common arm squid vs Formosan Serow

Brachioteuthis riisei compared with Capricornis swinhoei

Key Differences

• common arm squid is Data Deficient while Formosan Serow is Least Concern.

Taxonomic Classification

Rank	common arm squid	Formosan Serow
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Chordata (Chordates)
Class	Cephalopoda (Cephalopods)	Mammalia (Mammals)
Order	Oegopsida (Oegopsida)	Artiodactyla (Even-toed Ungulates)
Family	Brachioteuthidae	Bovidae (Bovids)
Genus	Brachioteuthis	Capricornis
Species	Brachioteuthis riisei	Capricornis swinhoei

Evolutionary Relationship

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

Conservation Status

common arm squid

DD — Data Deficient

Formosan Serow

LC — Least Concern

Physical Characteristics

Attribute	common arm squid	Formosan Serow
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.

Formosan Serow

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Taiwan.

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.