Geographical distribution of freshwater fishes in Saudi Arabia.

Species presence/absence data in different water bodies in different regions of Saudi Arabia were collated from the literature and collected from field surveys to determine the geographical distribution of fish species in the country. Freshwater fish are mainly located in drainages in the south-west of the Kingdom of Saudi Arabia, both in the lowlands (western drainage systems) and highlands (eastern drainage systems) of the Sarawat Mountain Range. The eastern drainage systems were dominated by three endemic species, while the western drainage systems had a variety of endemic and non-native species.

Two decades of body length measurements of larval and juvenile fish populations in English rivers.

Long-term datasets provide context and understanding of complex ecological processes, including temporal variations in species diversity and ecosystem dynamics. This dataset is comprised of body length measurements (mm) of more than 380,000 larval or juvenile fish of 30 species from five English river catchments collected almost monthly over two decades. Such information can be used to determine growth rates, future recruitment success, population structure and compliance with monitoring protocols and conservation objectives.