Chlorella vulgaris
Chlorella vulgaris
Chlorella vulgaris is a named green microalgal species, but green coccoid cells or aquarium blooms do not identify the species or a strain. Reference cultures show that named material can be maintained, while their conditions do not transfer to arbitrary green water. Individual cells are microscopic; a freshwater type strain and broader marine, brackish and freshwater records require habitat claims to remain conditional.
Water type
Freshwater / Brackish / Marine
Biological group
Chlorellaceae
Record type
Species
Recognition confidence
Medium
Ecological functions
Primary producer, Live food
Aquarium impact
Context-dependent
Culture and management
Dedicated starter culture
Typical size
2 µm – 10 µm
Visible to the naked eye
No, not as an individual
Useful starting magnification
No universal threshold supported by reliable evidence
Identity, habitat, and ecological role
Identity and taxonomic resolution: Chlorella vulgaris is the species addressed by this card. NCBI records type material as SAG 211-11b and UTEX documents UTEX 30 as an axenic type culture, but neither turns an unlabelled aquarium sample into that species. The class scalar is deliberately unset: NCBI and MBRIS present Trebouxiophyceae, whereas UTEX 30 displays Chlorophyceae for its strain. That source conflict must remain visible, not be silently resolved.
Morphology and dimensions: The reviewed description supports non-motile, roughly spherical cells in an approximately 2–10 µm working range. This is useful for finding and measuring representative cells with a calibrated scale, but it is not a diagnostic boundary. Cell appearance and dimensions can vary with strain, growth state and preparation, and similar microalgae may share them. Record several intact cells, sample history and preparation rather than choosing one photographic match.
Habitat and microhabitat: The exact-species record lists marine, brackish and freshwater occurrence. These categories document where the species has been recorded; they do not set universal culture tolerances or a salinity prescription for a particular lot. A freshwater aquarium remains a sample context, not proof of a freshwater-only species or of an introduced strain's origin. Water-column material, attached films and culture vessels also contain different local conditions and communities.
Role in the food web: Chlorella vulgaris is photosynthetic primary-producer biomass at species level. An authenticated culture may be used as named material in a defined food-web or production setting, but a green aquarium suspension is not thereby shown to be C. vulgaris, axenic, nutritionally complete, food-safe or suitable for a particular consumer. Biomass, light, nutrients, growth phase and the receiving organism all change the ecological meaning of a culture or visible bloom.
Observation, culture, and ecological relationships
Where to look and how to sample: Begin by separating a documented culture from unknown green water. For a named culture, retain its label, source, vessel, medium, date and the exact material sampled. For an aquarium observation, record the location, whether material came from water, a film or debris, and the visible trend. These sample types can contain different communities. A single drop can document only the material examined; it cannot establish absence elsewhere or make the colour of a suspension a species record.
How to observe and identify: Use microscopy with a calibrated scale to compare several intact cells and fields, while recording preparation and sample history. The 2–10 µm guide and a coccoid appearance help describe material but do not distinguish C. vulgaris from look-alikes. No reviewed source makes 400×, or any other fixed magnification, a species-identity or culture-quality threshold. If species or strain resolution matters, use evidence suited to that question, including molecular comparison where necessary.
Presence and meaning in an aquarium: A visible green suspension documents algal biomass or pigment in that system, not confirmed Chlorella vulgaris, a known strain, water quality, safety or a diagnosis. Interpret it with sample location, timing and the measured environmental context. The freshwater provenance of one type strain does not override the institutional record of marine, brackish and freshwater occurrence for the species. Do not turn either source into a universal salinity rule for an aquarium culture.
Culture, maintenance or use: A starter culture is authenticated, traceable material maintained for a defined purpose; it is not any green water that resembles a microalga. UTEX's documented type culture supports the distinction between named material and an arbitrary suspension, not a universal home-growth recipe. Its axenic status, maintenance conditions, food value and suitability are not inherited by another lot. Keep conclusions at the level supported by the culture's identity, current condition and intended use.
Documented ecological relationships: The supported directional role is photosynthetic primary production: cells use light to build biomass that may enter a food web when a documented culture is used in a defined setting. This does not prove that every green suspension is edible, beneficial or consumed by an animal. The consumer, culture strain, growth phase, concentration and preparation remain part of the relationship. Record named culture provenance before transferring an ecological role from published material to a local sample.
