scholarly journals Hatching and larval export of the intertidal crab Neohelice granulata in Mar Chiquita coastal lagoon, Argentina

2013 ◽  
Vol 103 (2) ◽  
pp. 124-133 ◽  
Author(s):  
Guillermina Sánchez Vuichard ◽  
Nahuel Farías ◽  
Tomás Luppi
Keyword(s):  
Embryonic Development ◽  
Coastal Lagoon ◽  
Time Scale ◽  
Tidal Range ◽  
Salinity Range ◽  
Dark Cycle ◽  
Endogenous Rhythms ◽  
Neohelice Granulata ◽  
Intertidal Crab ◽  
Larval Hatching

Synchronization in the events of the reproductive cycle in female Neohelice granulata Dana, 1851 were studied from samples taken weekly and biweekly from September to December 2006 in the Laguna Mar Chiquita. The timing and larval hatching and synchronicity were inferred from numbers of ovigerous females and observing the stages of embryonic development. Synchronization in larval hatching also was observed in females in experiments in dark for a period of 48 hours, at three different salinities (10, 23 and 33 ppm). In addition plankton sampling were performed in order to study larval exportation at the field and its link to the tidal and light/dark cycles. We found that ovigerous females of N. granulata have a marked synchronization in embryonic development which results in that most of berried females are close to hatching within a period of maximum tidal range (days). Within this period, there is a synchronization of hatching at a time scale of hours, governed by environmental conditions. The salinity range used in this study (10-32‰) did not affect hatching synchronicity neither time to hatch. Hatching was synchronized according to endogenous rhythms governed mainly by the tidal cycle and secondarily by the breadth of it. It is also conditioned by the light-dark cycle through an exogenous cycle, so that the hatchings would occur mostly at night high tides.

scholarly journals The influence of habitat on metabolic and digestive parameters in an intertidal crab from a SW Atlantic coastal lagoon

2021 ◽  
Vol 151 ◽  
Author(s):  
Eugenia Méndez ◽  
M. Soledad Michiels ◽  
Alejandra A. López-Mañanes
Keyword(s):  
Lipase Activity ◽  
Coastal Lagoon ◽  
Protein Concentration ◽  
Metabolic Parameters ◽  
Adult Males ◽  
Experimental Diet ◽  
Neohelice Granulata ◽  
Intertidal Crab ◽  
In The Wild ◽  
Sw Atlantic

The hepatopancreas of decapod crustaceans is an organ which can act as indicator for digestive and metabolic parameters under different physiological and / or environmental conditions. However, biochemical studies on digestive and metabolic parameters of the hepatopancreas of euryhaline burrowing crabs such as Neohelice granulata from habitats with different diet compositions are still scarce. In the wild, adult males of N. granulata from Mar Chiquita Coastal Lagoon (Argentina) in mudflat habitat have diets with higher lipid and protein content than crabs from the saltmarsh, suggesting that diets could be an important factor influencing hepatopancreas activities. We tested this hypothesis here by exposing adult male crabs to a similar experimental diet and comparing hepatopancreas parameters for lipid components and protein metabolism between males from these two habitat types at different times (up to three months). At month 3, we noticed a decrease of the triglyceride concentration and lipase activity and an increase of protein concentration in crabs from the mudflat. In contrast, triglycerides and protein concentration did not change in crabs from the saltmarsh, while lipase activity decreased and levamisole insensitive AP increased at month 3. The results indicate that digestive and metabolic parameters in the hepatopancreas of crabs from habitats varying in diet content remain different, even if crabs are subsequently fed by a similar experimental diet. This suggests that specific intrinsic regulations of these hepatopancreas parameters could operate differently in each habitat and could not be changed by recent diet conditions.

scholarly journals Embryonic development in Zungaro jahu

Zygote ◽  
2016 ◽  
Vol 25 (1) ◽  
pp. 17-31 ◽  
Author(s):  
Camila Marques ◽  
Francine Faustino ◽  
Bruno Bertolucci ◽  
Maria do Carmo Faria Paes ◽  
Regiane Cristina da Silva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Embryonic Development ◽  
Egg Cell ◽  
Gastrula Stage ◽  
Transmission Electron ◽  
Larval Hatching ◽  
Morula Stage ◽  
Zygote Stage ◽  
Scanning Electron

