae) amoebas. Pure cultures of ancient naked amoebas, two Leptomyxida and eight Acanthamoebidae strains, were obtained in laboratory settings. Acanthamoebas, like colpodean ciliates, are distributed worldwide (Page 1988; Foissner 1993).

In the samples from buried burrows, we found 27 species and forms of het-erotrophic flagellates from ten taxonomical groups and flagellates incertae sedis (Shatilovich et al. 2008). The taxonomical analysis of the ancient flagellate fauna revealed that amoeboid flagellates (Cercomonadida, Apusomonadidae) and stramenopiles (Chrysophyceae) were the most numerous and diverse groups (Fig. 8.4).

Table 8.1 Sites, age and genesis of the permafrost samples

Site

Location

Well no.

Depth (m)

Age

Genesis

Lithology

1

The coast of Laptev Sea, Bykovsky peninsula

1/01

0.40-0.56

Modern soil

1

QIII

Late Pleistocene sediments of ice complex

Peat

1.95-2.05

Sandy loam with peat

2.16

2.8

7

19

Sandy loam

2/01

1.0-1.1

QIV

Sediments of Holocene alases

Sandy loam with peat

2

2.25-2.33

2.4

2.5

7/03

4

QIII

Late Pleistocene sediments of ice complex

Peat

4.95-5.05

Sandy loam with peat

6.9

Peat

12/03

3.5

QIV

Sediments of Holocene alases

Sand with inclusions of peat

4

2

Yana-Indigirka lowland, mouth of Chroma bay

2/04

0.71

Modern soil

1.15

QIII

Late Pleistocene sediments of ice complex

Loam

3

Indigirka-Kolyma lowland,

Khomus-Yuryakh river

3/05

0.7

Modern soil

4.2

QII

Middle Pleistocene sediments of ice complex

Sandy loam

6.5

Sandy loam

4/05

9.3

Loam

4

Kolyma lowland, Chukochi cape

7/91

1

QIV

Sediments of Holocene alases

Loam with peat

Kolyma lowland, Oler ltake

1/95

1.25-1.3

Loam

2/95

0.3-0.35

Modern soil

Kolyma lowland,

Kuropatochia river

2/96

10,6-10,7

QIII

Late Pleistocene sediments of ice complex

Loam

Kolyma lowland, Kolyma river, Anuy river (Stanchikovsky and Duvanny yars)

Outcrop 1

Buried soils and burrows in the late Pleistocene sediments of ice complex

Outcrop 2

Table 8.2 Biodiversity of ancient protozoa isolated from Siberian permafrost (Adl et al. 2005)

Taxonomic groups

Species and forms

CHROMALVEOLATA Adl et al. 2005

Alveolata Cavalier-Smith 1991

Ciliophora Doflein 1901 [Ciliata: Perty 1852, Infusoria: Butschli 1887]

Oxytrichia sp. Colpoda steinii Maupas 1883 Colpoda inflata Kahl 1931 (Stokes 1884) Colpoda aff. augustini Foissner 1987 Colpoda aff.aspera Kahl 1926 Colpoda sp Platyophrya aff. vorax Kahl 1926 Vorticella sp.

Cryptophyceae Pascher 1913, emend. Schoenichen 1925

Goniomonadales Novarino and Lucas 1993

Goniomonas truncata (Fresenius) Stein 1878

Stramenopiles Patterson 1989, emend. Adl et. al. (2005)

Chrysophyceae Pascher 1914

Spumella elongata (Stokes) Belcher and Swale 1976 Spumella sp.

Incertae sedis Alveolata

Colponema edafi-cum Mylnikov et Tikhonenkov 2007

EXCAVATA Cavalier-Smith 2002, emend. Simpson 2003 (P?)

Heterolobosea Page and Blanton 1985

Vahlkampfiidae Jollos 1917

Vahlkampfia sp.

Fornicata Simpson 2003

Histionidae Flavin and Nerad 1993

Reclinomonas aff. americana Flavin and Nerad 1993

Euglenozoa Cavalier-Smith 1981, emend. Simpson 1997

Euglenida Bütschli, 1884, emend. Simpson 1997

Anisonema ovale Klebs 1893

Kinetoplastea Honigberg 1963

Bodo curvifilis Griessmann 1914 Bodo designis Skuja 1948

B. repens Klebs 1893 B. minimus Klebs 1893

AMOEBOZOA Luhe 1913, emend. Cavalier-Smith 1998

Tubulinea Smirnov in Adl et al. 2005

Leptomyxida Pussard and Pons 1976, emend. Page 1987

Leptomyxa sp.

Acanthamoebidae Sawyer Pons 1976, emend. Page 1987

Acanthamoeba sp.

Eumycetozoa Zopf, 1884, emend. Olive 1975

Incertae sedis Eumycetozoa

Hyperamoeba flagel-lata: Alexeieff 1923

(continued)

(continued)

Table 8.2 (continued)

Taxonomic groups

Species and forms

Incertae sedis AMOEBOZOA Spongomonadida: (Hibberd 1983) emend. Karpov 1990

Spongomonadidae Karpov 1990

Phalansterium soli-tarium Sandon 1924

Spongomonas uvella Stein 1878

OPISTOCONTA Cavalier-Smith 1987, emend. Cavalier-Smith and Chao 1995, emend. Adl et al. 2005

Choanomonada Kent 1880

Monosigidae Zhukov and Karpov 1985

Codonosiga botrytis Kent 1880

Desmarella moniliformis Kent 1880

Monosiga ovata Kent 1880

Salpingoecidae Kent 1880

Salpingoeca globulosa Zhukov 1978

RHIZARIA Cavalier-Smith 2002

Cercozoa Cavalier-Smith 1998, emend. Adl et al. 2005

Cercomonadida (Poche 1913), emend. Vickerman 1983, emend. Mylnikov 1986

Cercomonas angustus: (Skuja 1948) Mylnikov and Karpov 2004

Cercomonas crassi-cauda Dujardin 1841

Cercomonas granulif-era (Hollande 1942) Mylnikov and Karpov 2004

Cercomonas sp.

