Temporal and spatial differences in the reproductive biology of the sea urchin Arbacia dufresnii

2015 ◽  
Vol 66 (4) ◽  
pp. 329 ◽  
Author(s):  
Lucia Epherra ◽  
Damián G. Gil ◽  
Tamara Rubilar ◽  
Soledad Perez-Gallo ◽  
M. Belén Reartes ◽  
...  
Keyword(s):  
Sea Urchins ◽  
Seasonal Pattern ◽  
Seawater Temperature ◽  
Reproductive Traits ◽  
Wide Distribution ◽  
Eastern Coast ◽  
Spawning Period ◽  
Spatial Differences ◽  
Different Seasons ◽  
Temporal And Spatial

The reproductive cycle of Arbacia dufresnii was studied in two contrasting populations on the eastern coast of Patagonia (Nuevo Gulf and San Jorge Gulf) from January 2008 to August 2010. Sea urchins from San Jorge Gulf had larger test diameter and heavier gonads than did sea urchins from Nuevo Gulf. A. dufresnii showed an annual cycle in both populations, with gametogenesis occurring mainly in the autumn and the winter. An extended spawning period took place during the spring and the summer. Sea urchins from Nuevo Gulf had a strong seasonal pattern of reproduction, with presence of gonadal stages showing re-absortion and accumulation of reserves in nutritive cells at different seasons, whereas individuals from San Jorge Gulf had mature gametes during most of the year. Interannual variation of seawater temperature affected the gamete production and spawning duration in both populations. Higher temperatures during gametogenesis enhanced gonadal growth and gametes were released early. The major population differences found in gonadal cell composition highlight the plasticity in reproductive traits of A. dufresnii, and may be responsible for the wide distribution of A. dufresnii in different environments.

scholarly journals The Paracentrotus lividus populations from the northern Moroccan Atlantic coast: growth, reproduction and health condition

2005 ◽  
Vol 85 (4) ◽  
pp. 999-1007 ◽  
Author(s):  
Abdellatif Bayed ◽  
Françoise Quiniou ◽  
Ali Benrha ◽  
Monique Guillou
Keyword(s):  
Phytoplankton Bloom ◽  
Sea Urchins ◽  
Atlantic Coast ◽  
Seawater Temperature ◽  
Gonad Index ◽  
Paracentrotus Lividus ◽  
Health Condition ◽  
Abnormal Development ◽  
Spawning Period ◽  
High Wave Energy

The condition of three intertidal Paracentrotus lividus populations, which inhabit an area between Rabat and Casablanca (Morocco) known by its high wave energy and its substantial anthropogenic disturbances were described. The growth rate of the juvenile sea urchins in this intertidal zone was low compared with more sheltered populations. A sharp increase in the gonad index was observed between January and March at the beginning of a period of algal production, and was concomitant with increases in seawater temperature and food consumption rate. This gonad index increase was followed by a single spawning period occurring between March and June, probably triggered by the phytoplankton bloom induced by upwelling conditions. Larval development in all three populations was severely inhibited and could be explained, in part, by high and generalized Cu contamination throughout the region. Specific contamination of particular populations by Pb or Hg was attributed to local industries and the incomplete dispersion of pollutants in spite of the high hydrodynamics along the Moroccan Atlantic coast. One of the three populations studied showed strong indications of abnormal development; the degradation of its condition appeared to be due to the presence of a wadi (temporary river) which can seasonally reduce the salinity, directly affecting the sea urchin physiology and indirectly enhancing the metal toxicity.

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 TEMPERATURE-SENSITIVE MUTATIONS OF THE NOTCH LOCUS IN DROSOPHILA MELANOGASTER

Genetics ◽  
1975 ◽  
Vol 81 (1) ◽  
pp. 143-162 ◽  
Author(s):  
David L Shellenbarger ◽  
J Dawson Mohler
Keyword(s):  
Temperature Shift ◽  
Temperature Sensitive ◽  
Spatial Differences ◽  
Region Temperature ◽  
Complex Locus ◽  
Notch Locus ◽  
Temporal And Spatial ◽  
Chemical Conditions ◽  
Interallelic Complementation ◽  
The Right

