Life cycle of an endangered riffle beetle, Leptelmis gracilis Sharp (Coleoptera: Elmidae), in the Hiikawa River system, Shimane prefecture, Japan

2020 ◽  
Vol 23 (4) ◽  
pp. 445-452
Author(s):  
Ryosuke Morimoto ◽  
Masakazu Hayashi
Keyword(s):  
Life Cycle ◽  
River System

The life history of Cyclops scutifer Sars (Copepoda: Cyclopoida) in a small lake of the Matamek River System, Quebec

1978 ◽  
Vol 56 (12) ◽  
pp. 2603-2607 ◽  
Author(s):  
J. J. Boers ◽  
J. C. H. Carter
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Calanoid Copepod ◽  
River System ◽  
The Other ◽  
Cyclopoid Copepod ◽  
Small Lake ◽  
History Of ◽  
Cyclops Scutifer ◽  
Copepoda Cyclopoida

A study of the life history of the cyclopoid copepod Cyclops scutifer Sars in a small lake of the Matamek River System, Quebec, indicates a 1-year life cycle with four cohorts produced annually. The primary cohort overwinters as early nauplii and reaches maturity during midsummer when it spawns the primary cohort of the succeeding year. The other cohorts may merge with either each other or the primary cohort and contribute somewhat less to the overall cycle. Slower development of copepodites of the second cohort in 1976 may have been the result of an inadequate number of naupliar prey from the calanoid copepod Diaptomus minutus.

The biology of a landlocked form of the normally catadromous salmoniform fish Galaxias maculatus (Jenyns). I. Life cycle and origin

1971 ◽  
Vol 22 (2) ◽  
pp. 91 ◽  
Author(s):  
DA Pollard
Keyword(s):  
Life Cycle ◽  
New Zealand ◽  
River System ◽  
Heavy Rain ◽  
Early Spring ◽  
Ancestral Population ◽  
Late Winter ◽  
Eastern Australia ◽  
Galaxias Maculatus ◽  
Western Victoria

In contrast to most other members of the family Galaxiidae which live and reproduce in fresh water, Galaxias maculatus, the common jollytail of Australia and "whitebait" of New Zealand, is normaIly catadromous throughout its range (south-eastern Australia, New Zealand, and southern South America). In some athalassic inland lakes on the volcanic plains of south-western Victoria, however, a number of populations apparently descended from this species have becomelandlocked. The life cycle of the forminhabiting one of these lakes (the "landlocked jollytail" of Lake Modewarre) may be briefly summarized as follows: Gonadal maturation in the adult fish, which live in the slightly saline landlocked lake, begins around March and is almost completed by about June. The final stage of maturation is not reached, however, until these fish migrate short distances up intermittent inflowing creeks when the latter begin to flow in late winter and spring (July-October). Spawning takes place when the creeks are swollen after heavy rain, the eggs being deposited amongst flooded vegetation in shallow areas of slow-flowing water along the creek banks. Many of the spent fish die after spawning. The eggs, which are stranded when the flood-waters subside, develop amongst the vegetation on the banks above the normal water level. After development is complete reimmersion by the first flood to cover them stimulates hatching. The normal developmental period is probably about 2 weeks, but in the absence of flooding hatching can be delayed up to at least a month after fertilization. The newly hatched larvae are washed downstream into the lake where they feed and grow to maturity. They migrate upstream to spawn in the following late winter-early spring season at an age of approximately 1 year. The fish grow to about 9 cm in their first year, 14 cm in their second, and 17 cm in their third year. The average size of the females is greater than that of the males. The general features of the life history of this landlocked form are compared and contrasted with those of the stream-dwelling species G. maculatus and a number of other salmoniform fishes. The geological origin of the complex of lakes in south-western Victoria inhabited by landlocked galaxiid populations is discussed, and an hypothesis concerning the origin of the Lake Modewarre form from an ancestral population of G. maculatus in the Barwon-Leigh River system is advanced.

scholarly journals Comparative biology of two populations of Lutzomyia umbratilis (Diptera: Psychodidae) of Central Amazonia, Brazil, under laboratory conditions

2004 ◽  
Vol 64 (2) ◽  
pp. 227-235 ◽  
Author(s):  
S. C. B. Justiniano ◽  
A. C. Chagas ◽  
F. A. C. Pessoa ◽  
R. G. Queiroz
Keyword(s):  
Life Cycle ◽  
Cuticular Hydrocarbon ◽  
River System ◽  
Sand Fly ◽  
Amazon River ◽  
Adult Longevity ◽  
Isolated Populations ◽  
Rio Negro ◽  
Two Populations ◽  
Leishmania Guyanensis

Lutzomyia umbratilis is the main vector of cutaneous leishmaniasis due to Leishmania guyanensis in northern South America. It has been found naturally infected with this species of Leishmania only east of the Rio Negro and north of the Rio Amazonas. However, populations of this sand fly species are also present in areas south of the Amazon river system, which may act as a geographical barrier to the Leishmania guyanensis cycle. With the aim of looking for possible biological differences between populations of L. umbratilis from each side of this river system, their biology in the laboratory was investigated. Progenitors collected on tree bases in Manaus and Manacapuru (east and west, respectively, of the Rio Negro) were reared in the laboratory. Results from observations of the life cycle, fecundity, fertility, and adult longevity at 27ºC and 92% RH were analyzed by descriptive statistics and z, t, U, and chi2 tests. Although the Manaus and Manacapuru colonies showed a longer developmental time than most Lutzomyia species reared at similar temperatures, length of time of egg and 4th instar larva of the two populations differed significantly (p < 0.01). Females of the latter retained significantly (p < 0.001) less mature oocytes, and the general productivity (% adults from a known number of eggs) of the colony was significantly (p < 0.01) higher than that of the former. These results show that the L. umbratilis population of Manaus is more productive, and thus a better candidate for future mass-rearing attempts. The two populations differ in their life cycle, fecundity, fertility, adult longevity, and emergence. These differences may reflect some divergence of intrinsic biological features evolved as a result of their geographical isolation by the Rio Negro. It is expected that further investigations on morphometry, cuticular hydrocarbon, isoenzyme, molecular and chromossomal analyses, infection, and cross-mating experiments with these and other allopatric populations of both margins of the Amazon river system will help reveal whether or not L. umbratilis has genetically diverged into two or more reproductively isolated populations of vectors or non-vectors of Leishmania guyanensis.

