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.

scholarly journals Leeches as the intermediate host for strigeid trematodes: genetic diversity and taxonomy of the genera Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ewa Pyrka ◽  
Gerard Kanarek ◽  
Grzegorz Zaleśny ◽  
Joanna Hildebrand
Keyword(s):  
Intermediate Host ◽  
Life Cycles ◽  
Coi Gene ◽  
Small Rivers ◽  
Ecological Niches ◽  
Its2 Region ◽  
28S Rrna ◽  
Intermediate Hosts ◽  
Internal Transcribed Spacer Region ◽  
Wide Range

Abstract Background Leeches (Hirudinida) play a significant role as intermediate hosts in the circulation of trematodes in the aquatic environment. However, species richness and the molecular diversity and phylogeny of larval stages of strigeid trematodes (tetracotyle) occurring in this group of aquatic invertebrates remain poorly understood. Here, we report our use of recently obtained sequences of several molecular markers to analyse some aspects of the ecology, taxonomy and phylogeny of the genera Australapatemon and Cotylurus, which utilise leeches as intermediate hosts. Methods From April 2017 to September 2018, 153 leeches were collected from several sampling stations in small rivers with slow-flowing waters and related drainage canals located in three regions of Poland. The distinctive forms of tetracotyle metacercariae collected from leeches supplemented with adult Strigeidae specimens sampled from a wide range of water birds were analysed using the 28S rDNA partial gene, the second internal transcribed spacer region (ITS2) region and the cytochrome c oxidase (COI) fragment. Results Among investigated leeches, metacercariae of the tetracotyle type were detected in the parenchyma and musculature of 62 specimens (prevalence 40.5%) with a mean intensity reaching 19.9 individuals. The taxonomic generic affiliation of metacercariae derived from the leeches revealed the occurrence of two strigeid genera: Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928. Phylogenetic reconstructions based on the partial 28S rRNA gene, ITS2 region and partial COI gene confirmed the separation of the Australapatemon and Cotylurus clades. Taking currently available molecular data and our results into consideration, recently sequenced tetracotyle of Australapatemon represents most probably Au. minor; however, unclear phylogenetic relationships between Au. burti and Au. minor reduce the reliability of this conclusion. On the other hand, on the basis of the obtained sequences, supplemented with previously published data, the metacercariae of Cotylurus detected in leeches were identified as two species: C. strigeoides Dubois, 1958 and C. syrius Dubois, 1934. This is the first record of C. syrius from the intermediate host. Conclusions The results of this study suggest the separation of ecological niches and life cycles between C. cornutus (Rudolphi, 1808) and C. strigeoides/C. syrius, with potential serious evolutionary consequences for a wide range of host–parasite relationships. Moreover, phylogenetic analyses corroborated the polyphyletic character of C. syrius, the unclear status of C. cornutus and the separate position of Cotylurus raabei Bezubik, 1958 within Cotylurus. The data demonstrate the inconsistent taxonomic status of the sequenced tetracotyle of Australapatemon, resulting, in our opinion, from the limited availability of fully reliable, comparative sequences of related taxa in GenBank.

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.

Shark Nursery Grounds of the Gulf of Mexico and the East Coast Waters of the United States

2007 ◽  
Keyword(s):  
United States ◽  
Gulf Of Mexico ◽  
East Coast ◽  
Gulf Coast ◽  
Atlantic Coast ◽  
The United States ◽  
Shark Species ◽  
Carcharhinus Plumbeus ◽  
Nursery Areas ◽  
Pesticide Metabolites

<em>Abstract.</em>—Because of their tendency to accumulate in estuaries and coastal regions, organochlorine (OC) contaminants such as pesticides and polychlorinated biphenyls (PCBs) represent potential threats to the quality of essential fish habitat for many shark species. These compounds pose special risks to immature sharks in particular because of their ability to impair growth and sexual maturation in juvenile fish at environmentally relevant levels of exposure. In order to assess the extent of these risks in shark populations on the East Coast of the United States, the present study examined concentrations of 30 OC pesticides/pesticide metabolites and total PCBs in juvenile sandbar <em>Carcharhinus plumbeus </em>and blacktip <em>C. limbatus </em>sharks from seven major nursery areas in the western Atlantic Ocean and eastern Gulf of Mexico. Quantifiable levels of PCBs and 13 OC pesticides/ pesticide metabolites were detected via gas chromatography and mass spectrometry in liver of 25 young-of-the-year blacktip sharks from the southeastern U.S. Atlantic coast and three regions on Florida’s gulf coast: Cedar Key, Tampa Bay, and Charlotte Harbor. Similarly, quantifiable levels of PCBs and 14 OC pesticides/metabolites were detected in 23 juvenile <em>C. plumbeus </em>from three sites on the northeastern U.S. coast: middle Delaware Bay, lower Chesapeake Bay, and Virginia’s eastern shore. Liver OC concentrations in Atlantic sandbar and blacktip sharks were higher than expected and, in some cases, comparable with elevated levels observed in deep-sea and pelagic sharks. Although significantly lower than those observed in Atlantic sharks, pesticide and PCB levels in Florida blacktip sharks were similar to, if not greater than, OC concentrations reported in adults of other coastal shark species. Based on these data, OC contamination appears to pose significant threats to habitat quality in sandbar and blacktip shark nursery areas on the U.S. Atlantic coast.

