Seasonal variability in the gut ultrastructure of the parasitic copepod Neoergasilus japonicus (Copepoda, Poecilostomatoida)

2004 ◽  
Vol 82 (10) ◽  
pp. 1655-1666 ◽  
Author(s):  
A Baud ◽  
C Cuoc ◽  
J Grey ◽  
R Chappaz ◽  
V Alekseev

The gut structure and ultrastructure of Neoergasilus japonicus (Harada, 1930), a copepod from the family Ergasilidae (Copepoda, Poecilostomatoida) and a parasite of fish, were compared at different periods of the life cycle: in free-living specimens in October and after attaching to fish in January and June. Differences in the depth of the intestinal epithelium were prominent and other cellular characteristics appeared seasonally variable. We relate these to changes in the physiological activity. Preliminary data from stable-isotope analyses of attached specimens suggest nutritional contribution from parasitism. The possibility of a diapause in the life cycle, as well as the relationship between the morphology of the gut and early evolutionary parasitism of N. japonicus, are discussed.

Parasitology ◽  
1964 ◽  
Vol 54 (1) ◽  
pp. 1-41 ◽  
Author(s):  
B. L. James

1. Parvatrema homoeotecnum sp.nov. from the oystercatcher, Haematopus ostralegus occidentalis Neumann at Aberystwyth is described and compared with other species of the genus.2. The life cycle of this species is unique. The larval stages occur in the gastropod, Littorina saxatilis (Olivi) subsp. tenebrosa (Montagu) and include germinal sacs which have a structure and development similar to an adult digenean. There are no free-living stages and only one intermediate host.3. The significance of this unique life cycle is discussed.4. The family Gymnophallidae Morozov, 1955, is reviewed. Emended definitions are given for the family, subfamilies and genera. Keys, diagnostic features and brief notes of the species are included.I am very grateful to Dr Gwendolen Rees, who suggested the investigation which led to the discovery of this species, for her advice and indispensable assistance throughout the work and the preparation of this paper. I am also grateful to the late Professor T. A. Stephenson for his interest and for the provision of working facilities; to Mr W. A. Ballantine, Mr A. H. Clarke, Jr., Mr C. Curtis, Miss G. P. F. Evans, Dr V. Fretter, Professor L. A. Harvey, Mr D. H. Jones and Dr J. Lewis who sent me specimens of Littorina saxatilis; to Professor R. M. Cable and Emerit. Professor G. R. La Rue for helpful suggestions; to Mr J. R. Hirst and Mr D. Hemingway Jones for photographic and technical assistance and to the Department of Scientific and Industrial Research for a grant which made the work possible.


2002 ◽  
Vol 76 (3) ◽  
pp. 189-192 ◽  
Author(s):  
F. Audebert ◽  
H. Hoste ◽  
M.C. Durette-Desset

AbstractThe chronology of the life cycle ofTrichostrongylus retortaeformis(Zeder, 1800) (Nematoda, Trichostrongyloidea) is studied in its natural hostOryctolagus cuniculus. The free living period lasted 5 days at 24°C. Worm-free rabbits were each infectedper oswithT. retortaeformislarvae. Rabbits were killed at 12 h post-infection (p.i.) and every day from one day to 13 days p.i. By 12 h p.i., all the larvae were exsheathed and in the small intestine. The third moult occurred between 3 and 5 days p.i. and the last moult between 4 and 7 days p.i. The prepatent period lasted 12 to 13 days. The patent period lasted five and a half months. The four known life cycles of species ofTrichostrongylusin ruminants were compared with that ofT. retortaeformis. No significant difference was found except in the duration of the prepatent period. These similarities in the life cycles confirm the previously formulated hypotheses on the relationship between the parasites of the two host groups ().


Author(s):  
Lucas A Kaminski ◽  
Luis Volkmann ◽  
Curtis J Callaghan ◽  
Philip J DeVries ◽  
Roger Vila

Abstract Mutualistic interactions between butterflies and ants can evolve into complex social parasitism. ‘Cuckoo’ caterpillars, known only in the Lycaenidae, use multimodal mimetic traits to achieve social integration into ant societies. Here, we present the first known ‘cuckoo’ butterfly in the family Riodinidae. Aricoris arenarum remained in taxonomic limbo for > 80 years, relegated to nomen dubium and misidentified as Aricoris gauchoana. We located lost type material, designated lectotypes and documented the morphology and natural history of the immature stages. The multifaceted life cycle of A. arenarum can be summarized in three phases: (1) females lay eggs close to honeydew-producing hemipterans tended by specific Camponotus ants; (2) free-living caterpillars feed on liquids (honeydew and ant regurgitations); and (3) from the third instar onward, the caterpillars are fed and tended by ants as ‘cuckoos’ inside the ant nest. This life cycle is remarkably similar to that of the Asian lycaenid Niphanda fusca, despite divergence 90 Mya. Comparable eco-evolutionary pathways resulted in a suite of ecomorphological homoplasies through the ontogeny. This study shows that convergent interactions can be more important than phylogenetic proximity in shaping functional traits of social parasites.


