Swimming with the giant: coexistence patterns of a new redfin minnow from a global biodiversity hot spot.

Ecological niche theory predicts that coexistence is facilitated by resource partitioning mechanisms that are influenced by abiotic and biotic interactions. Alternative hypotheses suggest that under certain conditions, species may become phenotypically similar and functionally equivalent, which invokes the possibility of other mechanisms, such as habitat filtering processes. To test these hypotheses, we examined the coexistence of the giant redfin , a newly described freshwater fish, together with its congener and an anabantid by assessing their scenopoetic and bionomic patterns.

Historical abiotic events or human-aided dispersal: inferring the evolutionary history of a newly discovered galaxiid fish.

Range expansion of obligate freshwater fishes in the Cape Floristic Region (CFR) of South Africa has mostly been attributed to river capture events and confluence of rivers following sea-level regression. The role of low drainage divides and interbasin water transfers has received less attention. This study analyzed mitochondrial and nuclear DNA sequences to assess the processes that could have influenced the phylogeographic patterns of a newly discovered lineage of Galaxias zebratus (hereafter Galaxias zebratus "Joubertina") that occurs across two currently isolated river systems close to the Joubertina area in the eastern CFR.