On the biology of Dichelyne (Cucullanellus) cotylophora (Ward &Magath, 1917) (Nematoda, Cucullanidae) in perch (Perca flavescens) from Lake Erie, Ontario

1984 ◽  
Vol 62 (10) ◽  
pp. 2062-2073 ◽  
Author(s):  
M. R. Baker
Keyword(s):  
Larval Stage ◽  
Lake Erie ◽  
Late Summer ◽  
Early Summer ◽  
Intermediate Hosts ◽  
Stage Of Development ◽  
High Prevalence ◽  
Fourth Larval Stage ◽  
Third Stage ◽  
The One

Eggs of Dichelyne cotylophora embryonate in freshwater. There is one moult in the egg and a second moult when the egg hatches. Third stage larvae were not infective to perch or invertebrates (copepods, oligochaetes). However, these larvae were experimentally transmitted orally to small cyprinid fish in which they developed to the fourth larval stage and became encysted in the liver. It is hypothesized that prey fish act as intermediate hosts for this parasite. High prevalence of the parasite in large, piscivorous perch from Lake Erie supports thisliypothesis. In addition a histiotrophic stage of development occurs in the fish intermediate hosts rather than in perch. In other cucullanids studied, the life cycle is primarily monoxenous with a histiotrophic stage of development in the one host. Annual changes in prevalence, intensity, and worm development were followed in adult perch from Lake Erie. Worms are acquired in late summer, fall, and winter, but most larvae acquired at this time do not develop past the fourth larval stage until the following spring. Worms rapidly develop into adults in the spring and females begin to produce eggs in early summer. These adults disappear in late summer.

Seasonal population changes of Physaloptera maxillaris (Nematoda: Physalopteroidea) in striped skunk (Mephitis mephitis)

1976 ◽  
Vol 54 (4) ◽  
pp. 522-525 ◽  
Author(s):  
Richard J. Cawthorn ◽  
Roy C. Anderson
Keyword(s):  
Late Summer ◽  
Mephitis Mephitis ◽  
Fourth Stage ◽  
Intermediate Hosts ◽  
Population Changes ◽  
Striped Skunk ◽  
Third Stage ◽  
Early Fall ◽  
June July ◽  
Seasonal Population

The stomachs of 162 (89%) of 183 striped skunk (Mephitis mephitis) collected in the area of Guelph, Ontario, between September 1973 and August 1974 were infected with Physaloptera maxillaris. Adult worms were most abundant in midsummer (June–July) and rare in winter (December–March). Third-stage larvae were most abundant in late fall and midwinter (October–January) and least abundant in midsummer (June–July). Fourth-stage larvae were most abundant in spring (April–May) and least abundant in early fall (August–September). It is suggested that adults appear mainly when skunk are feeding regularly in spring and midsummer. Third-stage larvae acquired in late summer and fall fail to develop (probably because of inadequate food consumption by skunk) and persist over the winter. In spring when skunk start to feed again, overwintering larvae grow into adults and initiate the annual cycle in skunk and intermediate hosts.

scholarly journals Relative Abundance and Diet of Spiny Softshells (Apalone spinifera) in a Lake Erie Population

2017 ◽  
Vol 130 (4) ◽  
pp. 275
Author(s):  
Shannon M Mahoney ◽  
Peter V Lindeman
Keyword(s):  
Relative Abundance ◽  
Lake Erie ◽  
Capture Rate ◽  
Late Summer ◽  
Early Summer ◽  
Fecal Samples ◽  
Turtle Species ◽  
Quagga Mussels ◽  
Mobile Species ◽  
Apalone Spinifera

Populations of the Spiny Softshell (Apalone spinifera) in the Great Lakes are of conservation concern despite being secure elsewhere in their North American range. We examined the relative abundance of Spiny Softshells among the turtle fauna at Presque Isle, a peninsula on the Pennsylvania shoreline of Lake Erie. We also compared male and female diets to determine the presence of invasive Zebra and Quagga Mussels (Dreissena spp.). The Spiny Softshell was the fifth most common of six turtle species captured (2% of captures). in the peninsula’s largest bay there was a significant increase in capture rate and proportion of Spiny Softshell captures in late summer (5% of five species of turtles) compared to early summer (3% of all turtles). Recapture was considerably lower for Spiny Softshells (5%) than for four other turtle species suggesting that either its relative abundance is higher than trapping data indicate or that they are a mobile species with less habitat fidelity than other residents. Prey from fecal samples were quantified using an index of Relative importance (iRi). Males (n = 26) ate primarily unidentified insects (iRi = 59), followed by algal stalks (iRi = 35) and caddisfly larvae (iRi = 4). Females (n = 5) ate primarily algal stalks (iRi = 54), followed by crayfish (iRi = 22) and fish (iRi = 19). only two turtles, one male and one female, passedZebra and Quagga Mussels in fecal samples, thus Spiny Softshells do not appear to make significant use of these invasive molluscs.

