scholarly journals The life cycle of Gmelinoides fasciatus (Stebbing, 1899) and Gammarus lacustris (Sars, 1863) amphipods in the lake Arakhley littoral during the extreme low-water phase of the hydrological cycle

2020 ◽  
Vol 12 (1) ◽  
pp. 16-25
Author(s):  
Petr V. Matafonov
Keyword(s):  
Life Cycle ◽  
Hydrological Cycle ◽  
Water Phase ◽  
Gammarus Lacustris ◽  
Gmelinoides Fasciatus

scholarly journals The invaders as natural biondicators using the example invasive amphipod Gmelinoides fasciatus (Stebbing, 1899) in the Moscow River Basin: the suggestion of G. lacustris/G. fasciatus bioindication pair

2017 ◽  
Vol 7 (4) ◽  
pp. 457-461
Author(s):  
I. N. Marin
Keyword(s):  
River Basin ◽  
Native Species ◽  
Anthropogenic Pollution ◽  
Amphipod Species ◽  
Bioindicator Species ◽  
Gammarus Lacustris ◽  
Gmelinoides Fasciatus ◽  
Moscow City ◽  
Invasive Amphipod ◽  
Moscow River

The article presents data on the study of the diversity of crustacean communities in the Moscow-river basin. Two most common are two species of amphipods, invasive species Gmelinodes fasciatus and the native species Gammarus lacustris, were detected and studies during the study. However, the number of one of the most important bioindicator species of crustaceans, Asellus aquaticus found in our samples is insufficient for quantitative conclusions. At the same time, population of G. fasciatus can be characterized as stable at all studied stations and the species can be used as bioindicator of the natural condition of the river flowing within the Moscow City. The species seems to be significantly less sensitive to environment conditions and especially anthropogenic pollution than the native amphipod species G. lacustris and can successfully replace A. aquaticus as bioindicator species in the area where the latter species is absent. Thus, a new bioindicator pair Gammarus lacustris / Gmelinoides fasciatus is suggested for using in estimation water pollution In European part of the Russian Federation and adjacent areas.

The occurrence, life cycle, and pathogenicity of Echinuria uncinata (Rudolphi, 1819) Soloviev, 1912 (Spirurida, Nematoda) in waterfowl at Delta, Manitoba

1972 ◽  
Vol 50 (4) ◽  
pp. 385-393 ◽  
Author(s):  
F. G. Austin ◽  
H. E. Welch
Keyword(s):  
Life Cycle ◽  
Daphnia Magna ◽  
Infective Stage ◽  
Gammarus Lacustris ◽  
Lesser Scaup ◽  
Common Eiders ◽  
Third Stage ◽  
Mucosal Layer ◽  
Ceriodaphnia Reticulata ◽  
Sexually Mature

In the Delta Marsh, third-stage Echinuria uncinata juveniles were found in Daphnia magna, D. pulex, Simocephalus vetulus, and Gammarus lacustris. Daphnia magna, the major host, were found infected from late May to early November with a peak of 108 parasites per 100 Daphnia in early August. Experimentally, D. magna, D. pulex, Ceriodaphnia reticulata, C. acanthina, S. vetulus, Moina macrocopa, Eurycercus lamellatus, G. lacustris, Hyallela azteca, Chirocephalopsis bundyi, and Lynceus brachyurus became infected when exposed to E. uncinata eggs. Parasites developed to the infective stage in D. magna and D. pulex in 30 days at 15 °C and in 10 days at 20–24 °C.In mallard ducks, E. uncinata completed the fourth molt 20 days after infection; male worms were sexually mature after 30 days and females oviposited 40 days after infection. Parasites grew faster in 1-week-old Delta mallards than in 2- and 3-month-old birds. Adult nematodes were located beneath the mucosal layer at the junction of the proventriculus and gizzard where granulomas formed after 30 days. The number of granulomas was correlated with the number of parasites. Mallards, pintails, gadwalls, lesser scaup, common eiders, and domestic geese were more susceptible to Echinuria infection than were shovellers, blue-winged teal, redheads, ruddy ducks, and American coots. Parasite eggs died when frozen but 50% survived 85 days when dried on filter paper. Echinuria uncinata can survive winter in resident mallards.

Response of Amphipoda and Trichoptera to Lake Fertilization in the Canadian Arctic

1992 ◽  
Vol 49 (11) ◽  
pp. 2354-2362 ◽  
Author(s):  
John K. Jorgenson ◽  
Harold E. Welch ◽  
Martin F. Curtis
Keyword(s):  
Life Cycle ◽  
Primary Production ◽  
Northwest Territories ◽  
Canadian Arctic ◽  
Phytoplankton Production ◽  
Natural Conditions ◽  
Gammarus Lacustris ◽  
The Third ◽  
Biomass Ratio ◽  
Lake Fertilization

Small oligotrophic lakes at Saqvaqjuac, Northwest Territories, were fertilized with phosphorus and nitrogen after 2 yr of study and the response of macroinvertebrates to increased primary production was followed for 3 yr. The amphipod Gammarus lacustris lacustris (G. O. Sars) had a 2-yr life cycle, with three cohorts present in August. Biomass under natural conditions was approximately 0.1–0.2 g dry wt∙m−2. Gammarus responded immediately to a doubling of phytoplankton production with increased survival of young-of-year. Gammarus biomass increased steadily to 0.9 g dry wt∙m−2 and had not stabilized after 3 yr of fertilization. Trichoptera were represented by three species, with Grensia praeterita composing the bulk of the biomass, followed by Apatania zonella and an uncommon Hesperophylax species. Trichoptera biomass ranged from 0.04 to 0.3 g dry wt∙m−2 before fertilization. Response to increased primary production was slow, beginning in year 2 of fertilization. Trichoptera biomass had doubled by the third year of fertilization but was probably several years from equilibrium. Application of benthos models, in addition to the data, suggested that the production to biomass ratio was between 1 and 2, averaging 1.5.

