STUDIES ON HAEMOLYMPH CONSTITUENTS OF INDOPLANORBIS EXUSTUS (DESHAYES) AND LYMNAEA ACUMINATA (LAMARCK) F.RUFESCENS (GRAY) AND THE EFFECTS OF COPPER ON THE ACTIVITY PATTERN OF SELECTED TRANSAMINASES AND PHOSPHATASES

The problem investigated is on the haematological aspects of two freshwater pulmonate snails, Indoplanorbis exustus (Deshayes),and Lymnaea acuminata f.rufescens (Gray). An important aspect of the present investigation is to emphasize the utilization of freshwater organisms as models for research directed at understanding the basic biomedical problems that remain unresolved. Another aspect is to demonstrate how haemolymph can be treated as a tissue because of late, it has been shown that several parameters of blood can be taken as reliable indicators for diagnostic purposes, and also to monitor environmental pollution. The various haematological parameters studied are total haemocyte number,packed cell volume, haemoglobin, and inorganic as well organic constituents in three size groups of both the snail species. The effect of copper toxicity was measured in terms of total haemocyte count, and the activity pattern of selected phosphatases and transaminases.The study concluded that enzyme activity levels can be taken as reliable indicators to monitor pollution. Age is a factor that determines several of the physiological, biochemical and metabolic activities. This study also indicates that haemolymph can be taken as an organ system to study the various changes taking place at organ systems levels.

Physiological group differentiation in Lymnaea columella,

Bibliography: p. 123-127.

Study and comparison on freshwater snail fauna in the paddy fields and related river and lake (Babolroad & Parishan) water supply in Mazandaran & Frace provinces of Iran

As a result of this investigation, for the first time from Babolroud river in Iran is 15 species identified, which they belong to 8 genera, from 7 families. The most and least distribution, 13 and 5 species, belong to Miandasht and Rostaye Anarestane Babol stations respectively, which they are 50 kilometers away from each other. Also 20 species belong to 10 genera from 6 families were identified in Parishan lake. The most the distribution belong to stations 1 and 5 with 6 and 18 species respectively. The most commonly distributed family is Lymnaeidae with 6 species: Lyamnaea truncatula, L. auricularia, L. palustris, L. pereger, L. stagnalis and L. gedrosiana, which L. trancatula is identified as the most frequent and has medical importance. L. stagnalis is identified to be the most important to agriculture. Planorbis planorhis, Physa acuta, Lymnaea pereger, Bithynia tenculata and Vavata piscinalis are reported for the first time from this region.

Molecule Modeling of Human Pentameric alpha(7) Neuronal Nicotinic Acetylcholine Receptor and Its Interaction with its Agonist and Competitive Antagonist

The nicotinic Acetylcholine Receptor (nAChR) is the major class of neurotransmitter receptors that is involved in many neurodegenerative conditions such as schizophrenia, Alzheimer's and Parkinson's diseases. The N-terminal region or Ligand Binding Domain (LBD) of nAChR is located at pre- and post-synaptic nervous system, which mediates synaptic transmission. nAChR acts as the drug target for agonist and competitive antagonist molecules that modulate signal transmission at the nerve terminals. Based on Acetylcholine Binding Protein (AChBP) from Lymnea stagnalis as the structural template, the homology modeling approach was carried out to build three dimensional model of the N-terminal region of human alpha(7)nAChR. This theoretical model is an assembly of five alpha(7) subunits with 5 fold axis symmetry, constituting a channel, with the binding picket present at the interface region of the subunits. alpha-netlrotoxin is a potent nAChR competitive antagonist that readily blocks the channel resulting in paralysis. The molecular interaction of alpha-Bungarotoxin, a long chain alpha-neurotoxin from (Bungarus multicinctus) and human alpha(7)nAChR seas studied. Agonists such as acetylcholine, nicotine, which are used in it diverse array of biological activities, such as enhancements of cognitive performances, were also docked with the theoretical model of human alpha(7)nAChR. These docked complexes were analyzed further for identifying the crucial residues involved i interaction. These results provide the details of interaction of agonists and competitive antagonists with three dimensional model of the N-terminal region of human alpha(7)nAChR and thereby point to the design of novel lead compounds.

