Pattern of Macroinvertebrates Trophic Structure in Some Selected Streams of Kano River, Nigeria

Abstract

Aquatic macroinvertebrate are important organisms in the study of different water bodies of temperate and tropical regions world over, they relatively have longer life span, can easily sample and are good indicators of water conditions. This study aimed and scaled sampled macroinvertebrate communities of the Kano river selected streams into Five (5) Functional Feeding Groups (FFGs) Scrapers which form the base of the structure, Shredders, Gathering Collectors, Filtering Collectors and Predators at the top. The FFGs numerical structure indicate the linkage between shredders and filtering collectors. Gathering collectors Chironomidae revealed the highest (550 species, 48%) FFGs, an increase of collector-gatherers was recorded at sites A18% ; B29% ; D32% and 34% in site E, however declined to 23% was observed downstream at site F. This was followed by the simuliidae filtering collectors exhibited 233 species translating to 20% total abundance. However, other filtering collectors Gammaridae and Oligochaeta expressed equal abundances of 4% respectively and there low number could be due to the absence of preferred feeding host. Overall, scrapers were the most abundant FFG (593 species, 52%) dominated by Hydrophilidae (155 species, 14%), Bitidae (76 species, 6%), Hydrobidae (99 species, 9%), Corixidae (80species, 6%), Hydroptilidae (26species, 3%) and Siplonuridae (157 species, 14%). Species diversity of the Kano river revealed site F(414)>A(403)>E(390)>B(372)>C(303)>(329). This sustain a complex interactions of the functional feeding groups in the river ecosystem. it is therefore recommended, that effect of cascading power of the hydroelectric power plant on the distribution and abundance macroinvertebrate communities at the upstream to the downstream of the River Kano should be investigated.