SUMMARY

1. The influence of altitude and land-use changes on macroinvertebrate assemblages from riffles in forty-three streams in the Dolpo region of western Nepal were examined. Sampling sites ranged in altitude from 850 to 4250m, and land-use patterns fell into five categories: alpine, forest, grassland, pasture and agricultural land.



2. TWTNSPAN classification of physicochemical data separated streams into groups on the basis of climatic and physical factors. Streams from high, cold, alpine areas were separated from those in warmer, lower, agricultural areas.



3. In all, 138 macroinvertebrate taxa were collected from fifty-three insect families. Ephemeroptera were most common, especially Baetidae.



4. Taxonomic richness declined with increasing altitude. Ten insect families were significantly more abundant in lowland streams, and five were more common in alpine streams.



5. TWINSPAN and DECORANA revealed distinct invertebrate groupings of the forty-three streams surveyed. A high percentage of the variance (79.3%) in ordination space was explained by DECORANA axes 1 and 2. Altitude, temperature, stream width and land use were implicated in structuring invertebrate communities.

Macroinvertebrate communities of streams in western Nepal: effects of altitude and land use

Ephemeroptera is an important group of insects used in the bioassessment and monitoring of freshwater bodies worldwide because of their relative abundance in a wide variety of substrates and their increasing chances of detecting pollution impacts. In this study, their faunistic composition and spatiotemporal variations in density and diversity in River Orogodo (Southern Nigeria) was investigated at five ecologically distinct stations over a 12-month period. The mayfly nymph community responses to environmental variables were evaluated by means of biological measures and multivariate analysis (redundancy analysis [RDA]). Thirteen morphologically distinct taxa belonging to six families were identified. The dominant taxa were Afrobaetodes pusillus (23.1%), Baetis sp. (13.7%), and Caenis cibaria (11.4%). The density of Ephemeroptera differed significantly (p < 0.05) both in space and time. Diversity was influenced by substrate heterogeneity which in turn was influenced by catchment processes such as flooding and anthropogenic activities especially abattoir effluent. Based on the RDA ordination and relative abundance data, Baetis sp. dominated at impacted stations while a more equitable distribution of species were observed in less disturbed sites. Water velocity, canopy cover, nature of bottom sediments, and the amount of dissolved oxygen also accounted for the variations in Ephemeroptera densities at the different stations. Shannon diversity, taxa richness, and evenness were lowest in station 3 (the abattoir discharge site).

Mayfly (Insecta: Ephemeroptera) community structure as an indicator of the ecological status of a stream in the Niger Delta area of Nigeria

The eggs of many crustaceans are minute and resistant to desiccation. These properties favour their accidental dispersal and parthenogenesis ensures survival in the newly occupied niches. Agencies by which such dispersal is achieved have been long ensconced in the literature. The role of man as an agent of crustacean dispersal via the spread of useful plants, however, has been relatively neglected hitherto but the example provided by ostracode ospiti esteri of the Italian ricefields ecosystem indicates that this neglect is unwarranted. Italian historical and archaeobotanical records concerning the introductions of numerous other useful plants make it obvious that the dispersal potential of this agency cannot be restricted to rice only. When modern Ostracoda assemblages from Europe are compared against fossil ones, their dissimilarity suggests a high proportion of introduced species in the modern biota. The implications of this are discussed. Students of crustacean biogeography must come to terms with several aspects of crustacean physiology that can affect distribution patterns. One such aspect is the ability of numerous crustaceans inhabiting terrestrial aquatic ecosystems to reproduce parthenogenetically. The widespread dispersal of many taxa, even in tercontinentally, has been linked frequently to this phenomenon which is known as geographic parthenogenesis. We stress two particular facets of geographic parthenogenesis: firstly, that parthenogenetic populations tend to form the dispersal fringe of the taxa concerned; secondly, that where amphigonic populations are also known for the taxa under study they tend to be confined to the zoogeographic regions where these taxa are native (McKenzie, 1971a). Some possible exceptions will be discussed later, but these serve only to accentuate rather than invalidate our ideas. Another germane aspect of crustacean physiology is the ability of many taxa to produce desiccation-resistant eggs; and linked to this is the fact that the eggs of most crustaceans that inhabit terrestrial aquatic ecosystems are very small — for Ostracoda they rarely exceed 50-µm diameter. The combination of resistance to desiccation and minute size makes it unsurprising that passive dispersal is the rule for these Crustacea, as confirmed by a vast literature that is recycled regularly by reviewers. Our purpose in this paper is to stress the hitherto little emphasised role of man as an indirect agent of crustacean passive dispersal via the spread of useful plants. Our exemplars are Ostracoda of the ricefields ecosystem, specifically some species introduced into the major Italian rice-growing region of Lombardy-Padana (Fig. 1). We also cite records (historical as well as archaeoethnobotanical) of the introduction into Italy of rice and many other useful plants via which desiccation-resistant ostracode eggs might have been incidentally dispersed. Our discussion of this more general hypothesis will conclude with reference to comparisons between fossil and modern European ostracode assemblages.

