Selection pressure towards monoxeny in Camallanus cotti (Nematoda, Camallanidae) facing an intermediate host bottleneck situation

Parasitology ◽  
2002 ◽  
Vol 124 (6) ◽  
pp. 625-629 ◽  
Author(s):  
A. LEVSEN ◽  
P. J. JAKOBSEN
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Selection Pressure ◽  
Fish Host ◽  
Ornamental Fish Trade ◽  
In The Wild ◽  
Camallanus Cotti ◽  
Fish Trade ◽  
Direct Life Cycle ◽  
Freshwater Teleosts

This paper describes the ability of the Asian fish nematode Camallanuscotti to carry out both heteroxeny, i.e. an indirect life-cycle using copepods as intermediate host, and monoxeny, i.e. direct infection and development in the definitive fish host. C. cotti occurs naturally in various freshwater teleosts in Asia. During the past decades it has been disseminated into closed or semi-closed aquaculture systems and aquaria around the world, mainly due to the ornamental fish trade. Under such conditions the species may frequently face a bottleneck situation with regard to the availability of copepods. It is known that C. cotti may reproduce and persist in copepod-free aquaria for several months. In order to investigate whether C. cotti has selected towards monoxeny in water systems lacking copepods, in contrast to the opposite selection pressure when copepods are present, 2 separate infection trials were run. It was shown that the parasite can infect the fish host both indirectly via copepods, and directly. However, C. cotti has significantly higher fitness, expressed as survival to maturity, when transmitted indirectly compared to the direct transmission mode. We suggest that the ability of aquarium populations of C. cotti to carry out a direct life-cycle is favoured by selection in order to avoid extinction whenever copepods are absent. It still remains unknown, however, whether the parasite shows the same characteristics in the wild.

scholarly journals Infestations Myxobolus sp. in Gills Koi (Cyprinus carpio) That No Clinical Symptoms

2020 ◽  
Vol 11 (1) ◽  
pp. 20-25
Author(s):  
Zulkifli ◽  
Novia Christi Prihartini
Keyword(s):  
Water Quality ◽  
Life Cycle ◽  
Clinical Symptoms ◽  
Water Quality Management ◽  
Ornamental Fish ◽  
Parasitic Diseases ◽  
North Sulawesi ◽  
Ornamental Fish Trade ◽  
The Right ◽  
Fish Trade

Ornamental fish trade between regions in Indonesia allows the transfer of disease, especially if the disease does not show clinical symptoms in fish traded. Koi fish in Tahuna, North Sulawesi, mostly come from the area of ​​East Java, which is one area with many cases of myxobolusis. In addition, the potential for parasitic diseases that come along when koi fish are brought between areas cannot be avoided, because the examination of parasites, especially Myxobolus sp. no longer listed in the regulation as a quarantine inspection requirement. The purpose of this study was to see the Myxobolus sp infestation that infected koi in Tahuna, North Sulawesi, although there were no clinical symptoms using conventional techniques and histopathology. The results of the examination showed Myxobolus spore infestation on the gills of the koi, although the amount was not much, both conventional and histopathological techniques. This shows that our level of awareness of the types of parasites that can infect fish is still lacking. Myxobolus sp is only transmitted through the spore stage back and forth; there is no horizontal or vertical transmission in fish or tubifex T worm populations. More knowledge regarding the life cycle of the Myxobolus sp. in order to obtain the right handling to deal with outbreaks, especially water quality management at the location of the cultivation.

The effect of Toxoplasma gondii and other parasites on activity levels in wild and hybrid Rattus norvegicus

Parasitology ◽  
1994 ◽  
Vol 109 (5) ◽  
pp. 583-589 ◽  
Author(s):  
J. P. Webster
Keyword(s):  
Life Cycle ◽  
Toxoplasma Gondii ◽  
Intermediate Host ◽  
Definitive Host ◽  
Rattus Norvegicus ◽  
Parasite Load ◽  
Life Cycles ◽  
Parasitic Infections ◽  
Activity Levels ◽  
In The Wild