Heteromita minima (Hollande 1942) Mylnikov and Karpov 2004

Heteromita aff. globosa (Stein) Kent 1880

Incertae sedis Heteromitidae

Allantion tachyploon Sandon1924

Protaspis aff. gemmifera Larsen and Patterson 1990

Protaspis simplex V0rs 1992

Incertae sedis EUKARYOTA

Apusomonadida Karpov and Mylnikov 1989

Apusomonadidae Karpov and Mylnikov 1989

Apusomonas probosci-dea Alexeieff 1924

Centrohelida: Kühn 1926

Acanthocystidae Claus 1874

Choanocystis perpu-silla Siemensma 1991

Fig. 8.3 Light micrographs of protozoans isolated from permafrost: a, b, c heterotrophic flagellates; d, e, f naked amoebas; g, h, i ciliates. Bars = 10 |im

Most of the species were bacteriotrophs, and four forms (Goniomonas truncata, Allantion tachyploon Colponema edaphicum, Choanocystis perpusilla) were predators. In one of the samples from buried burrows, we found a centrohelid helio-zoan, Choanocystis perpusilla. For many species of ancient protozoa, we obtained monocultures and clonal cultures, which grew well at 20°C.

The permafrost samples that were collected up to 3 m below the surface (boreholes 1/95, 2/95, 7/91, 2/01, 1/01, 1/03, 2/04, 3/05 and 1/95) appeared to be more abundant in protozoa, since they were found in 60% of those samples. The maximal depth at which we managed to isolate viable protozoa was 19 m (borehole 1/01). The organisms found at the upper permafrost boundary are not older than a few hundred years, with single, the most ancient, findings dated to the middle Pleistocene, 200,000-300,000 years (borehole 4/05; 9.3 m deep).

There was a tendency for the number and diversity of viable protozoa species in the buried soils and burrows to be larger than those observed in the ice-complex sediments. This, probably, is explained by more favorable conditions of cryoconservation and a relatively rich initial fauna in buried soils and burrows. In addition, the collection

Flagelados Intestinales

Fig. 8.4 Morphology of ancient heterotrophic flagellates: 1, Hyperamoeba flagellat; 2, Phalansterium solitarium; 3, Spongomonas uvella; 4, Codonosiga botrytis; 5, Desmarella moniliformis; 6, Monosiga ovata; 7, Salpingoeca globulosa; 8, Cercomonas angustus; 9, Cercomonas crassicauda; 10, Cercomonas granulifera; 11, Cercomonas sp. 1; 12, Cercomonas sp. 2; 13, Cercomonas sp. 4; 14, Heteromita aff. globosa; 15, Allantion tachyploon; 16, Goniomonas trun-cata; 17, Protaspis aff. gemmifera; 18, Protaspis simplex; 19, 20, Spumella elongat; 21, Spumella sp. 1; 22, Colponema edaficum; 23, Anisonema ovale; 24, Bodo designis; 25, B. repens; 26, Apusomonas proboscidea; 27, Heteromita minima; 28, Cercomonas sp. 3; 29, Spumella sp. 2; 30, Spumella sp. 3; 31, Reclinomonas aff. americana; 32, Bodo curvifilis; 33, B. minimus. The bar is equal to 5 (1-27) or 10 (28-34) Jim

Fig. 8.4 Morphology of ancient heterotrophic flagellates: 1, Hyperamoeba flagellat; 2, Phalansterium solitarium; 3, Spongomonas uvella; 4, Codonosiga botrytis; 5, Desmarella moniliformis; 6, Monosiga ovata; 7, Salpingoeca globulosa; 8, Cercomonas angustus; 9, Cercomonas crassicauda; 10, Cercomonas granulifera; 11, Cercomonas sp. 1; 12, Cercomonas sp. 2; 13, Cercomonas sp. 4; 14, Heteromita aff. globosa; 15, Allantion tachyploon; 16, Goniomonas trun-cata; 17, Protaspis aff. gemmifera; 18, Protaspis simplex; 19, 20, Spumella elongat; 21, Spumella sp. 1; 22, Colponema edaficum; 23, Anisonema ovale; 24, Bodo designis; 25, B. repens; 26, Apusomonas proboscidea; 27, Heteromita minima; 28, Cercomonas sp. 3; 29, Spumella sp. 2; 30, Spumella sp. 3; 31, Reclinomonas aff. americana; 32, Bodo curvifilis; 33, B. minimus. The bar is equal to 5 (1-27) or 10 (28-34) Jim of samples from outcrops allowed us to choose samples abundant in organics, more structured and, therefore, more suitable for protozoological examination.

No correlation was revealed between the occurrence of viable protozoa in the sediment samples and the physical-chemical properties of these sediments (moisture, grading, pH and temperature).

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