scholarly journals The most important fishery resource in the Amazon, the migratory catfish Brachyplatystoma vaillantii (Siluriformes: Pimelodidae), is composed by an unique and genetically diverse population in the Solimões-Amazonas River System

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Kyara Martins Formiga ◽  
Jacqueline da Silva Batista ◽  
José Antônio Alves-Gomes
Keyword(s):  
Life Cycle ◽  
River System ◽  
Main Channel ◽  
Diverse Population ◽  
Single Population ◽  
Migration Patterns ◽  
Fishery Resource ◽  
Mitochondrial Dna Control Region ◽  
Molecular Variance ◽  
Management And Conservation

ABSTRACT The migratory catfish Brachyplatystoma vaillantii is one of the most important fishery resources in the Amazon. Intense capture occurs associated to its life cycle. In order to know the genetic status, we sequenced the mitochondrial DNA control region from 150 individuals of B. vaillantii, collected in five fishing landing locations, covering the length of the Solimões-Amazonas River in Brazil. Genetic diversity parameters suggest there is no genetic differentiation between the five localities. Population’s expansion indicated by R 2 and Fu’s Fs tests was also confirmed by the high number of unique haplotypes found. The Analyses of molecular variance indicated that nearly all variability was contained within locations (99.86%), and estimates of gene flow among B. vaillantii were high (F ST = 0.0014). These results suggest that Brachyplatystoma vaillantii forms a panmitic population along the Solimões-Amazonas River and, has greater genetic variability than other species of the Brachyplatystoma genus available so far. Although the influence of different tributaries on B. vaillantii migration patterns remains uncertain, a single population in the main channel should be consider in future policies for management of this resource. However, since the species’ life cycle uses habitats in several countries, its management and conservation depend greatly of internationally joined efforts.

Life-cycle duration, growth and spawning times of five species of atherinidae (Teleostei) found in a Western Australian estuary

1983 ◽  
Vol 34 (2) ◽  
pp. 287 ◽  
Author(s):  
JD Prince ◽  
IC Potter
Keyword(s):  
Life Cycle ◽  
River System ◽  
Marine Species ◽  
Sensu Stricto ◽  
Cycle Duration ◽  
Length Frequency ◽  
The Times ◽  
System Length ◽  
Australian Estuary ◽  
Marine Embayment

Five species of atherinid were collected monthly from the estuary of the Swan-Avon river system. Length-frequency data and gonadosomic indices showed that Atherinosoma presbyteroides, A. elongata, A. wallacei and Allanetta mugiloides typically have a 1-year life cycle and generally reach maturity at total lengths of 40-85 mm. The mean length of the mature females was significantly greater than that of the mature males in each Atherinosoma species, but not in Allanetta mugiloides. The fifth species, Pranesus ogilbyi, was often represented by many individuals with far greater total lengths (100-150 mm) than were found in the other four species, a feature that reflected the presence of two year classes. Length-frequency and gonadosomic data indicated that all five atherinid species breed over protracted periods during spring and summer. Values for the gonadosomic index and the absence of local marine populations of Atherinosoma elongata, Allanetta mugiloides and Atherinosoma wallacei confirmed that the populations of these species in the Swan-Avon are estuarine or estuarine-inland water sensu stricto. Gonadosomic values for the marine species A. presbyteroides and P. ogilbyi, allied with the times of disappearance of larger individuals from the estuary, suggested that only the former of these two species may breed to any extent in the estuary. Length-frequency histograms showed that the populations of A. presbyteroides and P. ogilbyi in the Swan-Avon are more heterogeneous than those of the same species in a nearby marine embayment.

Instar Succession, Vertical Distribution, and Interspecific Competition Among Four Species of Chaoborus

1977 ◽  
Vol 34 (1) ◽  
pp. 113-118 ◽  
Author(s):  
John C. H. Carter ◽  
Judith K. Kwik
Keyword(s):  
Life Cycle ◽  
Vertical Distribution ◽  
Interspecific Competition ◽  
River System ◽  
Spatial Separation ◽  
Oligotrophic Lakes ◽  
Intense Competition ◽  
Chaoborus Punctipennis ◽  
Competition For Food

Of four highly oligotrophic lakes of the Matamek River System, Quebec, Lac à la Croix contains Chaoborus punctipennis and C. trivittatus, Lac Gallienne C. americanus, Lac Randin C. americanus and C. trivittatus, and Lac Méchant C. flavicans and C. trivittatus. The instars are all planktonic except instars I–III of C. trivittatus in Lac à la Croix. All species have a 1-yr life cycle except C. americanus in Lac Gallienne which has a 2-yr cycle. The cycles of C. trivittatus in lacs Randin and Méchant are out of phase by 1 mo or more with those of C. americanus and C. flavicans, respectively. Seasonal increases in length occurred in most instars except those of C. punctipennis in Lac à la Croix. Both species in Lac à la Croix made fairly extensive diurnal migrations but in lacs Gallienne and Méchant all species remained near the surface. Intense competition for food is considered the most likely cause of seasonal or spatial separation of instars of similar size in all lakes.

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.

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