Brook Floater vs

Alasmidonta varicosa compared with Chrysococcus granulatus

Key Differences

• Brook Floater is Vulnerable while is Not Evaluated.

Taxonomic Classification

Rank	Brook Floater
Kingdom	Animalia (สัตว์)	Chromista (โครมิสตา)
Phylum	Mollusca (มอลลัสกา)	Ochrophyta (Ochrophyta)
Class	Bivalvia (ชั้นไบวาลเวีย)	Chrysophyceae (สาหร่ายสีทอง)
Order	Unionida (Unionida)	Chromulinales (Chromulinales)
Family	Unionidae	Dinobryaceae
Genus	Alasmidonta	Chrysococcus
Species	Alasmidonta varicosa	Chrysococcus granulatus

Conservation Status

Brook Floater

VU — Vulnerable

NE — Not Evaluated

Physical Characteristics

Attribute	Brook Floater
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Brook Floater

Habitat

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

Range

Found in United States. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden.

Brook Floater

The Brook Floater (Alasmidonta varicosa) is a species in the genus Alasmidonta. It is currently classified as Vulnerable on the IUCN Red List. Native to North America, inhabiting ecosystems characteristic of the region.

Chrysococcus granulatus is a unicellular freshwater chrysophyte microalga in the genus Chrysococcus, class Chrysophyceae. The species epithet granulatus — granular or granulated — describes a textured surface on the lorica of this species, a feature visible under electron microscopy that contrasts with the smooth surfaces of some congeners. In the genus Chrysococcus, the lorica is a secreted outer covering enclosing the cell, and its surface texture, shape, and any projections or pores form the primary morphological characters distinguishing species from one another. C. granulatus has been documented from Norwegian and Swedish freshwater bodies, consistent with the strong Scandinavian research tradition in chrysophyte taxonomy. Scandinavian oligotrophic and mesotrophic lakes are important reservoirs of chrysophyte diversity, harboring numerous species of Chrysococcus, Chromulina, Ochromonas, and related genera. Records from Brazil and Denmark extend the known distribution of C. granulatus, suggesting cosmopolitan or at least widespread dispersal capability through passive transport mechanisms such as wind, waterfowl, and hydrological connectivity. The species is a golden-brown phytoplankton organism with chlorophylls a and c and fucoxanthin carotenoids, enabling photosynthesis in the limnetic zone. Like other Chrysococcus species, C. granulatus may supplement photosynthesis with phagotrophic uptake of bacteria. It has not been assessed under IUCN criteria and carries a conservation status of Not Evaluated. The species contributes to understanding freshwater chrysophyte taxonomy and biodiversity in Scandinavian aquatic ecosystems.