Widespread colonisation of Tanzanian catchments by introduced Oreochromis tilapia fishes: the legacy from decades of deliberate introduction

From the 1950s onwards, programmes to promote aquaculture and improve capture fisheries in East Africa have relied heavily on the promise held by introduced species. In Tanzania these introductions have been poorly documented. Here we report the findings of surveys of inland water bodies across Tanzania between 2011 and 2017 that clarify distributions of tilapiine cichlids of the genus Oreochromis. We identified Oreochromis from 123 sampling locations, including 14 taxa restricted to their native range and three species that have established populations beyond their native range. Of these three species, the only exotic species found was blue-spotted tilapia (Oreochromis leucostictus), while Nile tilapia (Oreochromis niloticus) and Singida tilapia (Oreochromis esculentus), which are both naturally found within the country of Tanzania, have been translocated beyond their native range. Using our records, we developed models of suitable habitat for the introduced species based on recent (1960–1990) and projected (2050, 2070) East African climate. These models indicated that presence of suitable habitat for these introduced species will persist and potentially expand across the region. The clarification of distributions provided here can help inform the monitoring and management of biodiversity, and inform policy related to the future role of introduced species in fisheries and aquaculture

Virgil: the future?

The poet Virgil remains the most significant and influential figure in Latin literature, and this expanded and updated Companion covers his life, work, and reception from antiquity to the present. The Aeneid, the Eclogues, the Georgics, and the Appendix Vergiliana are all discussed, as are art, history, politics, and philosophy; Virgil's literary style is carefully explored along with poetic traditions before and since, and chapters engage with his poems and their reception from perspectives including intertextuality, narratology, gender theory, philology and historicism. Leading authors cover topics from translations and commentaries to genre, authority, and characterisation, providing revised and updated recommendations for further reading. This volume is an accessible introduction to Virgil and his legacy for students and teachers, while also providing wide-ranging and in-depth investigations that will appeal to scholars of classical literature and other disciplines