ABSTRACT Temperature-conditional mutations of the Notch locus were characterized in an attempt to understand the organization of a "complex locus" and the control of its function in development. Among 21 newly induced Notch alleles, about one-half are temperature-conditional for some effects, and three are temperature-sensitive for viability. One temperature-sensitive lethal, l(1)Nts1, is functionally non-complementing for all known effects of Notch locus mutations and maps at a single site within the locus. Among the existing alleles involved in complex patterns of interallelic complementation, Ax59d5 is found to be temperature-sensitive, while fag, spl, and l(1)N are temperature-independent. Whereas temperature-sensitive alleles map predominantly to the right-most fifth of the locus, fag, spl, and l(1)N are known to map to the left of this region. Temperature-shift experiments demonstrate that fag, spl, and l(1)N cause defects at specific, non-overlapping times in development.—We conclude (1) that the Notch locus is a single cistron (responsible for a single functional molecule, presumably a polypeptide); (2) that the right-most fifth of the locus is, at least in part, the region involved in coding for the Notch product; (3) that the complexity of interallelic complementation is a developmental effect of mutations that cause defects at selected times and spaces, and that complementation occurs because the mutant defects are temporally and spatially non-overlapping; and (4) that mutants express selected defects due to critical temporal and spatial differences in the chemical conditions controlling the synthesis or function of the Notch product. The complexity of the locus appears to reside in controlling the expression (synthesis or function) of the Notch product in development.

Proximate Composition and Spatio-temporal Heterogeneity of Phytochemicals in Agave sisalana (sisal) adapted in different agro-ecological zones of Punjab, Pakistan

2021 ◽  
Author(s):  
Sobia Shahzad ◽  
Mumtaz Hussain ◽  
Hassan Munir ◽  
Muhammad Arfan
Keyword(s):  
Environmental Conditions ◽  
Proximate Composition ◽  
Block Design ◽  
Temporal Variations ◽  
Proximate Analysis ◽  
Ecological Zones ◽  
Autumn Season ◽  
Spatial Differences ◽  
Different Seasons ◽  
Spatio Temporal

Abstract Exploring extractable phytochemicals from locally adapted sisal plant vegetation vary seasonally at different locations. This study elaborated proximate composition and phytochemical heterogeneity in sisal due to varying environmental conditions analyzed from five districts, i.e., Chakwal, Khushab, Rawalpindi, Faisalabad, and Layyah in Punjab, Pakistan. Extensive surveying and plant sampling across two years 2017-18 and 2018-19, during mid-spring, summer, autumn, and winter seasons were carried out for understanding the seasonal impact on sisal. The present study was designed in a randomized complete block design (RCBD) and analyzed considering seasonal, yearly, and locational impact. The spatial differences in phytochemicals concentration were strongly associated with environmental conditions prevailing in different seasons. Autumn season reflected saponins, tannins, and flavonoids in higher concentrations during 2018-19 while steroids and terpenoids were higher during spring 2018-19. While Spatio-temporal variations in the proximate analysis were more apparent in different samples collected from different districts. Data recorded for the Khushab district and autumn season reflected the higher composition of a proximate analysis and phytochemical contents as compared to other seasons. Overall, the spatial differences in phytochemicals concentration were strongly associated with soils and environmental conditions prevailing in different seasons in selected districts.

Temporal and spatial patterns of spawning in jack mackerel, Trachurus declivis (Pisces:Carangidae), during 1988-91 in eastern Tasmanian waters

1995 ◽  
Vol 46 (5) ◽  
pp. 831 ◽  
Author(s):  
A Jordan ◽  
G Pullen ◽  
J Marshall ◽  
H Williams
Keyword(s):  
Thermal Structure ◽  
Shelf Break ◽  
Eastern Coast ◽  
Jack Mackerel ◽  
Spatial And Temporal Patterns ◽  
Cold Event ◽  
Temporal And Spatial ◽  
High Concentrations ◽  
Break Region ◽  
Eggs And Larvae

Ichthyoplankton surveys conducted during the summer and autumn of 1988-89, 1989-90 and 1990-91 along the eastern coast of Tasmania were used to examine the spatial and temporal patterns of eggs and larvae of jack mackerel, Trachurus declivis. Results indicate that the species spawns along the entire eastern coast during summer. Trachurus declivis eggs were most abundant at shelf-break stations, indicating that spawning is concentrated in this region, although high concentrations of eggs were present on the inner shelf in 1988-89, which can be attributed to rapid onshore transport in that year. Larvae were evenly dispersed over the shelf, with the distribution of larval ages showing no indication of inshore recruitment. Considerable interannual differences in sea surface temperatures and vertical thermal structure were apparent, with the warmer waters and strong thermal stratification in the summer of 1988-89 resulting from the influx of subtropical East Australian Current (EAC) water onto the shelf, which corresponded with a major La Nina 'cold event' at that time. It is suggested that the distribution of spawning is unaffected by the interannual variations in oceanography as the mature population spawns in deeper water in the shelf-break region that is unaffected by the warming in surface waters.

