blue whale vs

Balaenoptera musculus compared with Colacium sideropus

Key Differences

blue whale is Vulnerable while is Not Evaluated.

Taxonomic Classification

Rank	blue whale
Kingdom	Animalia (動物)	Protozoa (原生動物)
Phylum	Chordata (脊索動物)	Euglenozoa (ユーグレノゾア門)
Class	Mammalia (哺乳類)	Euglenoidea (ユーグレナ藻)
Order	Cetacea (Whales & Dolphins)	Euglenida (Euglenida)
Family	Balaenopteridae (Rorquals)	Euglenaceae
Genus	Balaenoptera (Rorquals)	Colacium
Species	Balaenoptera musculus	Colacium sideropus

Conservation Status

blue whale

VU — Vulnerable

Population: ~15.0K

Trend: Increasing ↑

NE — Not Evaluated

Physical Characteristics

Attribute	blue whale
Diet	Carnivore	—
Average Lifespan	90 years	—
Average Length	30.0 m	—
Average Weight	150.0 t	—

Habitat & Geographic Range

blue whale

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 11 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (Taiwan), Europe (4 countries), and South America (Colombia, Ecuador). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Habitat

Native to Europe and South America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Brazil and Sweden.

blue whale

地球上で生きたことが知られている最大の動物であるシロナガスクジラ（Balaenoptera musculus）は、体長33メートル、体重200トンに達することができ、心臓だけで小型自動車ほどの重さがあります。全ての海洋に生息し、極地の餌場と熱帯の繁殖地の間を回遊します。1日最大4トンのオキアミを摂取する濾過摂食者です。20世紀の捕鯨による絶滅危機からの回復後、世界的な個体数は10,000〜25,000頭と推定される絶滅危惧種です。

Colacium sideropus is a microscopic euglenoid protist belonging to the family Euglenaceae, characterized by its sessile, colonial lifestyle attaching to aquatic invertebrates and zooplankton. Members of the genus Colacium are distinguished from free-swimming euglenoids by their stalked or clustered growth form, anchoring to the bodies of crustaceans such as copepods and cladocerans in freshwater environments. Like other photosynthetic euglenoids, Colacium possesses chloroplasts derived from secondary endosymbiosis with a green alga, allowing it to perform photosynthesis under favorable light conditions. The relationship with host invertebrates is generally considered epibiotic rather than parasitic, with the protist colonizing the external surfaces of its host without causing significant harm. Colacium sideropus occurs in freshwater lakes, ponds, and slow-moving streams where its zooplankton hosts are abundant. Its ecological role includes contributing to microbial food webs and nutrient cycling within freshwater ecosystems. As with many microscopic protists, its true distribution and abundance are difficult to assess from macroscopic surveys, and it is likely globally distributed wherever suitable hosts exist in freshwater habitats.