scholarly journals Anamorphic development of Apfelbeckia insculpta (L. Koch, 1867) (Diplopoda: Callipodida: Schizopetalidae)

2016 ◽  
Vol 68 (2) ◽  
pp. 445-450 ◽  
Author(s):  
Bojan Ilic ◽  
Vladimir Tomic ◽  
Luka Lucic ◽  
Bojan Mitic
Keyword(s):  
Life Cycle ◽  
Focal Species ◽  
Sexually Mature ◽  
Anamorphic Development

An overview of the anamorphic development of Apfelbeckia insculpta is provided. As in other myriapods and arthropods, this period of the life cycle includes different stages that are separated by molts. Based on an earlier description of post-embryogenesis of A. insculpta and on our data, we describe ten stadia that occur after juveniles of our focal species hatch from the egg. Each molt is accompanied by the addition of podous and apodous pleurotergites, leg-pairs and ocelli. Thus, the numbers of these structures can be used as reliable criteria for the separation of post-embryonic stadia in A. insculpta. Adulthood is reached through teloanamorphosis, i.e., with the ninth and last molt individuals become sexually mature and achieve adulthood. Sexes can be distinguished from stadium VIII onward.

Reproductive cycles, fat body cycles and socio-sexual behaviour in the Mallee dragon, Amphibolurus fordi (Lacertilia : Agamidae)

1978 ◽  
Vol 26 (4) ◽  
pp. 653 ◽  
Author(s):  
HG Cogger
Keyword(s):  
Life Cycle ◽  
Sex Ratio ◽  
Fat Body ◽  
New South ◽  
Reproductive Period ◽  
South Wales ◽  
Behavioural Types ◽  
Fat Bodies ◽  
Reproductive Cycles ◽  
Sexually Mature

A field study of the reproductive and fat cycles of the small agamid lizard Amphibolurus fordi was undertaken in two areas of mallee in central western New South Wales. The development of the gonads, including the histology of the testicular cycle, is described, together with correlated changes in the size of the inguinal fat bodies. The males emerge from winter torpor some 4-5 weeks before the females. The sex ratio approximates unity throughout the life cycle. Mating occurs from October to December; up to three clutches each of two or three eggs are laid in a season. The eggs hatch in 7-9 weeks after laying. The construction of the nesting chamber by the female is described. Apart from behaviour specifically geared to thermoregulation, two other behavioural types have been identified: male-female interactions involving only sexually mature individuals during the reproductive period, and non-sex-specific patterns which occur in both immature and mature individuals of either sex. Males are not territorial.

Destruction of immaturin activity in early mature mutants of Paramecium caudatum

1984 ◽  
Vol 72 (1) ◽  
pp. 111-120
Author(s):  
I. Miwa
Keyword(s):  
Life Cycle ◽  
Late Stage ◽  
The Other ◽  
Paramecium Caudatum ◽  
Wild Type ◽  
Mating Activity ◽  
Donor Cells ◽  
Immature Cells ◽  
Sexually Mature ◽  
Mutant Homozygote

Cells of Paramecium in the sexually immature period of the clonal life cycle contain a protein called immaturin, which represses mating activity when injected into sexually mature cells. The amount of immaturin at various stages of the immaturity period was examined by injecting cytoplasm from immature cells of one wild-type and two early mature mutant clones into mature cells of wild-type. The proportion of immature cells brought about by the injection increased until about 10–15 fissions after conjugation of the donor cells in all three clones. But the percentage of immature cells induced by the injection decreased rapidly from the 25th to the 30th fission of both early mature donors, while the percentage was still high with a wild-type donor of the same fission age. When cytoplasm of the Emt A (early mature mutant) homozygote taken immediately before maturation (about 27 fissions) was injected into the wild-type immature cells of 45 fissions after conjugation, 13% of the recipient cells expressed mating reactivity. But when cytoplasm of Emt A cells 20 and 50 fissions after conjugation was injected into the same cells, no reactive cell appeared. The results suggest that cytoplasm of the early mature mutant immediately before maturation contains some material that accelerates maturation when injected into wild-type cells in the late stage of immaturity. On the other hand, the immature cytoplasm of wild-type cells about 25 fissions after conjugation showed no effect when injected into early mature cells immediately before maturation. The function of the early mature gene product was suggested to be the destruction of immaturin activity.