Host and geographic distribution of Skrjabinoclava spp. (Nematoda: Acuarioidea) in Nearctic shorebirds (Aves: Charadriiformes), and evidence for transmission in marine habitats in staging and wintering areas

1990 ◽  
Vol 68 (12) ◽  
pp. 2539-2552 ◽  
Author(s):  
P. L. Wong ◽  
R. C. Anderson
Keyword(s):  
Gulf Of Mexico ◽  
Pacific Coast ◽  
The United States ◽  
Larval Stages ◽  
Marine Habitats ◽  
The Pacific ◽  
Southern Alberta ◽  
Wintering Areas ◽  
Charadrius Wilsonia ◽  
Charadrius Semipalmatus

Twelve species of shorebirds belonging to the families Charadriidae (N = 3) and Scolopacidae (N = 9) were infected with 11 species of Skrjabinoclava and there was little overlap of parasites between these two families of birds. Most Skrjabinoclava spp. are transmitted apparently in marine staging and (or) wintering areas of their hosts, as indicated by the presence of larval stages of six species. There was no evidence that transmission occurs on the breeding grounds in freshwater habitats. Skrjabinoclava tupacincai, found predominantly in sanderlings (Calidris alba (Pallas)), is transmitted on the Pacific (Washington, California, Chile) and Atlantic coasts (New Jersey) in winter and the Gulf of Mexico (Florida and Texas) in winter and spring. Skrjabinoclava myersi was found, with a single exception, only in sanderlings, and transmission is apparently restricted to coastal Washington and California in winter. Skrjabinoclava bakeri, found predominantly in western sandpipers (Calidris mauri Cabanis), is transmitted on the Pacific coast (California) and in the Gulf of Mexico in winter. Skrjabinoclava morrisoni and Skrjabinoclava pusillae were found mainly in semipalmated sandpipers (Calidrispusilla (L.)). Both parasites are transmitted in the Gulf of Mexico in spring, but S. morrisoni is also transmitted in the Bay of Fundy in fall. Skrjabinoclava inornatae, found mainly in willets (Catoptrophorus semipalmatus (Gmelin)), is transmitted in Louisiana, Texas, and Peru in winter. Skrjabinoclava kritscheri was found only in marbled godwits (Limosafedoa (L.)), and it is suggested that infected birds collected in southern Alberta in spring acquired their infections while wintering along the Pacific coast of the United States. Skrjabinoclava hartwichi, found in black turnstones (Arenaria melanocephala (Vigors)) wintering in California and ruddy turnstones (Arenaria interpres (L.)) wintering in Peru, is transmitted along the Pacific coast of North America. Skrjabinoclava semipalmatae was found in semipalmated plovers (Charadrius semipalmatus Bonaparte) wintering in California. Skrjabinoclava wilsoniae was found in Wilson's plover (Charadrius wilsonia Ord) wintering in Texas and in a black-bellied plover (Pluvialis squatarola (L.)) migrating through southern Alberta in spring. Skrjabinoclava bartlettae was found in black-bellied plovers collected in southern Alberta in spring and Louisiana in winter.

Life cycles of species of Proteocephalus, parasites of fishes in the Palearctic Region: a review

1999 ◽  
Vol 73 (1) ◽  
pp. 1-19 ◽  
Author(s):  
T. Scholz
Keyword(s):  
Intermediate Host ◽  
Body Cavity ◽  
Life Cycles ◽  
The Body ◽  
Individual Species ◽  
Intermediate Hosts ◽  
Palearctic Region ◽  
Second Intermediate Host ◽  
Planktonic Crustaceans ◽  
Fish Hosts

