Cobblestone Tiger Beetle vs Common Water Rat

Cicindela marginipennis compared with Hydromys chrysogaster

Key Differences

• Cobblestone Tiger Beetle is Vulnerable while Common Water Rat is Least Concern.

Taxonomic Classification

Rank	Cobblestone Tiger Beetle	Common Water Rat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (Arthropods)	Chordata (Chordates)
Class	Insecta (Insects)	Mammalia (Mammals)
Order	Coleoptera (Beetles)	Rodentia (Rodents)
Family	Carabidae	Muridae (Mice & Rats)
Genus	Cicindela	Hydromys
Species	Cicindela marginipennis	Hydromys chrysogaster

Evolutionary Relationship

Cobblestone Tiger Beetle and Common Water Rat share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Cobblestone Tiger Beetle

VU — Vulnerable

Common Water Rat

LC — Least Concern

Physical Characteristics

Attribute	Cobblestone Tiger Beetle	Common Water Rat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cobblestone Tiger Beetle

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

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

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Cobblestone Tiger Beetle

Cobblestone tiger beetle (Cicindela marginipennis) is a medium-sized ground beetle in the family Carabidae (tribe Cicindelini), native to riverbars and cobblestone beaches of major river systems in eastern North America, from Quebec and Ontario south through the Ohio and Mississippi river basins. It is a habitat specialist restricted to dynamic, open gravel and cobble bars on large rivers, where bare, sun-warmed substrate provides ideal conditions for hunting small invertebrate prey. Like all tiger beetles, it is a fast-running, visually acute predator that captures prey by rapid pursuit. Adults are active on sunny days from late spring through summer, capable of short bursts of flight. Cobblestone tiger beetle is assessed as Vulnerable by the IUCN due to severe declines caused by the loss of dynamic river cobblestone habitat through dam construction, channelisation, bank stabilisation, and loss of natural flood regimes that maintain bare substrate. Populations have disappeared from many historically occupied rivers. Conservation efforts focus on preserving and restoring natural river dynamics on rivers where the species persists.

Common Water Rat

<em>Hydromys chrysogaster</em>, commonly known as the common water rat or rakali, is a semi-aquatic rodent in the family Muridae, native to Australia and New Guinea. It is classified as Least Concern by the IUCN, reflecting its relatively stable population across a broad range of freshwater and estuarine habitats on the Australian continent and associated islands. The species typically inhabits the banks of rivers, lakes, wetlands, and estuaries, where it constructs burrows in streambanks. It is highly adapted for an aquatic lifestyle, with partially webbed hind feet, a flattened head, and a dense waterproof coat. <em>Hydromys chrysogaster</em> is a carnivore, typically feeding on fish, crustaceans, mussels, frogs, and aquatic invertebrates, which it often carries to elevated feeding platforms to consume. The species is nocturnal and crepuscular, most active during early morning and evening hours near the water's edge. Biological traits including average lifespan, body length, and weight remain poorly documented in standardized databases, though adults are generally robust for a rodent, reportedly reaching body lengths of 20–35 cm excluding the tail. Geographic range details for this particular record remain incompletely documented in available data sources. Ecologically, the common water rat is an important apex predator in small-scale freshwater food webs and serves as an indicator species for wetland health in Australian riparian systems.