The life history of Pleurogenoides malampuzhensis sp. nov. (Digenea: Pleurogenidae) from amphibious and aquatic hosts in Kerala, India

2013 ◽  
Vol 88 (2) ◽  
pp. 230-236 ◽  
Author(s):  
R. Brinesh ◽  
K.P. Janardanan

AbstractThe life-cycle stages of Pleurogenoides malampuzhensis sp. nov. infecting the Indian bullfrog Hoplobatrachus tigerinus (Daudin) and the skipper frog Euphlyctiscyanophlyctis (Schneider) occurring in irrigation canals and paddy fields in Malampuzha, which forms part of the district of Palakkad, Kerala, are described. The species is described, its systematic position discussed and compared with the related species, P. gastroporus (Luhe, 1901) and P. orientalis (Srivastava, 1934). The life-cycle stages, from cercaria to egg-producing adult, were successfully established in the laboratory. Virgulate xiphidiocercariae emerged from the snail Digoniostoma pulchella (Benson). Metacercariae are found in muscle tissues of dragonfly nymphs and become infective to the frogs within 22 days. The pre-patent period is 20 days. Growth and development of both metacercariae and adults are described.

2013 ◽  
Vol 58 (1) ◽  
Author(s):  
K. Subair ◽  
R. Brinesh ◽  
K. Janardanan

AbstractThe life-cycle stages of a new species of Uvulifer, U. iruvettiensis sp. nov. infecting the white-throated kingfisher Halcyon smyrnensis (Linnaeus) in Kerala, India are described. The new species is described in detail, and compared with its related species. The furcocercous cercariae emerged from the planorbid snail Indoplanorbis exustus (Deshayes). Metacercariae were found below the skin of tadpoles of Euphlyctis cyanophlyctis (Schneider). H. smyrnensis became infected when fed on tadpoles containing infective metacercariae. Pre-patent period is 10 days. Successive stages in the development of metacercariae and adults were followed in the laboratory.


1972 ◽  
Vol 46 (1) ◽  
pp. 35-46 ◽  
Author(s):  
S. C. Dutt ◽  
H. D. Srivastava

The life cycle of Gastrodiscoidcs hominis has been described using Helicorbis coenosus as the experimental intermediate host and the pig as the definitive host.The morphology of the miracidium, redia and metacercaria has been described. Data have been furnished on the infection and longevity, of and production of cercariae by the snail host, and the growth and development of the adult-fluke in the definitive host.


Parasitology ◽  
1959 ◽  
Vol 49 (3-4) ◽  
pp. 374-386 ◽  
Author(s):  
R. J. Thomas

1. The life history of N. battus is described, and a comparative description of the life history of N. filicollis is given.2. The life histories of these two species are compared with those of N. spathiger and N. helvetianus, two closely related species, and are shown to follow the same basic pattern, with minor variations in timing which appear to be specific in nature, and not related to differences in culture methods or host species.3. The pathogenesis of Nematodirus species is discussed and related to the migration of larvae into the intestinal mucosa during development.


2018 ◽  
Vol 10 (10) ◽  
pp. 3516 ◽  
Author(s):  
Angelina Roša (Rosha) ◽  
Natalja Lace

Organizations need innovation to be competitive and sustainable on their marketplace. Sustainable performance is an important precondition for growth and development. In spite of a body of literature, non-financial factors of sustainable performance remain an open issue. Coaching has gained considerable attention in the business world for its impact on sustainable performance. The current research investigates the use of coaching interaction to facilitate organizational sustainable growth and development in the context of Miller and Friesen’s five stage life-cycle model. The expert opinion survey is chosen as a central method of research. The questionnaire is developed on the literature review that is focused on the drivers for sustainable development throughout the life cycle, and the features of coaching that accelerate these driving forces. Fifteen experts took part in the survey conducted from November 2017 to January 2018. The results are estimated by considering the competence coefficient for each expert. The findings led to creation of an open innovation model, which displays relationships between the appropriate coaching forms and types and the organizational life cycle stages. The developed model enables choosing the optimal way of coaching delivery at any life cycle stage. This model is particularly valuable for the coaching support programs.


Author(s):  
J. B. Brown-Gilpin

The wide variety of reproductive patterns and behaviour in the many species of Nereidae already studied clearly justifies further research. But the life history of Nereis fucata (Savigny) is not only of interest from the comparative point of view. Its commensal habit (it occurs within shells occupied by hermit crabs) immediately gives it a special importance. This alone warrants a detailed study, particularly as no commensal polychaete has yet been reared through to metamorphosis and settlement on its host (Davenport, 1955; Davenport & Hickok, 1957). The numerous interesting problems which arise, and the experimental methods needed to study them, are, however, beyond the range of a paper on nereid development. It is therefore proposed to confine the present account to the reproduction and development up to the time when the larvae settle on the bottom. The complete life cycle, the mechanism of host-adoption, and related topics, will be reported in later papers.