Man As an Agent of Crustacean passive dispersal via useful plants-exemplified by Ostracoda Ospiti Esteri of the Italian ricefields ecosystem-and implications arising therefrom

The paper provides an overview of the developments in hydrobiological studies in India during the past fifty years, and links them with a historical perspective of the pre-independence studies. Hydrobiological studies which were well developed in the beginning of this century, gained momentum soon after independence as all kinds of aquatic habitats were investigated for the assessment, conservation and optimum utilization of inland fishery resources of the country. However, the environmental issues which dominated since the 1972 Stockholm Conference, and growing realization of the problem of water pollution, resulted in a rapid proliferation of hydrobiological studies which tend to focus on correlation between the distribution of various organisms and degree of water pollution or the effects of various organic and inorganic pollutants. A sampling of published literature reveals that long-term, analytical and experimental studies of the whole ecosystems (natural or experimental), and studies of population interactions, biomanipulation, food chain dynamics, and energy flows are wholly lacking. The paper calls for the strengthening of field and laboratory facilities, and establishment of regional and national institutes of aquatic ecology which will be necessary for the management of both the water quality and aquatic biological resources for sustainable development.

Fifty years of hydrobiological research in India

Populations of the yellow-tailed woolly monkey (Oreonax flavicauda) persist in increasingly isolated, threatened cloud forests in scattered areas of the departments of San Martin and Amazonas, in northern Peru. No long-term research has been conducted on this species in more than 20 years. The range of O. flavicauda continues to suffer rapid and widespread deforestation. From June to August 2004,I was involved in selecting a site for an extended study of its behavior and ecology. Here I document the species' continued existence and status in the Bosque de Proteccion (Protected Forest) of Alto Mayo. Three sightings of O. flavicauda provided a group size of 17–20 individuals—higher than previous sightings by Mariela Leo Luna in the early 1980s, who observed an average group size of nine. The difficulty we encountered in finding groups in the study area suggests that yellowtailed woolly monkeys have a large home range. This and its large body size, low density, low reproductive rate, its restrictio...

https://bioone.org/journals/primate-conservation/volume-22/issue-1/052.022.0102/Notes-on-the-Yellow-Tailed-Woolly-Monkey-Oreonax-flavicauda-and/10.1896/052.022.0102.pdf

Notes on the Yellow-Tailed Woolly Monkey (Oreonax flavicauda) and Its Status in the Protected Forest of Alto Mayo, Northern Peru

Summary A study of the ostracod fauna has been carried out in Madurai Area in Southern India. Nine species belonging to eight genera have been described as new to science. Comparisons have been made with related temperate and tropical ostracods and the relationships have been discussed.

Nine new species of freshwater ostracoda from Madurai area in Southern India

Diversity, distribution, seasonal changes in density and relative abundance of Ephemeroptera nymphs were studied in five stations on three streams in and around Shillong, Meghalaya state, North-eastern India. Seventeen species belonging to eight genera and five families were recorded. Diversity (Shannon's index) was governed by the heterogeneity of the substratum which in turn was influenced by catchment disturbances (quarrying, logging, and entry of sewage). Seasonal changes in density were governed by the spate-frequency regime of the streams. Relative abundance showed dominance of one or two species at impacted stations, while in less disturbed ones, a more equitable distribution of species was observed.

R. George Michael

Papers

Nine new species of freshwater ostracoda from Madurai area in Southern India

Diversity, distribution, and seasonal abundance of Ephemeroptera in streams of Meghalaya State, India