Development of Skrjabinocerca prima (Nematoda: Acuarioidea) in Hyalella azteca (Amphipoda) and Recurvirostra americana (Aves: Charadriiformes), with comments on its precocity

1989 ◽  
Vol 67 (12) ◽  
pp. 2883-2892 ◽  
Author(s):  
Cheryl M. Bartlett ◽  
R. C. Anderson ◽  
P. L. Wong

Skrjabinocerca prima Shikhobalova, 1930 developed to the infective third stage in 40 days in Hyalella azteca (Saussure) maintained at 21 °C. Infective larvae occur free in the haemocoel and may impede the amphipod's motility because they lie semirigid and parallel to the longitudinal axis in the posterior abdominal segments. The genital primordium in infective-stage males was 200–520 μm long (averaging 19% of body length) and in females 860–1175 μm (averaging 42% of body length). This is unusually large, even compared with other acuarioids in which precocial development of the third-stage genital primordium is known. Additional evidence is provided for the hypothesis that precocity in nematodes is related to rapid maturity in the final host; in experimentally infected American Avocets (Recurvirostra americana Gmelin), moulting third-stage S. prima were found 2 days postinfection and moulting fourth stage at 4 days. Female nematodes contained embryonated eggs at 7 days; eggs in females became larvated between 10 and 18 days postinfection. In birds, the heads of larval and adult nematodes were attached to the mucosa of the buccal cavity or the upper third of the oesophagus, and adults provoked chronic inflammation in the form of yellow plaques. Worms are able to detach and reattach. Third-stage S. prima given to Marbled Godwits (Limosa fedoa (L.)) and Western Willets (Catoptrophorus semipalmatus inornatus (Brewster)) developed to maturity; the parasite has not been reported from the former species in the wild.

1975 ◽  
Vol 53 (2) ◽  
pp. 105-113 ◽  
Author(s):  
Vincent Frederick Joseph Crichton ◽  
Mary Beverley-Burton

Larvae of Dracunculus insignis developed to the infective stage in experimentally infected Cyclops vernalis and C. bicuspidatus thomasi kept at 24 C. The first molt occurred at 8–9 days and the second at 13–16 days. Second- and third-stage larvae are briefly described. Infective larvae were administered to raccoon (Procyon lotor) and mink (Mustela vison) and necropsies were performed at predetermined intervals for the determination of the migratory route. In raccoon, third-stage larvae were recovered from the gut wall and mesentery of the abdominal cavity on the 1st day. Larvae were found in the intercostal muscles by the 5th day and in the subcutaneous tissue of the thorax and abdomen by the 7th day. Development to fourth stage was complete by the 19th day. Sexual differences were apparent by the 34th day and worms were present in subcutaneous tissue of the thorax, abdomen, and inguinal region. Male worms were mature at 60 days and females at 65–70 days. Larvigerous females were found in the extremities as early as 120 days post infection. The prepatent period was 354 (309–410) days. Similar results were obtained from mink. Quantitative data on the distribution of worms in various locations within the final host at different times after infection are included.


Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 921
Author(s):  
Damber Bista ◽  
Sonam Tashi Lama ◽  
Janno Weerman ◽  
Ang Phuri Sherpa ◽  
Purushotam Pandey ◽  
...  

It is sometimes essential to have an animal in the hand to study some of their ecological and biological characteristics. However, capturing a solitary, cryptic, elusive arboreal species such as the red panda in the wild is challenging. We developed and successfully tested a protocol for tracking, trapping, immobilization, and handling of red pandas in the wild in eastern Nepal. We established a red panda sighting rate of 0.89 panda/day with a capture success rate of 0.6. We trapped and collared one animal in 3.7 days. On average, we took nearly 136 (range 50–317) min to capture an animal after spotting it. Further processing was completed in 38.5 (21–70) min. Before capture, we found it difficult to recognize the sex of the red panda and to differentiate sub-adults above six months from adults. However, body weight, body length, tail length, shoulder height, and chest girth can be used for diagnosis, as these attributes are smaller in sub-adults. Our method is a welfare-friendly way of trapping and handling wild red pandas. We report new morphometric data that could serve as a guide for field identification.


