Nematomorpha Research Articles

The musculature of horsehair worm larvae ( Gordius aquaticus , Paragordius varius , Nematomorpha): F-actin staining and reconstruction by cLSM and TEM

The musculature of larvae of Gordius aquaticus was investigated by laser-scanning microscopy and compared to transmission electron microscopic data for the larva of Paragordius varius. In the anterior portion of the body, the preseptum, four different muscle groups can be distinguished: (1) 12 anterior parietal muscles in the body wall, (2) six oblique muscles that function as retractors of the introvert, (3) six proboscideal muscles, which function as retractors for the proboscis, and (4) six muscles associated with spines of the outermost of the three rings of spines. The posterior portion of the body, the postseptum, possesses four pairs of longitudinal muscle strands in G. aquaticus, the postseptal parietal muscles, that are located dorsolaterally and ventrolaterally. These are not clearly visible in P. varius, where instead three pairs of parietal muscles are present. Additional small muscles are associated with the terminal spines and with the duct running from the pseudointestine to the body wall. All fibers show a cross-striated pattern although this striation is less obvious at the ends of the fibers.

Are the genera of Nematomorpha monophyletic taxa?

Twenty‐two genera of horsehair worms (Nematomorpha) have been described to date, one (Nectonema) from the marine environment and the remaining ones (taxon Gordiida) from freshwater. The aim of this investigation was to test whether the genera represent monophyletic taxa or are likely to be paraphyletic assemblages. The recognition and delimitation of monophyletic taxa are prerequisites for further systematic analyses. From the 15 nematomorph genera containing more than one species, autapomorphies can be found for five genera (Chordodes, Nectonema, Beatogordius, Acutogordius, Noteochordodes). In three further genera (Paragordius, Parachordodes, Gordionus), the evaluation of characters as autapomorphies is likely, but relies on further investigations. For seven genera (‘Gordius’, ‘Paragordionus’, ‘Euchordodes’, ‘Neochordodes’, ‘Pseudochordodes’, ‘Spinochordodes’, ‘Digordius’), no autapomorphy could be found. Five genera (‘Digordius’, Lanochordodes, Progordius, Pantachordodes, Pseudogordius) are likely to be synonymous with other genera, and one genus (Chordodiolus) has been synonymized with Beatogordius recently. The importance of high quality documentation of characters in investigations of nematomorph species is stressed.

Problems and perspectives in the systematics of Nematomorpha

Problems and perspectives in the systematics of Nematomorpha

Horsehair Worms (Nematomorpha) as Parasites of Praying Mantids with a Discussion of their Life Cycle

Praying mantids (Mantoptera) are the most important hosts of horsehair worms (Nematomorpha) in tropical and subtropical regions worldwide. 82 reports of nematomorph-mantid relationships are reported, 11 of which are new to science. The majority of nematomorph species parasitizing mantids belongs to the genus Chordodes. The life cycle consists of a free-living stage in which copulation and early embryological and larval development take place and parasitic phases in an intermediate and a final host. The intermediate hosts, which are insects with aquatic larvae, serve as vectors between the aquatic and the terrestrial environment. Development can only be completed if the intermediate host is captured and eaten by the final host, praying mantids. Inside the host, the main development of the worms takes place, with a size increase from about 100 m up to several centimeters. The factors influencing emergence from the hosts, which must be established close to water, remain not well understood.

Predation on Horsehair Worms (Phylum Nematomorpha)

ABSTRACT Field observations revealed cases of predation on horsehair worms by brown trout (Salmo trutta) in Maryland and Minnesota, a rock bass (Ambloplites rupestris) in Kentucky, and a crayfish in Wisconsin. Some fish contained more than one worm and may have consumed reproductive aggregations. In laboratory feeding trials with Gordius robustus, most individuals of several fish species either ignored the horsehair worms or rejected them after taking them into their mouths briefly, but a green sunfish (Lepomis cyanellus) consumed both individual worms and a compact ball of 18 worms. A literature review yielded cases of predation on horsehair worms by at least 12 fish species. Horsehair worms usually were only a trace component of the diet, but some individual fish had eaten multiple worms.

External Morphology of Larvae of Chordodes morgani (Nematomorpha)