Macrophyte - mollusc relationship in Lake Kariba

Five species of submerged vegetation Lagarosiphon ilicifolius, Najas pectinata, Vallisneria aethiopica, Ceratophyllum demersum and Potamogeton octandrus; 7 species of gastropods Melanoides tuberculata, Bellamya capillata, Biomphalaria pfeifferi, Bullinus tropicus, Cleopatra sp, and Lymnaea natalensis and 4 species of bivalves Corbicula africana, Caelatura mossambicensis, Mutela dubia and Aspatharia wahlbergii are correlated with environmental variables particularly slope and transparency, in Lake Kariba. A stepwise regression analysis further revealed interdependence between (Cleopatra sp., B. pfeifferi, L. natalensis, B. capillata, and V. aethiopica as well as between as between C. mossambicensis and L. ilicifolius and N. pectinata. The dependence of B. pfeifferi, L. natalensis, B. capillata, Cleopatra sp. on V. aethiopica and C. mossambicensis on L. ilicifolius and N. pectinata implies that a change in the biomass of the vegetation species may affect distribution and biomass of the faunal species.

Benthic diversity of River Gomti in relation to the prevailing environmental conditions in Lucknow

To evaluate the benthic diversity of River Gomti in relation to the prevailing environmental conditions, four stations, viz., Maa Chandrika Devi, Daliganj, Ambedkar Park and Aquaduct, were identified from upstream to downstream along the course of the river in Lucknow. Dissolved oxygen was low on many occasions at all the stations except Maa Chandrika Devi and chemical oxygen demand values were high. There was a gradual increase in mean nitrite and phosphate values from up to downstream. Benthic fauna was dominated by oligochaetes and chironomus larvae. Other groups reported were leeches, nematodes, sponges, crustaceans, pelycypodes, gastropods and fish fry. Population density was exceptionally high at Daliganj (20,135 m sub(-1) ) followed by Ambedkar Park (5,199 m sub(-1)) and Aquaduct (3,287 m sub(-1)), and low at Maa Chandrika Devi (264 m sub(-1)). Oligochaete genera common at all the four stations were Lumbricillus, Limnodrillus, Branchiura, Chaetogaster, Nais and Tubifex. Odonates were reported only from Maa Chandrika Devi while sponges were encountered at Daliganj and Aquaduct. On some occasions, fish fry were also found at Ambedkar Park and Aquaduct. Seasonally, maxima for population density were observed during pre-monsoon and minima during monsoon. The organic pollution indicator benthic species reported were tubificids, chironomids, culicoid larvae, Lamellidens sp., Corbicula sp., Lymnaea sp. and leech. Branchiurans, Tubifex sp. and Chironomus larvae were reported at all the stations. Filthy condition with foul smell throughout the length of the river coupled with poor water quality and appearance of indicator organisms at all the stations indicate that the river is under severe pollution stress due to anthropogenic discharges and it has reached an alarming stage.

虹鳟复口吸虫病的研究——Ⅰ一种新的复口吸虫及其早期发育史观察

一种新的复口吸虫在中国虹鳟养殖场饲养的虹鳟(Salmo gairdneri)眼内发现,定名为山西复口吸虫新种(Diplostomulum shanxinensisn.sp)。虹鳟被严重感染后能引起角膜破裂或玻璃体脱落,即所谓“寄生虫性白内障病”,小鱼可导致消瘦或死亡,成鱼则可能影响性腺发育。胞蚴和尾蚴在萝卜螺(Lymnaea auricularia)内发现。尾蚴钻入鱼宿主的皮肤后到达鱼眼球水晶体内。尾蚴在虹鳟眼内发育成囊蚴阶段需时80天,而在白鲢(Aristichthys nobilis)眼内发育则只需要

浮选药剂对软体动物的毒性研究

<正> 浮选药剂随着选矿废水排入水体对水生态系统的影响如何?这是人们普遍关注的一个问题。水体中水生生物种类繁多,国内外学者较多的使用鱼类和浮游生物作为毒理学研究的试验生物。软体动物是底栖动物中的重要类群之一,并具有一定的经济价值。Gupta等和Stuart等用酚及其衍生物对尖头椎实螺(Lymnaea acum-inata)和用五氯苯酚对肥鳃螺(Gillia altilis)分别进行过毒性研究,均取得了较好的效果。本研究选用椭圆萝卜螺和大脐圆扁螺作为试验生

The distribution of Fasciola hepatica and Fasciola gigantica within southern Tanzania - constraints associated with the intermediate host

