On the Structure and Life Histories of British Fresh-water Furcocercariae

Parasitology ◽  
1931 ◽  
Vol 23 (3) ◽  
pp. 310-324 ◽  
Author(s):  
W. F. Harper
Keyword(s):  
Life Cycle ◽  
Fresh Water ◽  
Liver Tissue ◽  
Life Histories ◽  
Animal Experiment ◽  
Helminth Infection ◽  
Detailed Account ◽  
Double Infection ◽  
Parasitic Castration ◽  
Feeding Experiments

Three species of furcocercariae are described. By means of direct animal experiment with secondary, intermediate and final hosts I have shown that one species develops into Tetracotyle typica Dies., the larva of Strigea tarda Steenstrup, and a connected detailed account of this life cycle is here given. Of the two other species, both of which are new, I have been able to trace the development of one into Tetracotyle n.sp. in Planorbis crista L., and P. albus Müll. Feeding experiments with this new Tetracotyle using ducklings as final hosts failed, however, to produce the corresponding adult.Effect of the parasite on the host. The usual results of helminth infection of this nature are observable, namely, marked disruption of liver tissue and in many cases complete parasitic castration of the molluscs infected.Double infection. In the course of my investigations on larval Trematodes I have met with one example of double infection with sporocysts, viz. Cercaria F.1 and F.2, within one and the same individual of Planorbis albus Müll. This condition was found only on one occasion, Cercaria F.1 being in predominance. Instances of double infection have been recorded by Faust (1971) and Sewell (1922), and from this country by Hesse (1923) and Brown (1926). The condition, however does not appear to be a common one.

On the Structure and Life-histories of British Fresh-water Larval Trematodes

Parasitology ◽  
1929 ◽  
Vol 21 (1-2) ◽  
pp. 189-219 ◽  
Author(s):  
W. F. Harper
Keyword(s):  
Fresh Water ◽  
Life Histories ◽  
The Other ◽  
Trematode Species ◽  
Intermediate Hosts ◽  
Double Infection ◽  
Activity Duration ◽  
Large Numbers ◽  
Limnaea Stagnalis ◽  
First Time

A large number of fresh-water Invertebrates has been examined and the parasites obtained from them include examples of the commoner groups to be met with in any area surveyed. Six larval Trematodes have been described in detail, and by means of direct animal experiment two of them have been definitely related to known adults. Of these two one is the larva of Notocotylus seineti Fuhr., and is doubtfully Cercaria monostomi v. Linst., while the other is the larva of Echinoparyphium recurvatum v. Linst., and is described here in detail for the first time. The four xiphidiocercariae described are new. Data relating to the activity, duration of free life, and process of encystment of cercariae within the bodies of secondary intermediate hosts is also given.Effect of the parasite on the host. The disruption of the tissues brought about by the presence of sporocysts or rediae in the liver of a mollusc injures the host, and in many cases brings about its death. The gonads also are often attacked and completely destroyed. This latter feature of parasitic castration has been observed by Giard (1888) among certain species of Limnaea, Planorbis and Paludina attacked by sporocysts. Brown (1926) states that the gonads are rarely infected. As regards the encysted stages of cercariae these appear to do very little harm to their hosts even when present in large numbers. These observations are in agreement with those of Lebour (1912) for the sporocyst, rediae, and encysted stages of marine Trematodes.Double infection. I have found no instance of a double infection among the species described. In the literature, several records show the parasitism of two or more species of cercariae, within one and the same host. The occurrence of two species is most commonly met with, and as a rule one is in predominance. Sewell (1922) states that double infection is not common in India. Faust (1917), on the other hand, has found as many as four trematode species within the same host individual (Planorbis trivolis). Hesse (1923) states that “every large Limnaea peregra examined was heavily infected with sporocysts of either of the two species, but it was rare to find both together.” Brown (1926) in the neighbourhood of Birmingham has found three examples of associated xiphidiocercariae and furcocercariae, one example of xiphidiocercariae and echinostome cercariae, and two examples of echinostome cercaria, all from Limnaea stagnalis L.

On some British Larval Cestodes from Land and Fresh-water Invertebrate Hosts

Parasitology ◽  
1930 ◽  
Vol 22 (2) ◽  
pp. 202-213 ◽  
Author(s):  
W. F. Harper
Keyword(s):  
Fresh Water ◽  
Life Histories ◽  
Animal Experiment ◽  
Reproductive Organs ◽  
Body Cavity ◽  
The Body ◽  
Careful Comparison