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.

scholarly journals Anamorphic development and extended parental care in a 520 million-year-old stem-group euarthropod from China

2018 ◽  
Author(s):  
Dongjing Fu ◽  
Javier Ortega-Hernández ◽  
Allison C. Daley ◽  
Xingliang Zhang ◽  
Degan Shu
Keyword(s):  
Parental Care ◽  
Fossil Record ◽  
Growth Zone ◽  
Posterior Growth Zone ◽  
Stem Group ◽  
History Of ◽  
Sexually Mature ◽  
Chengjiang Lagerstätte ◽  
Extended Parental Care ◽  
Anamorphic Development

AbstractExtended parental care (XPC) is a complex reproductive strategy in which progenitors actively look after their offspring up to – or beyond – the first juvenile stage in order to maximize their fitness. Although the euarthropod fossil record has produced several examples of brood-care, the appearance of XPC within this phylum remains poorly constrained given the scarcity of developmental data for Palaeozoic stem-group representatives that would link juvenile and adult forms in an ontogenetic sequence. Here, we describe the post-embryonic growth of Fuxianhuia protensa from the early Cambrian Chengjiang Lagerstätte, and show parental care in this stem-group euarthropod. We recognize fifteen distinct ontogenetic stages based on the number and shape of the trunk tergites, and their allocation between the morphologically distinct thorax and abdomen. Our data demonstrate anamorphic post-embryonic development in F. protensa, in which tergites were sequentially added from a posterior growth zone. A life assemblage consisting of a sexually mature F. protensa adult alongside four ontogenetically coeval juveniles, constitutes the oldest occurrence of XPC in the panarthropod fossil record. These findings provide the most phylogenetically basal evidence of anamorphosis in the evolutionary history of total-group Euarthropoda, and reveal a complex post-embryonic reproductive ecology for its early representatives.

scholarly journals THE METAMORPHOSIS OF VISUAL SYSTEMS IN THE SEA LAMPREY

1957 ◽  
Vol 40 (6) ◽  
pp. 901-914 ◽  
Author(s):  
George Wald
Keyword(s):  
Life Cycle ◽  
Fresh Water ◽  
Petromyzon Marinus ◽  
Sea Lamprey ◽  
Mature Adult ◽  
Visual Systems ◽  
General Association ◽  
Vitamin A2 ◽  
Sexually Mature ◽  
Living Group

The life cycle of the sea lamprey, Petromyzon marinus, includes two metamorphoses. At the end of a period spent as a blind larva, buried in the mud of streams, a first metamorphosis prepares it to migrate downstream to the sea or a lake for its growth phase. Then, following a second metamorphosis, it migrates upstream as a sexually mature adult to spawn and die. The downstream migrants have a visual system based upon rhodopsin and vitamin A1, whereas that of the upstream migrants is based upon porphyropsin and vitamin A2. The livers contain vitamin A1 at all stages. The sea lamprey therefore exhibits a metamorphosis of visual systems, like those observed earlier among amphibia. The presence of porphyropsin in this member of the most primitive living group of vertebrates, as in fishes and amphibia, supports the notion that porphyropsin may have been the primitive vertebrate visual pigment. Its association with fresh water existence throughout this range of organisms also is consistent with the view that the vertebrate stock originated in fresh water. The observation that in the life cycle of the lamprey rhodopsin precedes porphyropsin is not at variance with the idea that porphyropsin is the more primitive pigment, since this change is part of the second metamorphosis, marking the return to the original environment. The observation that in lampreys, fishes, and amphibia, porphyropsin maintains the same general association with fresh water, and rhodopsin with marine and terrestrial habit, suggests that a single genetic mechanism may govern this association throughout this wide span of organisms.

scholarly journals The life cycle of Dendritobilharzia anatinarum cheatum, 1941 (Trematoda, Schistosomatidae)