BIOLOGY OF APHODIUS HYXOS PETROVITZ (COLEOPTERA: SCARABAEOIDEA: APHODIIDAE) AND DESCRIPTION OF THE THIRD LARVAL STAGE

1997 ◽  
Vol 129 (4) ◽  
pp. 657-665 ◽  
Author(s):  
J.R. Verdú ◽  
J.P. Lumaret ◽  
E. Galante
Keyword(s):  
Larval Stage ◽  
Life Histories ◽  
Late Summer ◽  
Early Spring ◽  
Stage Larva ◽  
Late Autumn ◽  
The Third ◽  
Third Stage

AbstractAphodius hyxos Petrovitz, 1962 was reared in the laboratory and the third-stage larva is described and illustrated. The third-stage larvae and life histories of Aphodius granarius (L.), 1767 and A. hyxos are compared. Adults of A. hyxos are active from late autumn until early spring, whereas adults of A. granarius are active chiefly from early spring to late summer. The larvae of both species may be separated by differences in the distribution of setae on the raster, the shape of the anal lobes, and the size and number of holes in the respiratory plate.

The life-cycle of the flatfish nematode Cucullanus heterochrous

2000 ◽  
Vol 74 (4) ◽  
pp. 323-328 ◽  
Author(s):  
M. Køie
Keyword(s):  
Life Cycle ◽  
Larval Stage ◽  
Post Infection ◽  
Gadus Morhua ◽  
Developmental Stages ◽  
Experimental Studies ◽  
Fourth Stage ◽  
Intermediate Hosts ◽  
Infective Larvae ◽  
Third Stage

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.

Seasonal pasture contamination and availability of nematodes for grazing sheep

1976 ◽  
Vol 27 (2) ◽  
pp. 277 ◽  
Author(s):  
WH Southcott ◽  
GW Major ◽  
IA Barger
Keyword(s):  
Larval Stage ◽  
Late Summer ◽  
Summer Rainfall ◽  
Gastrointestinal Nematodes ◽  
Early Spring ◽  
Late Winter ◽  
Maximum Inhibition ◽  
Fourth Larval Stage ◽  
Grazing Sheep ◽  
And Control

In December 1970 and in January, February, March, April, May and September 1971 separate plots of sown pasture, each 0.1 ha, were contaminated by grazing sheep infected with gastrointestinal nematodes. In succeeding months each plot was grazed by worm-free tracer lambs for 2 weeks; the lambs were then withdrawn and held for 2 weeks in pens before slaughter for total differential worm counts. Observations on each plot continued for 12 months; the numbers of worms found in the tracer lambs indicated the seasonal occurrence of nematode larvae on pasture. For Haemonchus contortus, larval availability from deposition was rapid in summer and slow in autumn, maximum inhibition at the fourth larval stage occurring in larvae picked up in the winter months. Ostertagia spp. presented a marked contrast, with curtailed development in summer and contamination in autumn producing high levels of infection on pasture in late winter and early spring when inhibition was at maximum levels. Of the other species studied, intestinal Trichostrongylus spp, showed a similar pattern of development to H. contortus in summer, but as with Ostertagia spp. autumn contamination could produce infection peaks in late winter and spring. Inhibition at the fourth larval stage was not a characteristic of intestinal Trichostrongylus spp. For T. axei autumn and winter conditions favoured development, and peak infestations occurred in spring and coincided with maximum inhibition. Nematodirus spp. developed mainly in summer and most inhibition occurred at this time. Spring (September) contamination with Nematodirus spp. did not result in detectable levels of infection. For all other species spring contamination was rapidly translated to pasture and the infection was comparatively short-lived. All species were capable of overwintering on pasture and with the possible exception of T. axei a persistence of infection of at least 12 months was demonstrated. For Ostertagia spp. the importance of late summer and autumn contamination in its epizootiology and control in a summer rainfall region has been confirmed.

