Two Guinea angelfish Holacanthus africanus, unknown to the Mediterranean were captured this spring in Senglea, the Spot the Alien Fish campaign said.

Alan Deidun, who heads the campaign, said the capture was a highly significant one since the fish is a non-migratory species associated with reefs at shallow depths in its native range.

The two individuals were caught within 10 of metres of each other, leading researchers to speculate that the species might have been introduced along with the oil rig stationed at Senglea for repairs and maintenance work, given that both the fish and the oil rig originated from the tropical west coast of Africa.

The intentional release of the species within Maltese waters through the aquarium industry was another possibility given its popularity within such an industry.

The Guinea angelfish is not dangerous to humans and can be consumed, although it is not prized in commercial fisheries.

Reports of new species can be sent to the Spot the Alien Fish campaign by e-mail through the campaign website or Facebook page.

The campaign is dedicated towards documenting the arrival of new species to Maltese waters, with such records surging in recent years.

The text of the scientific paper emerging from this find can be accessed here.