Description: Recognized as one of the largest aquatic hemipterans in South America, this species displays a flattened and sturdy body with brownish tones that provide excellent camouflage among submerged vegetation. Its forelegs are modified into strong grasping appendages designed to seize prey rapidly, while the elongated and flattened hind legs act as paddles that enable swift underwater movement. Like other Belostomatidae, it uses its piercing rostrum to inject digestive enzymes and subsequently extract the liquefied tissues of its prey. These adaptations position the species as a highly efficient predator within freshwater ecosystems.

Geographical distribution: It is broadly distributed across the Neotropical region, with frequent records from Argentina, Brazil, Paraguay, Uruguay and parts of Bolivia. International biodiversity sources describe a continuous distribution across warm temperate to subtropical areas of South America, where the species occupies freshwater habitats with low current.

Habitat: The species inhabits ponds, wetlands, quiet river margins, irrigation canals, rice fields and other freshwater environments with abundant aquatic vegetation. It prefers warm, shallow waters with soft substrates, where it remains concealed for long periods. Submerged plants and debris provide effective cover for ambush strategies.

Diet: This insect is an opportunistic predator, feeding on small fish, tadpoles, aquatic insects, crustaceans and various invertebrates. It captures its prey with its robust forelegs and pierces them with its rostrum, injecting digestive enzymes that allow external digestion. This enables it to prey upon organisms that may be quite large relative to its own size.

Behavior: It is generally stealthy, spending extended periods motionless while waiting for prey. Although capable of agile swimming, it typically performs short and precise movements. It is commonly attracted to artificial lights at night, which facilitates observation in urban and peri-urban environments. When threatened, it may deliver a painful defensive bite using its piercing rostrum.

Reproduction: Belostomatids exhibit remarkable parental care, and Belostoma elongatum follows this pattern. Males carry the eggs attached to their back, protecting them from predators and maintaining adequate moisture by frequently returning to the water. This strategy significantly increases the survival of the offspring and is a distinctive reproductive trait of the group.

Conservation status: The species is not currently assessed as threatened at a global level and remains relatively stable across its range. Its adaptability to modified habitats contributes to its persistence, although water pollution, pesticide use and wetland degradation may negatively affect certain populations.

Author of this compilation: EcoRegistros – 12/12/2025