common arm squid vs small tortoiseshell

Brachioteuthis riisei compared with Aglais urticae

Key Differences

• common arm squid is Data Deficient while small tortoiseshell is Near Threatened.

Taxonomic Classification

Rank	common arm squid	small tortoiseshell
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Arthropoda (Arthropods)
Class	Cephalopoda (Cephalopods)	Insecta (Insects)
Order	Oegopsida (Oegopsida)	Lepidoptera (Butterflies & Moths)
Family	Brachioteuthidae	Nymphalidae (Brush-footed Butterflies)
Genus	Brachioteuthis	Aglais
Species	Brachioteuthis riisei	Aglais urticae

Evolutionary Relationship

common arm squid and small tortoiseshell share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

common arm squid

DD — Data Deficient

small tortoiseshell

NT — Near Threatened

Physical Characteristics

Attribute	common arm squid	small tortoiseshell
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

common arm squid

Habitat

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

Range

Distributed across Chile and Norway.

small tortoiseshell

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (41 countries). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

common arm squid

<em>Brachioteuthis riisei</em>, commonly known as the Common Arm Squid, is a cephalopod mollusk in the family Brachioteuthidae. This species is classified as Data Deficient on the IUCN Red List, reflecting significant gaps in knowledge about its population size, ecology, and distribution. Records of this species have been reported from waters off Chile and Norway, suggesting a broad oceanic distribution. Common Arm Squids are typically mesopelagic or bathypelagic organisms, inhabiting the open ocean at considerable depths during the day and often migrating toward shallower waters at night to feed. Like other oceanic squids, they are likely important components of marine food webs, serving as both predators of small fish and invertebrates and as prey for larger marine predators such as cetaceans and seabirds. The Data Deficient listing underscores the need for additional research into the biology, population dynamics, and conservation requirements of this understudied species. Biological traits of this species remain poorly documented in the scientific literature.

small tortoiseshell

small tortoiseshell (Aglais urticae) is classified as Near Threatened (NT) on the IUCN Red List. Close to qualifying as threatened, with populations that may become vulnerable without conservation action.

Shared Countries

Both species can be found in 1 countries:

🇳🇴 Norway