Using both correlational and experimental evidence, the relationship between parasite load and host activity was assessed in brown rats, Rattus norvegicus. Two hypotheses were tested – (1) that parasites with indirect life-cycles, involving transmission between a prey and its predator, will alter the activity of the intermediate host so as to increase its susceptibility to predation by the definitive host and (2) that activity levels in parasitized rats would be increased rather than decreased. Four groups of rats (n = 140) were examined. One group (n = 50) were wild brown rats trapped from 3 UK farmsteads, with naturally occurring parasites. The others were purpose-bred wild/laboratory hybrid rats with experimentally induced parasitic infections of either (n = 15) adult-acquired or (n = 15) congenitally-acquired Toxoplasma gondii (an indirect life-cycle parasite), or (n = 15) Syphacia muris (a direct life-cycle parasite). Uninfected hybrid rats (n = 45), matched for sex, age and weight, served as controls. Rats were housed individually in outdoor cages, and their activities were recorded on video-tapes for 6 non-consecutive 10 h nights. Exercise wheels were also available for the hybrid rats. Out of 6 parasite species detected in the wild rats, T. gondii was the only one which required predation by a definitive host to complete its life-cycle, and was also the only parasite to be associated with higher activity levels in infected than uninfected rats. Hybrid rats infected with T. gondii were also more active than those uninfected, whereas there were no differences in activity levels between S. muris infected and uninfected rats. This study shows that the indirect life-cycle parasite T. gondii can influence the activity of its intermediate host the rat. I suggest that this may facilitate its transmission to the cat definitive host.

Other adult and larval cestodes

2011 ◽  
Author(s):  
Sheelagh Lloyd
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Related Species ◽  
Intermediate Hosts ◽  
Hymenolepis Nana ◽  
Taenia Multiceps ◽  
Raw Fish ◽  
Diphyllobothrium Latum ◽  
Direct Life Cycle

Adult Diphyllobothrium latum is acquired by consumption of raw fish by persons living around lakes/reservoirs/rivers. Hymenolepis nana can have a direct life cycle so eggs produced by adults in man are important in transfer between humans. The contribution of rodents and the indirect life cycle through arthropods need re-evaluation. Other minor adult cestode infections are described.Man can be an intermediate host for tissue metacestodes. Taenia multiceps and related species are that acquired from canids and produce a coenurus. Spirometra spp. pleurocercoids are acquired from copepod or reptile/amphibian/mammalian intermediate hosts. Other metacestode infections are very rare.

Alternative life-history and transmission strategies in a parasite: first come, first served?

Parasitology ◽  
2005 ◽  
Vol 132 (1) ◽  
pp. 135-141 ◽  
Author(s):  
R. POULIN ◽  
F. LEFEBVRE
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Intermediate Host ◽  
Host Location ◽  
Parasite Species ◽  
Fish Host ◽  
Transmission Strategy ◽  
External Cues ◽  
Host Life ◽  
Host Tissues

Alternative transmission strategies are common in many parasitic organisms, often representing discrete phenotypes adopted in response to external cues. The facultative truncation of the normal 3-host life-cycle to a 2-host cycle in many trematodes provides an example: some individuals mature precociously, via progenesis, in their intermediate host and produce eggs without the need to reach a definitive host. The factors that determine how many and which individuals adopt the truncated life-cycle within a parasite population remain unknown. We investigated the occurrence of progenesis in the trematode Stegodexamene anguillae within its fish intermediate host. Location within the host was a key determinant of progenesis. Although the size and egg output of progenetic metacercariae encysted in host gonads did not differ from those of the few progenetic metacercariae in other host tissues, the likelihood of metacercariae becoming progenetic was much higher for those in the gonads than those elsewhere in the host. Progenetic parasites can only evacuate their eggs along with host eggs or sperm, providing a link between the parasite's transmission strategy and its location in the host. Host size and sex, and the presence of other parasite species in the host, did not affect the occurrence of progenesis in S. anguillae. However, the proportion of metacercariae in host gonads and the proportion of progenetic metacercariae both decreased with increasing numbers of S. anguillae per host. These results suggest that progenesis is adopted mostly by the parasites that successfully establish in host gonads. These are generally the first to infect a fish; subsequent arrivals settle in other tissues as the gonads quickly become saturated with parasites. In this system, the site of encystment within the fish host both promotes and constrains the adoption of a facultative, truncated life-cycle by the parasite.

