Common Yellow Conch vs Compact Stonewort

Agapeta hamana compared with Nitella tenuissima

Key Differences

• Common Yellow Conch is Least Concern while Compact Stonewort is Extinct.

Taxonomic Classification

Rank	Common Yellow Conch	Compact Stonewort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Charophyta (Charophyta)
Class	Insecta (Insects)	Charophyceae (Charophyceae)
Order	Lepidoptera (Butterflies & Moths)	Charales (Charales)
Family	Tortricidae	Characeae
Genus	Agapeta	Nitella
Species	Agapeta hamana	Nitella tenuissima

Conservation Status

Common Yellow Conch

LC — Least Concern

Compact Stonewort

EX — Extinct

Physical Characteristics

Attribute	Common Yellow Conch	Compact Stonewort
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Yellow Conch

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

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.

Common Yellow Conch

<em>Agapeta hamana</em>, the common yellow conch moth, is a small moth in the family Tortricidae. It is widely distributed across Europe and central Asia, ranging from Britain and Scandinavia eastward through much of the Palearctic region. The species inhabits dry grasslands, heathlands, chalk downlands, and scrubby habitats where its larval host plants are found. Adult moths display distinctive pale yellow to golden-yellow forewings with irregular brown or reddish-brown markings near the wingtip, forming a pattern that resembles the shell of a conch, lending the species its common name. The wingspan typically measures around 15–22 mm. Biological traits such as average adult lifespan, precise body weight, and detailed population data remain poorly documented in consolidated scientific literature. Larvae feed internally on the roots of thistles and knapweeds, particularly <em>Centaurea</em> and <em>Cirsium</em> species. Adults fly from June to August and are frequently attracted to light. <em>Agapeta hamana</em> has been investigated as a potential biological control agent for invasive knapweed species in North America, where it has been introduced experimentally. The species is assessed as Least Concern given its broad distribution and stable habitat associations.

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.

Shared Countries

Both species can be found in 2 countries:

🇳🇴 Norway 🇸🇪 Sweden