Ten larval Cestodes, eight from aquatic and two from terrestrial hosts, have been described. Of these, eight species are new, and in the case of Cysticercus “A,” both larva and adult are new. By direct animal experiment the life-histories of three forms have been definitely established, while by careful comparison of the hooks of the scolex two larvae have been related to known adults. Cysticercus Hymenolepidis setigerae, previously recorded only from Copepods, is described here from an Ostracod host.Effect of the parasite on the host. It is difficult to estimate the effect of Cestode larvae parasitic in Invertebrata, especially in the smaller forms such as the Entomostraca. In the latter, I have found that the intestine and musculature suffer most, and that the reproductive organs remain unattacked. The same remarks also hold for Oligochaete hosts. Dady (1901) considers that the influence of these cystic stages on their hosts is considerable, particularly on the musculature, sexual organs and intestine, and that death of the host may follow. Lindner (1921) states that little or no harm is done to Ostracods by the presence of tapeworm larvae, and also that the ovary of the female remains unattacked. The same author considers that, among the Entomostraca, destruction of the intestine occurs only in Copepods, the body cavity of Ostracods being so roomy that a harming of the intestine by growth of the parasite is unlikely. Schmidt (1894) finds that for Cysticercus Hymenolepidis anatinae, the host, Cypris ovata, was not particularly affected.

DESCRIPTION OF CIRCUMONCOBOTHRIUM SINGHII N.SP. FROM CLARIAS BATRACUS OF SAVITRI RIVER AT DAPOLI DISTRICT RATNAGIRI (M.S.) INDIA

2018 ◽  
Vol 24 (2) ◽  
Author(s):  
R.R. DANDAWATE
Keyword(s):  
Life Cycle ◽  
Fresh Water ◽  
Summer Season ◽  
Fresh Water Fish ◽  
Water Fish

Present paper deals with study of cestode parasites of genus Circumoncobothrium from fresh water fish Clarius batracus at Savitri river, (Dapoli) for the percentages of infection occurance during summer season,minimum during winter and tolarate during rainy season.The parasite mainly infected the intestine of host and fed on nutrients from digested food. It completed its life cycle in the intestine of host. By camparing different characters of it to identify that the species is new

scholarly journals Man-made habitats - hotspots of evolutionary game between grass, fungus and fly

2009 ◽  
Vol 15 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Marlena Lembicz ◽  
Paweł Olejniczak ◽  
Ziemowit Olszanowski ◽  
Karolina Górzyńska ◽  
Adrian Leuchtmann
Keyword(s):  
Life Cycle ◽  
Life Histories ◽  
Early Stage ◽  
Scientific Evidence ◽  
Evolutionary Game ◽  
Long Distance ◽  
Puccinellia Distans ◽  
New Man ◽  
Epichloë Typhina ◽  
Vegetative Season

Man-made habitats - hotspots of evolutionary game between grass, fungus and flyThe origin and effects of an evolutionary game between species from three different kingdoms (plants, fungi and animals) are presented. We provide scientific evidence that the interaction discovered in man-made habitats leads to an early stage of coevolution. The grassPuccinellia distanswas observed to rapidly spread in new man-made habitats, while at the same time, it was colonised by the fungusEpichloë typhina.The invasion of infected grasses is accompanied by alterations in life histories of both species:P. distansdeveloped features promoting long-distance spreading, whereasE. typhinachanged its life cycle by forming sexual structures for the second time, later in the vegetative season. This enables the fungus to make use of the late shoots of the grass for sexual reproduction, even though it cannot be completed because the vector of spermatia necessary for fertilisation, femaleBotanophilaflies, is not present at that time. This indicates that such uncoordinated evolutionary processes had taken place before interactions between organisms became so specialised that it is difficult to presume they were the result of natural selection. Moreover, these processes could have been initiated in man-made habitats that, in particular circumstances, can become coevolutionary hotspots.

scholarly journals The chronic effects of salinity on the Crustacean Moina affinis Birge (1893)

2004 ◽  
Vol 1 (2) ◽  
pp. 200-206
Author(s):  
Baghdad Science Journal
Keyword(s):  
Life Cycle ◽  
Fresh Water ◽  
Chronic Exposure ◽  
Exposure Period ◽  
Control Group ◽  
Length Growth ◽  
Chronic Effects ◽  
Final Length

Thi s study included the effect of chronic exposure of di fferent concentrations of Nan on the biology of fresh water zroDplonk ton species Moina 41.112' ( Cladcxe'ra The concentrations used for chronic exposure were 03, 0.75. 1 960 to investigate iI effects on the life cycle and la lables of this species after exposure period and the range of this exposure effects on the rate of expectation for further life, also the effect of salinity on reproduotive parameters was studied which included average of total number of eggs and young produced, volume clutch's (6.95. indiclutch for control group , 14.516 indi clutch for 0.596a ,3_65 ind./ clutch for (175 5(.. and 03 Ind} cruel] for 1960) and number of Clutch's (5.5 clutch/ female for control group, 1.7 clutch/ funEoc for 0.5.9(z.z, 1:2 dutch?' female for 0,75960 and 0,1 oluchi female for 196.) which howed a reduction_ But had no effects on the time 10 tarsi clutch produced. Time of surviving ( 12.9 day for control g.roup. 63 day for 0.5%0, 15_2 day for 0.75%.0 and 4.6 day for I 9f,), average final length and average of daily length, growth increasing were studied_ In addition to the studying the orient of salinity on the number of moults which showed a reduction. in its number.

