Factors influencing cercarial emergence and settlement in the digenean trematode Parorchis acanthus (Philophthalmidae)

2010 ◽  
Vol 91 (8) ◽  
pp. 1673-1679 ◽  
Author(s):  
K. Prinz ◽  
T.C. Kelly ◽  
R.M. O'Riordan ◽  
S.C. Culloty
Keyword(s):  
Intermediate Host ◽  
Final Host ◽  
Seabird Species ◽  
Larval Stages ◽  
Factors Influencing ◽  
Dry Conditions ◽  
Parorchis Acanthus ◽  
Abiotic And Biotic Factors ◽  
Increasing Temperature ◽  
Cercarial Emergence

The trematode Parorchis acanthus is widely distributed and exhibits a broad host spectrum, with larval stages occurring in marine gastropods and adult flukes parasitizing on various seabird species. Unlike the majority of digeneans, its cercariae do not invade a second intermediate host but encyst on a substrate in the open. In a series of laboratory experiments, we investigated factors influencing cercarial emergence and settlement of P. acanthus. Emergence of cercariae from the gastropod intermediate host Nucella lapillus increased with increasing temperature, whereas cercarial encystment success decreased. Numbers of emerged cercariae were highest in the presence of light and water. However, although in much lower numbers, cercariae were also released from N. lapillus and successfully encysted under relatively dry conditions. Cercariae were found to settle predominantly on filtering blue mussels Mytilus edulis, suggesting that cercarial concentration on the valves is largely facilitated by the bivalve's inhalation current. After being inhaled, cercariae actively emerged from the mussels using their suckers and subsequently encysted on the shells, preferably along the rim of the valves. Barnacle epibionts Semibalanus balanoides were observed to impair cercarial settlement on mussels, by disturbing or preying on cercariae. Whilst settlement success of cercariae on M. edulis increased with increasing mussel density, intensity of encysted metacercariae decreased. Furthermore, cercariae settled more efficiently on small than on large mussels. Our findings suggest that the transmission of P. acanthus cercariae is regulated by a range of abiotic and biotic factors, with filtering activity of mussels playing a key role by enhancing accumulation of cercariae on a substrate suitable for transmission to the bird final host.

scholarly journals A Contribution towards the Life History of Parorchis acanthus Nicoll, A Trematode in the Herring Gull

1922 ◽  
Vol 12 (4) ◽  
pp. 829-832 ◽  
Author(s):  
Marie V. Lebour ◽  
Richard Elmhirst
Keyword(s):  
Intermediate Host ◽  
Mytilus Edulis ◽  
Final Host ◽  
Marine Bivalve ◽  
Herring Gull ◽  
Small Glass ◽  
History Of ◽  
The Common ◽  
Parorchis Acanthus ◽  
Glass Aquarium

Parorchis acanthus is a Trematode described by Nicoll (1907) from the bursa Fabricii and rectum of the Herring Gull, Larus argentatus; in 1906 he first described it as Zeugorchis acanthus. Originally found at St. Andrews, it is now known to be common at Millport and also occurs in gulls from the Northumberland coast, and probably is abundant elsewhere. Nicoll found it once in the Common Gull, Larus canus. In 1907 (Lebour, 1907) one of the present writers described a cercaria occurring in rediæ from Purpura lapillus. This was named Cercaria purpurœ sp. inq., and afterwards identified with young stages of Parorchis acanthus in the Herring Gull (Lebour, 1914). It was thus shown that the first host of this Trematode is Purpura lapillus and the final host the Herring Gull, but the intermediate host was unknown. Localities for the cercaria were Loch Ryan, Wigtownshire; Budle Bay, Fenham Flats and Cullercoats in Northumberland; Robin Hood's Bay in Yorkshire; and Millport. Adults occur at St. Andrews, Northumberland coast and Millport, as already stated.The Cercaria appeared to be closely related to Echinostomum cercariæ, and it was suggested (Lebour, 1914) that the intermediate host would probably be some marine bivalve, as it is often so with Echinostomum (e.g. E. secundum in Mytilus edulis and Cardium edule, E. leptosomum in Scrobicularia tenuis). This suggestion now proves to be correct, and we are able to show that the intermediate host of Parorchis acanthus is Mytilus edulis or Cardium edule.On August 13th, 1921, at the Millport Station some larval cercariæ were noticed by Elmhirst swimming in a small glass aquarium, which contained a collection of Purpura lapillus, Cardium edule and Mytilus edulis.