Breeding of the Stubble Quail, Coturnix pectoralis, in South-Eastern Australia

1980 ◽  
Vol 7 (1) ◽  
pp. 117
Author(s):  
HJ Frith ◽  
SM Carpenter
Keyword(s):  
Breeding Season ◽  
Late Summer ◽  
Early Summer ◽  
Hunting Season ◽  
Annual Cycles ◽  
South Eastern ◽  
Eastern Australia ◽  
Gonad Size ◽  
The One ◽  
Latitudinal Trend

The gonad cycle, breeding season, proportion of the population in primary moult and the relative amount of body fat were examined through the year in stubble quail at eight localities covering seven degrees of latitude and including several types of habitat and climate. There were significant effects of annual cycles and rainfall on each character at each location. In gonad size the seasonal cycle accounted for 39-71% of the variability in males and 21-41% in females according to locality. Effects of rainfall accounted for 5-18 % of the variability in males and 5-19% in females. There was a suggestion of a latitudinal trend in the date of the beginning of the annual gonad cycle. Breeding at all localities was in spring and early summer with a very frequent second peak of gonad size and breeding in late summer and autumn. The timing, the relative values of the spring and summer peaks and the success of the breeding varied from place to place and from year to year in the one locality. In some years breeding was continuous virtually throughout the year. Although in some regions the hunting season is appropriately timed, considering the biology of the birds, in others it is not as it overlaps the breeding season. There is a case for standardization in the south-eastern States to May-July.

The Belt and Road Initiative and Sino-Russian economic cooperation: Is there one more chance for us?

2019 ◽  
pp. 47-71
Author(s):  
Petr M. Mozias
Keyword(s):  
Regional Integration ◽  
Raw Materials ◽  
Belt And Road Initiative ◽  
Stage Of Development ◽  
Belt And Road ◽  
Flexible Framework ◽  
The One ◽  
International Transactions ◽  
The Belt And Road ◽  
Current Stage

China’s Belt and Road Initiative could be treated ambiguously. On the one hand, it is intended to transform the newly acquired economic potential of that country into its higher status in the world. China invites a lot of nations to build up gigantic transit corridors by joint efforts, and doing so it applies productively its capital and technologies. International transactions in RMB are also being expanded. But, on the other hand, the Belt and Road Initiative is also a necessity for China to cope with some evident problems of its current stage of development, such as industrial overcapacity, overdependence on imports of raw materials from a narrow circle of countries, and a subordinate status in global value chains. For Russia participation in the Belt and Road Initiative may be fruitful, since the very character of that project provides us with a space to manoeuvre. By now, Russian exports to China consist primarily of fuels and other commodities. More active industrial policy is needed to correct this situation . A flexible framework of the Belt and Road Initiative is more suitable for this objective to be achieved, rather than traditional forms of regional integration, such as a free trade zone.

The Application of UX Research in New Energy Vehicle Innovation

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Menghan TAO ◽  
Ning XIAO ◽  
Xingfu ZHAO ◽  
Wenbin LIU
Keyword(s):  
Early Stage ◽  
Rapid Expansion ◽  
The Other ◽  
Innovative Product ◽  
Stage Of Development ◽  
New Energy ◽  
New Energy Vehicle ◽  
The One ◽  
New Energy Vehicles ◽  
Degree Of Innovation

New energy vehicles(NEV) as a new thing for sustainable development, in China, on the one hand has faced the rapid expansion of the market; the other hand, for the new NEV users, the current NEVs cannot keep up with the degree of innovation. This paper demonstrates the reasons for the existence of this systematic challenge, and puts forward the method of UX research which is different from the traditional petrol vehicles research in the early stage of development, which studies from the user's essence level, to form the innovative product programs which meet the needs of users and being real attractive.

scholarly journals Infectivity of gastropod-shed third-stage larvae of Angiostrongylus vasorum and Crenosoma vulpis to dogs

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
William Robbins ◽  
Gary Conboy ◽  
Spencer Greenwood ◽  
Roland Schaper
Keyword(s):  
Tap Water ◽  
Natural Infection ◽  
Angiostrongylus Vasorum ◽  
Intermediate Hosts ◽  
Red Foxes ◽  
Romaine Lettuce ◽  
Crenosoma Vulpis ◽  
Artificial Digestion ◽  
Third Stage ◽  
Limax Maximus

