Broadnose cat shark vs Compact Stonewort

Apristurus investigatoris compared with Nitella mucronata

Key Differences

• Broadnose cat shark is Least Concern while Compact Stonewort is Vulnerable.

Taxonomic Classification

Rank	Broadnose cat shark	Compact Stonewort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Chordata (Chordates)	Charophyta (Charophyta)
Class	Chondrichthyes (Cartilaginous Fish)	Charophyceae (Charophyceae)
Order	Carcharhiniformes (Ground Sharks)	Charales (Charales)
Family	Scyliorhinidae	Characeae
Genus	Apristurus	Nitella
Species	Apristurus investigatoris	Nitella mucronata

Conservation Status

Broadnose cat shark

LC — Least Concern

Compact Stonewort

VU — Vulnerable

Physical Characteristics

Attribute	Broadnose cat shark	Compact Stonewort
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Broadnose cat shark

Habitat

Typically found in marine environments from coastal waters to deep ocean.

Compact Stonewort

Habitat

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

Range

Widely distributed across Europe (4 countries), North America (United States), and South America (Brazil). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Broadnose cat shark

The Broadnose Cat Shark (Apristurus investigatoris) is a species in the genus Apristurus. It is currently classified as Least Concern on the IUCN Red List. Typically found in marine environments from coastal waters to deep ocean.

Compact Stonewort

<em>Nitella mucronata</em>, compact stonewort, is a freshwater macroalga in the family Characeae, belonging to the charophyte lineage considered the closest algal relatives of land plants. It has been recorded from fresh and brackish water bodies in Belgium, Brazil, Denmark, Norway, Sweden, and the United States, inhabiting clear, nutrient-poor lakes, ponds, and slow-moving streams. Stoneworts of the genus Nitella are delicate, translucent plants lacking the calcium carbonate encrustation typical of the related genus Chara, growing submerged in well-lit, oligotrophic aquatic environments. They typically form dense underwater meadows that provide important habitat for invertebrates and small fish, while also stabilising sediments and contributing to water clarity through nutrient uptake. <em>Nitella mucronata</em> is classified as Vulnerable by the IUCN, reflecting sensitivity to water quality deterioration, eutrophication from agricultural runoff and sewage, and the loss of clear, unpolluted water bodies across its range in Europe and beyond. The species is particularly vulnerable to increased phosphorus and nitrogen loading, which promotes algal blooms that shade out submerged macrophytes. Biological traits including average lifespan, reproduction rates, and morphological measurements remain poorly documented compared to more widespread charophyte species. Conservation of <em>Nitella mucronata</em> depends on improving water quality in its freshwater habitats and protecting oligotrophic water bodies from nutrient pollution.