ENCAPSULATION OF RHABDITOID NEMATODES IN MOSQUITOES

1962 ◽  
Vol 40 (7) ◽  
pp. 1269-1275 ◽  
Author(s):  
Joan F. Bronskill

In third and fourth instar larvae of Aedes aegypti (L.), juveniles of the rhabditoid, DD136, penetrate the blood sinus and cardial epithelium of the proventriculus to enter the body cavity of the host, where they complete their development. By 5 hours, a thick capsule developed about many of the ensheathed immature adults of DD136 within the body cavity of A. aegypti larvae. This rapid defence reaction of the mosquito to DD136, which has both a melanin and a cellular manifestation, occurs both in the exotic mosquito A. aegypti and in the two endemic species tested, Aedes stimulans (Walker) and Aedes trichurus (Dyar). The resistance of A. stimulans to an endemic rhabditoid, possibly of the Diplogasteridae, is also similar. The histological structure of the capsule is not affected during metamorphosis in A. aegypti; however, during histogenesis of adult tissue displacement and (or) distortion of some tissues and organs may be caused by the presence of the capsule within the host's body cavity. The activity of the adult A. aegypti is normal when this distortion or displacement is minor. Though usually encapsulated DD136 are retained within the body cavity of A. aegypti during metamorphosis, sometimes they are partially or completely expelled from the host's body cavity at the time of molting.

1977 ◽  
Vol 55 (12) ◽  
pp. 2035-2041 ◽  
Author(s):  
F. Paré ◽  
L. Huot

Various doses of reserpine were injected in the body cavity of fourth-instar nymphal Schistocerca gregaria. Treatment within 48 h from the beginning of the instar significantly increased its duration, whereas treatment at 72 or 96 h did not affect the duration of the fourth stage. However the length of the fifth stage was markedly increased irrespective of the time of treatment in the preceding stage. Fresh body weight of treated larvae increased almost as fast as in the controls. Thus food intake was affected little or not at all by the treatment. In contrast with isolation, reserpine treatment did not affect body pigmentation. Reserpine treatment, destruction of the pars intercerebralis, and isolation were compared with regard to their effects on the molting process


Author(s):  
Shanghnesy Jovita Nirvana ◽  
Muhammad Ja’far Luthfi ◽  
Erna Ekasari ◽  
Lailatul Maghfiroh

Flying squirrel (Hylopetes lepidus) is an Eutherial mamal (placental mammal), belong to the order Rodentia and belong to the family Sciuridae. Hylopetes lepidus had gray cheek as its unique characteristics. The reproductive organs are the key to success in maintaining the new descendants. Male reproductive organs will produce the male sex cells or spermatozoa. The purpose of the research is to examine the anatomical structure, morphometry, histomorphometry, and histological structure of male reproductive organs (penis, testicle, vas deferens, bulbouretralis gland, prostate and seminal vesicles) of Hylopetes lepidus. The method used in examining histological characteristics is Hematoxyin–Eosin staining method. The histological structure of reproductive organs were observed using optilab microscope. The results of the study showed that the adult male flying squirrel weighed 104.28 ± 0.64 gram. Anatomically, it has oval white reddist testicle. The testicle is located side out of the body cavity in the scrotum. Morphometric observation testicular showed that the right testes has volume 0.35 ± 0.07 ml, and the left has volume 0.35 ± 0.07 ml, weight of the right testicular 0.19   ± 0.01 gram, weight of the left testicular 0.18 ± 0.01 gram, diameter of the right testicular 6.35 ± 0.21 mm, diameter of the left testicular 6.35 0.21 mm, short diameter of the right testicular 3.45 ± 0.21 mm, and short diameter of the left testicular 3.45 ± 0.21 mm. The diameter of tubulus seminiferus 261,4 ± 0.14 μm. The conclusion of this study compared to rodentia other testicular Hylopetes lepidus has a unique testicular bound by the connective tissue in the scrotum so that testicular included in class permanent descending testicular. The rhombus of the prostate gland are blunt, while histologically the sertoli cells in the seminiferus tubule shaped elongated, while in morphometry penis Hylopetes lepidus relatively longer than Mus musculus.


