Ephemeropterans and Trichopterans were also consumed, but at lower percentages relative to bivalves and chironomids (Table 1).
Effects of
ephemeropterans and shrimps on periphyton and sediments in a coastal stream (Atlantic forest, Rio de Janeiro, Brazil).
comm., December 2009) suggested that these triangular structures may represent abdominal gills of an immature animal, and that the posterior orientation of the legs, the squat stance (with the head, thorax, and abdomen all touching the surface), the presumed abdominal gills, and the elongate shape of the trace are strongly suggestive of
ephemeropterans. He pointed out, however, that plecopterans and other insects, such as palaeodictyopterans, cannot be ruled out due to the lack of terminal filament imprints.
High levels of zinc concentration in water are particularly toxic to many species of algae, crustaceans, and salmonids (Leland and Kuwabara, 1985) and have especially strong effects on macroinvertebrates such as molluscs, crustaceans, odonates, and
ephemeropterans (Gore and Bryant, 1986).
All predators relied heavily on
ephemeropterans (Table 1).
Ephemeroptera recorded their complete absence at St III and IV while comparatively more density of
ephemeropterans at St I (4.5 ind.[m.sup.-2] [+ or -] 10.71) as compared to St II (2.25 ind.[m.sup.-2] [+ or -] 7.46) was observed.
A greater supply of fine detritus, expected in areas of low turbulence, would explain the association with lower sites of Oligochaeta,
ephemeropterans Caenis ludicra, Tricorythodes popayanicus, and Leptohyphes eximius collector gatherer taxa.
The macrobenthic community was in terms of biomass and density dominated by the following taxa: oligochaetes Stylaria lacustris (L.), Limnodrilus hoffmeisteri Claparede, and species of the genus Nais; the hirudineans Erpobdella octoculata (L.) and Glossiphonia complanata (L.); the amphipods Gmelinoides fasciatus (Stebbing) and Pontogammarus robustoides (Sars); the
ephemeropterans Caenis spp.