Chungan Sucker Frog vs Compact Stonewort

Amolops chunganensis compared with Nitella tenuissima

Key Differences

• Chungan Sucker Frog is Least Concern while Compact Stonewort is Extinct.

Taxonomic Classification

Rank	Chungan Sucker Frog	Compact Stonewort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Chordata (Chordates)	Charophyta (Charophyta)
Class	Amphibia (Amphibians)	Charophyceae (Charophyceae)
Order	Anura (Frogs & Toads)	Charales (Charales)
Family	Ranidae	Characeae
Genus	Amolops	Nitella
Species	Amolops chunganensis	Nitella tenuissima

Conservation Status

Chungan Sucker Frog

LC — Least Concern

Compact Stonewort

EX — Extinct

Physical Characteristics

Attribute	Chungan Sucker Frog	Compact Stonewort
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Chungan Sucker Frog

Habitat

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

Compact Stonewort

Habitat

Native to Asia and Europe and North America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Brazil, Norway, Sweden, Taiwan, and United States.

Chungan Sucker Frog

The Chungan Sucker Frog (Amolops chunganensis) is a Least Concern torrent frog in the family Ranidae, endemic to central China, particularly associated with the mountains of Chongqing (formerly Chungan County, from which the species name derives) and surrounding areas. The genus Amolops, commonly known as torrent frogs or cascade frogs, is adapted for life in and around fast-flowing mountain streams, with expanded toe pads and sucker-like discs that allow clinging to wet, smooth rock surfaces in high-velocity water. Breeding occurs in stream environments, where males call from boulders at the stream edge and larvae develop in oxygenated torrent pools with specialized mouthparts for adhering to rock substrates. A. chunganensis inhabits subtropical and montane forests at elevations ranging from low to mid altitudes in Sichuan and Chongqing. The IUCN assesses this species as Least Concern, reflecting a relatively wide distribution within suitable stream habitats across central China. However, it faces ongoing pressure from water quality degradation, dam construction and stream modification, deforestation, and pollution from agricultural and urban runoff. Amolops frogs are sensitive to siltation and chemical contamination of breeding streams.

Compact Stonewort

<em>Nitella tenuissima</em>, a stonewort formerly found in fresh and brackish water habitats, was a member of the charophyte family Characeae — the algal lineage most closely related to land plants. Historical records document its occurrence across Brazil, Norway, Sweden, Taiwan, and the United States, where it inhabited clear, oligotrophic lakes, ponds, and slow-flowing water bodies with low nutrient levels. Like other Nitella species, it was a delicate, translucent, submerged aquatic plant lacking the calcium carbonate encrustation of related genera, forming low-growing mats on soft sediments in well-illuminated shallow water. The species played a role in aquatic ecosystems by stabilising lake sediments, contributing to water clarity, and providing microhabitat for invertebrates and small aquatic organisms. <em>Nitella tenuissima</em> is classified as Extinct by the IUCN, having not been recorded from any of its former localities despite targeted searches. The primary causes of its extinction are believed to be widespread eutrophication of freshwater habitats driven by agricultural nutrient runoff and sewage discharge, which eliminated the clear, nutrient-poor conditions on which the species depended. The loss of this stonewort is emblematic of the broader decline of freshwater charophyte diversity across the Northern Hemisphere. Biological traits including historical morphological measurements and reproductive parameters are documented only in sparse historical herbarium specimens and early botanical literature.