1982 ◽  
Vol 77 (4) ◽  
pp. 389-396 ◽  
Author(s):  
Antonio Cesar Rios Leite ◽  
Hélio Martins de Araújo Costa ◽  
José Oswaldo Costa ◽  
Marcos Pezzi Guimarães ◽  
Walter dos Santos Lima
Keyword(s):  
Life Cycle ◽  
Blood Vessels ◽  
Portal System ◽  
Morphological Description ◽  
Domestic Duck ◽  
Intermediate Hosts ◽  
Snail Infection ◽  
Biomphalaria Straminea ◽  
Cairina Moschata ◽  
Sexually Mature

The life cycle of Dendritobilharzia anatinarum was completed experimentally in the laboratory. Cairina moschata domestica (domestic duck) and Biomphalaria straminea served respectively as definitive and intermediate hosts. Eggs passed in duck faeces hatch miracidia in 10 minutes when placed in water. Eight days after the snail infection, the mother sporocyst contains daughter sporocysts ready to migrate. Cercariae are present within the daughter sporocysts 23 days after infection and emerge from the snail on the 25th day. They actively penetrate the skin of the duck and after a prepatent of 39 days, sexually mature trematodes are present in the blood vessels of the bird. The adult parasite is predominantly in the renal-portal system and to a lesser degree in the lungs and mesentery. A detailed morphological description of the egg. miracidium, sporocyst and cercaria is presented.

CHANGES IN THE MULTIPLE HEMOGLOBIN PATTERNS OF SOME PACIFIC SALMON, GENUS ONCORHYNCHUS, DURING THE PARR–SMOLT TRANSFORMATION

1964 ◽  
Vol 42 (6) ◽  
pp. 697-703 ◽  
Author(s):  
W. E. Vanstone ◽  
Eve Roberts ◽  
H. Tsuyuki
Keyword(s):  
Life Cycle ◽  
Gel Electrophoresis ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Starch Gel Electrophoresis ◽  
Mature Adults ◽  
Salmon Fry ◽  
Starch Gel ◽  
Sexually Mature

By employing starch gel electrophoresis it has been found that coho salmon fry and smolts contain 10 anodal-migrating, and 12 cathodal-migrating, hemoglobin fractions. Prepuberal [Formula: see text]-year-old coho salmon caught at sea and sexually mature adults taken from fresh water contained the same anodal fractions and at approximately the same concentrations as were found in fry and smolts. However, the concentrations of the cathodal fractions had increased so that these were very nearly equal to those of the anodal fractions. Similar hemoglobin changes were found in both anadromous and land-locked sockeye salmon, but in this species seven anodal and six cathodal fractions were present at their "adult" concentrations in fry and smolts. Six other cathodal fractions which were absent entirely or present only in trace amounts in fry and smolts increased to their adult concentrations some time later in the life cycle of both varieties of sockeye. It is postulated that these changes reflect an ecological adaption to life in the ocean.

Ultrastructure of the basal body apparatus in epidermal cells of a sponge larva (Aplysilla SP: Demospongiae)

1992 ◽  
Vol 50 (1) ◽  
pp. 928-929
Author(s):  
R.L. Pinto ◽  
R.M. Woollacott
Keyword(s):  
Sodium Bicarbonate ◽  
Epoxy Resin ◽  
Basal Body ◽  
Phosphate Buffer ◽  
Similar Data ◽  
Basal Apparatus ◽  
Striated Rootlet ◽  
The Common ◽  
Basal Foot ◽  
Sexually Mature

The basal body and its associated rootlet are the organelles responsible for anchoring the flagellum or cilium in the cytoplasm. Structurally, the common denominators of the basal apparatus are the basal body, a basal foot from which microtubules or microfilaments emanate, and a striated rootlet. A study of the basal apparatus from cells of the epidermis of a sponge larva was initiated to provide a comparison with similar data on adult sponges.Sexually mature colonies of Aplysillasp were collected from Keehi Lagoon Marina, Honolulu, Hawaii. Larvae were fixed in 2.5% glutaraldehyde and 0.14 M NaCl in 0.2 M Millonig’s phosphate buffer (pH 7.4). Specimens were postfixed in 1% OsO4 in 1.25% sodium bicarbonate (pH 7.2) and embedded in epoxy resin. The larva ofAplysilla sp was previously described (as Dendrilla cactus) based on live observations and SEM by Woollacott and Hadfield.

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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