Pratylenchidae: Achlysiella, Hirschmanniella, Nacobbus, Pratylenchus, Radopholus and Zygotylenchus species.

2021 ◽  
pp. 337-406
Author(s):  
Ziaul Haque ◽  
Mujeebur Rahman Khan
Keyword(s):  
Life Cycle ◽  
Risk Analysis ◽  
Host Resistance ◽  
Chemical Control ◽  
Economic Importance ◽  
Detailed Account ◽  
Pest Risk Analysis ◽  
Management Measures ◽  
Pest Risk

Abstract This chapter provides information on geographical distribution; host plants; symptoms; biology and life cycle; economic importance; movement and means of dispersal; pest risk analysis; invasiveness rating; management measures, including cultural, host resistance, biological, and chemical control; and detailed account of diagnosis procedures, such as morphological, biochemical, and molecular characterization, of Achlysiella, Hirschmanniella, Nacobbus, Pratylenchus, Radopholus and Zygotylenchus species.

Hoplolaimidae: Aphasmatylenchus, Helicotylenchus, Hoplolaimus and Scutellonema species.

2021 ◽  
pp. 197-240
Author(s):  
Ziaul Haque ◽  
Mujeebur Rahman Khan
Keyword(s):  
Life Cycle ◽  
Risk Analysis ◽  
Molecular Characterization ◽  
Geographical Distribution ◽  
Economic Importance ◽  
Detailed Account ◽  
Pest Risk Analysis ◽  
Management Measures ◽  
Pest Risk

Abstract This chapter provides information on geographical distribution; host plants; symptoms; biology and life cycle; economic importance; movement and means of dispersal; pest risk analysis; invasiveness rating; management measures; and detailed account of diagnosis procedures, such as morphological, biochemical, and molecular characterization, of Aphasmatylenchus, Helicotylenchus, Hoplolaimus and Scutellonema species.

Challenges for Diadromous Fishes in a Dynamic Global Environment

2009 ◽  
Keyword(s):  
Life Cycle ◽  
Life Histories ◽  
Life Cycles ◽  
Partial Migration ◽  
Environmental Stochasticity ◽  
Species Dynamics ◽  
Life Cycle Pattern ◽  
Aquatic Sciences ◽  
Diversity Of Life

<em>Abstract</em>.-In the study of species life histories and the structure of diadromous populations, an emerging trend is the prevalence of life cycle diversity-that is, individuals within populations that do not conform to a single life cycle pattern. A rapid rise in publications documenting within-population variability in life cycles has resulted in the use of numerous terms and phrases. We argue that myriad terms specific to taxa, ecosystem types, and applications are in fact describing the same phenomenon-life cycle diversity. This phenomenon has been obscured by the use of multiple terms across applications, but also by the overuse of typologies (i.e., anadromy, catadromy) that fail to convey the extent of life cycle variations that underlay population, metapopulation, and species dynamics. To illustrate this, we review migration and habitat-use terms that have been used to describe life cycles and life cycle variation. Using a citation index (Cambridge Scientific Abstracts © Aquatic Sciences and Fisheries Abstracts), terms were tallied across taxonomic family, ecosystem, type of application, analytical approach, and country of study. Studies on life cycle diversity have increased threefold during the past 15 years, with a total of 336 papers identified in this review. Most of the 40 terms we identified described either sedentary or migratory lifetime behaviors. The sedentary-migratory dichotomy fits well with the phenomenon of partial migration, which has been commonly reported for birds and Salmonidae and is postulated to be the result of early life thresholds (switch-points). On the other hand, the lexicon supports alternate modes of migration, beyond the simple sedentary-migratory dichotomy. Here more elaborate causal mechanisms such as the entrainment hypothesis may have application. Diversity of life cycles in fish populations, whether due to partial migration, entrainment, or other mechanisms, is increasingly recognized as having the effect of offsetting environmental stochasticity and contributing to long-term persistence.

Belonolaimidae: Belonolaimus species.

2021 ◽  
pp. 100-105
Author(s):  
Ziaul Haque ◽  
Mujeebur Rahman Khan
Keyword(s):  
Life Cycle ◽  
Risk Analysis ◽  
Molecular Characterization ◽  
Economic Importance ◽  
Detailed Account ◽  
Pest Risk Analysis ◽  
Management Measures ◽  
Wide Range ◽  
Pest Risk

Abstract The sting nematode, Belonolaimus spp., is one of the most destructive nematode pests of turfgrass and attacks a wide range of monocotyledonous plants and gymnosperms, including vegetables, legumes, cereals, etc. This chapter includes information on: geographical distribution; host ranges; symptoms; biology and life cycle; ecology; physiological races; economic importance; invasiveness; pest risk analysis; movement and means of dispersal; management measures; and detailed account of diagnosis procedures, such as morphological, biochemical, cytogenetic and molecular characterization, of Belonolaimus species.

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