Biology of Bothrimonus (= Diplocotyle) (Pseudophyllidea: Cestoda): Ecology, Life Cycle, and Evolution; a Review and Synthesis

1972 ◽  
Vol 29 (10) ◽  
pp. 1381-1395 ◽  
Author(s):  
I. M. Sandeman ◽  
M. D. B. Burt
Keyword(s):  
Life Cycle ◽  
Life Span ◽  
Intermediate Host ◽  
Brackish Water ◽  
Sexual Maturity ◽  
Fish Host ◽  
Short Life ◽  
Larval Stages ◽  
Short Life Span ◽  
Fish Hosts

An integrated account of the ecology and life cycle of Bothrimonus is synthesized from the literature, experiment, and observation of larval and adult stages of the parasite. Bothrimonus has a circumpolar distribution in boreal or subarctic conditions. As an adult it is found in a wide variety of fish hosts which feed in littoral or estuarine waters. Adult worms have a short life-span in the fish host and occur only seasonally. A single intermediate host appears to be involved in the life cycle and this is most commonly a brackish-water gammarid. The operculate eggs, which contain unciliated larvae, possess characteristic polar filaments which have an adhesive function. Entry is almost certainly by ingestion of eggs by the gammarid host; the larval forms often attain sexual maturity within the gammarid host with accompanying production of apparently normal eggs. Although it has been possible to infect fish hosts experimentally with larval stages, it has not yet been possible to infect gammarids with eggs obtained either from neotenic individuals in gammarids or from adults in the fish host.The life cycle of Bothrimonus indicates closer affinities of the Cyathocephalidae with caryophyllaeid than with other pseudophyllidean tapeworms. Distribution is discussed in terms of its evolution and a freshwater origin in the Ponto–Aralo–Caspian province is proposed.

Modeling spatial distribution of the unionid mussels and the core-satellite hypothesis

1998 ◽  
Vol 38 (7) ◽  
pp. 73-79 ◽  
Author(s):  
Hooi-Ling Lee ◽  
Donald DeAngelis ◽  
Hock-Lye Koh
Keyword(s):  
Spatial Distribution ◽  
Life Cycle ◽  
Success Rate ◽  
Distribution Patterns ◽  
Fish Host ◽  
Limited Movement ◽  
Unionid Mussels ◽  
Species Characteristics ◽  
Major Factors ◽  
Fish Hosts

This paper discusses the spatial distribution patterns of the various species of the Unionid mussels as functions of their respective life-cycle characteristics. Computer simulations identify two life-cycle characteristics as major factors governing the abundance of a species, namely the movement range of their fish hosts and the success rate of the parasitic larval glochidia in finding fish hosts. Core mussels species have fish hosts with large movement range to disperse the parasitic larval glochidia to achieve high levels of abundance. Species associated with fish host of limited movement range require high success rate of finding fish host to achieve at least an intermediate level of abundance. Species with low success rate of finding fish hosts coupled with fish hosts having limited movement range exhibit satellite species characteristics, namely rare in numbers and sparse in distributions.

The Output of First Stage Larvae by Cats Infested with Aelurostrongylus abstrusus

1968 ◽  
Vol 42 (3-4) ◽  
pp. 295-298 ◽  
Author(s):  
J. M. Hamilton ◽  
A. W. McCaw
Keyword(s):  
Life Cycle ◽  
Great Britain ◽  
Intermediate Host ◽  
World Wide ◽  
Wide Distribution ◽  
Clinical Disease ◽  
Complex Life Cycle ◽  
Patent Period ◽  
Aelurostrongylus Abstrusus

Aelurostrongylus abstrusus, the lungworm of the cat, has a world wide distribution and has been reported from countries as far apart as America, Great Britain and Palestine. It has a complex life cycle insofar as a molluscan intermediate host is essential and it is possible that auxiliary hosts also play an important part. In Britain, the incidence of active infestation of cats with the parasite has been recorded as 19·4% (Lewis, 1927) and 6·6% (Hamilton, 1966) but the latter author found that, generally, the clinical disease produced by the parasite was of a mild nature. It is known that the average patent period of the infestation in the cat is 8–13 weeks and it seems likely that, in that time, a considerable number of first stage larvae would be evacuated. Information on that point is not available and the object of the following experiment was to ascertain the number of larvae produced by cats during the course of a typical infestation.

