A further revision in the classification of the family Metastrongylidae Leiper [1909] (Phylum Nematoda)

Parasitology ◽  
1951 ◽  
Vol 41 (1-2) ◽  
pp. 91-96 ◽  
Author(s):  
Ellsworth C. Dougherty
Keyword(s):  
Chromosome Number ◽  
Intermediate Host ◽  
Life Cycles ◽  
The Body ◽  
Basic Pattern ◽  
Histological Studies ◽  
Evolutionary Scheme ◽  
The Family ◽  
Marine Littoral

1. Recent studies by Gerichter have demonstrated that I have erred in referring the skrjabingylin lungworms to the family Trichostrongylidae.2. On the basis of his data and a re-evaluation of my theories of metastrongylid evolution it is suggested that the Skrjabingylinae (except Dictyocaulus) are close to the Filaroidinae and that quite possibly the position of the vulva in the former is the consequence of a secondary shift from opening just anterior to the anus to opening in the mid-region of the body; the ‘trichostrongylid’ configuration of the ovejectoral apparatus would thus be convergent.3. The genus Dictyocaulus is removed from the Skrjabingylinae and left in a subfamily Dictyocaulinae in the family Metastrongylidae, although its trichostrongylid affinities are very suggestive. If trichostrongylid, this genus is considered to exhibit convergence with the metastrongylids and not to represent an evolutionary link between the two families.4. The nature of metastrongylid life cycles is discussed, and the compatibility of known data with the evolutionary scheme proposed for the family is pointed out. It is evident that in metastrongylids symbiotizing marine littoral and pelagic hosts (Pinnipedia and Odontoceti) larval development must rely upon new intermediate host groups if the basic pattern has been retained from ancestors in terrestrial hosts.5. The possible importance of histological studies and of investigations on chromosome number and structure for a further understanding of the evolution of the suborder Strongylina is pointed out.6. A revised scheme for the evolution of the Metastrongylidae is presented as Fig. 1. The family Metastrongylidae now includes six subfamilies: Metastrongylinae, Filaroidinae, Skrjabingylinae, Pseudaliinae, Protostrongylinae, and Dictyocaulinae. The basic premises previously expressed (Dougherty, 1949b) on the evolution of the family are retained in the amended scheme.

The Life Cycles of Dipetalonematid Nematodes (Filarioidea, Dipetalonematidae): The Problem of Their Evolution

1957 ◽  
Vol 31 (4) ◽  
pp. 203-224 ◽  
Author(s):  
Roy C. Anderson
Keyword(s):  
Life Cycle ◽  
Skin Lesion ◽  
Intermediate Host ◽  
Definitive Host ◽  
Life Cycles ◽  
The Body ◽  
Intermediate Hosts ◽  
Cutaneous Lesions ◽  
The Family ◽  
Subcutaneous Tissues

The evolution of the life cycles of the members of the family Dipetalonematiidae Wehr, 1935 (Filarioidea) is considered in the light of existing knowledge of spirurid nematodes. The hypothesis that the life cycles of the dipetalonematids originated from life cycles similar to those of Draschia megastoma, Habronema muscae and H. microstoma is considered to be incorrect. Alternatively, it is pointed out that in the primitive subfamily Thelaziinae Baylis and Daubney, 1926 there are forms with typical spiruroid life cycles (Rhabdochona ovifilamenta), forms with life cycles approaching those of the dipetalonematids (Thelazia spp.), and forms with life cycles intermediate between these two (Oxyspirura spp.). It is suggested that intestinal species similar to Rhabdochona gave rise to the more specialized spiruroids and forms that left the gut (Oxyspirura, Thelazia) gave rise to the dipetalonematids.The dipetalonematids are believed to have originated from nematodes resembling the species of Thelazia and having life cycles like those of T. rhodesii, T. skrjabini and T. gulosa. Some of these worms established themselves in subcutaneous tissues. Like Parafilaria multipapillosa, they released their eggs through a break in the skin of the definitive host, thus causing a skin lesion that attracted various haematophagous arthropods which finally became involved as intermediate hosts in the life cycle. Certain species like the members of Parafilaria and Stephanofilaria (?) came to rely upon intermediate hosts that were unable to break the skin of the definitive host (Musca) and cutaneous lesions became permanent features of their life cycles. Other species became dependent upon intermediate hosts that could puncture the skin (mosquitoes, simuliids etc.) and skin lesions became unnecessary to the life cycle. The larvae of these worms then began to spread into the tissues of the skin, as found in Stephanofilaria, Onchocerca, and some species of Dipetalonema, and the infective larvae developed the ability to penetrate into the wound made by the intermediate host and perhaps, in some cases, the intact skin. Ultimately the larvae of some species habitually entered, or were deposited into, the blood stream and the adult worms were then free to colonize the vertebrate body as their larvae would then be available to the intermediate host no matter where the latter fed on the body of the definitive host; this group of worms gave rise to the many members of the family Dipetalonematidae.The family Filariidae Claus, 1883 is briefly reviewed in the light of the above hypothesis. It is pointed out that many species, e.g. Diplotriaeninae Skrjabin, 1916, live in the air sacs of reptiles and birds and probably have life cycles similar to that of Diplotriaenoides translucidus, i.e. the eggs pass through the lungs, up the trachea and out in the faeces. It is thought that these forms may represent a separate line of evolution from that which gave rise to the Dipetalonematidae. Certain genera (Lissonema, Aprocta), occurring in the orbits of birds, probably have life cycles like Thelazia or Oxyspirura. Many other genera occurring in superficial muscles and subcutaneous tissues (Squamofilaria, Ularofilaria, Tetracheilonema, Pelecitus, Monopetalonema) may release their eggs through some sort of skin lesion. Studies on these forms are urgently needed as the details of their life cycles may shed fresh light on the origins of the more specialized filarioids.

