Observations on the Larval Stages of Muellerius capillaris within the Intermediate Hosts Agriolimax agrestis and A. reticulatus

1957 ◽  
Vol 31 (1-2) ◽  
pp. 1-16 ◽  
Author(s):  
J. H. Rose
Keyword(s):  
Intermediate Host ◽  
Infective Stage ◽  
Intermediate Hosts ◽  
Rate Of Development ◽  
Larval Stages ◽  
Infective Larvae ◽  
Artificial Digestion ◽  
Do So ◽  
Muellerius Capillaris

1. The rate of development of the larvae of M. capillaris is slowed down as the temperature is lowered; at 25°C. the infective stage is reached after 8 days; at 5°C. after 98 days.2. The differences between “pre-infective” and “infective” larvae, as described by Gerichter (1948), have been confirmed.3. Larvae at the “infective” stage can withstand artificial digestion, but “pre-infective” larvae are unable to do so.4. The infective larvae can survive for long periods within the foot of the intermediate host.5. Pre-infective larvae can survive for seven days after the death of the intermediate host; infective larvae can live for sixteen days.6. Naturally-infected slugs were found throughout the greater part of the year. 13.5 per cent of the slugs collected were infected but in most instances only a few larvae were present in any one slug.

The paramphistomes (Trematoda) of Australian ruminants.

1953 ◽  
Vol 1 (2) ◽  
pp. 193 ◽  
Author(s):  
PH Durie
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Marked Effect ◽  
Mantle Cavity ◽  
Developmental Period ◽  
Intermediate Hosts ◽  
Minimum Period ◽  
Rate Of Development ◽  
Larval Stages

A description of the development at 27�C. of Ceylonocotyle streptocoelium (Fischoeder 1901) Nasmark 1937, a paramphistome from the rumen and reticulum of sheep and cattle in Australia, is given in detail. Eggs hatched after 16 days' incubation and miracidia penetrated the intermediate host, a planorbid snail, Glyptanisus gilberti Dunker 1848, through the mantle cavity. The development of the larval stages of the parasite within the intermediate host was completed 34 days after infection, when cerariae were secreted by snails. Cysts of C. streptocoelium fed to sheep and cattle showed that flukes reached maturity in the rumen in 48 and 56 days respectively. The life cycle of the fluke, therefore, was completed in a minimum period of approximately 3.5 months under these conditions. It was found that temperature had a marked effect on the rate of development of larval stages within the molluscan intermediate host, the developmental period at 20�C. being twice as long as that at 27�C. The various stages occurring in the molluscan intermediate host are described in detail. The development of Paramphistomum ichikauiai Fukui 1922 is compared with that of C. streptocoelium. The rate of development was found to be more rapid than for C. streptocoelium under the same conditions. Eggs hatched after 12 days incubation and cercariae were secreted from the intermediate host, Segnitilia alphena Iredale 1943, 25 days after infection. Flukes were found to reach maturity in sheep 49-51 days after cysts had been fed. The eggs and intra-molluscan stages are similar in both species, but the cercariae may be readily distinguished by anatomical differences in their excretory systems. The life cycle in this species takes approximately 3 months to complete under these conditions. The molluscan intermediate hosts of the two species of amphistomes are described and notes on their bionomics are given.

scholarly journals Molecular data reshape our understanding of the life cycles of three digeneans (Monorchiidae and Gymnophallidae) infecting the bivalve, Donax variabilis: it’s just a facultative host!

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 34
Author(s):  
Kristina M. Hill-Spanik ◽  
Claudia Sams ◽  
Vincent A. Connors ◽  
Tessa Bricker ◽  
Isaure de Buron
Keyword(s):  
Gulf Of Mexico ◽  
Intermediate Host ◽  
Atlantic Coast ◽  
The United States ◽  
Life Cycles ◽  
Intermediate Hosts ◽  
Larval Stages ◽  
Complete Life Cycle ◽  
Morphological Criteria ◽  
Donax Variabilis

