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 colony
Single-layered spherical to ellipsoidal colonies containing hundreds to thousands of cells. Contains somatic and reproductive cells where somatic cells are identical, spherical, ellipsoidal, pyriform (pear-shaped) or stellate. Each cell contains a chloroplast which is typically cup-shaped or irregularly disciform, and a single pyrenoid. The eyespot is usually largest in outside cells and smaller or absent in the inside cells. Daughter colonies develop within the maternal colony and can be seen as brighter green inclusions. They break free by rupturing the surface of the colony. Sample was collected from a sponge set in the shallow fresh water of Crystal Lake, Appledore Island.
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Volvox
From the collection
SML Crystal Lake
| Description of Volvox: Colonies large (up to 1.5 mm), more or less spherical to ellipsoidal, usually containing many hundreds to thousands (up to 60,000) cells in a single layer on periphery of a common gelatinous matrix; colonial boundary tripartite, each cell also surrounded by an individual extracellular matrix; 2 cell types, somatic and reproductive; somatic cells identical, spherical, ellipsoidal, pyriform or stellate, with 2 outwardly directed flagella; neighbouring cells attached by cytoplasmic connections; chloroplast single, cup-shaped or irregularly disciform, with a single (rarely several) pyrenoid(s); eyespot single, usually largest in anterior cells and progressively smaller or absent in posterior cells; nucleus more or less central; contractile vacuoles 2-6; reproduction, both asexual and sexual, restricted to relatively few reproductive cells (gonidia) which lose flagella and are somewhat larger than somatic cells; asexual reproduction by formation of 2-80 daughter colonies; initial sequence of cell divisions leading to small hollow spheres of cells or plakeas, in which flagellar bases and nuclei are oriented inwards; new gonidial cells being formed by unequal division of certain cells early in cleavage process; developing daughter colonies undergo inversion; sexual reproduction strictly oogamous; most species heterothallic, some homothallic, either monoecious or dioecious, some species heteromorphic with dwarf male colonies; female reproductive cells (2 to 700 per colony) enlarging to form oogonia with single non-flagellated eggs (oospheres); male reproductive cells dividing and developing into plate-like or globose sperm packets or plakeas of 16-512 biflagellate spindle-shaped antherozoids; zygotes thick-walled, smooth or variously ornamented, often with reddish contents; on germination, a single (rarely 4) biflagellate (sometimes aflagellate) gone cell escaping from zygote wall and dividing into a gone colony; nutrition phototrophic or photo-organotrophic; common, in bogs, pools, ponds, ditches, but most species with restricted geographical distribution. |
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Volvox in other collections
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Uroglena volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Askenasia volvox, from
Protozoan biomonitors in China
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Sphaeroeca volvox, from
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Uroglena volvox, from
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Volvox africanus, from
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Volvox aureus, from
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Volvox globator, from
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Sphaeroeca volvox, from
Images by Guy Brugerolle
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Sphaeroeca volvox, from
Images by Guy Brugerolle
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Sphaeroeca volvox, from
Images by Guy Brugerolle
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Volvox globator, from
Protsville
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Volvox, from
Protsville drawings of freshwater protists
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Volvox aureus, from
Limnic and marine Protists of Northern Germany and the Alps
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Volvox aureus, from
Limnic and marine Protists of Northern Germany and the Alps
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Volvox aureus, from
Limnic and marine Protists of Northern Germany and the Alps
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Volvox aureus, from
Limnic and marine Protists of Northern Germany and the Alps
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Volvox aureus, from
Limnic and marine Protists of Northern Germany and the Alps
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Volvox aureus, from
Limnic and marine Protists of Northern Germany and the Alps
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Askenasia volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Uroglena volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Askenasia volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Uroglena volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Uroglena volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Askenasia volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Askenasia volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Askenasia volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Askenasia volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Askenasia volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Askenasia volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Askenasia volvox, from
Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
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Volvox, from
Athens, Georgia, USA
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Volvox, from
Athens, Georgia, USA
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Volvox, from
Athens, Georgia, USA
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Volvox, from
Athens, Georgia, USA
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