Cochran Frog vs common grey sea slug

Nymphargus cochranae compared with Aeolidia papillosa

Key Differences

• Cochran Frog is Vulnerable while common grey sea slug is Least Concern.

Taxonomic Classification

Rank	Cochran Frog	common grey sea slug
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Chordata (Chordates)	Mollusca (Mollusks)
Class	Amphibia (Amphibians)	Gastropoda (Gastropoda)
Order	Anura (Frogs & Toads)	Nudibranchia (Nudibranchia)
Family	Centrolenidae	Aeolidiidae
Genus	Nymphargus	Aeolidia
Species	Nymphargus cochranae	Aeolidia papillosa

Evolutionary Relationship

Cochran Frog and common grey sea slug share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Cochran Frog

VU — Vulnerable

common grey sea slug

LC — Least Concern

Physical Characteristics

Attribute	Cochran Frog	common grey sea slug
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cochran Frog

Habitat

Typically found in freshwater habitats, moist forests, and wetlands.

Range

Found in Colombia. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

common grey sea slug

Habitat

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

Range

Distributed across Belgium, Chile, Denmark, Norway, and Sweden.

Cochran Frog

The Cochran frog (Nymphargus cochranae) is a small glass frog in the family Centrolenidae, native to the cloud forests of the western and central Andes in Colombia. Like other centrolenid frogs, it is characterised by semi-transparent or translucent ventral skin through which internal organs — including the heart, liver, and digestive tract — are visible, a feature that gives the family its common name. The species inhabits humid montane rainforest along streams at elevations typically between 1,500 and 2,800 metres, where males call from vegetation overhanging fast-flowing streams to attract females. Eggs are deposited in gelatinous masses on leaves or rocks above the water; upon hatching, tadpoles drop into the stream below and develop in the current-swept environment. Nymphargus cochranae is classified as Vulnerable by the IUCN, primarily due to ongoing deforestation and degradation of cloud forest habitats driven by agricultural expansion, cattle ranching, and coca cultivation across its Colombian Andean range. Glass frogs are additionally sensitive to stream water quality, making them useful bioindicators of watershed health. The species was named in honour of the eminent American herpetologist Doris Mable Cochran of the Smithsonian Institution, who made foundational contributions to Central and South American amphibian taxonomy in the mid-twentieth century. Continued habitat protection and reforestation efforts are critical for its long-term survival.

common grey sea slug

<em>Aeolidia papillosa</em>, commonly known as the common grey sea slug, is a nudibranch mollusc belonging to the genus Aeolidia within the family Aeolidiidae. Despite the species name referencing terrestrial and aquatic habitats including forests and freshwater, <em>Aeolidia papillosa</em> is primarily a marine organism. Its range includes Belgium, Chile, Denmark, Norway, and Sweden, indicating a distribution across the North Atlantic and into South American waters. Common grey sea slug is assessed as Least Concern on the IUCN Red List. The species is typically found in intertidal and subtidal zones, where it preys on sea anemones and stores stinging cells from its prey in its dorsal cerata for defense. Biological traits of this species remain poorly documented in the scientific literature.