scholarly journals Embryonic, Larval, and Early Juvenile Development of the Tropical Sea Urchin,Salmacis sphaeroides(Echinodermata: Echinoidea)

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
M. Aminur Rahman ◽  
Fatimah Md. Yusoff ◽  
A. Arshad ◽  
Mariana Nor Shamsudin ◽  
S. M. N. Amin
Keyword(s):  
Sea Urchins ◽  
Morphological Changes ◽  
Sperm Concentration ◽  
Fertilization Rate ◽  
Life History Strategies ◽  
Early Juvenile ◽  
Culture Techniques ◽  
Unicellular Algae ◽  
Tropical Sea ◽  
Juvenile Development

Salmacis sphaeroides(Linnaeus, 1758) is one of the regular echinoids, occuring in the warm Indo-West Pacific, including Johor Straits, between Malaysia and Singapore. In order to investigate the developmental basis of morphological changes in embryos and larvae, we documented the ontogeny ofS. sphaeroidesin laboratory condition. Gametes were obtained from adult individuals by 0.5 M KCl injection into the coelomic cavity. Fertilization rate at limited sperm concentration (10−5dilution) was96.6±1.4% and the resulting embryos were reared at 24°C. First cleavage (2-cell), 4-cell, 8-cell, 16-cell, 32-cell, and multicell (Morulla) stages were achieved 01.12, 02.03, 02.28, 02.51, 03.12, and 03.32 h postfertilization. Ciliated blastulae with a mean length of174.72±4.43 μm hatched 08.45 h after sperm entry. The gastrulae formed 16.15 h postfertilization and the archenteron elongated constantly while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larva started to feed unicellular algae in 2 d, grew continuously, and finally attained metamorphic competence in 35 d after fertilization. Metamorphosis took approximately 1 h 30 min from attachment to the complete resorption of larval tissues and the development of complete juvenile structure with adult spines, extended tubefeet and well-developed pedicellaria, the whole event of which usually took place within 1 d postsettlement. This study represents the first successful investigation on embryonic, larval, and early juvenile development ofS. sphaeroides. The findings would greatly be helpful towards the understanding of ontogeny and life-history strategies, which will facilitate us to develop the breeding, seed production, and culture techniques of sea urchins in captive condition.

Fate of sperm membrane in fertilized ova

1993 ◽  
Vol 51 ◽  
pp. 40-41
Author(s):  
Frank J. Longo
Keyword(s):  
Electron Microscopy ◽  
Electrical Activity ◽  
Sea Urchins ◽  
Morphological Changes ◽  
Integrated System ◽  
Electrophysiological Recording ◽  
Experimental Conditions ◽  
The Status ◽  
Sperm Membrane ◽  
Temporal And Spatial

Measurement of the egg's electrical activity, the fertilization potential or the activation current (in voltage clamped eggs), provides a means of detecting the earliest perceivable response of the egg to the fertilizing sperm. By using the electrical physiological record as a “real time” indicator of the instant of electrical continuity between the gametes, eggs can be inseminated with sperm at lower, more physiological densities, thereby assuring that only one sperm interacts with the egg. Integrating techniques of intracellular electrophysiological recording, video-imaging, and electron microscopy, we are able to identify the fertilizing sperm precisely and correlate the status of gamete organelles with the first indication (fertilization potential/activation current) of the egg's response to the attached sperm. Hence, this integrated system provides improved temporal and spatial resolution of morphological changes at the site of gamete interaction, under a variety of experimental conditions. Using these integrated techniques, we have investigated when sperm-egg plasma membrane fusion occurs in sea urchins with respect to the onset of the egg's change in electrical activity.

scholarly journals Relationship of arctic fox (Alopex lagopus L.) sperm morphology with age of males, sperm concentration, ejaculate volume and acrosin activity

2018 ◽  
Vol 18 (3) ◽  
pp. 741-752 ◽  
Author(s):  
Karolina Stasiak ◽  
Stanisław Kondracki ◽  
Maria Iwanina
Keyword(s):  
Sperm Morphology ◽  
Semen Quality ◽  
Morphological Changes ◽  
Sperm Concentration ◽  
Arctic Fox ◽  
Young Males ◽  
Arctic Foxes ◽  
Relationship Of ◽  
Acrosin Activity ◽  
Sperm Acrosome

