Cigar shark vs Colonial bentgrass

Isistius brasiliensis compared with Agrostis capillaris

Taxonomic Classification

Rank	Cigar shark	Colonial bentgrass
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Chordata (Chordates)	Magnoliophyta (Flowering Plants)
Class	Elasmobranchii	Liliopsida (Monocots)
Order	Squaliformes (Squaliformes)	Poales (Grasses)
Family	Dalatiidae	Poaceae (Grass Family)
Genus	Isistius	Agrostis
Species	Isistius brasiliensis	Agrostis capillaris

Conservation Status

Cigar shark

LC — Least Concern

Colonial bentgrass

LC — Least Concern

Physical Characteristics

Attribute	Cigar shark	Colonial bentgrass
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.

Colonial bentgrass

Habitat

Inhabits tropical and subtropical moist broadleaf forests within the Neotropic biogeographic realm.

Range

Widely distributed across Europe (8 countries), North America (Canada, Costa Rica, United States), Oceania and the Pacific (Australia, New Zealand), and South America (5 countries).

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.

Colonial bentgrass

<em>Agrostis capillaris</em>, colonial bentgrass, is a perennial grass in the family Poaceae with an extensive native range across Europe and naturalised populations in North America, South America, and Oceania, including Australia and New Zealand. This species is highly adaptable, colonising tropical and subtropical moist broadleaf forests, temperate grasslands, disturbed soils, roadsides, and cultivated landscapes within the Neotropical realm. It is assessed as Least Concern by the IUCN. Colonial bentgrass is a fine-leaved, low-growing species often used in lawn and sports turf applications due to its tolerance for close mowing and its capacity to form dense, even swards. Its panicle inflorescences bear numerous small spikelets on delicate, hair-like branches, giving the species a feathery appearance when in flower. In its naturalised range, <em>Agrostis capillaris</em> can become invasive, competing with native grass species in acid grasslands and open heathlands. The species tolerates acidic and nutrient-poor soils, attributes that contribute to its widespread persistence in degraded landscapes. Biological traits of this species remain poorly documented in the scientific literature.