The life-cycle of the flatfish nematode Cucullanus heterochrous

2000 ◽  
Vol 74 (4) ◽  
pp. 323-328 ◽  
Author(s):  
M. Køie

AbstractMature specimens of Cucullanus heterochrous Rudolphi, 1802 (Nematoda: Cucullanidae) were obtained from the intestine of the flounder, Platichthys flesus, from Danish waters. Eggs embryonate in seawater but do not hatch. Fully developed larvae pressed out of eggs are 430 μm long with amphids and dereids and enclosed within the cuticle of a previous larval stage. Infective larvae are believed to be in their third stage. Experimental studies showed that the polychaetes, Nereis spp., Scoloplos armiger, Brada villosa and Capitella sp., may act as intermediate hosts. In N. diversicolor the larvae increase their length to 1 mm within four weeks (15°C) without moulting. Experimental infections showed that larvated eggs are not infective to fish, whereas >550 μm long larvae from polychaetes survived in 4–24 cm long flounders and plaice, Pleuronectes platessa. Third-stage larvae 550 μm to 1.1 mm long were found in the submucosa of the intestine one week post infection. At a length of about 800 μm to 1.4 mm they moult to fourth-stage larvae. Fourth-stage larvae, immature and mature worms occur in the intestine and rectum. Fourth-stage larvae and adults survived experimental transfer from one flounder to another. Similar developmental stages survived for two weeks in the intestine of experimentally infected cod, Gadus morhua.

2000 ◽  
Vol 78 (2) ◽  
pp. 182-190 ◽  
Author(s):  
Marianne Køie

Mature specimens of Cucullanus cirratus O.F. Müller, 1777 (Cucullanidae) were obtained from the pyloric caeca and intestine of Atlantic cod, Gadus morhua L., from Danish waters. Eggs embryonate in seawater. Third-stage larvae about 400 µm long, with amphids and dereids, hatch from the egg. Experimental studies indicated that third-stage larvae were infective to calanoid and cyclopoid copepods and sand gobies, Pomatoschistus minutus (Pisces, Gobiidae). Larvae entered the haemocoel of copepods but did not grow. In gobies, the third-stage larvae entered the intestinal mucosa and grew to 800 µm in length within 6 months. They were not encapsulated. Experimental infections of cod (8-30 cm long) showed that free-living third-stage larvae are not infective, whereas >700 µm long third-stage larvae from gobies survived in the cod. Third-stage larvae 700-1200 µm long occur in the stomach mucosa, where they develop and moult to fourth-stage larvae. The fourth-stage larvae then migrate to the pyloric caeca and anterior part of the intestine, where they moult and develop to the mature adult stage. No developmental stage became encapsulated. Naturally infected cod (>20 cm total length) harboured moulting third-stage larvae and <2 mm long fourth-stage larvae 2 months post capture. Naturally infected 4- to 5-month-old codlings (8-10 cm total length) harboured 2-3 mm long fourth-stage larvae only, indicating that they acquired the third-stage larvae as planktivorous fry only a few centimetres long. Cucullanus cirratus may have a life-cycle that involves copepod transport hosts and fish (gobies or cod fry) intermediate hosts. Postcyclic development occurs in gadoids when an infected cod is consumed by another cod (cannibalism). Examinations of 350 (8-78 cm total length) naturally infected cod showed that group 1 and older cod are infected throughout the year, with maximum prevalence of third-stage larvae in spring and summer. The greatest prevalence of gravid worms was observed in autumn.


1970 ◽  
Vol 19 (2) ◽  
pp. 171-179 ◽  
Author(s):  
MH Arju ◽  
MA Bashar ◽  
G Moula

The overall life cycle, duration and survival rate of different developmental stages (egg, larva and pupa) of Catopsilia pyranthe conducted at 27 ± 3°C and RH 75% ± 2. showed that within 6.4 days 68% eggs hatched. The average duration from egg to adult, larval stage and pupal were 23.87, 10.93 and 6.8 days, respectively. Fifty six out of 68 larvae successfully completed their whole 5 instars. There were positive correlation among the larval instars, amount of food consumption and excretion of faeces. About 52% pupa were emerged as adult at laboratory condition. Key words: Life cycle; Catopsilia pyranthe; Developmental stages; Rearing DOI: http://dx.doi.org/10.3329/dujbs.v19i2.8961 DUJBS 2010; 19(2): 171-179


Parasitology ◽  
1983 ◽  
Vol 86 (1) ◽  
pp. 147-160 ◽  
Author(s):  
J. H. Ali ◽  
J. Riley

SUMMARYThe life-cycles of two closely related cephalobaenid pentastomids, Raillietiella gehyrae and Raillietiella frenatus, which utilize geckos as definitive hosts and cockroaches as intermediate hosts, have been investigated in detail. Early development in the fat-body of cockroaches involves 2 moults to an infective, 3rd-stage larva which appears from 42–44 days post-infection. Complete development in geckos involves a further 5 moults in the case of males and 6 for females. Males mature precociously and copulation is a once-in-a-lifetime event which occurs around day 80 post-infection when both sexes are the same size but the uterus of the female is undeveloped. Sperm, stored in the spermathecae, is used to fertilize oocytes which slowly accumulate in the developing saccate uterus. Patency commences when the uterus carries approximately 4000–5500 eggs but only 25–36 % of these contain fully developed primary larvae. Since only mature eggs are deposited, we postulate that the vagina (?) of the female must be equipped with a selective filter that allows through large eggs but retains smaller, immature eggs. Thus the only limit on fecundity is the total number of sperms in the spermathecae and this is precisely the same factor that constrains egg production in the advanced order Porocephalida.