Observations on the Morphology and Life Cycle ofNeodiplostomum intermedium(Trematoda: Diplostomatidae)

Parasitology ◽  
1961 ◽  
Vol 51 (1-2) ◽  
pp. 133-172 ◽  
Author(s):  
J. C. Pearson
Keyword(s):  
Life Cycle ◽  
Special Reference ◽  
Intermediate Host ◽  
Technical Assistance ◽  
Snail Host ◽  
Tree Frog ◽  
Mother Sporocyst ◽  
Egg Transformation ◽  
Hydromys Chrysogaster ◽  
Paratenic Hosts

1.Neodiplostomum intermediumPearson is recorded from four new hosts; as an adult from the water rat,Hydromys chrysogasterGeoffroy, and as a metacercaria (diplostomulum), from tadpole and adult of an undescribed tree frog,Hylasp., tadpole of (Hyla latopalmata(Günther)Mixophyes fasciolatusGünther and frog of an unidentified leptodactylid.2. The life cycle ofNeodiplostomum intermediumwas followed experimentally; the hosts were:Pettancylus assimilis(Petterd), a fresh-water limpet, as first intermediate host; tadpole ofHyla pearsoniCopland as second intermediate host;Hyla caerulea(Shaw) a tree frog, andHemisphaerodon gerrardiPeters, the pinktongued skink, as paratenic hosts; andRattus assimilis(Gould) and laboratory rats as definitive hosts.3. Descriptions are given of the morphology of the miracidium, mother sporocyst, daughter sporocyst, cercaria, and diplostomulum, with special reference to the structure of the miracidium and of the cercarial tail.4. Observations are given on the embryology of the miracidium, hatching of the egg, transformation of the miracidium into the mother sporocyst with special reference to the germinal cells, the route and manner of escape of cercariae from the snail host, the development of the diplostomulum with special reference to the reserve excretory system, and the movements of diplostomula during metamorphosis of the tadpole host.5. The haploid chromosome number is ten, as determined from squashes of testes. One paratype and a series of experimental adults have been compared with and found different fromNeodiplostomum(Fibricola)sarcophilusn.comb. The orthography and formal proposing of the names of the species ofFibricolatransferred toNeodiplostomumby Pearson (1959b) are corrected.The writer wishes to thank Dr M. J. Mackerras, Queensland Institute for Medical Research, for generously supplying water rats; Professor J. F. A. Sprent, University of Queensland Veterinary School, for his criticism of the manuscript; Mr K. Webber and his sons for their assistance in catching rats and for permission to collect snails, frogs and tadpoles from their streams; and Mr R. J. Ballantyne for technical assistance. This study was supported by a grant from the Rural Credits Fund of the Commonwealth Bank of Australia.

Copulation order, density cues and variance in fertilization success in a cestode

Parasitology ◽  
2014 ◽  
Vol 141 (7) ◽  
pp. 934-939
Author(s):  
D. ANDREOU ◽  
D. P. BENESH
Keyword(s):  
Reproductive Success ◽  
Intermediate Host ◽  
Fertilization Success ◽  
Final Host ◽  
Fish Host ◽  
Multiple Infection ◽  
Single Infection ◽  
Male Reproductive Success ◽  
Mating Order ◽  
Potential Partner

SUMMARYSimultaneous hermaphrodites maximize their fitness by optimizing their investment into male or female functions. Allocation of resources to male function (tissues, traits, and/or behaviours increasing paternity) is predicted to increase as density, and the associated level of sperm competition, increases. We tested whether the simultaneous hermaphroditic cestode Schistocephalus solidus uses cues of potential partner densities in its fish intermediate host to improve its male reproductive success in the final host. We had two worms, one originating from a multiple infection in the fish intermediate host and one from a single infection, sequentially compete to fertilize the eggs of a third worm. The fertilization rates of the two competitors nearly always differed from the 50–50 null expectation, sometimes considerably, implying there was a ‘winner’ in each experimental competition. However, we did not find a significant effect of density in the fish host (single vs multiple) or mating order on paternity. Additional work will be needed to identify the traits and environmental conditions that explain the high variance in male reproductive success observed in this experiment.

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