scholarly journals Stability and spatio-temporal structure in fish assemblages of two floodplain lagoons of the lower Orinoco River

2009 ◽  
Vol 7 (4) ◽  
pp. 719-736 ◽  
Author(s):  
Nirson González ◽  
Carlos Lasso ◽  
Judith Rosales
Keyword(s):  
Aquatic Vegetation ◽  
Fish Assemblages ◽  
Hydrological Cycle ◽  
Temporal Structure ◽  
Biotic Interactions ◽  
High Water ◽  
Water Phase ◽  
Fish Assemblage Structure ◽  
Biological Interactions ◽  
The Mean

Fish assemblage structure and variability were analyzed in two floodplain lagoons (Las Arhuacas and Los Cardonales) along the lower Orinoco over a hydrological cycle. Every three months during continuous three-day sampling, experimental gill nets (5 to 12.5 cm of mesh opening) and 1 mm-mesh seine nets were utilized according to the types of habitats presents. A total of 133 fish species were found in Las Arhuacas and 95 species in Cardonales. Fifty five and 17 species were exclusive to Las Arhuacas and Los Cardonales respectively, and 77 were common to both lagoons. In Las Arhuacas, the most speciesrich orders were Characiformes, Siluriformes, Perciformes and Gymnotiformes and in Los Cardonales, the most species-rich orders were Characiformes, Siluriformes, Clupeiformes and Perciformes. The richness, abundance and biomass were significantly higher (p < 0.001) in Arhuacas than in Cardonales. In general, the fishes assemblage was highly variable during the high water phase and moderately stable during low water phase in both lagoons, with more stability or less variability in Cardonales than Arhuacas. Also, there were significant differences in the fish assemblages between the two lagoons, mainly during low waters (ANOSIM; p < 0.001). The species that contributed most to the mean dissimilarity between the lagoons were Hypostomus argus, Aphanotorulus ammophilus, Potamorhina altamazonica, Prochilodus mariae, Loricaria gr. cataphracta, Oxydoras sifontesi, Hydrolycus armatus, Hyphopthalmus edentatus and Pterodoras rivasi. The last four species were more commonly collected in Los Cardonales. Also, the species of small size (mainly SL < 5 cm) such as Rhinosardinia amazonica, Moenkhausia sp. 1 "lepidura", Moenkhausia sp. 2, Aphyocharax alburnus, Characidium sp. 1, Moenkhausia sp. 3, Exodon paradoxus and Roeboides dientonito contributed to the mean dissimilarity among the beach and aquatic vegetation habitats. The patterns of the species assemblage organization were related to the dynamics of the floods. Non-random (i. e., deterministic) associations between species caused by the selection of habitats and/or to biological interactions, apparently were more common during low waters when there is an increased density of fish and so the biotic interactions are intensified. Stochastic associations, on the other hand, seemed to be more common during high water when species are more dispersed.

Ultrastructural analysis of “Sensory” surface nerve endings and “putative” neurotransmitter sites in Schistosoma mansoni Miracidia

1989 ◽  
Vol 47 ◽  
pp. 962-963
Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tang Pan
Keyword(s):  
Nervous System ◽  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Snail Host ◽  
Complex Life Cycle ◽  
Rational Approach ◽  
Effective Control ◽  
The Social ◽  
Social And Economic Development ◽  
Basic Biology

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).

A freeze-fracture-etched study of the physarum polycephalum plasma membrane during early formation of the macroplasmodial stage

1993 ◽  
Vol 51 ◽  
pp. 346-347
Author(s):  
Randolph W. Taylor ◽  
Henrie Treadwell
Keyword(s):  
Plasma Membrane ◽  
Life Cycle ◽  
Growth Phase ◽  
Filter Paper ◽  
Physarum Polycephalum ◽  
Freeze Fracture ◽  
Petri Dish ◽  
Wire Screen ◽  
Wide Mouth ◽  
Sterile Filter

The plasma membrane of the Slime Mold, Physarum polycephalum, process unique morphological distinctions at different stages of the life cycle. Investigations of the plasma membrane of P. polycephalum, particularly, the arrangements of the intramembranous particles has provided useful information concerning possible changes occurring in higher organisms. In this report Freeze-fracture-etched techniques were used to investigate 3 hours post-fusion of the macroplasmodia stage of the P. polycephalum plasma membrane.Microplasmodia of Physarum polycephalum (M3C), axenically maintained, were collected in mid-expotential growth phase by centrifugation. Aliquots of microplasmodia were spread in 3 cm circles with a wide mouth pipette onto sterile filter paper which was supported on a wire screen contained in a petri dish. The cells were starved for 2 hrs at 24°C. After starvation, the cells were feed semidefined medium supplemented with hemin and incubated at 24°C. Three hours after incubation, samples were collected randomly from the petri plates, placed in plancettes and frozen with a propane-nitrogen jet freezer.

A Spreadsheet Life Cycle Cost Model for System Modernization Studies

1994 ◽  
Vol 11 (1) ◽  
pp. 47-56
Author(s):  
Virginia C. Day ◽  
Zachary F. Lansdowne ◽  
Richard A Moynihan ◽  
John A. Vitkevich
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Cost Model
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