In East Africa, Fasciola gigantica is generally the causative agent of fasciolosis but there have been reports of F. hepatica in cattle from highland regions of Kenya, Ethiopia, Uganda and Zaire. The topography of the Southern Highlands of Tanzania provides an environment where the climatic conditions exist for the sustenance of lymnaeid species capable of Supporting both Fasciola hepatica and F. gigantica. Theoretically this would allow interaction between fasciolid species and the possible creation of hybrids. In this report we present molecular data confirming the existence of the snail, Lymnaea truncatula, at high altitude on the Kitulo Plateau of the Southern Highlands, Tanzania, along with morphometric and molecular data confirming the presence of F. hepatica in the corresponding area. At lower altitudes, where climatic conditions were unfavourable for the existence of L. truncatula, the presence of its sister species L. natalensis was confirmed by molecular data along with its preferred fasciolid parasite, F. gigantica. Analysis based on a 618 bp sequence of the 28S rRNA gene did not reveal the presence of hybrid fasciolids in our fluke samples.

Molecule modeling of human pentameric alpha(7) neuronal nicotinic acetylcholine receptor and its interaction with its agonist and competitive antagonist

The nicotinic Acetylcholine Receptor (nAChR) is the major class of neurotransmitter receptors that is involved in many neurodegenerative conditions such as schizophrenia, Alzheimer's and Parkinson's diseases. The N-terminal region or Ligand Binding Domain (LBD) of nAChR is located at pre- and post-synaptic nervous system, which mediates synaptic transmission. nAChR acts as the drug target for agonist and competitive antagonist molecules that modulate signal transmission at the nerve terminals. Based on Acetylcholine Binding Protein (AChBP) from Lymnea stagnalis as the structural template, the homology modeling approach was carried out to build three dimensional model of the N-terminal region of human alpha(7)nAChR. This theoretical model is an assembly of five alpha(7) subunits with 5 fold axis symmetry, constituting a channel, with the binding picket present at the interface region of the subunits. alpha-netlrotoxin is a potent nAChR competitive antagonist that readily blocks the channel resulting in paralysis. The molecular interaction of alpha-Bungarotoxin, a long chain alpha-neurotoxin from (Bungarus multicinctus) and human alpha(7)nAChR seas studied. Agonists such as acetylcholine, nicotine, which are used in it diverse array of biological activities, such as enhancements of cognitive performances, were also docked with the theoretical model of human alpha(7)nAChR. These docked complexes were analyzed further for identifying the crucial residues involved in interaction. These results provide the details of interaction of agonists and competitive antagonists with three dimensional model of the N-terminal region of human alpha(7)nAChR and thereby point to the design of novel lead compounds.

Comunidade de moluscos bentônicos na área de abrangência da Usina Hidrelétrica de Dona Francisca, Rio Jacuí, Rio Grande do Sul, Brasil : fase de pré e pós-enchimento do reservatório