2000 ◽  
Vol 15 (1) ◽  
pp. 47-75 ◽  
Author(s):  
MASAO TAKAGI

This article examines, on the basis of landholding patterns, the relationship between the peasant family economy and its family life cycle in the latter half of the Tokugawa era (1603–1867). The analysis is focused on the life-cycle patterns of the stem family. In such a system, the continuation of the family and its assets assumed prime importance while hired labour did not provide a substantial proportion of the workforce on the farm. In fact, the stem family was officially recognized as the lawful family form by the Meiji government, but even in earlier periods the stem family system provided the dominant form. Among the samurai it was always the required form. Among the peasantry, by the early eighteenth century the stem family was the predominant family system.The family system observed here differs in structure from that found in western-European family systems. Even when developmental aspects of European households are discussed, it is the relationship between the simple, nuclear family forms and their economic and social correlates – especially poverty, inheritance and landholdings – that is analysed. How Japanese stem family households operated with respect to landholding and other variables is the main theme of this article. The data come from an agrarian and considerably backward area of north-east Japan where harvest failures were not infrequent even in the late eighteenth and early nineteenth centuries.


Parasitology ◽  
1973 ◽  
Vol 67 (3) ◽  
pp. 245-251 ◽  
Author(s):  
Victoria Bryant

The growth of the three free-living stages of N. dubius was measured in terms of dry and fresh weight. Changes in body water content during moulting were demonstrated by variations in dry weight when expressed as a percentage of fresh weight. The respiration rate of the larvae increased until they became infective, after which time it decreased until five days later no oxygen consumption could be recorded. The inability of all larval stages to withstand anaerobic conditions indicated that their metabolism was essentially aerobic. The relationship between body size and metabolic rate was established for each stage and its significance in relation to the life-cycle discussed.


Author(s):  
Agata Zdun-Ryżewska ◽  
Natalia Nadrowska ◽  
Magdalena Błażek ◽  
Katarzyna Białek ◽  
Ewa Zach ◽  
...  

A child’s illness and hospitalization are particularly difficult and most often an unpredictable situation in a family’s life cycle. The level of stress of a parent of a hospitalized child depends on many factors, such as the psychological characteristics of the child and the parent, the child’s health condition, and support from the family and medical staff. Our research aimed to search for interactions between the stress experienced by the parent and the temperamental variables of both the child and the parent, and the support received from the family and hospital staff. Using three pencil-paper questionnaires—PSS, EAS-D, EAS-C—and interview questionnaire, we tested 203 parent–child dyads at the time of children hospitalization. It was revealed that the most notable moderator of the relationship between temperamental traits and the characteristics of the hospital-related situation is the child’s age. When analyzing the situation of a family with a hospitalized child, particular attention should be paid to parental emotional distress, which, regardless of the child’s age, predicts a high level of parental stress.


Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1100
Author(s):  
Victor Alekseev ◽  
Corinne Cuoc ◽  
Dominique Jamet ◽  
Jean-Louis Jamet ◽  
Remi Chappaz

The fish parasite, Neoergasilus japonicus (Harada, 1930), native to Eastern Siberia and the Amur River catchment area, invaded European water bodies in the middle of the last century, possibly due to the human-mediated distribution of fish in the Amur complex (i.e., the genera Hypophthalmichthys and Ctenopharyngodon). In the deep karst lake, Grand Laoucien (Marseille area, France), this species had an unusually high population density (from 1000 ind./ m3 in zooplankton to 4000 ind./ m3 in the nearshore area) during the free-living period of its life cycle. The annual cycle of N. japonicus includes a 5-month overwintering of fertilized females attached to fish fins and, following this, a five- to six-generation chain from March to November, when the free-living stages in the population alternate with parasite females which attach to their hosts for breeding. The population density of the parasites in zooplankton increased exponentially from spring to autumn, which positively correlated with temperature. We found a strong correlation between N. japonicus density and the community development of microphytobenthos, but not between N. japonicus and phyto- or zooplankton dynamics. The local contributing factors included a seasonal three-fold decrease in water levels and the development of anoxia in profundal waters, which led to a high ambient fish density and thus susceptibility to the parasite. Although the free-living parasite represented only 1% of zooplankton production, it consumed up to 25% of small invertebrate productivity. The maximum intensity of infection reached 140 parasites per fish, or 4.14 per g of weight. The high infection of fish with this parasite, in our opinion, indicated the danger it poses to the local ichthyofauna, which first encountered this new parasite.


2013 ◽  
Vol 18 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Isabelle Albert ◽  
Dieter Ferring ◽  
Tom Michels

According to the intergenerational solidarity model, family members who share similar values about family obligations should have a closer relationship and support each other more than families with a lower value consensus. The present study first describes similarities and differences between two family generations (mothers and daughters) with respect to their adherence to family values and, second, examines patterns of relations between intergenerational consensus on family values, affectual solidarity, and functional solidarity in a sample of 51 mother-daughter dyads comprising N = 102 participants from Luxembourgish and Portuguese immigrant families living in the Grand Duchy of Luxembourg. Results showed a small generation gap in values of hierarchical gender roles, but an acculturation gap was found in Portuguese mother-daughter dyads regarding obligations toward the family. A higher mother-daughter value consensus was related to higher affectual solidarity of daughters toward their mothers but not vice versa. Whereas affection and value consensus both predicted support provided by daughters to their mothers, affection mediated the relationship between consensual solidarity and received maternal support. With regard to mothers, only affection predicted provided support for daughters, whereas mothers’ perception of received support from their daughters was predicted by value consensus and, in the case of Luxembourgish mothers, by affection toward daughters.


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