Abstract The aim of the study was to determine the relationship of sperm morphology with age of males, ejaculate concentration and volume, as well as with acrosin activity determined in sperm acrosome extracts. The study used manually collected ejaculates from 9 male arctic foxes, including 6 young males aged one year and 3 older males (between 3 and 5 years of age). All of the 39 ejaculates used in the study were classified as normal based on motility exceeding 70%. The ejaculates collected from the foxes were evaluated for volume, sperm concentration and frequency of morphological changes including primary and secondary defects. The spermiograms of the male arctic foxes were classified according to a six-grade subjective scale. In addition, acrosin activity was determined in the sperm acrosome extracts. The data were analysed using the criteria of male age, sperm concentration, ejaculate volume, and acrosin activity. The morphology of arctic fox spermatozoa was dependent on the age of the male. A greater number of morphologically altered spermatozoa tended to occur in the ejaculates of young foxes, which were in their first breeding season. In addition, statistical analysis revealed positive relationships between the frequency of morphological changes in sperm and their ejaculate concentration. In contrast, there were no significant correlations between the percentages of morphologically changed spermatozoa and the ejaculate volume and the content of acrosin, which is an indicator of acrosomal integrity. Semen quality is dependent on the number of sperm in ejaculate with morphological defects which prevent oocyte fertilization. Therefore, morphological assessment of semen, which covers both the number and type of morphological changes, is highly useful when selecting appropriate males for reproduction.

P–031 The effect of ejaculatory abstinence period on embryological and clinical outcomes in ICSI cycles: A retrospective analysis of 3,353 cycles

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
G C Cermisoni ◽  
L Pagliardini ◽  
A Alteri ◽  
L D Santis ◽  
S Esposito ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Live Birth ◽  
Sperm Quality ◽  
Sperm Concentration ◽  
Live Birth Rate ◽  
Fertilization Rate ◽  
Ongoing Pregnancy ◽  
Abstinence Period ◽  
Blastulation Rate ◽  
Ejaculatory Abstinence

Abstract Study question Does ejaculatory abstinence period in male affect embryological and pregnancy outcomes following fresh embryo transfers in ICSI cycles? Summary answer Shorter ejaculatory abstinence period is associated with lower triploid zygotes rate per ICSI cycle but it does not affect clinical outcomes after fresh embryo transfers. What is known already Lower sperm quality may negatively impact on fertilisation rate and embryo morphokinetic parameters after ICSI and the effect of the ejaculatory abstinence period before semen collection on seminal parameters and sperm quality has been widely reported. However, the impact of ejaculatory abstinence on clinical outcomes is still controversial. WHO (World Health Organization) guideline recommended that abstinence period should be 2–7 days. Even so, there are no larger prospective trials determining the optimal timing for ejaculatory abstinence period for infertile couples. Study design, size, duration This is a single center retrospective observational study of 3,353 fresh cycles from January 2017 to December 2020. Semen analysis was done according to the WHO criteria. Exclusion criteria for this study were frozen gametes and cycles with no retrieved oocytes. Primary outcomes were fertilization rate and triploid zygotes rate. Secondary outcomes were blastulation rate, ongoing pregnancy rate and live birth rate per fresh embryo transfer. Participants/materials, setting, methods The correlation between ejaculatory abstinence and continuous outcomes was evaluated by Spearman’s correlation analysis in order to detect potential non-linear associations. Generalized linear model and logistic regression were used, respectively for continuous and binary outcomes, in order to adjust for confounders such as female age, male age, number of retrieved oocytes, percentage of mature oocytes, infertility causes, seminal volume, sperm concentration and total progressive sperm motility. A p value <0.05 was considered significant. Main results and the role of chance The male mean age was 40.3±5.5 and mean duration of abstinence was 2.9±1.7 days. The mean age of female patients was 38.2±4.0. Higher ejaculatory abstinence period was associated with a higher sperm concentration (Spearman p = 3.1x10–6) but not with a higher total sperm progressive motility. Even so, no significant correlation with EA were observed when considering fertilization rate, blastulation rate, ongoing pregnancy and live birth rate per transfer in analyzed cycles. Triploid zygote rate was positively associated with a higher ejaculatory abstinence period. For the ejaculatory abstinence period of 1 day (n = 64), 2 days (n = 1523), 3 days (n = 1032), 4 days (n = 408), 5 days (n = 174), 6 days (n = 47) and ≥7 days (n = 105) the mean triploid rate was 2.4%, 2.4%, 2.5%, 4.1%, 3.6%, 5.4% and 4.3%, respectively (Spearman p = 9x10–3). Triploid zygote rate was independent of semen volume, concentration and total progressive motility. Limitations, reasons for caution This is a large observational study with a retrospective data collection. Despite our methodological approach, the presence of biases related to retrospective design can not be excluded and it may be a reason for caution. Wider implications of the findings: Our results demonstrate that ejaculatory abstinence period do not affect blastulation, ongoing pregnancy and live birth rates. The current findings discourage an abstinence time longer than 3 days due to its association with a higher abnormal fertilization rate. Trial registration number Not applicable