The surface features of larvae of a gordian worm, Chordodes morgani (Gordioidea), studied by scanning electron microscopy, were compared to those of other larval nematomorphs, until now known only from light microscopical studies. Larvae of C. morgani have a cylindrical body with 22 to 24 superficial segments, superficially divided at an ectodermal septum into a presoma and a trunk with a roughly 90? bend. Papillae are located distally on the proboscis, the base of which is surrounded by circles of spines or scales. Although the major features of the larvae are similar to those known in other species, details visible with SEM hold promise for providing useful diagnostic characters. Additional key words: horsehair worm, gordian worm Several electron microscropical studies have described adult features of gordian worms (e.g., Zapotosky 1971; Eakin & Brandenburger 1974; Chandler & Wells 1989) and others have treated the ultrastructure of larval forms (e.g., Zapotosky 1974, 1975). Less attention has been given to external features of larval forms (e.g., see Hyman 1951; Poinar & Doelman 1974), and such studies to date have been based on light microscopy. Our objective was to examine, using scanning electron microscopy (SEM), the external morphology of larvae of Chordodes morgani in order to document features that might be used as diagnostic characters, and to better understand their biology. Descriptions of adults of Chordodes morgani MONTGOMERY 1898 were augmented and C. morgani synonymized with C. puerilis MONTGOMERY 1898 by Montgomery (1901). Camerano (1915), in his revised monograph on gordian worms, published important diagnostic features characteristic of adults of C. morgani. Chandler (1985) reviewed the taxonomy and distribution of this species in North America.

Horsehair Worms (Phylum Nematomorpha) in Wisconsin, With Notes on Their Occurrence in the Great Lakes

ABSTRACT Wisconsin records for Chordodes morgani, Gordius robustus, and Paragordius varius are summarized. The occurrence of horsehair worms in the Great Lakes Is reviewed. Sexual size differences are demonstrated In G. robustus, with females being significantly longer than males. Skewing of sex ratios in horsehair worm populations is discussed.

A Record of the Horsehair WormNeochordodes occidentalis(Nematomorpha) in the State of Washington

ABSTRACT The horsehair worm Neochordodes occidentalis (Montgomery) is reported from Whitman County, Washington. This is the first record of the phylum Nematomorpha in the state of Washington.

A Record of the Horsehair WormChordodes morgani(Nematomorpha) in Wisconsin

ABSTRACT The horsehair worm Chordodes morgani Montgomery is reported from Shawano County, Wisconsin. This is the first record for this species in Wisconsin. This report fills a gap in the known distribution.

Horsehair Worms (Phylum Nematomorpha) in Lake Michigan

Horsehair worms, Gordius robustus, were collected on four occasions during 3 years along the shore of Lake Michigan in Door County, Wisconsin. These apparently represent the first published records from a Great Lakes environment. Although they are a predictable component of the benthic fauna at the study site, horsehair worms probably do not successfully complete the adult phase of their life cycle in Lake Michigan. Rather, animals found in Lake Michigan probably originate from a population in a more suitable aquatic habitat inland and are transported to the lake during their terrestrial parasitic stage. Within the study area, there are several likely sources for strays that reach Lake Michigan.

Gordius villoti(Nematomorpha) life cycle in relation with caddis fly larvae

Abstract The relationships between Gordius villoti Rosa and Allogamus auricollis Pictet larvae are described. The horsehair worms and host life cycles have been investigated in laboratory and field conditions and aspects of their morphology and behaviour are discussed.

Larval horsehair worms (Nematomorpha) from the tissues of native freshwater fish in New Zealand

Abstract Encysted larval horsehair worms (Phylum Nematomorpha) were recovered from the tissues of upland bullies (Gobiomorphus breviceps) and a galaxiid (Galaxias vulgaris) from the Seaward River, Canterbury. The cysts were mostly in the alimentary submucosa. A few occurred in the liver. An adult digenean fluke (Coitocaecum sp.), parasitic within the gut of a bully, also contained nematomorph larvae in its tissues. It is suggested that the fish became infected by eating nematomorph larvae or egg strings.

The rod-shaped sperm of Gordioidea (Aschelminthes, Nematomorpha)

The spermatozoon of hair worm Gordius panighettensis (Nematomorpha, Gordioidea) has been studied under the electron microscope in the male genital tract. This immotile, rod-like sperm is made up of an acrosomal complex and an elongated nucleus with chromatin condensed in the central part. Both the acrosomal complex and the nucleus are surrounded by vesicular structures varying in complexity. This aberrant spermatozoon appears to have no equivalent in the zoological scale.

NOTES ON THE BIOLOGY AND REARING OF TWO SPECIES OF GROUND BEETLES, PTEROSTICHUS MELANARIUS AND HARPALUS PENSYLVANICUS (COLEOPTERA: CARABIDAE)

AbstractAdult carabid beetles of the species Harpalus pensylvanicus (DeGeer) and Pterostichus melanarius (Illiger) were collected from a cultivated field near London, Ont., and brought into the laboratory for observation and mass culture in terraria; the culture method is described. Both species oviposited successfully in the laboratory; P. melanarius produced as many as 134 eggs/female over a 6-month period, whereas H. pensylvanicus deposited only about 10 eggs/female under similar conditions. However, percentage emergence in Harpalus was substantially higher (62.6) than with Pterostichus (36.8 and 45.7). Large numbers of first- and second-instar P. melanarius larvae may be obtained by using the rearing method described. The low oviposition rate of H. pensylvanicus made large-scale rearing of this species difficult.Observations are made on the mating behaviour and adult parasitization by horsehair worms (Nematomorpha) of Pterostichus.