A malacofauna límnica exerce importante papel como constituinte da comunidade bentônica e alterações em sua estrutura podem tornar-se prejudiciais para a vida nesses ecossistemas. Com o objetivo de avaliar quali-quantitativamente a malacofauna límnica na área de abrangência da Usina Hidrelétrica de Dona Francisca (UHEDF) (29°26’50’’S e 53°16’50’’W), Agudo, Rio Grande do Sul, Brasil, tomadas as amostras nas fases de pré-enchimento do reservatório em oito estações de coleta em áreas localizadas à montante (E3B, E4B, E5B), à jusante (E1) e na calha central do futuro lago da barragem (E2, E3, E4, E5) e pós-enchimento nas estações E1, E3B e E4B. No período de junho a outubro de 2000 (fase de pré-enchimento) e de junho a outubro de 2001 (fase de pós-enchimento) foram realizadas amostragens mensais, consistindo de três réplicas por estação de coleta (margens-centro), através do uso do amostrador de Surber modificado com área de 60 cm² e 15 cm de altura, delimitando o tamanho amostral. A fauna foi retirada manualmente dos clastos maiores sendo o sedimento de granulometria mais fina, passada através de peneira com malha de 1mm. Em laboratório foi realizada a identificação específica dos moluscos e da fauna acompanhante de macroinvertebrados , quando possível até família. Os organismos foram fixados em álcool 70%. Foram identificadas 10 famílias de Mollusca com quinze espécies. Para Gastropoda foram registradas seis famílias com nove espécies: Ampullariidae – Pomacea canaliculata (Lamarck, 1801); Hydrobiidae – Potamolithus aff. catharinae Pilsbry, 1911, Potamolithus ribeirensis Pilsbry, 1911, Potamolithus sp.1 e Heleobia sp.; Chilinidae – Chilina parva Martens, 1868; Lymnaeidae – Lymnaea columella Say, 1817; Ancylidae – Gundlachia concentrica (Orbigny, 1835); e Physidae – Stenophysa marmorata (Guilding, 1938). Para Bivalvia: Corbiculidae – Corbicula fluminea (Müller, 1774); Mycetopodidae – Anodontites iheringi (Clessin, 1882), Anodontites lucidus (Orbigny, 1835); Hyriidae – Diplodon charruanus (Orbigny, 1835); Sphaeriidae – Pisidium punctiferum (Guppy, 1817) e Pisidium sp. Na fase de pré-enchimento do reservatório, a correlação de Pearson apontou correlação positiva entre a granulometria e a densidade de moluscos (r=0,15) e correlação negativa entre os fatores físico-químicos e a densidade de moluscos bentônicos (r=-0,28). A análise de agrupamento das espécies de moluscos na fase de pré-enchimento evidenciou a formação de dois grupos distintos: o primeiro formado por espécies acidentais, segundo o cálculo da Constância, e o segundo formado por espécies constantes, xviii acessórias e uma acidental (Potamolithus sp.1) que no entanto foi abundante em E1 e E2. O resultado da freqüência relativa em relação à fase de pré-enchimento do reservatório mostrou a família Hydrobiidae, com quatro espécies, com maior abundância e riqueza de espécies, seguida por Chilinidae, representada por C. parva. Ambas as famílias representaram um total de 93,9% em relação à comunidade de moluscos amostrados. Tais resultados refletem o tipo de ambiente da área: leito formado por matacões e calhaus, favoráveis à instalação e manutenção daqueles moluscos. Na fase de pós-enchimento do reservatório foram registrados o aumento na riqueza e diversidade de espécies nas três estações de coleta amostradas (exceto em E3B – com menor diversidade no pós-enchimento) e diminuição significativa nas densidades mensais e totais de moluscos bentônicos. Os testes de aleatorização, entretanto, não revelaram diferenças significativas entre as duas fases e em relação ao funcionamento da UHEDF. Os fatores físico-químicos apontaram correlação positiva com a densidade de moluscos (r=0,19), ressaltando as diferenças significativas nos valores de pH, oxigênio dissolvido, oxigênio saturado nesta fase. Em E1 mais atingida pelo funcionamento da UHEDF, registrou-se uma acentuada diminuição nas densidades mensais e totais de moluscos bentônicos, não obstante, a riqueza e diversidade apresentaram maiores valores nesta fase. As espécies mantiveram-se as mesmas em ambas as fases.

Retenção do cátion do sulfato de cobre nos compartimentos biótico e abiótico de mesocosmos com sistema de fluxo contínuo de água