Parasitology ◽  
1960 ◽  
Vol 50 (1-2) ◽  
pp. 111-153 ◽  
Author(s):  
John O. Corliss

A holotrichous ciliate found repeatedly in very large numbers in the body cavity of larval midges (Chironomus plumosus) from Paris and Berlin areas is described as a new species of the genus Tetrahymena, named T. chironomi sp.nov. It appears to represent a true example of facultative parasitism, since parasites released from the host survive in laboratory cultures, and free-living ciliates believed identical have been isolated from fresh-water sources in nature. Over a 3-month period more than 2000 larvae, principally fourth-instar stages, were examined; about 9 % of these were found to be infected with ciliates.T. chironomi is the thirteenth species to be added to the growing holotrich hymenostome genus Tetrahymena. It is taxonomically distinguishable from other members of the genus on the basis of a combination of characteristics related to its morphology and bionomics. It is one of the smallest species, has 24–27 ciliary meridians and a relatively large, spherical micronucleus, does not exhibit dimorphism or cystic stages in its life cycle, and does not possess a caudal cilium.


2007 ◽  
Vol 55 (4) ◽  
pp. 211 ◽  
Author(s):  
T. M. Berra ◽  
B. Gomelsky ◽  
B. A. Thompson ◽  
D. Wedd

The nurseryfish, Kurtus gulliveri, of northern Australia, is remarkable for the fact that the males carry the egg mass on a supraoccipital hook on their forehead. Plankton samples of larval nurseryfish indicate a prolonged spawning season (June–November) that more or less corresponds with the dry season in the Northern Territory. The paired, elongate testes are located in the posterior portion of the body cavity suspended by the mesorchium. The gonadosomatic index (GSI) of males was small and highly variable (mean 0.14, range 0.01–0.27) from June to November. The histological structure of testicular lobes showed maturing and mature stages that contained spermatocytes, spermatids, and spermatozoa. The paired, bean-shaped ovaries contained about 5500 oocytes (1176–9783) and were located in the rear of the abdominal cavity. GSI averaged 1.58 (range 0.36–4.48). Ovarian histology revealed primary growth, cortical alveolar oocytes, vitellogenic oocytes, coalesced yolk, and atresia. The occurrence of postovulatory follicles and late vitellogenetic oocytes in the ovaries clearly indicate that nurseryfish females are batch spawners. Maturing testes showed signs of previous spawnings indicating that males are capable of spawning several times throughout the spawning season. We speculate that nurseryfish may spawn in a manner similar to their closest relatives, cardinalfishes (Apogonidae), with eggs carried on the male’s hook instead of orally.


Parasitology ◽  
1924 ◽  
Vol 16 (1) ◽  
pp. 111-112
Author(s):  
Edward Hindle

In December, 1922, whilst dissecting a large female example of Bufo regularis, one of my students noticed a cylindrical structure extending along the ventral region of the body-cavity. A careful examination showed that this structure consisted of an elongated sac-like diverticulum of the right lung, containing an almost full-grown specimen of a dipterous larva, which could be seen through the membraneous wall of the diverticulum. The base of the latter, in addition to its point of origin from the lung, was also connected to the dorsal surface of the liver by strands of fibrous tissue, suggesting that the growth had been in existence some considerable time in order to cause such adhesions. Posteriorly, the diverticulum hung freely in the body cavity and extended to the extreme hinder end. Its dimensions were 5·5 cm. in length, by 0·5 cm. in diameter, but tapering towards each extremity.


2007 ◽  
Vol 4 (1) ◽  
pp. 87-90 ◽  
Author(s):  
Zerina Johanson ◽  
Mikiko Tanaka ◽  
Natalie Chaplin ◽  
Moya Smith

Regular scale patterning, restricted to the caudalmost tail and organized into two opposing rows on each side of the tail, is observed in few chondrichthyans. These evenly spaced scales, in dorsal and ventral rows, develop in an iterative sequence from the caudal tip, either side of the notochord. They are subsequently lost as a scattered pattern of placoid scales develops on the body and fins. An identical organized pattern is observed in tail scales of Scyliorhinus canicula (catshark), where the expression of sonic hedgehog signal is restricted to the epithelium of developing scales and remains localized to the scale pocket. Regulation of iterative scale position by sonic hedgehog is deeply conserved in vertebrate phylogeny. These scales also reveal an archaic histological structure of a dentine type found in the oldest known shark scales from the Ordovician and Silurian. This combination of regulated pattern and ancient dentine occurs only in the tail, representing the primary scalation. Scattered body scales in elasmobranchs such as S. canicula originate secondarily from differently regulated development, one with typical orthodentine around a central pulp cavity. These observations emphasize the modular nature of chondrichthyan scale development and illustrate previously undetected variation as an atavism in extant chondrichthyan dentine.