Risks, control and limits: This is not a disease, treatment or chemical-control card. The reviewed evidence does not support medication, algaecides, a fixed prevention regime, or a general transfer protocol for an untyped culture. It supports a narrower limit: do not infer species, strain, axenicity, food safety or an aquarium response from colour or simple morphology. When a conclusion affects feeding, production or research, use traceable material and methods appropriate to the particular taxonomic and quality question.
Geographic origin and distribution
Origin
Selective breeding and cultivarsCosmopolitan or introduced
Identification and observation data
- Record type
- Species
- This is a species-level entry for Chlorella vulgaris. NCBI records type material as SAG 211-11b and UTEX documents a named type culture, but neither record identifies an unlabelled aquarium bloom. A green coccoid cell, supplier label or visible suspension must remain an observation until traceable provenance and suitable taxonomic evidence support a species or strain conclusion.
- Recognition confidence
- Medium
- Confidence is low for an aquarium observation because green coccoid morphology and a working size range overlap with Chlorella-like microalgae. The reviewed taxonomy study distinguished a C. vulgaris strain from a similar Chloroidium using molecular data. Use microscopy to document representative cells and a scale, but retain group-level wording when provenance and methods cannot resolve species or strain.
- Biological group
- Chlorellaceae
- Chlorella vulgaris is a green microalga considered in the phytoplankton and microalgae context. NCBI and MBRIS present Trebouxiophyceae, while UTEX 30 displays Chlorophyceae for its strain; the class scalar is therefore deliberately unset. The group label explains photosynthetic biomass, not the identity of every green-water event, which still needs its own traceable sample history and evidence.
- Ecological functions
- Primary producer, Live food
- Primary producer and live-food labels are conditional ecological roles. Chlorella vulgaris can make photosynthetic biomass, and an authenticated culture may enter a defined food-web setting. These labels do not establish that an untyped aquarium bloom is this species, axenic, nutritionally complete or suitable for a chosen consumer. Growth phase, preparation, concentration and consumer context remain material facts.
- Aquarium impact
- Context-dependent
- Impact is context-dependent. A green suspension indicates visible algal biomass or pigment, not confirmed Chlorella vulgaris, a known strain, safe feed, poor water quality or a treatment target. A freshwater type strain and an institutional record spanning marine, brackish and freshwater habitats show why colour and one water context cannot be promoted to a universal species or salinity conclusion.
- Culture and management
- Dedicated starter culture
- Starter culture means authenticated, traceable material maintained for a defined purpose. UTEX records a named axenic type culture, but its status and collection conditions do not transfer to an arbitrary culture or aquarium bloom. The evidence supplies no universal home-growth recipe, food-safety statement or consumer recommendation. Assess any other lot from its own identity, condition, contamination evidence and intended use.
- Typical size
- 2 µm – 10 µm
- Approximately 2–10 µm is a working observation range for non-motile, roughly spherical Chlorella vulgaris cells, not a strain or species boundary. Measure several intact cells with a calibrated scale and retain sample preparation, because dimensions can vary with strain and growth state. A cell inside or outside the guide cannot, on size alone, identify C. vulgaris or establish culture quality.
- Visible to the naked eye
- No, not as an individual
- Individual Chlorella vulgaris cells are microscopic and not identifiable with the naked eye. Dense biomass can make water or a suspension look green, yet that visible colour does not establish the species, a strain, purity, nutritional value or a cause of the event. Keep the observation tied to its sample and examine representative material with scale-bearing microscopy before assigning a name.
- Useful starting magnification
- No universal threshold supported by reliable evidence
- No universal magnification value is stored because the reviewed evidence does not make 400×, or any fixed setting, a species-identification or culture-quality threshold. Microscopy with a calibrated scale can document representative cells, while molecular comparison may be needed to distinguish Chlorella vulgaris from look-alikes. Magnification records how material was observed; it does not itself establish species, strain or axenicity.
Links to Aquarium SOS
Microworld ecological network
Links based on documented kinship, food webs, biofilms, and ecological functions.
