In many biomes, a variety of different small freshwater habitats, such as pools and phytotelmata can occur together in the same habitat matrix. However, both the biodiversity and the functioning of these ecosystems remain poorly known. Three freshwater habitat types in a tropical West African biodiversity hotspot were studied. The study demonstrated that animal communities in water‐filled tree holes, temporary ponds and granite rock pools were strongly differentiated with exclusive faunas despite their spatial proximity and similar disturbance in the form of seasonal drought. In particular, granite rock pools stood out with a high gamma diversity. Rock pools were also functionally different from the other two habitat types. The three habitats had contrasting predator assemblages, a differential reliance on primary production and different concentrations of available nutrients. The work illustrates that the biodiversity and functions of small temporary freshwater habitats can be strongly differentiated. This shows the unique and potentially complementary roles that these habitats can fulfil in mediating fluxes of energy and nutrients and preserving aquatic biodiversity in landscapes. Temporary aquatic habitats are typically overlooked in conservation policy and local management plans despite being threatened by habitat transformation. In addition, livestock can threaten savanna ponds, wood exploitation can threaten tree holes, and mining and sediment disruption can threaten rock pools. Hence, better knowledge about the ecological functioning of these ecosystems is vital to the implementation of effective conservation strategies.

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Developmental plasticity can help organisms to survive in temporally variable environments. However, it is not well understood how variation in life history plasticity helps species coexist in heterogeneous environments. Here, we investigate the extent to which life‐history plasticity explains species distributions in a diverse assemblage of odonates in a tropical freshwater rock pool system characterized by substantial variation in pond permanence. Some dragonflies and damselflies (Odonata) can accelerate their development to leave the water before their habitat dries. However, how they sense habitat drying is poorly understood. Here, we experimentally tested the extent to which elevated concentrations of salts in water or reductions in water level can be used as cues for developmental acceleration in a neotropical Odonata assemblage from granite rock pools. Libellulidae dragonflies were found along the permanence gradient and accelerated their growth in response to elevated dissolved salts (measured as conductivity). Anax amazili (Aeshnidae) was also found in all environments and did the same in response to lower water levels. In turn, larvae of the damselfly Telebasis simulata (Coenagrionidae) were restricted to deeper long‐lived pools and did not respond to the tested cues. Differentiation in life‐history strategies can contribute to niche differentiation in this diverse predator assemblage. Developmental plasticity triggered by different cues helps odonates avoid mortality and exploit short‐lived habitats. The global acceleration of freshwater salinisation due to human activities might disrupt the delicate links between low levels of dissolved salts and life‐history responses and represent a significant threat to these ecosystems and their biodiversity.