common arm squid vs Harmless Serotine

Brachioteuthis riisei compared with Eptesicus innoxius

Key Differences

• common arm squid is Data Deficient while Harmless Serotine is Near Threatened.

Taxonomic Classification

Rank	common arm squid	Harmless Serotine
Kingdom same	Animalia (动物界)	Animalia (动物界)
Phylum	Mollusca (软体动物门)	Chordata (脊索动物门)
Class	Cephalopoda (头足纲)	Mammalia (哺乳動物)
Order	Oegopsida (开眼目)	Chiroptera (翼手目)
Family	Brachioteuthidae	Vespertilionidae
Genus	Brachioteuthis	Eptesicus
Species	Brachioteuthis riisei	Eptesicus innoxius

Evolutionary Relationship

common arm squid and Harmless Serotine share a common ancestor at the Kingdom level: Animalia. (动物界)

Conservation Status

common arm squid

DD — Data Deficient

Harmless Serotine

NT — Near Threatened

Physical Characteristics

Attribute	common arm squid	Harmless Serotine
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.

Harmless Serotine

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Ecuador. 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.