Black roughscale catshark vs

Apristurus melanoasper compared with Chrysococcus cystophorus

Key Differences

Black roughscale catshark is Least Concern while is Not Evaluated.

Taxonomic Classification

Rank	Black roughscale catshark
Kingdom	Animalia (Animals)	Chromista (Chromista)
Phylum	Chordata (Chordates)	Ochrophyta (Ochrophyta)
Class	Chondrichthyes (Cartilaginous Fish)	Chrysophyceae (Chrysophyceae)
Order	Carcharhiniformes (Ground Sharks)	Chromulinales (Chromulinales)
Family	Scyliorhinidae	Dinobryaceae
Genus	Apristurus	Chrysococcus
Species	Apristurus melanoasper	Chrysococcus cystophorus

Conservation Status

Black roughscale catshark

LC — Least Concern

NE — Not Evaluated

Physical Characteristics

Attribute	Black roughscale catshark
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Black roughscale catshark

Habitat

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

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden.

Black roughscale catshark

The Black roughscale catshark (Apristurus melanoasper) 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.

Chrysococcus cystophorus is a unicellular freshwater chrysophyte microalga in the genus Chrysococcus, family Chromulinaceae, class Chrysophyceae. The specific epithet cystophorus, meaning cyst-bearing, references this species' relationship with siliceous cyst formation — a shared feature across many chrysophytes that produce species-specific resting stages called stomatocysts or statospores. In chrysophytes, the stomatocyst is a silicified internal cyst with a characteristic plug-sealed pore, and its morphology is often used as an additional taxonomic character in species identification. C. cystophorus inhabits freshwater environments and has been recorded from Norwegian waters along with other Scandinavian localities, fitting the pattern of chrysophyte species diversity documented through freshwater surveys in the region. Chrysococcus cells are enclosed within a lorica — a proteinaceous or organic outer vessel — from which flagella emerge for locomotion. The lorica shape and ornamentation, along with the dimensions and flagellar arrangement, are primary characters used for species identification. Like other chrysophytes, C. cystophorus is golden-brown in color owing to chlorophylls a and c together with fucoxanthin pigments in the chloroplast. Chrysococcus species function as primary producers in freshwater plankton communities, particularly in oligotrophic lakes where smaller algae outcompete larger taxa. C. cystophorus has not been evaluated under IUCN Red List criteria and is listed as Not Evaluated, consistent with the general status of freshwater microalgal taxa.