Planaria: a ‘nightmare’ for mussels and oysters

The planaria is a species of worm that poses a very serious threat to local ecosystems and the aquaculture industry, as this is possible become an invasive species. Mussels and oysters are the favorite molluscs of this voracious bivalve devourer.

Marinas are ideal places to explore early arrival of exotic or invasive species. Maritime transport acts as a conduit for the spread of species between different areas, and habitat degradation in ports facilitates their establishment.

A multidisciplinary team consisting of researchers from the University of Oviedo and the Regional Agri-Food Research and Development Service (SERIDA) has exotic species in European waters: the planaria Postenterogonia orbicularis. The study was published in the journal Regional Studies in Marine Science.

Planaria and its risks

This species, native to the Pacific Ocean, has been found in the port of Avilés, in San Juan de Nieva and in the marina of Gijón. Researchers point out that this is the first appearance of this species in Europe. Postenterogonia orbicularis is a flatworm (planaria) dark brown on the dorsal side and lighter on the ventral side. This species represents a pest at its place of origin, where losses have been recorded aquaculture plants associated with this animal. In Asturias, the species is associated with mussels and oysters, both in port and naturalized environments.

Ricardo López Alonso, predoctoral researcher at the Department of Biology of Organisms and Systems of the University of Oviedo, points out that this species poses a “serious threat” to local ecosystems and the aquaculture sector, “especially to bivalve crops such as mussels and oysters. .”, since it is a voracious predator of these mollusks”. The authors of the work also point out that this discovery highlights the need to implement control measures to limit its expansion protect marine biodiversity and the economic interests of the region.

Know how to avoid

The researchers point out that a total of 73 specimens were collected from the different sampled points, most of which (45) were found in the port of Avilés. The research has also revealed the existence of a reproductively active population of this species (24 specimens) on the coast of Asturias, in particular on a beach near the port of Avilés (La Peña del Caballo).

Scientists explain that these advances in knowledge of the diversity of exotic speciespotentially invasive, would not have been possible without the joint effort of the researchers from several Asturian institutions involved, the Marina of Gijón, the Port Authority of Puerto del Musel, the Directorate General of Maritime Fisheries and the Center for Fisheries Experiments, which has once been demonstrated once again the importance of interdisciplinary cooperation for the protection of the marine environment.

In the study of the planarian, researchers have participated from the University of Oviedo, from the Departments of Biology of Organisms and Systems, from the Higher School of the Civil Navy, together with researchers from the SERIDA Animal Biotechnology Center.

This discovery highlights the need to implement control measures to limit its expansion before the planaria become and bring an invasive species serious damage to nature and ecosystems where it settles.