Ultrastructural features of a Gordian worm (Nematomorpha)

The major tissues of a horsehair worm (Gordius sp., Nematomorpha) were studied by transmission and scanning electron microscopy. The epicuticle is a thin superficial layer whose surface shows rows of polygonal elevations. The cuticle has many layers of cylindrical, nonperiodic collagenous fibers, spirally wound about the long axis of the worm. Alternating layers of fibers cross one another diagonally at angles of approximately 60° and 120°. Additionally there are large radial fibers and strata of small fibers. The epidermis is a single layer of highly interdigitated cells. The musculature consists of overlapping, longitudinally arranged, flat cells, each containing many thick and thin filaments in anteroposterior orientation. Circular muscles are absent. Striated collagenous fibers completely surround the following: the muscle cells, a degenerate gut, a nerve cord composed of neural and glial cells, and mesenchyme that nearly fills the pseudocoel. Functional, developmental, and comparative morphology is discussed.

The Gordiidæ in Folk-lore

THE sudden appearance of the Gordiidae or hair worms in puddles of water or similar situations has caused the primitive peoples of many countries to evolve a theory of their seemingly mysterious origin. In parts of Scotland they are believed to be the intermediate stage in the development of a horse-hair into an eel; in Iceland and the Faeroes, and also in some of the Malayan islands, they are thought to come down with the rain; in the Malay Peninsula they are said to be the offspring of an unnatural union between an earthworm and a female mantis, and to turn into a fern (Lygodium sp.), the creeping rhizome of which some of them (for example, Chorodes montoni, Camer.) closely resemble. (I found that a very large proportion of the true Mantidae were infested by them in the Malay States.) In the same country, by an application of the principle of the doctrine of signatures, they are used in the manufacture of a hair-wash. I have thought that it might be interesting to trace out the beliefs held about them among different races, but I find references to them extremely scanty in ethnographical or general literature. If any of your correspondents could furnish in formation of the kind I would be extremely grateful, for I believe that an interesting contribution to the biological philosophy of savages might be made by collecting and analysing the different theories held by primitive peoples regarding a small and easily recognised group of animals like the Gordiidae.

Synopses of North-American Invertebrates. II. Gordiacea (Hair Worms)

Previous articleNext article FreeSynopses of North-American Invertebrates. II. Gordiacea (Hair Worms)Thomas H. Montgomery, Jr.Thomas H. Montgomery, Jr. Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The American Naturalist Volume 33, Number 392Aug., 1899 Published for The American Society of Naturalists Article DOIhttps://doi.org/10.1086/277381 Views: 119Total views on this site Citations: 6Citations are reported from Crossref PDF download Crossref reports the following articles citing this article: Literature Citations, (Jan 2010): 1022–1194.https://doi.org/10.1016/B978-0-12-374855-3.00027-3George O. Poinar NEMATODA AND NEMATOMORPHA, (Jan 2001): 255–295.https://doi.org/10.1016/B978-012690647-9/50010-7Dreux J. Watermolen, Ginny L. Haen Horsehair Worms (Phylum Nematomorpha) in Wisconsin, With Notes on Their Occurrence in the Great Lakes, Journal of Freshwater Ecology 9, no.11 (Jan 2011): 7–11.https://doi.org/10.1080/02705060.1994.9664421Douglas G. Smith Observations on the morphology and taxonomy of two Parachordodes species (Nematomorpha, Gordioida, Chordodidae) in southern New England (USA), Journal of Zoology 225, no.33 (Mar 2009): 469–480.https://doi.org/10.1111/j.1469-7998.1991.tb03829.xPhilip A. Cochran, Dreux J. Watermolen, Ginny L. Haen Horsehair Worms (Phylum Nematomorpha) in Lake Michigan, Journal of Great Lakes Research 16, no.33 (Jan 1990): 485–487.https://doi.org/10.1016/S0380-1330(90)71440-2G. W. M�ller �ber gordiaceen, Zeitschrift f�r Morphologie und �kologie der Tiere 7, no.1-21-2 (Jan 1926): 134–219.https://doi.org/10.1007/BF00540721

ON MERMIS, A PARASITE OF THE LARVA OF CARPOCAPSA POMONELLA

The interesting paper by Mr. J. A. Lintner, Entom. Contributions, No. iv., induces me to give some extracts from the papers by Prof. von Siebold, which the author could not compare himself, the more as they answer some important questions.“I examined with much interest, in the Museum in Breslau, Prussia, the specimens of hair worms communicated by different persons. Those worms were found living in the heart of the apple some years ago, very frequently in Silesia (by F. S. Leuckart, Zoolog. Bruchstuecke, Heft I., 1820, p. 5). Four of them belong to Mermis acuminata, and others also to Mermis; also a specimen in Prof. Otto's collection. The Filaria found in an apple by Prof. Waga will probably also be a Mermis (Revue Zool.,1844, P. 366).”