Sperm concentration and fertilization rate in Bufo arenarum (Amphibia: Anura)

1975 ◽  
Vol 62 (2) ◽  
pp. 481-486
Author(s):  
M. O. Cabada
Keyword(s):  
Sperm Concentration ◽  
Fertilization Rate ◽  
Experimental Results ◽  
General Validity ◽  
Psammechinus Miliaris ◽  
Bufo Arenarum

The influence of sperm concentration upon the fertilization rate of Bufo arenarum oocytes was determinated. The experimental results were analysed according to the theories of Rothschild and Swann, and Hultin and Hagstrom for Psammechinus miliaris. The experimental results agreed with the predictions of the latter theory. Since Bufo arenarum and Psammechinus miliaris oocytes differ in both size and disposition of jelly envelopes, the postulations of Hultin and Hagstrom's theory appear to have a general validity.

scholarly journals Decapodid and early juvenile development in the protandrous shrimp Campylonotus vagans (Crustacea: Decapoda: Caridea), with notes on larval morphology

2003 ◽  
Vol 83 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Sven Thatje ◽  
Gustavo A. Lovrich
Keyword(s):  
Low Temperatures ◽  
Juvenile Stage ◽  
Tierra Del Fuego ◽  
Caridean Shrimp ◽  
Early Juvenile ◽  
Morphological Variations ◽  
Sexual Determination ◽  
Juvenile Stages ◽  
Two Stages ◽  
Juvenile Development

The decapodid and first two juvenile stages of the caridean shrimp Campylonotus vagans from the Subantarctic Beagle Channel (Tierra del Fuego, Argentina) are described and illustrated in detail. The complete larval and early juvenile development of this species from rearings under controlled laboratory conditions were analysed. Zoeal morphology in two stages of an abbreviated development was identical to a description from plankton and hatched larvae of a previous work, and therefore we only compare and discuss slight morphological variations in this study. The first juvenile is large and already resembles some features of adults, lacking all ventral rostral and the fourth dorsal rostral spine only which appears in the following stage, and the second pereiopod not yet being as predominant as in adults. Sexual determination is not yet possible up to the described second juvenile stage. The abbreviated larval development in a Subantarctic shrimp species is discussed as an adaptation to low temperatures and pronounced seasonality.

scholarly journals The Most Extreme Sexual Size Dimorphism among Birds: Allometry, Selection, and Early Juvenile Development in the Great Bustard (Otis tarda)

The Auk ◽  
2009 ◽  
Vol 126 (3) ◽  
pp. 657-665 ◽  
Author(s):  
Juan C. Alonso ◽  
Marina Magaña ◽  
Javier A. Alonso ◽  
Carlos Palacín ◽  
Carlos A. Martín ◽  
...  
Keyword(s):  
Sexual Size Dimorphism ◽  
Great Bustard ◽  
Size Dimorphism ◽  
Otis Tarda ◽  
Early Juvenile ◽  
Juvenile Development

Survival of seaweeds ingested by three species of tropical sea urchins from Brazil

Hydrobiologia ◽  
1991 ◽  
Vol 222 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Mariana Cabral de Oliveira
Keyword(s):  
Sea Urchins ◽  
Tropical Sea
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