Broadgill Catshark vs

Apristurus riveri compared with Chrysosphaerella longispina

Key Differences

Broadgill Catshark is Least Concern while is Not Evaluated.

Taxonomic Classification

Rank	Broadgill Catshark
Kingdom	Animalia (Animals)	Chromista (Chromista)
Phylum	Chordata (Chordates)	Ochrophyta (Ochrophyta)
Class	Chondrichthyes (Cartilaginous Fish)	Chrysophyceae (Chrysophyceae)
Order	Carcharhiniformes (Ground Sharks)	Ochromonadales (Ochromonadales)
Family	Scyliorhinidae	Paraphysomonadaceae
Genus	Apristurus	Chrysosphaerella
Species	Apristurus riveri	Chrysosphaerella longispina

Conservation Status

Broadgill Catshark

LC — Least Concern

NE — Not Evaluated

Physical Characteristics

Attribute	Broadgill Catshark
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Broadgill Catshark

Habitat

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

Range

Found in Venezuela.

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, and Sweden.

Broadgill Catshark

The Broadgill Catshark (Apristurus riveri) 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.

Chrysosphaerella longispina is a colonial chrysophyte alga in the genus Chrysosphaerella, notable for the long silica spines (longispina: Latin, long spine) that project from each cell in the colony. The genus is characterized by spherical or discoid colonies of photosynthetic cells that each secrete siliceous scales and elongated spine-like appendages, making Chrysosphaerella colonies distinctively bristled and visible under light microscopy. The long spines of C. longispina likely serve as anti-predation structures that make the colonies more difficult for zooplankton to ingest. C. longispina is found in cold, oligotrophic freshwater lakes, particularly in Scandinavia, where comprehensive chrysophyte surveys have documented its presence. Chrysosphaerella colonies contribute to freshwater primary production and the cycling of biogenic silica, which upon cell dissolution is deposited in lake sediments as microscopically identifiable remains. These silica structures are widely used by paleolimnologists to reconstruct past changes in lake water chemistry, thermal stratification, and climate. The conservation status of C. longispina has not been assessed by the IUCN; the species is listed as Not Evaluated.