Dissolved Inorganic Nitrogen Fluxes at Sediment-Water Interface in Yangtze Estuarine Tidal Flat

2013 ◽  
Vol 726-731 ◽  
pp. 288-295 ◽  
Author(s):  
Huan Guang Deng ◽  
Dong Qi Wang ◽  
Zhen Lou Chen
Keyword(s):  
Tidal Flat ◽  
Environmental Gradients ◽  
Inorganic Nitrogen ◽  
Yangtze Estuary ◽  
Water Interface ◽  
Dissolved Inorganic Nitrogen ◽  
Overlying Water ◽  
Spatial Differences ◽  
Estuary Sediment ◽  
Temporal And Spatial

Yangtze estuary data, collected over three years, indicates that the temporal and spatial distributions of the environmental gradients reflect complicated seasonal changes and spatial differences in the exchange flux of the dissolved inorganic nitrogen (DIN= NH4++ NO3-+ NO2-) across the sediment-water interface. Overall in northern sites of Yangtze estuary, sediment was a source of ammonium (NH4+) (-3.67~10.65 mmol·m-2·d-1) probably because of higher salinities. Sediment was a sink for NH4+ in southern sites (-18.45~3.33 mmol·m-2·d-1) during most years. The exchange behavior of nitrate (NO3-) showed temporal and spatial variation from the upper to lower estuary and ranged from-32.8 mmol·m-2·d-1 to 35.8 mmol·m-2·d-1. The interface exchange direction of ammonium was affected by NH4+ concentration, but the relationship between NO3- concentration and the direction of flux was not obvious. The concentration of nitrite (NO2-) was very low and its interface flux was not related to DIN concentration. Overall, the sediment of Yangtze Estuarine tidal flat was a source of DIN to overlying water in the spring, but a sink for DIN during the other three seasons of the year.

Reproduction of the sea urchins Echinometra mathaei and Diadema savignyi on the South African eastern coast

1995 ◽  
Vol 46 (4) ◽  
pp. 751 ◽  
Author(s):  
AE Drummond
Keyword(s):  
South African ◽  
Sea Urchins ◽  
Gonad Index ◽  
Extended Period ◽  
Eastern Coast ◽  
The South ◽  
Annual Cycles ◽  
Echinometra Mathaei ◽  
Reproductive Cycles

The reproductive cycles of Echinometra mathaei and Diadema savignyi on the South African eastern coast were investigated by means of gonad index and histological methods. Both species showed annual cycles, with spawning occurring during the summer months (December to March-April), but the degree of gametogenic synchrony differed markedly between the two species. In D. savignyi, gametogenesis within and between sexes was in close synchrony and there was evidence suggesting that repeated spawning with a monthly rhythm occurred. In contrast, gametogenesis in E. mathaei was poorly synchronized and spawning occurred over an extended period.

Chamelea gallina reproductive biology and Minimum Conservation Reference Size: implications for fishery management in the Adriatic Sea

BMC Zoology ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Giada Bargione ◽  
Fortunata Donato ◽  
Giulio Barone ◽  
Massimo Virgili ◽  
Pierluigi Penna ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Adriatic Sea ◽  
Seawater Temperature ◽  
Reproductive Capacity ◽  
Great Effort ◽  
Important Species ◽  
Spawning Period ◽  
The Past ◽  
Chamelea Gallina ◽  
Size At Sexual Maturity

Abstract Background The striped venus clam Chamelea gallina is an economically important species in Adriatic Sea fisheries. The use of hydraulic dredging for its catch has a long history in Italy and its management faced several stages of development in the last 40 years. A great effort has been made in the past two decades to move from poorly or weakly managed fisheries to a well-structured co-management system to improve the sustainability of this fishery. However, a prerequisite for appropriate resource management is a sound knowledge of the biology and reproductive strategy of the species. Results We investigated three major biological features– the gametogenic cycle, size at sexual maturity and partial fecundity – by microscopic, histological and video analysis techniques. We demonstrated that its breeding season is driven by rises in seawater temperature and chlorophyll-a concentration and that its spawning period lasted from March to September. Size at sexual maturity was reached very early in the life cycle. As regards partial fecundity – the number of mature oocytes potentially released by females with ripe gonads in a single release event – varied in relation to size. Nevertheless, the reduction on the Minimum Conservation Reference Size (MCRS) from 25 to 22 mm (Delegated Regulation (EU) 2020/2237) lead to a 40% reduction in the number of emitted eggs. Conclusions We suggest that the ability of Adriatic clam stocks to withstand the strong fishing pressure of the past 40 years and the present one is due to their high reproductive potential and multiple spawning events combined with the effect of management measures (closed areas/seasons, quota, MCRS) and technical constraints on the gear and the sieve on board. Moreover, since the reduced MCRS for Venus shells is still larger than the size at maturity, it will probably not be detrimental to the reproductive capacity of the stock.

scholarly journals Temporal and spatial differences in three-egg clutch frequency of the African Black Oystercatcher

Ostrich ◽  
2015 ◽  
Vol 86 (1-2) ◽  
pp. 35-41 ◽  
Author(s):  
Dane M Paijmans ◽  
Douglas Loewenthal ◽  
Peter G Ryan ◽  
Philip AR Hockey
Keyword(s):  
Spatial Differences ◽  
African Black ◽  
Temporal And Spatial
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