24 articles from 23 countries in 5 continents are presented in the fourth release of this year.

 Is there a honeybees’ invasion in the Sea of Cortés southern islands?

 Birdwatcher alert! The Red-vented Bulbul (Pycnonotus cafer), one of the hundred most invasive species in the world, has been found breeding in Europe.

 Citizen-science and social networks help scientists to reveals the presence of alien species. See how Facebook reveals distributions of non-indigenous land snails in a European capital, and photos uploaded on iSea online data platform reveal the presence of mangrove red snapper (Lutjanus argentimaculatus) in the East Mediterranean Sea.

 Botanical headlines! An overview of the first occurrences of black jebead (Rhodotypos scandens) in Austria, the taxonomy of one of the most invasive plant species in the world (Ehrharta erecta), and the first record of the red alga (Compsopogon caeruleus) in the High Paraná River, Argentina-Paraguay

Alien mysteries revealed by DNA: genetic evidences confirm the presence of the Japanese mystery snail (Cipangopaludina japonica) in northern New York, the invasion of the dark false mussel (Mytilopsis leucophaeata) in shrimp farms in Venezuela, the first record of the neotropical ant (Brachymyrmex cordemoyi) in Germany, and authenticate Gambusia affinis as the invasive mosquitofish in Taiwan.

 Useful updates on the distribution of several alien species from all over the world: the updated checklist of non-native marine fishes in Florida, the American bullfrog (Rana catesbeiana) in the Republic of Korea, the introduced freshwater fishes in the Guadalquivir River Basin (Spain), the invasive snail (Potamopyrgus antipodarum) in Lithuanian inland water, the dwarf surf clam (Mulinia lateralis) in the Wadden Sea, and the spread of the non-native redclaw crayfish (Cherax quadricarinatus) into natural waters of Western Australia.

 More and more alien first records from all over the world for: molluscs (the alien fissurellid Diodora ruppellii record in Libya, and the biofouling mussel Mytella strigata in Indian waters), crustaceans (Laticorophium baconi in European marine waters, Gammarus tigrinus in Bornholm-Denmark, American blue crab Callinectes sapidus in the Gulf of Lions, Penaeus aztecus reached the Black Sea coasts), and fishes (the Montague’s blenny Coryphoblennius galerita in the North-Western Black Sea, Ukraine).

 Please visit our website and download Vol. 8, Issue 4 of BioInvasions Records – it's Open Access!