SummaryThe aim of this study was to characterize the embryonic development of Zungaro jahu, a fresh water teleostei commonly known as ‘jaú’. Samples were collected at pre-determined times from oocyte release to larval hatching and analysed under light microscopy, transmission electron microscopy and scanning electron microscopy. At the first collection times, the oocytes and eggs were spherical and yellowish, with an evident micropyle. Embryo development took place at 29.4 ± 1.5°C and was divided into seven stages: zygote, cleavage, morula, blastula, gastrula, organogenesis, and hatching. The differentiation of the animal and vegetative poles occured during the zygote stage, at 10 min post-fertilization (mpf), leading to the development of the egg cell at 15 mpf. From 20 to 75 mpf, successive cleavages resulted in the formation of 2, 4, 8, 16, 32 and 64 blastomeres. The morula stage was observed between 90 and 105 mpf, and the blastula and gastrula stage at 120 and 180 mpf; respectively. The end of the gastrula stage was characterized by the presence of the yolk plug at 360 mpf. Organogenesis followed, with differentiation of the cephalic and caudal regions, elongation of the embryo by the cephalo-caudal axis, and somitogenesis. Hatching occurred at 780 mpf, with mean larval total length of 3.79 ± 0.11 mm.

Fish composition in a south-western Atlantic temperate coastal lagoon: spatial–temporal variation and relationships with environmental variables

2009 ◽  
Vol 89 (3) ◽  
pp. 593-604 ◽  
Author(s):  
M. González Castro ◽  
J.M. Díaz de Astarloa ◽  
M.B. Cousseau ◽  
D.E. Figueroa ◽  
S.M. Delpiani ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Coastal Lagoon ◽  
Environmental Variables ◽  
Mesh Size ◽  
High Abundance ◽  
Spatial And Temporal Variation ◽  
Salinity Range ◽  
Buenos Aires Province ◽  
Western Atlantic ◽  
Odontesthes Argentinensis

Mar Chiquita, an irregularly shaped brackish-water coastal lagoon, is located in the Buenos Aires province of Argentina and considered since 1996 by the Coordination Council of the Man and Biosphere Program of UNESCO as a World Reserve of Biosphere. The present paper aims to study both the spatial and temporal variation of fish composition in this coastal lagoon and the influence of some environmental variables on the relative abundance of the main fish species. Monthly sampling surveys over a two-year period in three different areas were conducted, using a beach-seine net and three monofilament-gill nets with different mesh size. Twenty-eight species belonging to four bio-ecological categories were identified, five of them are new records for Mar Chiquita fish community. The correspondence analysis showed strong relationships between high salinity range and the abundance of Brevoortia aurea, Cynoscion guatucupa and Pomatomus saltatrix. Conversely, low salinity range corresponded to high abundance of Mugil platanus and Odontesthes argentinensis. High temperatures were corresponded with abundance of Micropogonias furnieri and Brevoortia aurea. In contrast, high abundance of both Odontesthes argentinensis and Oligosarcus jenynsii were corresponded to low temperatures. Brevoortia aurea, Mugil platanus and Odontesthes argentinensis were the most abundant species, representing more than 80% of the total capture. The group of estuarine-nondependent-marine fish presented the highest species richness. Estuarine-dependent-marine species presented for both juveniles and adults specimens the highest abundance values.

scholarly journals Influence of the nycthemeral cycle on the roosting behaviour of the Orange-winged Amazon

2012 ◽  
Vol 84 (2) ◽  
pp. 509-516
Author(s):  
Leiliany N. de Moura ◽  
Maria Luisa da Silva ◽  
Jacques M.E. Vielliard
Keyword(s):  
Light Intensity ◽  
Weather Conditions ◽  
Ambient Light ◽  
Dark Cycle ◽  
Weather Factors ◽  
Endogenous Rhythms ◽  
Circadian Periodicity ◽  
Environmental Stimuli ◽  
Amazona Amazonica

Environmental stimuli exert important effects on the expression of the endogenous rhythms. Daily movements of groups of parrots in response to the light/dark cycle have been studied by several researchers. However, the factors modifying the intrinsic rhythmicity of this behaviour remain little known. This study describes how the nychthemeral/circadian periodicity of roost daily movements of the Orange-winged Amazon Amazona amazonica is modified by weather factors. Numbers of parrots arriving or leaving the roosting site Ilha dos Papagaios were determined on a minute by minute basis. More parrots have significantly arrived at the roost after sunset than before, while more parrots have significantly left the roost before sunrise than after. The peak exodus of parrots occurred at 23 ± 5.24 minutes before sunrise, when the average light intensity was 1 lux. The peak influx of parrots occurred at 6 ± 6.1 minutes after sunset, when the average light intensity was 50 lux. By altering ambient light intensity, weather conditions have significantly influenced the arrival and departure times, with parrots leaving later and arriving earlier when conditions were overcast at the roost site.

