Brook Floater vs Coachwhip ray

Alasmidonta varicosa compared with Urogymnus granulatus

Taxonomic Classification

Rank	Brook Floater	Coachwhip ray
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Chordata (Chordates)
Class	Bivalvia (Bivalvia)	Elasmobranchii
Order	Unionida (Unionida)	Myliobatiformes (Myliobatiformes)
Family	Unionidae	Dasyatidae
Genus	Alasmidonta	Urogymnus
Species	Alasmidonta varicosa	Urogymnus granulatus

Evolutionary Relationship

Brook Floater and Coachwhip ray share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Brook Floater

VU — Vulnerable

Coachwhip ray

VU — Vulnerable

Physical Characteristics

Attribute	Brook Floater	Coachwhip ray
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.

Coachwhip ray

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.

Coachwhip ray

The coachwhip ray, Urogymnus granulatus, is a large elasmobranch in the family Urogymidae found across the Indo-Pacific region, ranging from the Red Sea and East Africa through South and Southeast Asia to northern Australia and the western Pacific islands. It inhabits shallow coastal waters including coral reef flats, sandy lagoons, seagrass beds, and estuarine habitats, where it forages for benthic invertebrates and small fishes buried in the substrate. The coachwhip ray is characterized by an oval disc and a long, whip-like tail with one or more venomous spines at its base, giving the species its common name. The disc reaches up to 1.4 meters in width, making it one of the larger members of its family. Urogymnus granulatus is ovoviviparous, giving birth to live young after internal development, and has low reproductive rates that make populations slow to recover from exploitation. The species is classified as Vulnerable by the IUCN due to significant declines caused by intensive coastal fisheries across its range, particularly in South and Southeast Asia where it is commonly caught as bycatch or targeted for its valuable meat, skin, and gill plates in local markets. Habitat degradation from coastal development and coral reef decline compounds the threat to wild populations.