Abstract Background Metastrongyloid parasites Angiostrongylus vasorum and Crenosoma vulpis infect wild and domestic canids and are important pathogens in dogs. Recent studies indicate that gastropod intermediate hosts infected with various metastrongyloids spontaneously shed infective third-stage larvae (L3) into the environment via feces and mucus under laboratory conditions. Shed L3 retain motility up to 120 days, but whether they retain infectivity was unknown. Methods To assess the infectivity of shed L3, the heart/lungs of six red foxes (Vulpes vulpes) were obtained from trappers in Newfoundland, Canada. Lungs were examined for first-stage larvae (L1) by the Baermann technique. A high number of viable A. vasorum L1 and a low number of C. vulpis L1 were recovered from one fox; these were used to infect naïve laboratory-raised Limax maximus. L3 recovered from slugs by artificial digestion were fed to two naïve purpose-bred research beagles (100 L3/dog). L1 shed by these two dogs was used to infect 546 L. maximus (2000–10,000 L1/slug). L3 shedding was induced by anesthetizing slugs in soda water and transferring them into warm (45 °C) tap water for at least 8 h. Shed L3 recovered from slugs were aliquoted on romaine lettuce in six-well tissue culture plates (80–500 L3/well) and stored at 16 °C/75% relative humidity. Four naïve research beagles were then exposed to 100 L3/dog from larvae stored for 0, 2, 4, or 8 weeks, respectively, after shedding. Results All four dogs began shedding C. vulpis L1 by 26–36 days post-infection (PI). All four dogs began shedding A. vasorum L1 by 50 days PI. Conclusions L3 infectivity for the definitive host was retained in both metastrongyloids, indicating the potential for natural infection in dogs through exposure from environmental contamination. As an additional exposure route, eating or licking plant or other material(s) contaminated with metastrongyloid L3 could dramatically increase the number of dogs at risk of infection from these parasites. Graphic Abstract

Effects of Dried Distillers’ Grains Cube Supplementation for Steers Grazing Introduced Pastures on Animal Performance and Forage Production

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 12-13
Author(s):  
Jordan Adams ◽  
Rodney Farris ◽  
Scott Clawson ◽  
Earl Ward ◽  
Paul Beck
Keyword(s):  
Festuca Arundinacea ◽  
Statistical Power ◽  
Cynodon Dactylon ◽  
Animal Health ◽  
Late Summer ◽  
Early Summer ◽  
Distillers Grains ◽  
Forage Production ◽  
Trenbolone Acetate ◽  
Dried Distillers Grains

Abstract We evaluated the effects of supplementing dried distillers’ grains cubes (DDGS) and re-implantation of steers (n = 149; BW = 238 ± 13.8 kg) grazing tall fescue (Festuca arundinacea)/bermudagrass (Cynodon dactylon) pastures (n = 9 pastures, 7.2 ± 2.90 ha) from 14 April to 17 September 2020 (n = 155 d) in a split-plot design on steer performance and forage production. Main plot supplemental treatments (n = 3 pastures/treatment) included 1) Fertilized Control (FC), no supplementation on fertilized pastures (112 kg N/ha); 2) Fertilized Supplement (FS), supplemental DDGS fed at 2.9 kg 3-d/wk on fertilized pastures; and 3) Supplement (S), supplemented DDGS at 0.75% BW/d on unfertilized pastures prorated for 5-d/wk feeding. Steers were previously implanted during receiving with 40 mg trenbolone acetate and 8 mg estradiol (REV-G; Revalor G, Merck Animal Health). On July 7, steers in each pasture were randomly assigned to one of three re-implant treatments: 1) no re-implant; 2) REV-G; or 3) 200 mg progesterone and 20 mg estradiol (Synovex S, Zoetis Animal Health). Steers in FS and S gained more (P < 0.01) than FC throughout the trial and final BW was greater (P < 0.01) for FS and S compared with FC. Unexpectedly, re-implanting had no effect on ADG (P = 0.57) or BW (P = 0.34), but statistical power may be lacking. Supplemental efficiency was greater in the late summer for FS (P = 0.05) compared to S. Fertilizing pastures in FS and FC did not affect biomass (P = 0.39), however, CP was increased (P = 0.01) and acid and neutral detergent fibers tended to decrease (P = 0.06) relative to S in the early summer (April, May, June, and July), but did not differ in late summer (August and September). Based upon our analysis, DDGS is a suitable supplement and can replace N fertilizer for steers grazing introduced pastures.

Sign in / Sign up

Export Citation Format

Share Document