The coquina, Donax variabilis, is a known intermediate host of monorchiid and gymnophallid digeneans. Limited morphological criteria for the host and the digeneans’ larval stages have caused confusion in records. Herein, identities of coquinas from the United States (US) Atlantic coast were verified molecularly. We demonstrate that the current GenBank sequences for D. variabilis are erroneous, with the US sequence referring to D. fossor. Two cercariae and three metacercariae previously described in the Gulf of Mexico and one new cercaria were identified morphologically and molecularly, with only metacercariae occurring in both hosts. On the Southeast Atlantic coast, D. variabilis’ role is limited to being a facultative second intermediate host, and D. fossor, an older species, acts as both first and second intermediate hosts. Sequencing demonstrated 100% similarities between larval stages for each of the three digeneans. Sporocysts, single tail cercariae, and metacercariae in the incurrent siphon had sequences identical to those of monorchiid Lasiotocus trachinoti, for which we provide the complete life cycle. Adults are not known for the other two digeneans, and sequences from their larval stages were not identical to any in GenBank. Large sporocysts, cercariae (Cercaria choanura), and metacercariae in the coquinas’ foot were identified as Lasiotocus choanura (Hopkins, 1958) n. comb. Small sporocysts, furcocercous cercariae, and metacercariae in the mantle were identified as gymnophallid Parvatrema cf. donacis. We clarify records wherein authors recognized the three digenean species but confused their life stages, and probably the hosts, as D. variabilis is sympatric with cryptic D. texasianus in the Gulf of Mexico.

Life cycle studies on two Digenea, Paradistomum geckonum (Dicrocoeliidae) and Mesocoelium sociale (Mesocoeliidae), in geckonid lizards from Indonesia

1987 ◽  
Vol 65 (10) ◽  
pp. 2491-2497 ◽  
Author(s):  
Murray J. Kennedy ◽  
L. M. Killick ◽  
M. Beverley-Burton
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Intermediate Hosts ◽  
Larval Stages ◽  
Hemidactylus Frenatus ◽  
Pulmonate Gastropod ◽  
First Intermediate Host

Life cycle studies of Paradistomum geckonum (Dicrocoeliidae) were attempted experimentally. The pulmonate gastropod Lamellaxis gracilis served as the first intermediate host; geckonid lizards (Cosymbotus platyurus, Gehyra mutilata, and Hemidactylus frenatus) served as definitive hosts. The life cycle of Mesocoelium sociale (Mesocoeliidae) was studied in naturally infected first intermediate hosts (L. gracilis, Huttonella bicolor) and experimentally in geckonid definitive hosts (C. platyurus, G. mutilata, and H. frenatus). Some naturally infected L. gracilis were infected concurrently with larval stages of both digeneans. Second intermediate hosts, presumed to be arthropods, were experimentally unnecessary. Metacercariae of P. geckonum were not found. Cercariae of M. sociale formed encysted metacercariae in the same individual snails.

Some Observations on the Transmission of Bacteria by Infective Larvae of Nippostrongylus brasiliensis

1955 ◽  
Vol 29 (1-2) ◽  
pp. 27-32 ◽  
Author(s):  
H. M. Gharib
Keyword(s):  
Life Cycle ◽  
Definitive Host ◽  
Infected Host ◽  
Nippostrongylus Brasiliensis ◽  
Infective Stage ◽  
Natural Conditions ◽  
Larval Stages ◽  
Infective Larvae ◽  
External Development

It is well known that the first two larval stages in the life cycle of nematodes belonging to the superfamily Strongloidea, have a freeliving existence. During this time, the larva which hatches from the egg feeds actively, undergoes two moults and grows considerably before reaching the infective stage, when it is ready to invade a definitive host. Under natural conditions this external development takes place in the faeces, which have been deposited by the infected host on ground likely to be contaminated with various bacteria.

Observations on the free-living stages of strongylid nematodes of the horse

Parasitology ◽  
1972 ◽  
Vol 64 (3) ◽  
pp. 461-477 ◽  
Author(s):  
C. P. Ogbourne
Keyword(s):  
Laboratory Experiments ◽  
Field Observations ◽  
Infective Stage ◽  
Free Living ◽  
Rate Of Development ◽  
Infective Larvae ◽  
Strongylus Vulgaris ◽  
Different Temperatures ◽  
Eggs And Larvae

Observations have been made on the development and survival of the free-living stages in faeces deposited out of doors at different times of year, and on the migration of infective larvae to the surrounding herbage. Laboratory experiments were performed to assist in the interpretation of the field observations. Studies were made on the rate of development to the infective stage in faeces kept at different temperatures. The rates at which eggs and larvae of Strongylus vulgaris, S edentatus, S. equinus and Trichonema nassatum developed on faecal-agar cultures at different temperatures were compared. Studies were also made on the effect of desiccation of faeces on the development and survival of the free-living stages. The results of these observations are discussed in relation to the development of herbage infestations on British pastures.

