Cigar shark vs common greasewort

Isistius brasiliensis compared with Aneura pinguis

Taxonomic Classification

Rank	Cigar shark	common greasewort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Chordata (Chordates)	Marchantiophyta (liverwort)
Class	Elasmobranchii	Jungermanniopsida (Jungermanniopsida)
Order	Squaliformes (Squaliformes)	Metzgeriales (Metzgeriales)
Family	Dalatiidae	Aneuraceae
Genus	Isistius	Aneura
Species	Isistius brasiliensis	Aneura pinguis

Conservation Status

Cigar shark

LC — Least Concern

common greasewort

LC — Least Concern

Physical Characteristics

Attribute	Cigar shark	common greasewort
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cigar shark

Habitat

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

Range

Distributed across Chile, Norway, and Taiwan.

common greasewort

Habitat

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

Range

Widely distributed across Asia (Taiwan), Europe (6 countries), North America (United States), and South America (Brazil, Colombia).

Cigar shark

The cigar shark, also known as the cookiecutter shark (Isistius brasiliensis), is a small but remarkable shark in the family Dalatiidae, found throughout warm oceanic waters worldwide in tropical and subtropical latitudes. Reaching only 40–50 centimeters in length, it possesses oversized jaws with large, triangular lower teeth arranged in a saw-like series that cut distinctive circular plugs of flesh from much larger prey—including tuna, dolphins, whales, billfish, and even submarine cables and human bodies. It does not kill its prey but instead latches on, rotates its body, and excises a characteristic cookie-cutter-shaped bite. The cigar shark is bioluminescent, emitting a green glow from photophores on its ventral surface that may serve as counter-illumination or to attract prey from below. It undertakes diel vertical migrations, ascending to shallower waters at night and descending to mesopelagic depths during the day. The species is classified as Least Concern by the IUCN, with a vast oceanic distribution and no targeted commercial fishery. It is occasionally taken as bycatch. The geographic epithet brasiliensis refers to Brazil, where early specimens were described, but the species' range is circumglobal in warm oceans. The cookiecutter shark's feeding strategy is one of the most unusual among elasmobranchs.

common greasewort

<em>Aneura pinguis</em>, commonly known as common greasewort, is a liverwort belonging to the genus Aneura within the family Aneuraceae. This cryptogamic plant inhabits ecosystems across Asia, Europe, and North America, thriving in moist or waterlogged environments. Its range encompasses Taiwan in Asia, six European countries, the United States in North America, and Brazil and Colombia in South America, indicating a broad geographic distribution across multiple continents. Common greasewort is assessed as Least Concern on the IUCN Red List. The species typically forms flat, ribbon-like thalli in damp habitats such as stream banks, wet rocks, and boggy ground. Biological traits of this species remain poorly documented in the scientific literature.

Shared Countries

Both species can be found in 2 countries:

🇳🇴 Norway 🇹🇼 Taiwan