common arm squid vs common bottlenose dolphin

Brachioteuthis riisei compared with Tursiops truncatus

Key Differences

• common arm squid is Data Deficient while common bottlenose dolphin is Least Concern.

Taxonomic Classification

Rank	common arm squid	common bottlenose dolphin
Kingdom same	Animalia (สัตว์)	Animalia (สัตว์)
Phylum	Mollusca (มอลลัสกา)	Chordata (สัตว์มีแกนสันหลัง)
Class	Cephalopoda (ชั้นเซฟาโลพอด)	Mammalia (สัตว์เลี้ยงลูกด้วยน้ำนม)
Order	Oegopsida (Oegopsida)	Cetacea (Whales & Dolphins)
Family	Brachioteuthidae	Delphinidae (Oceanic Dolphins)
Genus	Brachioteuthis	Tursiops (Bottlenose Dolphins)
Species	Brachioteuthis riisei	Tursiops truncatus

Evolutionary Relationship

common arm squid and common bottlenose dolphin share a common ancestor at the Kingdom level: Animalia. (สัตว์)

Conservation Status

common arm squid

DD — Data Deficient

common bottlenose dolphin

LC — Least Concern

Population: ~600.0K

Trend: Stable →

Physical Characteristics

Attribute	common arm squid	common bottlenose dolphin
Diet	—	Carnivore
Average Lifespan	—	45 years
Average Length	—	3.0 m
Average Weight	—	300.0 kg

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.

common bottlenose dolphin

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 12 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (Taiwan), Europe (6 countries), and South America (Colombia, Ecuador, Venezuela).

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.

common bottlenose dolphin

The most studied and recognized dolphin species, bottlenose dolphins inhabit warm and temperate oceans worldwide, from coastal shallows to the open sea. Highly intelligent with large brains relative to body size, they demonstrate self-recognition, complex communication, and social learning. They live in fluid fission-fusion societies and cooperate to herd fish. A keystone indicator species for marine ecosystem health.

Shared Countries

Both species can be found in 1 countries:

🇳🇴 Norway