Parasitology ◽  
1971 ◽  
Vol 62 (3) ◽  
pp. 355-360 ◽  
Author(s):  
Kenneth Smith ◽  
Eric Harness

A comparative study was made of defined regions of the alimentary tract of third-stage larvae of T. colubriformis and H. placei. The general organization of the tract was similar in both nematodes. The mouth, buccal cavity and oesophagus were lined with cuticle. Muscle cells, apical cells and gland cells were present in the oesophagus. In both species the gland cells contained secretory granules of similar morphology. The lumen of the intestine was ill-defined and apparently nonfunctional. Dense bodies observed in the intestinal cells differed in the two species.We are grateful to Dr D. W. Brocklesby for his help and advice. We would also like to thank Dr D. L. Lee and Dr W. G. MacMillan for helpful discussions.


Nematology ◽  
2001 ◽  
Vol 3 (6) ◽  
pp. 503-514 ◽  
Author(s):  
Maurice Moens ◽  
Ngoc Chau Nguyen ◽  
Ke Long Phan

AbstractTwo new species of Steinernema (Rhabditida), Steinernema loci sp. n. and S. thanhi sp. n., were isolated from beach soil in Thanhhoa and Hatinh provinces in the northern part of Vietnam. A combination of morphological, morphometric and rDNA-RFLP features indicated the distinctness of both species from other Steinernema spp. Diagnostic characters of Steinernema loci sp. n. include: total body length (896-1072 μm), distance from anterior end to excretory pore (EP = 71-86 μm), tail length (66-83 μm), lateral field in mid-body with eight ridges (nine distinct lines) and rounded, broad and smooth anterior end of the third stage infective juvenile; first generation males were characterised by body width, spicule length and the ratio spicule length : anal body width (SW). Diagnostic characters of Steinernema thanhi sp. n. third stage infective juveniles include: total body length (720-960 μm), EP (68-84 μm), tail length (52-72 μm), lateral field in mid-body with eight ridges (nine distinct lines) and rounded, broad and smooth anterior end. Spicule length, ratio SW and arrangement of genital papillae characterised the first generation males.


1963 ◽  
Vol 37 (4) ◽  
pp. 251-254 ◽  
Author(s):  
M. G. Christie ◽  
J. E. Patterson

A pellet of sheep faeces containing eggs of Haemonchus contortus forms an adequate environment for the development of those eggs to third stage infective larvae, provided that it is kept moist. Observation shows a concentration of developing larvae on the external mucous coat of the pellet. These data suggest that optimum conditions for development would occur when pellets are separated one from another and standing on a water repellent surface, thus presenting the maximum free surface area and minimum opportunity for aggregation and hence of over crowding. The best method of recovering the infective larvae would be one that obtained larvae free from contamination without requiring them to expend energy in separating themselves from the contamination.


1950 ◽  
Vol 1 (3) ◽  
pp. 285 ◽  
Author(s):  
DF Stewart

All antigen was developed to detect circulating antibodies by means of the complement fixation test in sheep infested with Haemonchus contortus and Trichostrongylus spp. Extraction of worm material at 100°C. for 10 minutes was found to be the most satisfactory method for the preparation of antigens. Potent antigens were prepared from young adult H. contortus, from third-stage infective larvae, and from the eggs. Old mature adult H. contortus yielded antigens of low potency. No significant difference was found between the potency of antigens prepared from male and female adult H. contortus collected from the same sheep. Both adult Trichostrongylus spp. and third-stage infective larvae consistently yielded antigens of high potency. No significant difference was found in the results obtained with larval or adult H. contortus antigens, adjusted to the same potency and tested with natural H. contortus antisera. H. contortus and Trichostrongylus spp. absorbed the antiserum to each other. It was shown that a lipid was an essential constituent of the boiled antigen in the complement fixation reaction with natural antisera. Lipid-free antigens from H. contortus failed to react with natural antisera. The lipid was not antigenic when injected into rabbits. The carbohydrate fraction of H. contortus did not fix complement in the presence of natural antisera and was not antigenic when injected into rabbits. The lipid fraction of a variety of nematode parasites reacted with natural antisera to H. contortus infestation. Similar lipid fractions of two species of trematodes did not react with natural antisera to H. contortus infestation. Normal saline suspensions of the lipid-free material from a variety of helminths showed a greater degree of specificity when tested with artificially prepared antisera than did the lipid fractions.