The life cycles of species of Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidea) parasitizing fishes in the Palearctic Region are reviewed on the basis of literary data and personal experimental observations, with special attention being paid to the development within the intermediate and definitive hosts. Planktonic crustaceans, diaptomid or cyclopid copepods (Copepoda), serve as the only intermediate hosts of all Proteocephalus species considered. A metacestode, or procercoid, develops in the body cavity of these planktonic crustaceans and the definitive host, a fish, becomes infected directly after consuming them. No previous reports of the parenteral location of metacestodes within the second intermediate host as it is in the Nearctic species P. ambloplitis have been recorded. Thus, the life cycles of Proteocephalus tapeworms resemble in their general patterns those of some pseudophyllidean cestodes such as Eubothrium or Bothriocephalus, differing from the latter in the presence of a floating eggs instead of possessing an operculate egg from which a ciliated, freely swimming larva, a coracidium, is liberated. The scolex of Proteocephalus is already formed at the stage of the procercoid within the copepod intermediate host; in this feature, proteocephalideans resemble caryophyllidean rather than pseudophyllidean cestodes. The morphology of procercoids of individual species is described with respect to the possibility of their differentiation and data on the spectrum of intermediate hosts are summarized. Procercoids of most taxa have a cercomer, which does not contain embryonic hooks in contrast to most pseudophyllidean cestodes. The role of invertebrates (alder-fly larvae — Megaloptera) and small prey fishes feeding upon plankton in the transmission of Proteocephalus tapeworms still remains unclear but these hosts are likely to occur in the life cycle. Data on the establishment of procercoids in definitive hosts, morphogenesis of tapeworms within fish hosts, and the length of the prepatent period are still scarce and new observations are needed. Whereas extensive information exists on the development of P. longicollis (syns. P. exiguus and P. neglectus), almost no data are available on the ontogeny of other taxa, in particular those occurring in brackish waters (P. gobiorum, P. tetrastomus). The morphology of P. cernuae and P. osculatus procercoids from experimentally infected intermediate hosts is described for the first time.

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.

Pan-American marine coastal distribution of the acanthocephalan Profilicollis altmani based on morphometric and phylogenetic analyses of cystacanths from the mole crab Emerita brasiliensis

2016 ◽  
Vol 91 (3) ◽  
pp. 371-375 ◽  
Author(s):  
S.M. Rodríguez ◽  
G. D'Elía
Keyword(s):  
Phylogenetic Analyses ◽  
Atlantic Coast ◽  
Life Cycles ◽  
Morphological Evidence ◽  
South American ◽  
Intermediate Hosts ◽  
Complex Life Cycles ◽  
Present Complex ◽  
The World ◽  
Pan American

AbstractThorny-headed acanthocephalan worms of the genus Profilicollis are widely distributed in the oceans of the world and present complex life cycles with intermediate and definitive hosts. The genus is still poorly known, with an unstable taxonomy and, for most species, incompletely characterized geographical distributions. In this study, based on molecular and morphological evidence, we report that the species Profilicollis altmani is also distributed along the South American Atlantic coast, using the mole crab Emerita brasiliensis as an intermediate host. As such, our record shows that P. altmani has a Pan-American distribution where five species of Emerita are utilized as intermediate hosts.

Helminths and the transmammary route of infection

Parasitology ◽  
1981 ◽  
Vol 82 (2) ◽  
pp. 335-342 ◽  
Author(s):  
Grover C. Miller
Keyword(s):  
Mammary Glands ◽  
Life Cycles ◽  
Helminth Parasites ◽  
Intermediate Hosts ◽  
Sweet Potatoes ◽  
Infected Female ◽  
Larval Stages ◽  
Route Of Infection ◽  
Lactating Mammary Gland ◽  
Major Route

SUMMARYThe transfer of infective larval stages of helminths via the mammary glands is probably more common than generally recognized. Recent investigations of both natural and experimental infections of various animals have shown that the transmammary transmission of some helminths is a major avenue of infection. Other studies indicate that there are at least 13 helminth parasites which may be transmitted as prenatal infections and at least 17 transmitted via the mammary glands. The majority of these are nematodes. However, in one case the tetrathyridia of the cestode Mesocestoides was observed. In this report the life-cycle and transmission of 2 species of diplostomatid trematodes in the genus Pharyngostomoides is described. The raccoon, Procyon lotor, is the only definitive host; a planorbid snail, Menetus dilatatus, and a branchiobdellid annelid, Cambarincola osceola, a commensal on crayfishes, are intermediate hosts. Records for a period of 11 years are now available for the maternal transmission and longevity of this trematode. During this time one infected female raccoon was maintained in the laboratory on a diet of commercial dog food, sweet potatoes and corn. She produced 25 offspring, most of which were infected with Pharyngostomoides, through the 6th litter. There was a declining number of worms in each litter, ranging from nearly 2000 in one of the 1st litter, to none in the 7th litter. After nearly 12 years she continues to pass a few trematode ova. Rather than assume she has retained the same adult worms for 12 years, it is reasonable to conclude that mesocercariae move through her body and eventually mature in the intestine. Because the mesocercariae have a predilection for the lactating mammary gland, it seems likely that a hormonal influence is present. The transmammary transmission of larvae is a viable alternative in the life-cycles of a number of helminths, and in some instances it is probably the major route of infection.

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