Highlights d Global-scale analysis of marine species shows abundance changes linked to warming d Increases at poleward sides of species ranges reflect new ecological opportunities d Declines at equatorward sides show failure to adapt to rapid climate change d Results imply future warming will impact further on abundance of marine species

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. Electronic supplementary material The online version of this article (10.1007/s10750-018-3597-9) contains supplementary material, which is available to authorized users.

Aim Lanternfish (Myctophidae) are one of the most abundant and ecologically important families of pelagic teleosts, yet how these species will respond to climate change is unclear, especially within polar regions. The aim of this study was to predict the impact of climate change on the distribution of Southern Ocean lanternfish and to relate these predicted responses to species traits. Location Circumpolar, 35–75°S. Methods We used MaxEnt ecological niche models to estimate the present and predict the future distributions of 10 biomass‐dominant lanternfish species throughout the region. Future conditions were simulated using eight climate models, in both stabilizing (RCP 4.5) and rising (RCP 8.5) emission scenarios, for the time periods 2006–2055 and 2050–2099. Species responses were then related to their realized thermal niche (i.e., thermal tolerance range), latitudinal preference and body size. Results Despite large variation between climate model simulations, all but one species are consistently predicted to undergo a poleward distribution shift. Species show contrasting projections relating to a gain or loss of suitable habitat which was best explained by their thermal niche. Overall, high‐latitude Antarctic species were found to have narrower thermal niches and a higher likelihood of losing habitat than sub‐Antarctic species. Main conclusions The direction of a species response was dependent on the interplay between physiology (realized thermal niche) and biogeography (latitudinal preference). Antarctic species with restricted thermal niches and limited available habitat in which to disperse will be the most vulnerable group of Southern Ocean lanternfish in the face of climate change. Predicted range shifts may alter the size structure of the myctophid community as smaller, sub‐Antarctic species reach further south. This could have implications for trophic interactions and thus the wider Southern Ocean ecosystem.