Predaceous water beetles (Coleoptera, Hydradephaga) of the Lake St Lucia system, South Africa: biodiversity, community ecology and conservation implications

Abstract

Water beetles are one of the dominant macroinvertebrate groups in inland waters and are excellent ecological indicators, reflecting both the diversity and composition of the wider aquatic community. The predaceous water beetles (Hydradephaga) make up around one-third of known aquatic Coleoptera and, as predators, are a key group in the functioning of many aquatic habitats. Despite being relatively well-known taxonomically, ecological studies of these insects in tropical and subtropical systems remain rare. A dedicated survey of the hydradephagan beetles of the Lake St Lucia wetlands (South Africa) was undertaken between 2013 and 2015, providing the first biodiversity census for this important aquatic group in the iSimangaliso Wetland Park, a UNESCO World Heritage Site within the Maputaland biodiversity hotspot. A total of 32 sites covering the entire spectrum of waterbody types were sampled over the course of three collecting trips. The Lake St Lucia wetlands support at least 68 species of Hydradephaga, a very high level of diversity comparing favourably with other hotspots on the African continent and elsewhere in the world and a number of taxa are reported for South Africa for the first time. This beetle assemblage is dominated by relatively widespread Afrotropical taxa, with few locally endemic species, supporting earlier observations that hotspots of species richness and centres of endemism are not always coincident. Although there was no significant difference in the number of species supported by the various waterbody types sampled, sites with the highest species richness were mostly temporary depression wetlands. This contrasts markedly with the distribution of other taxa in the same system, such as molluscs and dragonflies, which are most diverse in permanent waters. Our study is the first to highlight the importance of temporary depression wetlands and emphasises the need to maintain a variety of wetland habitats for aquatic conservation in this biodiverse region.

Taxonomic revision of the genus Copelatus of Madagascar (Coleoptera, Dytiscidae, Copelatinae): the non- erichsonii group species

“…Copelatus pulchellus is now interpreted as a widespread Afrotropical and Middle Eastern species with the male penis similar to that illustrated in Figure 5C. Dorsal colouration is interpreted as very variable, even consisting of several distinct colour forms such as the darker forms described as C. obtusus Boheman and later as C. africanus Sharp (compare figure 24 with photographs in Perissinotto et al (2016: fig. 24) and Hájek and Reiter (2014: fig.…”

Biodiversity and temporal patterns of macrozoobenthos in a coal mining subsidence area in North China

“…The time of subsidence has led not only to changes in the macrozoobenthos community of the newly formed wetlands but also to the internal and external characteristics of the newly formed wetlands. The water quality of the wetlands has been shown to affect the diversity of macrozoobenthos (Lupi, Rocco & Rossaro, 2013; Perissinotto, Bird & Bilton, 2016). This is especially true for macrozoobenthos in wetlands in agricultural landscapes, where extreme changes in the parameters of the aquatic environment often occur (Meyer, Davis & Dvorett, 2015), which in turn, affect the macrozoobenthos communities.…”

Peer Review #2 of "Biodiversity and temporal patterns of macrozoobenthos in a coal mining subsidence area in North China (v0.1)"

“…The time of subsidence has led not only to changes in the macrozoobenthos community of the newly formed wetlands but also to the internal and external characteristics of the newly formed wetlands. The water quality of the wetlands has been shown to affect the diversity of macrozoobenthos (Lupi et al, 2013;Perissinotto et al, 2016). This is especially true for macrozoobenthos in wetlands in agricultural landscapes, where extreme changes in the parameters of the aquatic environment often occur (Meyer et al, 2015), which in turn, affect the macrozoobenthos communities.…”