Three new species, two new genera, and new family Biphragmosagittidae (Сhaetognatha) from Southwest Pacific Ocean

2011 ◽  
Vol 20 (1) ◽  
pp. 161-173
Author(s):  
A.P. Kassatkina
Keyword(s):  
New Species ◽  
Type Species ◽  
Morphological Characters ◽  
The Body ◽  
New Order ◽  
New Genera ◽  
New Family ◽  
The Family ◽  
Three New Species

Resuming published and own data, a revision of classification of Chaetognatha is presented. The family Sagittidae Claus & Grobben, 1905 is given a rank of subclass, Sagittiones, characterised, in particular, by the presence of two pairs of sac-like gelatinous structures or two pairs of fins. Besides the order Aphragmophora Tokioka, 1965, it contains the new order Biphragmosagittiformes ord. nov., which is a unique group of Chaetognatha with an unusual combination of morphological characters: the transverse muscles present in both the trunk and the tail sections of the body; the seminal vesicles simple, without internal complex compartments; the presence of two pairs of lateral fins. The only family assigned to the new order, Biphragmosagittidae fam. nov., contains two genera. Diagnoses of the two new genera, Biphragmosagitta gen. nov. (type species B. tarasovi sp. nov. and B. angusticephala sp. nov.) and Biphragmofastigata gen. nov. (type species B. fastigata sp. nov.), detailed descriptions and pictures of the three new species are presented.

New data on life cycles for three species of Fellodistomidae (Digenea) in the White Sea

2020 ◽  
Vol 94 ◽  
Author(s):  
D. Krupenko ◽  
A. Uryadova ◽  
A. Gonchar ◽  
G. Kremnev ◽  
V. Krapivin
Keyword(s):  
Intermediate Host ◽  
White Sea ◽  
Taxonomic Status ◽  
Life Cycles ◽  
The White Sea ◽  
Arctic Seas ◽  
Buccinum Undatum ◽  
The Family ◽  
Second Intermediate Host ◽  
First Time

Abstract Few digeneans of the family Fellodistomidae are known from the Russian Arctic seas. The taxonomic status of these species, their life cycles and host range raised recurrent questions, some of which remain unanswered. To revise the species composition and life cycles of fellodistomids in the White Sea, we searched for them in several known and suspected hosts: wolffish, flatfishes (definitive), gastropods of the family Buccinidae (second intermediate) and protobranch bivalves (first intermediate). Species identification was based both on morphology and 28S ribosomal RNA gene sequences. We found Fellodistomum agnotum in the White Sea for the first time. Buccinum undatum was proved to be intermediate host of both F. agnotum and Fellodistomum fellis, and metacercariae of F. fellis were registered from two more buccinid species: Buccinum scalariforme and Neptunea despecta. We also found metacercariae of F. agnotum and F. fellis producing eggs in the second intermediate host. Two fellodistomids were found in protobranch bivalves: sporocysts and cercariae of Steringophorus furciger in Nuculana pernula, and sporocysts with large furcocercous cercariae in Ennucula tenuis. The latter were identified as F. agnotum by molecular analysis; thus, the entire life cycle of this species was reconstructed.

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.