Salinity Distribution in the Tay Estuary.

1975 ◽  
Vol 75 (1-2) ◽  
pp. 29-39
Author(s):  
D. J. A. Williams ◽  
J. R. West
Keyword(s):  
River Flow ◽  
Tidal Range ◽  
Salinity Range ◽  
Salinity Distribution ◽  
Strong Function ◽  
Tidal Circulation ◽  
Tidal State ◽  
Minimum Depth ◽  
The Relationship ◽  
Tay Estuary

SynopsisSalinity distribution in the Tay estuary measured during the years 1969–70 is influenced by freshwater flow and tidal range. Between Pool and Flisk, tidal-depth-mean salinity is a strong function of river flow but is much less influenced by tidal range. The relationship between salinity range (difference between maximum and minimum depth-mean salinities) and tidal range can be approximated by a linear function. The observed vertical salinity distribution varies with tidal state. The net non-tidal circulation has been estimated at Pool, Broughty Ferry, Newport, Balmerino and Flisk, and found to be dependent on river flow and position.

Feeding and osmoregulation in the euryhaline crab Neohelice granulata: digestive parameter responses

2019 ◽  
Vol 69 (4) ◽  
pp. 433-449 ◽  
Author(s):  
Eugenia Méndez ◽  
Alejandra A. López Mañanes ◽  
Silvina A. Pinoni
Keyword(s):  
Proteolytic Activity ◽  
Coastal Lagoon ◽  
Environmental Conditions ◽  
Digestive Enzymes ◽  
Buenos Aires ◽  
Amylase Activity ◽  
Metabolic Flexibility ◽  
Buenos Aires Province ◽  
Neohelice Granulata

Abstract When a species often experiences variation in its environmental conditions, metabolic flexibility is required. We studied the duration of the digestive cycle and the activity of key digestive enzymes (proteolytic, amylase, lipase) at short and long times after feeding in the hepatopancreas of the osmoregulator crab Neohelice granulata from the Mar Chiquita coastal lagoon (Buenos Aires Province, Argentina). We compared these responses upon hyper-regulation and under osmoconformation conditions (10 and 35 psu). The results show the ability of this crab to hyper-regulate in different feeding states. No significant differences were observed in the duration pattern of the digestive cycle between hyper-regulation and osmoconformity. However, distinct responses after feeding were observed in the activities of the digestive enzymes studied in relation to the osmoregulatory state. In individuals exposed to 35 psu, proteolytic activity was higher at 8 h and remained constant until 72 h after feeding. At 10 psu, this activity was higher at 48 h after feeding than before feeding. At 35 psu, the amylase activity after feeding was greater than the prefeeding activity. No differences were observed in the activity of lipase at 35 psu, but at 10 psu this activity was lower 1 h after feeding than before feeding. This work constitutes a contribution to our knowledge of the physiology of crustaceans and attempts to clarify the possible mechanisms of digestive settings associated with hyper-regulation.

scholarly journals Land Feature Extraction-Identification and Descrimincation using Geospatial Technique

10.29007/ckgd ◽  
2018 ◽  
Author(s):  
Dharmesh Modi ◽  
Subhash Bhandari ◽  
Laxmansinh B. Zala
Keyword(s):  
Remote Sensing ◽  
Time Scale ◽  
Regional Scale ◽  
High Tide ◽  
River Mouth ◽  
Tidal Currents ◽  
Tidal Range ◽  
Large Contribution ◽  
Geological Time Scale ◽  
Geomorphological Features

The Gulf of Cambay/Khambhat, (GoC), the study area is highly influenced by the tidal currents other than geological and structural set up of the region. In Gulf of Cambay, a large tidal range during high and low tides give rise to strong tidal currents and develops a mechanism of sediment transportation. Interestingly the inverted funnel shape of GoC has large contribution for the sediment deposition in this region. During high tide the tide currents move into the Gulf and encroaches the river mouth whereas during low tide, they move out. This regular phenomena since long period on geological time scale has modified the geomorphological features in this region.Along the major estuaries of Sabarmati, Mahi, Narmada and Tapi, the sediment budget is controlled by seasonal variation and also by tide and ebb phenomena.Using remote sensing images of different time scale and topographical map one can study the changes in geomorphological features. Satellite remote sensing technique has proven to be the paramount tool for studying surficial land features, especially for the inaccessible area or where time variable studies and regional scale studies are carried out. The well-developed natural or artificial features near to coastline viz salt pan, marshy land, mudflats, rocky cliffs, alluvial cliffs, wet land, mangroves, erosional and depositional features are well studied with the help of remote sensing techniques.

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