The exotic Bivalve Electroma vexillum (Reeve, 1857) (Bivalvia: Vulsellidae) on the Brazilian coast.

Abstract

The presence of the Indian Ocean and Red Sea bivalve Electroma vexillum (Reeve, 1857) was observed for the first time on the coasts of Ceará and Piauí. The occurrence of Electroma vexillum was recorded in association with solid waste deposited in the wrack zone, algae and marine angiosperm samples, on sandy beaches, sandstone reefs and sand-mud flats in estuarine areas. Local fishermen also reported the bivalve attached to nets and other fishing gear. The shell of E. vexillum is inequivalve, with the left valve being flattened and the right valve convex, overlapping the left. The average length of the specimens was 7.8mm, with and average length/height (L/H) ratio of 1.36mm. Further investigations are necessary to assess the ecological impact of this bivalve, which has previously caused damage to oyster farming structures in its native range. The potential consequences to native fauna, coastal ecosystems and mariculture facilities in Brazil raise concerns, emphasizing the urgency for continued monitoring and mitigation efforts. The recently described Electroma electra Simone, 2024 is discussed.