1988 ◽  
Vol 66 (10) ◽  
pp. 2212-2222 ◽  
Author(s):  
Lena N. Measures

In Guelph Lake, a man-made reservoir in Ontario, Canada, prevalence of larval Eustrongylides tubifex in pumpkinseed (Lepomis gibbosus), rock bass (Ambloplites rupestris), and yellow perch (Perca flavescens) was 12.9% and mean intensity ranged from 1 to 1.8. Larvae were encapsulated on the mesentery of fish. Pumpkinseed and yellow perch were the important fish hosts in Guelph Lake as most larvae in these fish were alive. In contrast, 40% of larvae in rock bass were dead and calcified. Third- and fourth-stage larvae from naturally infected fish are described. Larvae in the three species of fish elicited a granulomatous inflammatory reaction. Attempts to transfer third-stage larvae from experimentally infected oligochaetes and third-stage larvae from naturally infected fish to laboratory-reared pumpkinseed were unsuccessful. Fourth-stage larvae from naturally infected fish were transferred successfully to pumpkinseed. Eutropic lakes such as Guelph Lake are particularly suitable enzootic areas because of the abundant populations of tubificid intermediate hosts and the presence of fish hosts such as pumpkinseed and perch. The advanced stage and development of larvae (to the fourth stage) in fish likely represents an adaptation for a parasite that occurs in a migratory host such as Common Mergansers (Mergus merganser), which frequent Guelph Lake for only about 1 month in spring and fall.


1960 ◽  
Vol 50 (4) ◽  
pp. 737-757 ◽  
Author(s):  
Fred D. Bennett

In Trinidad, the only serious pod borer attacking pigeon peas is Ancylostomia stercorea (Zell.). This species breeds throughout the year. The eggs are laid on the young pods and the larvae feed on the developing seeds and later pupate in the soil. The complete life-cycle requires 26–32 days.Eight species of parasites were reared from the larvae of Ancylostomia. Life-history studies and rearing techniques for the six commonest species are presented.Apantelcs etiellae isolatus Mues. is a solitary endoparasite attacking first- to third-stage host larvae. It emerges from the fourth-stage host and constructs a white cocoon in the pod. The life-cycle takes 14–18 days.Phanerotoma bennetti Mues. is a solitary egg-larval parasite. The egg is laid in that of the host, but the parasite does not complete development until the host has reached the final larval stage and constructed a cocoon. A generation is completed in 20 to 28 days. A method of breeding this species on Ephestia cautella (Wlk.) is described.Eiphosoma annulatum Cress, is a solitary endoparasite attacking first- to fourth-stage hosts. The parasites emerge from fifth-stage hosts which may be stunted in size but construct normal cocoons. The life-cycle is completed in 26–35 days.Bracon thurberiphagae (Mues.) and Bracon cajani Mues. are gregarious ectoparasites of similar habit. They paralyse second- to fifth-stage larvae and deposit eggs on or near them. The life-cycle is completed in 13 to 16 days. A method of rearing field-collected immature stages is described.Perisierola sp. is a gregarious ectoparasite. The adult enters the pod, paralyses a host, and attaches her eggs directly on to the caterpillar. Second- to fifth-stage hosts may be attacked but the larger hosts are preferred. The female frequently remains with her progeny until they have completed their development, which requires 11 to 15-days.Hyperparasites attacking the parasite pupae are listed.Details of a shipping container and methods of rearing and shipping parasites to Mauritius for trial against Etiella zinckenella (Treitschke) and Maruca testulalis (Geyer) are described. From a stock of more than 44,000 cocoons so sent two species, Bracon cajani and Eiphosoma annulatum, have been successfully established in Mauritius.


