The mayflies (Ephemeroptera) of the upper River Sigi, north-east Tanzania

The work reported here results from material collected by the author made during 12 years residence in the East Usambaras in the 1950s and early 1960s, as well as a more recent visit. The faunal list the author has compiled comprises 45 species. As well as named species known to occur in the torrential section of the River Sigi, it includes those that are distinct but insufficiently well defined at present to have been formally described. For the sake of completeness, five species of Cloeon and one of Procloeon known to occur in ponds and pools formed by the damming of end-streams in forest clearings, have been included.

The first reported occurrence of the mayfly parasite Spirinella adipophila (Sporozoa) in a British river

During a 2-year survey on the distribution and ecology of mayflies in the upper reaches of the River Wey (a tributary of the River Thames) in Surrey, Spirinella was found in large numbers in the larvae of Ephemera Danica, and in low numbers in larvae of E. ignita and H. lateralis. Samples of E. danica taken from seven other tributaries of the Thames showed that Spirinella is present in most of them and often in high numbers.

Ground beetles and rove beetles be associated with temporary ponds in England

To date, research on the ecology and conservation of wetland invertebrates has concentrated overwhelmingly on fully aquatic organisms. Many of these spend part of their life-cycle in adjacent terrestrial habitats, either as pupae (water beetles) or as adults (mayflies, dragonflies, stoneflies, caddisflies and Diptera or true-flies). However, wetland specialist species also occur among several families of terrestrial insects (Williams & Feltmate 1992) that complete their whole life-cycle in the riparian zone or on emergent vegetation. There are 441 terrestrial invertebrate species which characteristically occur in riparian habitats along British rivers. Most of these species belong to two families of predatory beetles: the ground beetles (Carabidae) and the rove beetles (Staphylinidae). This paper describes the diversity of ground and rove beetles around ponds, summarises life-histories, hibernation strategies, and morphological and behavioural adaptions.

A seven year study of the life cycle of the Mayfly Ephemera danica

Ephemera danica Müller, 1764 (Ephemeroptera) is one of the largest mayflies found in the British Isles with some females reaching over 30 mm. It is a common and widespread species found in rivers, lakes and streams throughout Europe and is particularly abundant in many of the lowland rivers of the British Isles. The larvae are burrowers – mainly found where silt accumulates below macrophytes. This article gives a general overview of research work on the factors affecting the life cycle of Ephemera danica over a seven year period (1995–2002) on two rivers, the River Test at Leckford in Hampshire and the North Wey at Tilford in Surrey.

The diversity of macro invertebrates in the Victoria and Kyoga lake basin and their relationship to ecosystem functioning

Aquatic macro-invertebrates encompass all those organisms that be seen with unaided eyes. Most macro-invertebrates are categorised as semi-aquatic in that they are aquatic in early stages, but live as terrestrial organisms as adults, while others like gastropods, bivalves, Oligochaetae, Hirudinae and ostracods are exclusively aquatic. Some of them such as mayflies lay eggs in water and subsequent stages also live in water until adulthood when they emerge to live a terrestrial life. In others, eggs are laid near the water, while some like members of Tendipedidae (midges) lay their eggs on the leaves of aquatic macrophytes and after hatching their larvae creep into water

Variation in composition of macro-benthic invertebrates as an indication of water quality status in three bays in Lake Victoria

Knowledge of how biota can be used to monitor ecosystem health and assess impacts by human alterations such as land use and management measures taken at different spatial scales is critical for improving the ecological quality of aquatic ecosystems. This knowledge in Uganda is very limited or unavailable yet it is needed to better understand the relationship between environmental factors at different spatial scales, assemblage structure and taxon richness of aquatic ecosystems. In this study, benthic invertebrate community patterns were sampled between June 2001 and April 2002 and analysed in relation to water quality and catchment land use patterns from three shallow near-shore bays characterized by three major land uses patterns: urban (Murchison Bay); semi-urban (Fielding Bay); rural (Hannington Bay). Variations in density and guild composition of benthic macro-invertebrates communities were evaluated using GIS techniques along an urban-rural gradient of land use and differences in community composition were related to dissolved oxygen and conductivity variation. Based on numerical abundance and tolerance values, Hilsenhoff's Biotic Index ofthe invertebrates was determined in order to evaluate the relative importance of water quality in the three bays. Murchison Bay supported a relatively taxa-poor invertebrate assemblage mainly comprising stenotopic and eurytopic populations of pollution-tolerant groups such as worms and Chironomus sp. with an overall depression in species diversity. On the contrary, the communities in Fielding and Hannington bays were quite similar and supported distinct and diverse assemblages including pollution-intolerant forms such as Ephemeroptera (mayflies), Odonata (dragonflies). The Hilsenhoff Biotic Index in Murchison Bay was 6.53. (indicating poor water quality) compared to 6.34 for Fielding Bay and 5.78 for Hannington Bay (both indicating fair water quality). The characterization of maximum taxa richness balanced among taxa groups with good representation of intolerant individuals in Hannington Bay relative to Fielding and Murchison bays concludes that the bay is the cleanest in terms of water quality. Contrary, the dominance of few taxa with many tolerant iqdividuals present in Murchison Bay indicates that the bay is degraded in terms of water quality. These result are ofimportance when planning conservation and management measures, implementing large-scale biomonitoring programs, and predicting how human alterations (e.g nutrient loading) affect water ecosystems. Therefore, analysis of water quality in relation to macro-invertebrate community composition patterns as bio-indicators can lead to further understanding of their responses to environmental manipulations and perturbations.