Flagship umbrella species needed for the conservation of overlooked aquatic biodiversity

Despite a long-standing debate about the utility of species-centered conservation approaches (Roberge & Angelstam 2004), surrogate species remain popular by providing useful-or even necessary-"shortcuts" for successful conservation programs (Caro 2010). Flagship species, as one prime example of surrogates, are primarily intended to promote public awareness and to raise funds for conservation (Veríssimo et al. 2011). In contrast, the protection of umbrella species is expected to benefit a wide range of co-occurring species (Roberge & Angelstam 2004; Caro 2010). Accordingly, the main criteria for selecting flagships should be based on socio-cultural considerations, whereas umbrellas are principally chosen based on ecological criteria (Caro 2010; Veríssimo et al. 2011; see Table 1). Since these two concepts are often confused or mistakenly used interchangeably, Caro (2010, p. 248) coined the term "flagship umbrellas" for those species that explicitly integrate both functions. Indeed, Li and Pimm (2016) recently demonstrated that the classic flagship species, the giant panda (Ailuropoda melanoleuca), can simultaneously act as an umbrella species, as its protection benefits many co-occurring endemic mammals, birds and amphibians. This challenges the often held views that: (i) the umbrella concept has to be abandoned as it is not efficiently working at local scales (Caro 2015); (ii) most flagship species are weak predictors for efficient reserve planning (Caro 2010); and (iii) ecosystem- or landscape-based conservation approaches should consequentially be favored over species-based approaches whenever feasible (Roberge & Angelstam 2004; Caro 2010). Further commotion in the discussion is the increasingly demanded paradigm shift in conservation strategies to specifically target hidden or neglected biodiversity for its intrinsic value and its contribution to ecosystem processes (Dougherty et al. 2016).