Pós-graduação em Aquicultura - FCAV

Nuove tecniche per l'allevamento massale di Ditteri del genere Coenosia Meigen

The species of the genus Coenosia Meigen are polyphagous predators both in the larval and in the adult stage. In Europe five Coenosia species of the ‘tigrina group’ are naturally present in greenhouses, where they can establish for long periods. As their wide preys range includes important pests of protected crops, as Aleyrodidae, Sciaridae and Agromyzidae, Coenosia species are considered promising potential biological control agents. A method for rearing Coenosia species in vivo was developed for the first time in 1993 in Germany, where C. attenuata, C. strigipes and C. humilis were bred on Bradysia paupera (Diptera Sciaridae), reared on Fusarium spp. cultivated on wood fibre. Although this method was partially simplified afterwards, it is still too complex and expensive for a mass production. This research aimed at simplifying this rearing procedure and making it cheaper, in the perspective of an eventual mass production. Studies on potential preys were conducted, to determine their suitability for C. attenuata larvae and adults and to develop rearing methods. Biology and rearing methods of Bradysia paupera Tuomikoski, Scatella stagnalis Fallén and Drosophila melanogaster Meigen (Diptera: Sciaridae, Ephydridae, Drosophilidae) were compared. B. paupera resulted the most suitable prey for rearing C. attenuata in vivo. The Sciarid fly was effectively reared on damp coconut fibre with fresh Agaricus bisporus (J.E. Lange) Pilát, thus simplifying the existing method. After preliminary trials with different potential preys, attempts to rear C. attenuata in vivo on B. paupera and D. melanogaster were made. The best results were obtained with B. paupera, reared on coconut fibre and A. bisporus, but the method needs further improvement. Trials of in vitro rearing of C. attenuata were also made: as no specific diet for Coenosia species is reported in literature, different potentially suitable media were tested. Among these, a specific diet for Diptera Tachinidae resulted a good starting point for further studies and improvements. The biology of C. attenuata adults captured in greenhouses was also studied, by observing both groups and isolated individuals. Data on lifespan, daily number of preys per adult, daily number of laid eggs and hatching rate were recorded, and the effects of different foods on these parameters were analyzed. The following foods were compared: D. melanogaster adults only, as preys for C. attenuata; D. melanogaster adults and a water-honey solution; the water-honey solution only. Honey resulted an effective food integration for C. attenuata, increasing lifespan and the number of egg laying females. It is possible that in greenhouses Coenosia adults complete the preys diet with nectar and/or honeydew. Moreover, the integration with honey reduced the daily preys consumption. This may allow to prevent cannibalism among Coenosia adults in the rearing conditions, where high population densities are required. A survey of the Coenosia species naturally present in Lombardy greenhouses was conducted. The species C. attenuata, C. strigipes, C. tigrina and C. atra were detected. C. attenuata resulted the most common, recorded in most greenhouses and for consecutive years. Besides, the presence of potential preys, weeds and the crops were recorded in each greenhouse. Nevertheless, it is difficult to determine the relation between these parameters and the presence of Coenosia species.

Macroinvertebrate abundance and proportion of trait categories in river biotopes across England and Wales

There is a long tradition of river monitoring using macroinvertebrate communities to assess environmental quality in Europe. A promising alternative is the use of species life-history traits. Both methods, however, have relied on the time-consuming identification of taxa. River biotopes, 1-100 m**2 'habitats' with associated species assemblages, have long been seen as a useful and meaningful way of linking the ecology of macroinvertebrates and river hydro-morphology and can be used to assess hydro-morphological degradation in rivers. Taxonomic differences, however, between different rivers had prevented a general test of this concept until now. The species trait approach may overcome this obstacle across broad geographical areas, using biotopes as the hydro-morphological units which have characteristic species trait assemblages. We collected macroinvertebrate data from 512 discrete patches, comprising 13 river biotopes, from seven rivers in England and Wales. The aim was to test whether river biotopes were better predictors of macroinvertebrate trait profiles than taxonomic composition (genera, families, orders) in rivers, independently of the phylogenetic effects and catchment scale characteristics (i.e. hydrology, geography and land cover). We also tested whether species richness and diversity were better related to biotopes than to rivers. River biotopes explained 40% of the variance in macroinvertebrate trait profiles across the rivers, largely independently of catchment characteristics. There was a strong phylogenetic signature, however. River biotopes were about 50% better at predicting macroinvertebrate trait profiles than taxonomic composition across rivers, no matter which taxonomic resolution was used. River biotopes were better than river identity at explaining the variability in taxonomic richness and diversity (40% and <=10%, respectively). Detailed trait-biotope associations agreed with independent a priori predictions relating trait categories to near river bed flows. Hence, species traits provided a much needed mechanistic understanding and predictive ability across a broad geographical area. We show that integration of the multiple biological trait approach with river biotopes at the interface between ecology and hydro-morphology provides a wealth of new information and potential applications for river science and management.

Pollen and macroremains from three sediment cores from Göttingen, Germany

In a borehole in the southern outskirts of the town of Göttingen, limnic sediments of several Pleistocene warm periods occur intercalated with coarse solifluction debris and gravel of the river Leine. Pollen analysis of the limnic sediments in a borehole at Ottostrasse gave evidence of three warm periods of interglacial character, followed by three interstadial phases. The warm phases are separated one from another by stadial phases with, at least in one case, indications of periglacial solifluction. This sequence belongs to the Brunhes magnetic epoch. The pollen data allow to exclude an Eemian or Holsteinian age of the warm period sediments. Thus a Cromerian age is assumed, though the exact position of the newly described warm periods within the ''Cromerian'' remains uncertain. A section in a borehole at Akazienweg is of Holsteinian age.