Uptake of 59Fe as a Tool for Study of the Crowding Effect in Biomphalaria Glabrata *

Gazzinelli, Giovanni; Ramalho-Pinto, F. J.; Pellegrino, J.; Gilbert, Brian A.

doi:10.4269/ajtmh.1970.19.1034

Cited by 21 publications

(3 citation statements)

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“…Iron, probably chelated to humic or fulvic acids, as the water was oxygenated, was also present in measurable amounts (0.12-1.20 mg 1_1). Both iron and calcium can be taken up actively from the medium by the snails at rates that are proportional to their growth rates (Gazzinelli et al 1970;.…”

Section: Water Chemistrymentioning

confidence: 99%

Control of the snail hosts of schistosomiasis by environmental manipulation: a field and laboratory appraisal in the Ibadan area, Nigeria

Thomas

Tait

1984

Phil. Trans. R. Soc. Lond. B

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An account is given of an ecological investigation of freshwater habitats near Ibadan, Nigeria, which was designed to identify and evaluate key factors that might be m anipulated to achieve control of the snail hosts of schistosomiasis and fascioliasis. Statistical analyses of data from 24 stations from both lentic and lotic habitats showed that there were statistically significant tendencies for the following snail species to coexist: at the macro-distribution level Lanistes libycus and Bulinus (P.) globosus , in lotic habitats, Lymnaea natalensis , Bulinus forskali , Biomphalaria pfeifferi and Bulinus rohlfsi in lentic habitats; at the micro-distributional level, B. rohlfsi , B. pfeifferi , B. forskali and Anisus coretus . Several species of aquatic macrophytes, including species that occur at water margins ( Acroeasand Commelina spp.) and those that occur in more persistent aquatic habitats ( Nymphaea and Ceratophyllum spp.) also coexist to a statistically significant extent both with each other and with snail species in the same microhabitats. However, Salvinia proved exceptional as it was negatively associated with four of the snail species. Persistent snail refugia, including areas at stream origins, backwaters and the deeper bays or inlets in lentic habitats, were characterized by the presence of particular macrophyte species. The reasons for the associations between snails and macrophytes are discussed and it is argued that they may be mutualistic. The snails proved tolerant to a wide range of chemical conditions with the exception of low oxygen concentration. However, the absence of aquatic macrophytes and lentic refugia in head waters and the presence of fast flowing water and high temperatures in shallow water are harmful. Although the indigenous snails, L. libycus and Aplexa waterloti , proved to be efficient predators on the eggs and juveniles of snail hosts, other laboratory and field evidence appear to preclude the possibility that they may be useful as biological control agents. In contrast, there is evidence that Melanoides tuberculata might exclude the snail hosts from eroding substrates in lentic habitats. The following integrated control measures in lotic habitats are discussed: ( a ) judicious drainage and canalization of marshy areas at stream origins, combined with replacement of key marginal macrophytes; ( b ) dredging and straightening of stream courses; ( c ) replacement of key macrophytes along the banks; ( d ) introduction of M. tuberculata if not present. In lentic habitats the following control measures are discussed: ( a ) prevention of immigration of both macrophytes and snails from feeder streams; ( b ) control of subaquatic emergent plant species by using grazing domestic animals or competitor species; ( c ) maximizing wind-generated surface currents to exclude floating plants; ( d ) eradication of submerged rooting plants by herbivorous fish or invertebrates; ( e ) the management of such water bodies as either plankton herbivorous fish or plankton - herbivorous fish - carnivorous fish systems; ( f ) introduction of efficient, detritivorous non-host molluscs or fish to feed on bottom deposits.

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Section: Water Chemistrymentioning

confidence: 99%

Control of the snail hosts of schistosomiasis by environmental manipulation: a field and laboratory appraisal in the Ibadan area, Nigeria

Thomas

Tait

1984

Phil. Trans. R. Soc. Lond. B

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“…The effects of snail crowding in population were observed in one of the experiments as reported by Gazzinelli et al (1970), in B. glabrata. In the former, the 50 snails developed faster than those in the latter experiment in which 343 and 401 specimens were growing together (Tables I, II).…”

Section: Discussionmentioning

confidence: 80%

Rearing of Lymnaea columella (Say, 1817), intermediate host of Fasciola hepatica (Linnaeus, 1758)

Souza

Magalhães

2000

Mem. Inst. Oswaldo Cruz

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“…Inhibition of growth and egg-laying at high population densities has also been demonstrated for other pulmonate snail species (Turner, 1927;Chernin & Michelson, 1957a and b;Wright, 1960;Sturrock & Sturrock, 1970;Thomas, 1973). These observations have been attributed to absolute or relative food shortage (Turner, 1927), chemical secretions (Wright, 1960;Berrie & Visser 1963;Gazzinelli et al, 1970;Levy et al, 1972), mechanical interference between snails (Chernin & Michelson, 1957) and depletion of some essential factors (Thomas, 1973). Thomas (1973) found that both high and low densities of Biomphalaria glabrata would inhibit growth and egg laying while growth promotion was observed at 50-100 ml per snail.…”

Section: Discussionmentioning

confidence: 81%

Egg laying and growth in Helisoma duryi (Wetherby) (Pulmonata: Planorbidae): Effect of population density and mode of fertilization

Madsen¹,

Thiongo²,

Ouma³

1983

Hydrobiologia

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Helisoma duryi is a planorbid snail that has been proposed as biological control agent against intermediate hosts of schistosomiasis. When the population density of this species is increased from 200 to 25 ml per snail in containers of constant volume (i.e. 200 ml) growth decreases. Whereas the single snails (i.e. 200 ml/ snail) laid no egg masses, egg-laying in the other groups decreased with increasing density. When four snails were kept in various volumes of water giving the same population densities as above both growth and egg-laying decreased with increasing density.Cross-breeding experiments between an albino and a pigmented strain of H. duryi showed that the albino character is inherited as a recessive autosomal character, cross-fertilization appears to be the only mode of reproduction in H. duryi, stored foreign sperm remains viable for up to five months and stored sperm can survive when snails are aestivating or starving.The implications of the present findings for the use of H. duryi in biological control are discussed.

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Uptake of 59Fe as a Tool for Study of the Crowding Effect in Biomphalaria Glabrata *

Cited by 21 publications

References 0 publications

Control of the snail hosts of schistosomiasis by environmental manipulation: a field and laboratory appraisal in the Ibadan area, Nigeria

Control of the snail hosts of schistosomiasis by environmental manipulation: a field and laboratory appraisal in the Ibadan area, Nigeria

Rearing of Lymnaea columella (Say, 1817), intermediate host of Fasciola hepatica (Linnaeus, 1758)

Egg laying and growth in Helisoma duryi (Wetherby) (Pulmonata: Planorbidae): Effect of population density and mode of fertilization

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