The influence of population density on patterns and physiology of growth in Hymenolepis diminuta (Cestoda:Cyclophyllidea) in the definitive host

Roberts, Larry S.

doi:10.1016/0014-4894(61)90040-6

Cited by 132 publications

(60 citation statements)

References 54 publications

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“…The population consequences of 'crowding' on size, establishment (Donald, Dineen, Turner & Wagland, 1964;Jarrett, Jarrett & Urquahart 1968;Hesselberg & Andreassen, 1975;Love, 1975) and developmental rates (Roberts, 1961;Halvorsen & Andersen, 1974) must be assessed by translating their effects into influences on parasite survival and fecundity, since these are the two parameters of importance in the generation of epidemiological patterns and the determination of evolutionary fitness.…”

Section: Life-cyclesmentioning

confidence: 99%

Density-dependent mechanisms in the regulation of intestinal helminth populations

Keymer

1982

Parasitology

146

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The regulation of helminth populations tends to occur primarily as a result of limitations imposed on the build up of parasite subpopulations within individual hosts (Anderson & May, 1979; May & Anderson, 1979). Considering the relevance of these factors to the success or otherwise of intestinal helminth control programmes, it is perhaps surprising that more information is not yet available concerning the particular mechanisms which may be responsible, and in particular, the population consequences of the immune responses which such parasites may precipitate. Density-dependence in a single rate parameter, if operative over the naturally observed numerical range, is sufficient to regulate parasite population flow throughout the life-cycle, whether direct or indirect (Anderson, 1976). For the genera given in Table 1, this could be provided by the observed pattern of parasite mortality and/or fecundity. It is of interest to note, however, that circumstantial evidence cited in the Table suggests that each of the 6 genera is also potentially able to induce host mortality under certain conditions. Whether this acts in a density-dependent manner in natural infections is almost entirely unknown. Rapid reproduction may be of great selective advantage to intestinal helminths, even if it is necessarily accompanied by pathogenicity (see Anderson, 1981). If the manner in which this pathogenicity acts in any way enhances the stability of the host-parasite interaction, then perhaps it may have contributed to the selection pressures which have led so many genera to continue to break the rules of the ‘well-adapted’ parasite (see, for example, Noble & Noble, 1971).

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Section: Life-cyclesmentioning

confidence: 99%

Density-dependent mechanisms in the regulation of intestinal helminth populations

Keymer

1982

Parasitology

146

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“…Growth and maturation in cestodes are also believed to be influenced by the number of cestodes present in the host, i.e. crowding effect (Read 1951, Roberts 1961, Halvorsen and Andersen 1974, Hesselberg and Andreassen 1975, Davydov 1978, Sato and Kamiya 1990. Wootten (1972) found no evidence suggesting that size of E. crassum was affected by the number of cestodes.…”

Section: Discussionmentioning

confidence: 99%

Experimental infection of Atlantic salmon (Salmo salar) with marine Eubothrium sp. (Cestoda: Pseudophyllidea): observations on the life cycle, aspects of development and growth of the parasite

Saksvik¹,

Nylund²,

Nilsen³

et al. 2001

FOLIA PARASIT

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Abstract. The life cycle of marine Eubothrium sp. (Cestoda: Pseudophyllidea), from Atlantic salmon (Salmo salar L.) was experimentally completed in one year and included only one intermediate host (Acartia tonsa Dana) (Copepoda: Calanoida). Adult cestodes were collected from farmed salmon, and ripe eggs released by the cestodes were fed to Acartia tonsa. Ingested eggs hatched in the gut and the larvae developed in the haemocoel of the copepod for 15 days at 16°C. A total of 170 seawaterreared salmon were exposed to infected copepods and the total prevalence of Eubothrium sp. in the salmon after infection was 95.3%, with a mean intensity of 15.0 (range 1-87). The infected salmon were kept in the laboratory where the growth of the cestodes was studied for eleven months. Mean length of the cestodes increased with time, but a large variation among the cestodes was observed. Growth and maturation of the cestodes were dependent on host size and the number of worms present in the intestine. No evidence of mortality of Eubothrium sp. was observed during the experimental period.

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“…diminuta reaches reproductive maturity in 2-3 weeks and can remain healthy and reproductively active inside the rat intestine for the duration of the rat's lifespan. In this time, H. diminuta reaches an equilibrium length of~60 cm and roughly 2000 proglottids (Chandler, 1939;Roberts, 1961).…”

Section: Body Plan Organizationmentioning

confidence: 99%

“…Sperm is deposited into the vagina (V) and stored in the seminal receptacle (SR). Since reproductive development is protandrous in H. diminuta, the sperm can be stored in the SR even before the ovary has matured sufficiently to produce oocytes Nollen, 1975;Roberts, 1961). Mature oocytes and sperm are trafficked to the oviduct (OD) where fertilization occurs.…”

Section: Reproductive Structuresmentioning

confidence: 99%

A confocal microscopy-based atlas of tissue architecture in the tapeworm Hymenolepis diminuta

Rozario

Newmark

2015

Experimental Parasitology

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Tapeworms are pervasive and globally distributed parasites that infect millions of humans and livestock every year, and are the causative agents of two of the 17 neglected tropical diseases prioritized by the World Health Organization. Studies of tapeworm biology and pathology are often encumbered by the complex life cycles of disease-relevant tapeworm species that infect hosts such as foxes, dogs, cattle, pigs, and humans. Thus, studies of laboratory models can help overcome the practical, ethical, and cost-related difficulties faced by tapeworm parasitologists. The rat intestinal tapeworm Hymenolepis diminuta is easily reared in the laboratory and has the potential to enable modern molecular-based experiments that will greatly contribute to our understanding of multiple aspects of tapeworm biology, such as growth and reproduction. As part of our efforts to develop molecular tools for experiments on H. diminuta, we have characterized a battery of lectins, antibodies, and common stains that label different tapeworm tissues and organ structures. Using confocal microscopy, we have assembled an "atlas" of H. diminuta organ architecture that will be a useful resource for helminthologists. The methodologies we describe will facilitate characterization of loss-of-function perturbations using H. diminuta. This toolkit will enable a greater understanding of fundamental tapeworm biology that may elucidate new therapeutic targets toward the eradication of these parasites.

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The influence of population density on patterns and physiology of growth in Hymenolepis diminuta (Cestoda:Cyclophyllidea) in the definitive host

Cited by 132 publications

References 54 publications

Density-dependent mechanisms in the regulation of intestinal helminth populations

Density-dependent mechanisms in the regulation of intestinal helminth populations

Experimental infection of Atlantic salmon (Salmo salar) with marine Eubothrium sp. (Cestoda: Pseudophyllidea): observations on the life cycle, aspects of development and growth of the parasite

A confocal microscopy-based atlas of tissue architecture in the tapeworm Hymenolepis diminuta

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