Orientocreadium elegans n. sp. and Orientocreadium pseudobagri Yamaguti (Digenea: Orientocreadiidae), from freshwater fish of the Primorsky region (southern far east, Russia) with a description of their life cycles

Zootaxa ◽  
2009 ◽  
Vol 2176 (1) ◽  
pp. 22-32
Author(s):  
VLADIMIR V. BESPROZVANNYKH ◽  
ALEXEY V. ERMOLENKO ◽  
MARTY R DEVENEY
Keyword(s):  
Intermediate Host ◽  
Freshwater Fish ◽  
Ventral Sucker ◽  
Far East ◽  
Life Cycles ◽  
The Body ◽  
Trematode Species ◽  
Pelteobagrus Fulvidraco ◽  
Amur Sleeper ◽  
Yellow Catfish

Until recently only one species from the genus Orientocreadium was recorded from the southern part of the Primorye Region, far eastern Russia: O. pseudobagri Yamaguti. A new species, Orientocreadium elegans n. sp., was found recently in the yellow catfish, Pelteobagrus fulvidraco in rivers running into Khanka Lake and in the Arsenjevka River (part of the Ussuri River basin). It is distinguished from other species of Orientocreadium by possessing a body that is longer and narrower than Orientocreadium pseudobagri and shorter and narrower than Orientocreadium siluri and Orientocreadium chaenogobii. The suckers of O. elegans n. sp. are smaller than those of all other species of Orientocreadium and the pharynx is smaller than those of O. siluri and O. chaenogobii. Orientocreadium elegans n. sp. has spines on the cirrus and inside the metraterm and has the ovary in the posterior half of the body, differentiating it from O. siluri. Orientocreadiium elegans n. sp. has a cirrus sac that lies on the median line of the body dorsal to the ventral sucker, whereas the cirrus sac of O. pseudobagri passes laterally around the ventral sucker. Both trematode species use Lymnaea spp. snails as their first intermediate host, and tadpoles, freshwater fish and snails as the second intermediate host. The following fish have been recorded as definitive hosts in this region: the Amur sleeper, Perccottus glehni and P. fulvidraco for O. pseudobagri, and P. fulvidraco for O. elegans n. sp.

scholarly journals NOTES ON THRIPIDÆ, WITH DESCRIPTIONS OF NEW SPECIES

1883 ◽  
Vol 15 (8) ◽  
pp. 151-156 ◽  
Author(s):  
Herbert Osborn
Keyword(s):  
New Species ◽  
Food Habits ◽  
Native Species ◽  
The Body ◽  
The Family

The family Thripidæ, though possessing many characters of peculiar interest, and being of no little importance economically, has received but very little attention from American Entomologists, either systematic or economic. With the exception of a few notes upon their habits, and descriptions of some four or five species by Dr. Fitch, and also a few notes by Mr. Walsh and Prof. Riley, concerning their food habits, scarcely anything has been written of our native species.Without going into a discussion of the classification of the group, or the peculiar characters which seem to ally it to different orders, it will be sufficient here to state that the wings are entirely membranous and folded flat upon the back, which, with the general conformation of the body, would seem to place it with the Homopterous division of the Hemiptera. The mouth parts, however, are free, composed of both mandibles and maxillæ, and the maxillæ and labium are palpigerous—characters very diverse from those of the group just mentioned.

Ontogenesis, morphology and higher classification of archaeococcids (Homoptera: Coccinea: Orthezioidea)

2018 ◽  
pp. 1-260
Author(s):  
I.A. Gavrilov-Zimin
Keyword(s):  
Scale Insect ◽  
Life Cycles ◽  
Individual Development ◽  
Scale Insects ◽  
Original Research ◽  
Traditional Concept ◽  
The Family ◽  
Generic Composition ◽  
Reproduction Pattern

The monograph summarizes original research data and published literature data on reproduction, life cycles, individual development and morphology of scale insects of the superfamily Orthezioidea (archaeococcids). The superfamily system is accepted mainly in its traditional concept, i.e. with four well-defined families: Margarodidae s. l., Ortheziidae, Carayonemidae, and Phenacoleachiidae. The tribe Matsucoccini (Margarodidae s. l.: Xylococcinae s. l.) is considered as a most archaic group of scale insects according to morphological, reproductive and ontogenetic characters. A complicated ontogenesis with an alternation of movable/immovable instars and with arostrate imago of both sexes (as in Matsucoccus Cockerell, 1909 and many other Margarodidae s. l.) is presumed to be initial in scale insect evolution and such ontogenesis is supposed to be an apomorphy of suborder Coccinea. Distribution of different variants of ovoviviparity/viviparity amongst scale insect families is overviewed. It is demonstrated that the evolution of scale insects shows multiple cyclic conversions of oviparous reproduction pattern to ovoviviparous/viviparous ones with the appearance of new and new peculiar adaptations to eggs protection; the most ancient scale insects (Matsucoccini and their ancestor) were probably facultatively ovoviviparous, whereas the origin of the whole neococcid phylogenetic line (Coccoidea s. s.) was probably connected with obligate complete ovoviviparity, which also appeared in some “derived” archaeococcids of the tribe Iceryini (Margarodidae s. l.), in the families Phenacoleachiidae and Carayonemidae. New taxonomic additions and changes in generic composition of some tribes are provided for the family Margarodidae s. l., in its subfamilies Monophlebinae and Callipappinae s. l. The tribe Labioproctini tr. nov. (Monophlebinae) is erected for six genera possessing peculiar quadrilocular wax pores: Aspidoproctus Newstead, 1901, Hemaspidoproctus Morrison, 1927, Labioproctus Green, 1922, Lecaniodrosicha Takahashi, 1930, Misracoccus Rao, 1950, and Walkeriana Signoret, 1876. The presence of quadrilocular pores are considered as a synapomorphic character of the Labioproctini tr. nov. and Ortheziidae. Disputable taxonomic position of Xenococcidae Tang, 1992 is discussed and this family is also placed in Orthezioidea. New genera and species are described and illustrated, based mainly on material collected in the Oriental region: Eremostoma klugei gen. et sp. nov., Crambostoma largecicatricosum gen. et sp. nov. (both in Callipappinae s. l.: Coelostomidiini s. l.), Buchnericoccus reynei sp. nov., Monophlebus neglectus sp. nov. (both in Monophlebinae: Monophlebini), Crypticerya ovivivipara sp. nov., Icerya oculicicatricata sp. nov., I. siamensis sp. nov. (all three in Monophlebinae: Iceryini).