Larval development of Angiostrongylus chabaudi, the causative agent of feline angiostrongylosis, in the snail Cornu aspersum

Parasitology ◽  
2017 ◽  
Vol 144 (14) ◽  
pp. 1922-1930 ◽  
Author(s):  
V. COLELLA ◽  
M. A. CAVALERA ◽  
G. DEAK ◽  
V. D. TARALLO ◽  
C. M. GHERMAN ◽  
...  
Keyword(s):  
Intermediate Host ◽  
Developmental Stages ◽  
Land Snails ◽  
Morphological Description ◽  
Intermediate Hosts ◽  
Mammal Species ◽  
Larval Stages ◽  
Ecological Features ◽  
Cornu Aspersum ◽  
Angiostrongylus Chabaudi

SUMMARYNematodes of the Angiostrongylidae family, such as Angiostrongylus vasorum and Angiostrongylus cantonensis, may cause potentially life-threatening diseases in several mammal species. Alongside these well-known species, Angiostrongylus chabaudi has been recently found affecting the cardiopulmonary system of domestic and wild cats from Italy, Germany, Greece, Romania and Bulgaria. Nonetheless, significant gaps in the understanding of A. chabaudi epidemiology include the lack of information of species acting as intermediate host and of the morphological description of larval stages. Cornu aspersum (n = 30) land snails were infected with 100 first-stage larvae of A. chabaudi collected from a naturally infected wildcat in Romania. Larvae at different developmental stages were found in 29 out of 30 (96·7%) infected snails and a total of 282 (mean 9·8 ± 3·02 larvae per each specimen) were collected from the gastropods. Here we demonstrate that A. chabaudi develops in snails and report C. aspersum as potential intermediate host for this parasitic nematode. Findings of this study are central to understand the ecological features of feline angiostrongylosis and its epidemiology within paratenic and intermediate hosts.

scholarly journals Larval trematodes in freshwater gastropods from Mato Grosso, Brazil: diversity and host-parasites relationships

2013 ◽  
Vol 13 (4) ◽  
pp. 34-38 ◽  
Author(s):  
Aline Carvalho de Mattos ◽  
Maria Fernanda Furtado Boaventura ◽  
Monica Ammon Fernandez ◽  
Silvana Carvalho Thiengo
Keyword(s):  
Schistosoma Mansoni ◽  
Intermediate Host ◽  
Intermediate Hosts ◽  
Mato Grosso ◽  
Freshwater Gastropods ◽  
Larval Stages ◽  
Pomacea Maculata ◽  
Surrounding Areas ◽  
First Time

A survey for freshwater gastropods carrying trematodes parasites was conducted in Manso Dam and the surrounding areas frequented by tourist, focusing particularly on the Pantanal region. Infected snails were recovered from twelve of the eighteen investigated municipalities and forty-one cercaria-snail pairings were recorded. Among these pairings were several first records of snails serving as intermediate hosts for trematodes in Brazil including Biomphalaria amazônica Paraense, 1966, Biomphalaria occidentalis Paraense, 1981, Marisa planogyra Pilsbry, 1933, Pomacea maculata Perry, 1830, Pomacea scalaris (d'Orbigny, 1835) and Gundlachia radiata (Guilding, 1828). Echinostomatidae and Strigeidae were the most common trematode families (ca. 47%) and the greatest diversity of larvae were obtained from Drepanotrema lucidum (Pfeiffer, 1839). Paramphistomatidae, Schistosomatidae or Spirorchiidae and Notocotylidae or Pronocephalidae were recovered in D. lucidum for the first time extending the number of families which use this gastropod as intermediate host. Although no specimens were found harboring larval stages of Schistosoma mansoni Sambon, 1907 other trematode larvae were discovered, including the Schistosomatidae Brevifurcate apharingeate cercaria that can cause dermatitis in humans. Continued studies on the taxonomy and biology of trematodes are essential to better understand the biodiversity of these parasites as well as the epidemiological aspects for control of associated zoonosis.