1949 ◽  
Vol 26 (1) ◽  
pp. 1-15
Author(s):  
J. D. SMYTH

1. Plerocercoid larvae of the pseudophyllidean cestode Ligula intestinalis from the body cavity of roach, were cultured in vitro at 40°C. in a variety of saline and nutrient media. About 65% of such cultures were aseptic. 2. During cultivation, larvae produced acid by-products (unidentified) and the pH fell rapidly. 3. The presence of these acid by-products slowed down development, or, if present in sufficient quantity, caused death. 4. In order to obtain development in nutrient media in a period (3 days) comparable to that required in a bird (the normal host) it was necessary to renew the medium 24-hourly. 5. 6% of the eggs produced from a worm cultured in horse serum were fertile. Fertile eggs were never obtained from larvae cultured in any other media. 6. Certain bacterial infections had no apparent detrimental effect on development, but others were toxic. 7. Some larvae underwent development in non-nutrient medium (¾ strength Locke's solution). The exact conditions under which this occurred was not determined. 8. Fragments (3 cm. long), of larvae or larvae with either scolex or posterior half removed, underwent development to the stage of oviposition in nutrient media. 9. Histochemical examination revealed that the plerocercoid larvae were almost fat-free. During cultivation, very large quantities of cytoplasmic fat were produced the quantity being proportional to the duration of cultivation. Fat was produced even under starvation conditions (i.e. during cultivation in saline) and can be considered a metabolic by-product. 10. The fresh plerocercoid contained great quantities of glycogen in the parenchyma and muscle regions. After cultivation in nutrient or saline media, considerable quantities were still present.


Author(s):  
M. Barson

Clarias gariepinus were collected from Lake Chivero, Zimbabwe, and examined for nematode parasites from November 2000 to May 2002. Of the 202 specimens collected, 42.6 % were infected with third-stage larvae of Contracaecum sp. in the body cavity. The intensity of the infection was 1-7 worms per fish (mean intensity = 2.2). Seasonal variation in the prevalence of the parasite was not obvious and there was no significant difference in the prevalence of infection between males and females (c2 = 2.228; P > 0.05). No significant relationship between host size and prevalence was established. There was also no significant relationship between intensity and the body condition factor (r = 0.11; P > 0.05). The low parasite prevalence may have been caused by the disruption of the infection cycle since piscivorous birds, which are the final hosts of the parasite, do not feed on C. gariepinus in Lake Chivero.


2016 ◽  
Vol 48 (2) ◽  
pp. 137
Author(s):  
Soujita Pramanik ◽  
Sampa Banerjee ◽  
Soumyajit Banerjee ◽  
Goutam K. Saha ◽  
Gautam Aditya

Among the natural predators, larval stages of the mosquito <em>Lutzia fuscana (</em>Wiedemann, 1820) (Diptera: Culicidae) bear potential as a biological control agent of mosquitoes. An estimation of the predatory potential of the larva of <em>L. fuscana</em> against the larva of the dengue vector <em>Aedes aegypti</em> (Linnaeus, 1762) (Diptera: Culicidae) was made to highlight its use in vector management. Laboratory experiments revealed that the larva of<em> L</em>. <em>fuscana</em> consumes 19 to 24 <em>A. aegypti</em> larvae per day, during its tenure as IV instar larva. The consumption of <em>A. aegypti</em> larvae was proportionate to the body length (BL) and body weight (BW) of the predatory larva<em> L. fuscana</em> as depicted through the logistic regressions: y = 1 / (1 + exp(-(-2.09 + 0.35*BL))) and y = 1 / (1 + exp(-(0.4+ 0.06*BW))). While the prey consumption remained comparable among the days, the net weight gained by the <em>L</em>. <em>fuscana</em> larva showed a decreasing trend with the age. On the basis of the results, it is apparent that the larva of the mosquito <em>L. fuscana</em> can be used in the regulation of the mosquito <em>A. aegypti</em> through augmentative release, particularly, in the smaller mosquito larval habitats.


1998 ◽  
Vol 72 (4) ◽  
pp. 3377-3382 ◽  
Author(s):  
John W. Barrett ◽  
Andy J. Brownwright ◽  
Mark J. Primavera ◽  
Subba Reddy Palli

ABSTRACT A recombinant Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) expressing the green fluorescence protein (GFP) under the control of the AcMNPV polyhedrin promoter was constructed to study the spatial and temporal regulation of baculovirus infection in a permissive host. Larvae that ingested AcMNPV-GFP showed localized expression of GFP in the midgut epithelial cells, as well as hemocytes, at 24 h postinfection. The presence of fluorescence in these tissues indicated not only that the virus was replicating but also that the very late viral proteins were being synthesized. Secondary infection occurred within the tracheal cells throughout the body cavity, confirming earlier reports, and these foci of infection allowed entry of the virus into other tissues, such as the epidermis and the fat body.


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