Lafoeina amirantensis (Cnidaria: Hydrozoa, Campanulinoidea), the hydroid stage of the medusa Cirrholovenia tetranema (Cnidaria: Hydrozoa, Lovenelloidea)

Zootaxa ◽  
2005 ◽  
Vol 919 (1) ◽  
pp. 1 ◽  
Author(s):  
ALVARO E. MIGOTTO ◽  
ANDRÉ S. CABRAL
Keyword(s):  
Life History ◽  
Sao Paulo ◽  
Life Cycles ◽  
Important Method ◽  
Constituent Species ◽  
The Family ◽  
Polyp Stage ◽  
The Many ◽  
Species Being

The metagenetic Lafoeina is one of the many leptothecate genera with uncertain affinities, the life cycles of its constituent species being poorly known. The genus has traditionally been recognized as belonging to the polyphyletic superfamily Campanulinoidea, family Campanulinidae, taxa that artificially group together a variety of probably unrelated species. Life-history studies are the most important method to link species that were originally based solely on medusa or polyp stage, as is the case of Lafoeina spp. Findings of Lafoeina amirantensis at the coast of São Sebastião (São Paulo, Brazil) allowed us to study its juvenile medusa and to observe new facts pertinent to the classification of the Order Leptothecata. The hydrotheca of L. amirantensis is similar to those of the genus Cuspidella, except for the absence of nematophores in the latter. The newly released medusa of L. amirantensis is similar in morphology to the young medusae of Cirrholovenia tetranema, a species belonging to the family Cirrholoveniidae (superfamily Lovenelloidea).

scholarly journals VICTOR: Genome-based Phylogeny and Classification of Prokaryotic Viruses

2017 ◽  
Author(s):  
Jan P. Meier-Kolthof ◽  
Markus Göker
Keyword(s):  
Sequence Divergence ◽  
Life Cycles ◽  
Bacterial Strains ◽  
Data Set ◽  
Archaeal Viruses ◽  
Serious Infections ◽  
The Family ◽  
Branch Support ◽  
The Common

AbstractBacterial and archaeal viruses (“phages”) play an enormous role in global life cycles and have recently regained importance as therapeutic agents to fight serious infections by multi-resistant bacterial strains. Nevertheless, taxonomic classification of phages is up to now only insufficiently informed by genome sequencing. Despite thousands of publicly available phage genomes, it still needs to be investigated how this wealth of information can be used for the fast, universal and accurate classification of phages. The Genome BLAST Distance Phylogeny (GBDP) approach is a truly whole-genome method currently used forin silicoDNA: DNA hybridization and phylogenetic inference from prokaryotic genomes. Based on the principles of phylogenetic systematics, we here established GBDP for phage phylogeny and classification, using the common subset of genome-sequenced and officially classified phages. Trees inferred with the best GBDP variants showed only few deviations from the official phage classification, which were uniformly due to incorrectly annotated GenBank entries. Except for low resolution at the family level, the majority of taxa was well supported as monophyletic. Clustering genome sequences with distance thresholds optimized for the agreement with the classification turned out to be phylogenetically reasonable. Accordingly modifying genera and species is taxonomically optional but would yield more uniform sequence divergence as well as stronger branch support. Analysing an expanded data set containing > 4000 phage genomes from public databases allowed for extrapolating regarding the number, composition and host specificity of future phage taxa. The selected methods are implemented in an easy-to-use web service “VICTOR” freely available athttp://ggdc.dsmz.de/victor.php.

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