Gastropods as intermediate hosts of Pneumostrongylus tenuis Dougherty of white-tailed deer

1968 ◽  
Vol 46 (3) ◽  
pp. 373-383 ◽  
Author(s):  
Murray W. Lankester ◽  
Roy C. Anderson
Keyword(s):  
Larval Development ◽  
Heavy Rainfall ◽  
Spring Water ◽  
Intermediate Hosts ◽  
Rate Of Development ◽  
Faecal Pellets ◽  
Forested Area ◽  
Infective Larvae ◽  
The Family

From May to October, 1966, gastropods from three different habitats on Navy Island, Ontario, were examined for larvae of Pneumostrongylus tenuis. Of 9940 examined individually, 4.2% contained larvae. A mean of 2.9 larvae was recovered from each infected gastropod. Deroceras laeve and Zonitoides nitidas were the most abundant and commonly infected species. The incidence of infective larvae in adult D. laeve from a wet forested area rose to 25% by late June but dropped to 1.5% during July, coinciding with the disappearance of adult slugs. The level of infection in Z. nitidus (4.3%) remained relatively constant. The wet forested habitat where gastropods were abundant, commonly infected, and active from May to October was probably most important for transmission. Experiments showed that snails already containing larvae can be reinfected and there is some evidence that they are repeatedly infected in nature. Larval development was retarded in aestivating snails. Numbers of larvae recovered and their rate of development differed in various species of experimentally infected gastropods. Snails of the family Polygyridae were the most suitable intermediate hosts studied. Larvae passed by deer were situated in the film of mucus covering faecal pellets. In this location, larvae may be dispersed by high spring water or heavy rainfall. Snails became infected when exposed to larvae in wet and dried soil. Larvae on pellets survived freezing at −15 to −20 °C for up to 306 days.

Some Common Queensland Mosquitoes as Intermediate Hosts of Wuchereria bancrofti (Filaria bancrofti)

Parasitology ◽  
1931 ◽  
Vol 23 (4) ◽  
pp. 415-427 ◽  
Author(s):  
G. M. Heydon
Keyword(s):  
Intermediate Host ◽  
Wuchereria Bancrofti ◽  
Intermediate Hosts ◽  
Infective Larvae ◽  
Aedes Vigilax ◽  
Culex Fatigans ◽  
New Britain

1. Anopheles amictus in North Queensland is a favourable intermediate host for Wuchereria bancrofti, comparable but perhaps not quite equal to Culex fatigans. The two described varieties of A. amictus were both tested.2. Experiments with Aëdes vigilax and Culex sitiens show that the former is a rather poor host and the latter a very poor one though infective larvae develop in some mosquitoes.3. In experiments with Aëdes argenteus none of the sixty-two mosquitoes used proved hospitable.4. Some observations on the transmission of filariasis in New Britain and on mosquitoes there are mentioned.

Studies on the behaviour, and development in fish, ofSubtriquetra subtriquetra: a uniquely free-living pentastomid larva from a crocodilian

Parasitology ◽  
1986 ◽  
Vol 93 (1) ◽  
pp. 81-98 ◽  
Author(s):  
Judith M. Winch ◽  
J. Riley
Keyword(s):  
Intermediate Host ◽  
Larval Development ◽  
Host Location ◽  
Stereotyped Behaviour ◽  
Infective Stage ◽  
Swim Bladder ◽  
Free Living ◽  
Larval Stages ◽  
Nasal Passages ◽  
Host Invasion

SUMMARYThe primary larva of the porocephalid pentastomidSubtriquetra subtriquetra, which infects the nasopharynx ofCaiman sclerops, is uniquely free-living. Eggs hatch within the nasal passages and the emergent larvae can remain infective to the fish intermediate host for 4–5 days. During this period larvae exhibit very stereotyped behaviour, alternating between a characteristic stationary ‘fishing’ posture and very brief periods of movement. Larval activity increases significantly at 3 days, probably effecting dispersal to a more favourable site for host invasion. Host location is passive and invading larvae penetrate to the swim-bladder where subsequent larval development, which involves 7 moults, occurs. All 8 larval stages are freely mobile in the swim-bladder and possess hooks. Sensilla, disposed in characteristic patterns, are present throughout development, increasing in number to the infective stage; the majority of sensilla are located on sensory papillae.

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