Clawed enope squid vs common river snail

Abraliopsis felis compared with Viviparus viviparus

Taxonomic Classification

Rank	Clawed enope squid	common river snail
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Mollusca (Mollusks)	Mollusca (Mollusks)
Class	Cephalopoda (Cephalopods)	Gastropoda (Gastropoda)
Order	Oegopsida (Oegopsida)	Architaenioglossa (Architaenioglossa)
Family	Enoploteuthidae	Viviparidae
Genus	Abraliopsis	Viviparus
Species	Abraliopsis felis	Viviparus viviparus

Evolutionary Relationship

Clawed enope squid and common river snail share a common ancestor at the Phylum level: Mollusca. (Mollusks)

Conservation Status

Clawed enope squid

LC — Least Concern

common river snail

LC — Least Concern

Physical Characteristics

Attribute	Clawed enope squid	common river snail
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Clawed enope squid

common river snail

Habitat

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

Range

Found across Europe (7 countries).

Clawed enope squid

The Clawed Enope Squid, Ancistrocheirus lesueurii, is a medium-sized oceanic squid in the family Ancistrocheiridae found in mesopelagic and bathypelagic zones of the Atlantic, Pacific, and Indian Oceans. It is the sole species in its family, representing a phylogenetically isolated lineage of deep-sea squids. The species is characterized by powerful, hook-bearing tentacles used to capture prey, an adaptation reflected in its common name. The mantle is muscular and elongated, bearing lateral fins, and the arms bear suckers modified into sharp hooks in adults. Ancistrocheirus lesueurii performs diel vertical migrations, ascending toward the surface at night and retreating to deeper waters during daylight hours. It is a voracious predator of fish and other squids, and is in turn preyed upon by sperm whales, large pelagic fishes, and sharks. Bioluminescent photophores are present on the body and arms, likely functioning in counterillumination or signaling. As a mesopelagic species distributed throughout major ocean basins, the Clawed Enope Squid contributes significantly to vertical carbon transport in marine ecosystems, processing organic material from surface waters and redistributing it at depth. Population status is unknown; the species has not been assessed by IUCN. It is occasionally recovered in the stomach contents of top predators and from deep-sea trawl surveys.

common river snail

<em>Viviparus viviparus</em>, the common river snail, is a freshwater gastropod mollusk in the family Viviparidae, order Architaenioglossa. It is distributed across Europe, with populations documented in Austria, Belgium, Bulgaria, Czech Republic, France, Germany, and Hungary, among other countries, typically inhabiting slow-moving and still freshwater bodies including rivers, canals, ponds, and ditches. The species is assessed as Least Concern on the IUCN Red List. Common river snails typically live in soft-sediment benthic habitats, grazing on algae, aquatic plant material, and organic detritus using a radula — a ribbon-like feeding organ characteristic of gastropods. <em>Viviparus viviparus</em> is notable among freshwater mollusks for being viviparous, giving birth to fully formed juvenile snails rather than laying eggs, an adaptation reflected in both the genus and family names. This reproductive strategy typically results in small litter sizes but high juvenile survival compared to egg-laying mollusks. The species plays a role in benthic nutrient cycling and serves as prey for waterfowl, fish, and crayfish. Biological traits such as precise lifespan, body measurements, and population density data vary across localities and remain incompletely documented in comprehensive studies.