Life cycle of a new echinostome from Egypt, Echinostoma liei sp.nov. (Trematoda: Echinostomatidae)

Parasitology ◽  
1972 ◽  
Vol 65 (2) ◽  
pp. 203-222 ◽  
Author(s):  
U. Jeyarasasingam ◽  
D. Heyneman ◽  
Hok-Kan Lim ◽  
Noshy Mansour
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Sibling Species ◽  
Developmental Stages ◽  
Nile Delta ◽  
Biomphalaria Glabrata ◽  
Final Host ◽  
Similar Species ◽  
Aquatic Bird ◽  
Larval Stages

A 37-spined Egyptian echinostome, Echinostoma liei sp.nov., is described in adult and larval stages. The parasite develops readily in the laboratory in chicks and ducklings, hamsters and rats. Its natural final host in or near irrigation ditches of the Nile delta involves the roof rat, Egyptian giant shrew and aquatic bird hosts. Developmental forms are described from infection of the NIH strain of Biomphalaria glabrata in the laboratory. B. alexandrina, is infected in the normal habitat in Egypt and contains both developmental stages in the heart or aorta and the hepatopancreas, and metacercariae encyst in the pericardium and kidney. E. liei sp.nov. is one of six very similar species characterized by 37 collar spines with a pattern of (3 + 2) corner spines in each lappet, six laterals on each side, and 15 dorsals in alternating rows; two pairs of dorsoventral and one small pair of ventro-lateral finfolds on the cercarial tail; and rodlike cystogenous material filling the cercarial encystation glands. In addition to distinctive intermediate-host specificity, differentiating characteristics of E. liei cercariae include presence of six sets of three flame cells each per side (total 36), seven oesophageal cells, eight penetration gland outlets on the dorsal lip of the oral sucker, and an absence of paraoesophageal gland cells as determined by intravital dyes. Significance of these and other cercarial traits is emphasized to aid in defining highly similar, but none the less distinct, sibling species.

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.

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.

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.

Sarcocystosis (sarcosporidiosis)

2010 ◽  
pp. 1109-1111
Author(s):  
John E. Cooper
Keyword(s):  
Intermediate Host ◽  
Muscle Biopsy ◽  
Clinical Examination ◽  
Specific Treatment ◽  
Final Host ◽  
Domestic Pig ◽  
Gastrointestinal Upset

Sarcocystosis is characterized by the invasion of muscles and sometimes other tissues by protozoa of the genus Sarcocystis, of which S. hominis (intermediate host domestic cattle) and S. suihominis (domestic pig) are the most significant to humans, to whom they are transmitted by ingestion of uncooked beef or pork. Humans serve as either intermediate or final host: (1) intermediate host—presence of cysts in muscle is usually asymptomatic, but may cause myositis or myopathy; detected on clinical examination or muscle biopsy; (2) final host—may be asymptomatic or cause fever and gastrointestinal upset; oocysts or sporocysts can be detected in faeces. There is no specific treatment. Prevention is by not eating uncooked meat from any animal....

The Colonization of Necrophagous Larvae Accelerates the Decomposition of Chicken Carcass and the Emission of Volatile Attractants for Blowflies (Diptera: Calliphoridae)

2019 ◽  
Vol 56 (6) ◽  
pp. 1590-1597 ◽  
Author(s):  
Yensy María Recinos-Aguilar ◽  
Maria Dolores García-García ◽  
Edi A Malo ◽  
Leopoldo Cruz-López ◽  
Julio C Rojas
Keyword(s):  
Dimethyl Disulfide ◽  
Sulfur Compounds ◽  
Decomposition Process ◽  
Larval Stages ◽  
Cochliomyia Macellaria ◽  
Chicken Carcass ◽  
Volatile Attractants ◽  
Tissue Degradation ◽  
Decomposition Stages ◽  
Abiotic And Biotic Factors

AbstractThe decomposition of a living being involves a series of changes produced by a number of interacting abiotic and biotic factors. In this study, we analyzed the effect of the colonization of blowflies on the decomposition of chicken carcasses and on the emission of sulfur compounds. The loss of the mass of carcasses and the release rate of sulfur compounds were compared for 30 d in chicken carcasses with and without blowflies in field conditions. The tissue degradation was slower in the carcasses without insects compared to those colonized by blowflies. The decomposition stages of fresh, bloated, active decay, and advanced decay were observed in the carcasses without flies; while the decomposition stages of fresh, active decay, advanced decay, and dry remains were identified in carcasses with flies. Two sulfur compounds, dimethyl disulfide and dimethyl trisulfide, were present during the entire decomposition process. The emission of these compounds is not directly associated with the presence of the blowflies’ immature stages during the whole decomposition process. However, in cadavers with insects, the highest emission of both compounds occurred in day 2, while in cadavers without insects, the peak of emission was observed in day 4. In addition, the presence of the larval stages I and II of Lucilia eximia (Wiedemann, 1819) (Diptera: Calliphoridae), Chrysomya rufifacies (Macquart, 1842) (Diptera: Calliphoridae), Chrysomya megacephala (Fabricius, 1794) (Diptera: Calliphoridae), and Cochliomyia macellaria Fabricius, 1775 (Diptera: Calliphoridae) matched with the peak of emission of both compounds.

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