Topic
Mermithida
About: Mermithida is a research topic. Over the lifetime, 5 publications have been published within this topic receiving 132 citations.
Papers
Journal Article•
TL;DR: Development of the infective stage appears to be an important step toward the acquisition of molluscs as definitive hosts, and the association with specific bacteria may have arisen in conjunction with the evolution of necromeny.
Abstract: Although there are no confirmed fossil records of mollusc parasitic nematodes, diverse associations of more than 108 described nematode species with slugs and snails provide a fertile ground for speculation of how mollusc parasitism evolved in nematodes. Current phylogenic resolution suggests that molluscs have been independently acquired as hosts on a number of occasions. However, molluscs are significant as hosts for only two major groups of nematodes: as intermediate hosts for metastrongyloids and as definitive hosts for a number of rhabditids. Of the 61 species of nematodes known to use molluscs as intermediate hosts, 49 belong to Metastrongyloidea (Order Strongylida); of the 47 species of nematodes that use molluscs as definitive hosts, 33 belong to the Order Rhabditida. Recent phylogenetic hypotheses have been unable to resolve whether metastrongyloids are sister taxa to those rhabditids that use molluscs as definitive hosts. Although most rhabditid nematodes have been reported not to kill their mollusc hosts prior to their reproduction, some species are pathogenic. In fact, infective juveniles of Phasmarhabditis hermaphrodita vector a lethal bacterium into the slug host in which they reproduce. This life cycle is remarkably similar to the entomopathogenic nematodes in the families Steinernematidae and Heterorhabditidae. Also, the discoveries of Alloionema and Pellioditis in slugs are interesting, as these species have been speculated to represent the ancestral forms of the entomopathogenic nematodes. Development of the infective stage appears to be an important step toward the acquisition of molluscs as definitive hosts, and the association with specific bacteria may have arisen in conjunction with the evolution of necromeny.
115 citations
1 Jan 1987
TL;DR: Nematode parasites of spiders can be discussed under two aspects: nematode infections which occur naturally and have been reported in the literature for over a century and a large group which parasitize exclusively invertebrates, especially arthropods.
Abstract: Nematode parasites of spiders can be discussed under two aspects. The first constitutes nematode infections which occur naturally and have been reported in the literature for over a century. All of these reports refer to nematodes of the family Mermithidae (order Mermithida), a large group which parasitize exclusively invertebrates, especially arthropods.
28 citations
1 Jan 1988
TL;DR: Representatives of three groups of nematodes naturally parasitize Chrysomelidae; the Mermithidae of the order Mermithida in the class Adenophorca, the Allantonematidae in the order Tylenchida of the class Secernentea and the Steinernematidac and Hetcrorhabditidac of theOrder Rhabditida inThe class SecERNentea.
Abstract: Representatives of three groups of nematodes naturally parasitize Chrysomelidae; the Mermithidae of the order Mermithida in the class Adenophorca. the Allantonematidae in the order Tylenchida of the class Secernentea and the Steinernematidac and Hetcrorhabditidac of the order Rhabditida in the class Secernentea. Each one of these three groups possesses a distinct life cycle and host parasite relationship which will be covered below. Because of their conspicuous size, members of the family Mermithidae appear to be the first recorded nematode parasites of Chrysomelidae. The earliest of such reports was made by Holten in 1797 when he described Filaria chrysomelae from Agelastica alni in Denmark. Since the description was insufficient, the above name will have to remain ’species inquirenda’. In the 18th century, many mermithids were placed in the collective genus Filaria which has no nomenclatorial status at present. The first discussion of nematode-chrysomelid associations was presented in 1950 by Jolivet and Theodorides. who treated all helminth parasites including hairworms or members of the Phylum Nematomorpha. Superficially, hairworms often resemble mermithids however the former are not nematodes and will not be covered in the present work. Some of the early reports of chrysomelid parasites are difficult to interpret because of this similarity between mermithids and nematomorphs.
14 citations
TL;DR: New morphological features of a moulting juvenile of the Rhaptothyreus genus are described and are consistent with the existence of a parasitic juvenile life stage in the genus.
Abstract: Rhaptothyreus is arguably the most enigmatic nematode taxon due to a combination of unusual morphological features (e.g., large feather-like amphids, vestigial mouth, trophosome, single spicule), unclear phylogenetic relationships (possible affinities with the Enoplida, Mermithida and Benthimermithida) and a distribution restricted to the deep sea. Here I provide the first record of the genus in the Western Pacific Ocean and describe new morphological features of a moulting juvenile. This specimen is characterised by features that differ markedly from the adults, the most prominent being the absence of cephalic sensillae and amphids and presence of a stylet-like structure in the buccal cavity. Similar contrasts in morphology are found between adults and juveniles of the order Benthimermithida, which is characterised by free-living adults and parasitic juveniles. Other morphological (large body size, presence of trophosome) and distributional characteristics (predominantly deep-sea distribution, juveniles rare/absent in sediments) are also common to both groups. Published records show that Rhaptothyreus is commonly found in oligotrophic environments (e.g., abyssal plain) where organisms bearing symbiotic bacteria are not typically found, which makes the presence of endosymbiotic bacteria inside the trophosome unlikely. These observations are consistent with the existence of a parasitic juvenile life stage in Rhaptothyreus .
5 citations
Journal Article•
TL;DR: Nematodes of the new genus are parasites of marine invertebrates unlike mermithids which are parasitic in land and freshwater arthrpods and sometimes in mollusks.
Abstract: A new genus and species of the marine parasitic nematode Abos bathycola gen. et sp. n. are described. The diagnosis of the new order Marimermithida with one family Marimermithidae Rubtzov et Platonova including 6 genera of marine parasitic nematodes is given. The new order resembles the order Mermithida in its extraintestinal feeding but differs from it in the following characters. The mouth, oesophagus, rectum and anus are reduced or absent. The mid-gut is transformed into trophosome, without lumen as a rule. If the lumen is present, no food is traced in the trophosome. The location of rudiments of oesophagus, chords, undeveloped trophosome, rudiments of rectum, if present, is consecutive. Stichosome is absent in contrast to the order Mermithida, in which it is well developed and is located in parallel with trophosome. Nematodes of the new genus are parasites of marine invertebrates unlike mermithids which are parasitic in land and freshwater arthrpods and sometimes in mollusks.
4 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2014 | 1 |
| 2003 | 1 |
| 1988 | 1 |
| 1987 | 1 |
| 1980 | 1 |