2020 ◽  
Vol 12 (3) ◽  
pp. 272-276
Author(s):  
C.S. Oaya

Abstract. Study on the biology of groundnut bruchid, Caryedon serratus Olivier was carried out in the Laboratory of the Department of Agricultural Technology, Adamawa State College of Agriculture, Ganye, Adamawa State from June to September, 2015. The sex of the bruchid (male and female) was assigned the sub-treatment while the period of development was the main treatment and was replicated three times. The work considered the pre-oviposition stage, incubation stage, larval stage, pupal stage, adult stage and the total life cycle of the bruchid (male and female). The experiment was carried out under Laboratory conditions at 30-35°C temperature and 70-90% relative humidity. After the experiment was established, weekly counting of the total number of eggs laid was carried out at intervals. The results showed that, the mean developmental stages in both female and male bruchids were: 6.50 and 6.00 days; 17.00 and 18.00 days; 13.50 and 13.50 days; 12.00 and 13.50 days; 48.00 and 50.00 days for incubation stage, larval stage, pupal stage, adult stage and total life cycle of the bruchids, respectively. Moreover, the mean pre-oviposition and oviposition stages in female adult bruchid were 1.50 and 5.50 days, respectively.


2018 ◽  
Vol 15 (4) ◽  
pp. e1010 ◽  
Author(s):  
Manuel López-Gómez ◽  
Soledad Verdejo-Lucas

Meloidogyne javanica has showed less reproductive success than M. incognita in watermelon genotypes. This study was conducted to elucidate the low reproduction of M. javanica in watermelon. The post-infection development of M. javanica in watermelon ‘Sugar Baby’ was determined at progressively higher initial population (Pi) levels at two time points during the life cycle. Plants were inoculated with 0, 25, 50, 100, 200, and 300 second-stage juveniles (J2)/plant. The increase in Pi was correlated with the penetration rates (R2= 0.603, p<0.001) and total numbers of nematodes in the root (R2 =0.963, p< 0.001) but there was no correlation between the Pi and the reproduction factor (eggs/plant/Pi). The population in the roots at 26 days post-inoculation (dpi) consisted primarily of third-stage juveniles (J3) with a small presence of J2 and fourth stages, and egg-laying females. The dominance of the J3, when egg-laying females are expected, point to the malfunction of the feeding sites that failed to support nematode development beyond the J3 stage. The similarities in egg-laying females at 26 and 60 dpi imply the disruption of the life cycle. Watermelon compensated for M. javanica parasitism by increasing vine length (19% to 33%) and dry top weight (40%) in comparison with the non-inoculated plants. The area under the vine length progress curve was significantly larger as the Pi progressively increased (R²=0.417, p<0.001). Physiological variation was detected between the M. incognita populations. M. arenaria had less ability to invade watermelon roots than did M. incognita and M. javanica.


1970 ◽  
Vol 5 (1) ◽  
pp. 26-33
Author(s):  
Mohd Zacaery Khalik ◽  
Adibah Mohamed Shariff ◽  
Wan Nurainie Wan Ismail

A study on blowfly developmental stages to estimate the time of death (TOD) of small mammal had been conducted during a rainy season. During this study, fresh Muller’s rat (Sundamys muelleri) carcasses were used as the host sample, and the developmental duration of every larval stage, decomposition stages of host animal, ambient temperature and relative humidity were recorded. Hypopygiopsis violacea (Family: Calliphoridae) was recorded to be the first blowfly visiting and ovipositing on the carcass after the carcass being deposited, while Chrysomya megacephala and C. ruffacies were recorded as the most dominant calliphorids present during the decomposition process. This study estimated that the time for calliphorids to complete their life cycle, from an egg to an adult was approximately twenty-three days, and the decomposition of Sundamys muelleri took about nine days. Useful information on succession and rate of development of blowfly could enhance the knowledge of the length of time elapsed since death in particular host animal.


1976 ◽  
Vol 50 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Rosemary Rogers ◽  
D. A. Denham

AbstractThe effects of levamisole on adults, third stage infective larvae, and microfilariae of Brugia pahangi were studied in in vitro culture and in vivo against developing stages in the vector mosquito and in infected cats. In vitro the drug was effective only at dose levels much higher than can be tolerated by mammals. It was active against the developmental stages of the worm in the vector Aedes aegypti.The drug was strongly microfilaricidal in cats but less effective against adult worms.


1980 ◽  
Vol 54 (3) ◽  
pp. 223-232 ◽  
Author(s):  
O. C. Nwaorgu ◽  
R. M. Connan

ABSTRACTFor the first 66 hours after the subcutaneous injection of rabbits with the infective larvae of Strongyloides papillosus, larvae spread gradually from the injection site to other parts of the body musculature. Their number and distribution suggests that they do so by the direct penetration of the tissues as the majority remain close to the site of injection. By 90 hours, however, the appearance of larvae in the lungs, trachea and oesophagus suggests that migration is taking place within the circulation.Although some 90% of the total worms recovered were already established in the intestine by 8 days post-infection, significant numbers of larvae continued to be present in the muscles at 14 and 21 days. Even by 35 days the muscles of 1 of 2 rabbits still contained 43 larvae. This prolonged presence of Strongyloides papillosus in the muscle of rabbits uniformly at the early fourth stage may be analogous to the arrested development of other nematodes. While there is evidence to suggest that immunity is a major factor in the aetiology of arrested development in Strongyloides ransomi, it is an unimportant factor in the case of Strongyloides papillous in rabbits.


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