1953 ◽  
Vol 31 (4) ◽  
pp. 351-373 ◽  
Author(s):  
Liang-Yu Wu

A cause of swimmer's itch in the lower Ottawa River is Trichobilharzia cameroni sp. nov. Its life cycle has been completed experimentally in laboratory-bred snails and in canaries and ducks, and the various stages are described. The eggs are spindle-shaped. The sporocysts are colorless and tubular. Mother sporocysts become mature in about a week. The younger daughter sporocyst is provided with spines on the anterior end and becomes mature in about three weeks. The development in the snail requires from 28 to 35 days. A few cercariae were found to live for up to 14 days at 50 °C., although their life at 16° to 18 °C. was about four days. Cercariae kept at room temperature for 60 to 72 hr. were found infective. The adults become mature in canaries and pass eggs in about 12 to 14 days. Physa gyrina is the species of snail naturally infected. It was found in one case giving off cercariae for five months after being kept in the laboratory. Domestic ducks were found to become infected until they were at least four months old, with the parasites developing to maturity in due course; no experiments were made with older ducks. Furthermore, miracidia were still recovered from the faeces four months after the duck had been experimentally infected, and it is suggested that migratory birds are the source of the local infection.


The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 35-51 ◽  
Author(s):  
Jerry D. Jacobs ◽  
John C. Wingfield

Abstract Most organisms live in seasonal environments that fluctuate on a predictable schedule and sometimes unpredictably. Individuals must, therefore, adjust so as to maximize their survival and reproductive success over a wide range of environmental conditions. In birds, as in other vertebrates, endocrine secretions regulate morphological, physiological, and behavioral changes in anticipation of future events. The individual thus prepares for predictable fluctuations in its environment by changing life-cycle stages. We have applied finite-state machine theory to define and compare different life-history cycles. The ability of birds to respond to predictable and unpredictable regimes of environmental variation may be constrained by the adaptability of their endocrine control systems. We have applied several theoretical approaches to natural history data of birds to compare the complexity of life cycles, the degree of plasticity of timing of stages within the cycle, and to determine whether endocrine control mechanisms influence the way birds respond to their environments. The interactions of environmental cues on the timing of life-history stages are not uniform in all populations. Taking the reproductive life-history stage as an example, arctic birds that have short breeding seasons in severe environments appear to use one reliable environmental cue to time reproduction and they ignore other factors. Birds having longer breeding seasons exhibit greater plasticity of onset and termination and appear to integrate several environmental cues. Theoretical approaches may allow us to predict how individuals respond to their environment at the proximate level and, conversely, predict how constraints imposed by endocrine control systems may limit the complexity of life cycles.


1967 ◽  
Vol 15 (4) ◽  
pp. 739 ◽  
Author(s):  
RK Keith

Observations are reported on the morphology of the egg and infective larva, and on the development in calves of the parasitic stages of Cooperia pectinata Ransom. The third and fourth moults occurred 2 and 8 days, respectively, after infection. The pre-patent period was 13-14 days.


1952 ◽  
Vol 84 (10) ◽  
pp. 316-321 ◽  
Author(s):  
R. W. Stark

General.—The purpose of this paper is to analyse a sampling method devised to assess larval populations in an outbreak of the lodgepole needle miner, Recurvaria milleri Busck (Busck 1914, Hopping 1945).The problem of developing an adequate sampling method is intimately concerned with the life-history of the insect, the region of the outbreak and the nature of the forest stand in which the outbreak occurs. In sampling most defoliator populations the problem is made more difficult by external feeding and wandering habits, hence it is usually done in some relatively inactive stage at a fixed time. de Gryse (1934) describes the problems inherent in sampling these insects. The needle miner, however, is fixed in its location for most of its life-cycle and is therefore readily obtainable for study. The problem here is reduced to a statistical one, that of obtaining an acceptable sample i.e. within suitable error limits with due regard for existing variables.


1957 ◽  
Vol 35 (6) ◽  
pp. 641-689 ◽  
Author(s):  
Gordon K. Sweatman

Chorioptic mange mites have been reared in vitro on epidermal debris. The life history of the mite has been observed, and each stage in the cycle described. Mites from the cow, horse, goat, sheep, and llama have been shown to be identical biologically and morphologically, and the specific names of equi, caprae, and ovis have been synonymized with C. bovis. The in vitro life cycle has been completed on epidermal debris from a variety of wild Cervidae, Bovidae, and Equidae, as well as on material from several breeds of domestic cattle, horses, sheep, and goats. From these and other data, three additional species or subspecies of Chorioptes were synonymized also with C. bovis. Only one other species, namely C. texanus, remains in the genus.


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