2020 ◽  
Vol 117 (30) ◽  
pp. 17913-17923 ◽  
Author(s):  
Spencer S. Gang ◽  
Michelle L. Castelletto ◽  
Emily Yang ◽  
Felicitas Ruiz ◽  
Taylor M. Brown ◽  
...  

Approximately 800 million people worldwide are infected with one or more species of skin-penetrating nematodes. These parasites persist in the environment as developmentally arrested third-stage infective larvae (iL3s) that navigate toward host-emitted cues, contact host skin, and penetrate the skin. iL3s then reinitiate development inside the host in response to sensory cues, a process called activation. Here, we investigate how chemosensation drives host seeking and activation in skin-penetrating nematodes. We show that the olfactory preferences of iL3s are categorically different from those of free-living adults, which may restrict host seeking to iL3s. The human-parasitic threadwormStrongyloides stercoralisand hookwormAncylostoma ceylanicumhave highly dissimilar olfactory preferences, suggesting that these two species may use distinct strategies to target humans. CRISPR/Cas9-mediated mutagenesis of theS. stercoralis tax-4gene abolishes iL3 attraction to a host-emitted odorant and prevents activation. Our results suggest an important role for chemosensation in iL3 host seeking and infectivity and provide insight into the molecular mechanisms that underlie these processes.


2020 ◽  
Vol 131 (2) ◽  
pp. 449-463
Author(s):  
David N Fisher ◽  
Jonathan N Pruitt ◽  
Justin Yeager

Abstract Extended phenotypes are traits that exist outside the physical body of organisms. Despite their role in the lives of the organisms that express them and other organisms influenced by extended phenotypes, the consistency and covariance with morphological and behavioural traits of extended phenotypes has rarely been evaluated. We repeatedly measured an extended phenotype involved in prey acquisition (web structure) of wild orb-weaving spiders (Micrathena vigorsii), which re-build their webs daily. We related web structure to behaviours and spider body length. Web diameter and web density were repeatable among individuals, reaction to a predation threat was very marginally so, and response to a prey stimulus and web evenness were not repeatable. Larger spiders spun wider webs, had webs with increased thread spacing, and the spider possibly tended to react more slowly to a predation threat. When a spider built a relatively larger web it was also a relatively less dense and less even web. The repeatability of web construction and relationship with spider body size we found may be common features of intra-population variation in web structure in spiders. By estimating the consistency and covariances of extended phenotypes we can begin to evaluate what maintains their variation and how they might evolve.


1994 ◽  
Vol 68 (3) ◽  
pp. 223-229 ◽  
Author(s):  
P. Mendoza-de Gives ◽  
E. Zavaleta-Mejia ◽  
D. Herrera-Rodriguez ◽  
H. Quiróz-Romero

AbstractThe trapping capability of Arthrobotrys oligospora and A. conoides (Hyphomycetales) against third stage larvae (L3) of Haemonchus contortus (Trichostrongylidae) was evaluated in an in vitro trial. Arthrobotrys oligospora showed a 35.87% and 25.71% trapping effectiveness against H. contortus infective larvae at 18 and 25°C, respectively; whereas the trapping capability of A. conoides was 92.17% and 90.40% at the same temperatures, respectively. Microscopic examination demonstrated that A. conoides spontaneously developed a large quantity of three-dimensional loops before the nematodes were added. Neither of the two species studied developed three-dimensional adhesive loops at 30°C, consequently no trapped nematode was observed. In a second trial, the trapping capability of A. conoides against H. contortus (L3) and second stage larvae (J2) of Nacobbus aberrans (Pratylenchidae), was evaluated at 25°C. The trapping capability shown by A. conoides was higher than 90% for both kinds of nematode. The possible use of A. conoides to control ovine haemonchosis is discussed.


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