common sea hare vs Common Tansy

Aplysia punctata compared with Tanacetum vulgare

Taxonomic Classification

Rank	common sea hare	Common Tansy
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Mollusca (Mollusks)	Magnoliophyta (Flowering Plants)
Class	Gastropoda (Gastropoda)	Magnoliopsida (Dicots)
Order	Aplysiida (Aplysiida)	Asterales (Daisies & Sunflowers)
Family	Aplysiidae	Asteraceae (Daisy Family)
Genus	Aplysia	Tanacetum
Species	Aplysia punctata	Tanacetum vulgare

Conservation Status

common sea hare

LC — Least Concern

Common Tansy

LC — Least Concern

Physical Characteristics

Attribute	common sea hare	Common Tansy
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

common sea hare

Habitat

Typically found in terrestrial and aquatic habitats including forests and freshwater.

Range

Distributed across Denmark, Norway, Portugal, and Sweden.

Common Tansy

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Widely distributed across Asia (China, Japan), Europe (13 countries), North America (Canada, United States), Oceania and the Pacific (Australia), and South America (4 countries).

common sea hare

<em>Aplysia punctata</em>, the common sea hare, is a large opisthobranch sea slug in the family Aplysiidae, order Aplysiida, found in the northeastern Atlantic Ocean and Mediterranean Sea, with confirmed records from Denmark, Norway, Portugal, and Sweden. This species typically inhabits shallow subtidal and intertidal zones with abundant macroalgae, feeding primarily on red and green algae — a diet that influences the color of the defensive purple ink it secretes when threatened. <em>Aplysia punctata</em> is a simultaneous hermaphrodite, capable of acting as both male and female during mating, and often forms mating chains involving multiple individuals. It can reach considerable size among European opisthobranch species, though body dimensions vary considerably with age and feeding conditions. The species is classified as Least Concern by the IUCN, reflecting stable populations across its coastal range. Biological traits for this species remain poorly documented in the scientific literature, including precise average data on lifespan, body length, weight, and detailed seasonal dietary patterns, though its general herbivorous feeding on macroalgae is well established.

Common Tansy

<em>Tanacetum vulgare</em>, common tansy, is a perennial herbaceous plant in the family Asteraceae, native to temperate regions of Asia and Europe and widely naturalized across North America, Australia, and South America. It typically grows in disturbed habitats, roadsides, riverbanks, and waste ground, forming dense colonies through vigorous rhizome spread. The plant bears deeply divided, fernlike leaves and clusters of bright yellow, button-like flower heads in late summer. It is classified as Least Concern on the IUCN Red List given its expansive, growing range. Common tansy contains toxic compounds including thujone and camphor, making it poisonous to livestock and humans in large quantities, though historically it was used as a culinary herb and medicinal plant. Its strong aromatic scent has traditionally been used as an insect repellent. The species is considered invasive in several regions outside its native range. It provides nectar and pollen for various insects. Biological traits such as precise seed output figures, individual lifespan, and biomass data remain poorly documented in standardized assessments.

Shared Countries

Both species can be found in 4 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇵🇹 Portugal 🇸🇪 Sweden