scholarly journals Growth parameters estimates of Maurolicus stehmanni Parin & Kobyliansky 1996 (Teleostei, Sternoptichydae) from south and southeastern Brazilian waters

2004 ◽  
Vol 52 (3-4) ◽  
pp. 195-205 ◽  
Author(s):  
Andre Bellucco ◽  
Ana Hara ◽  
Eduardo Machado Almeida ◽  
Carmen Lucia Del Bianco Rossi-Wongtschowski
Keyword(s):  
Life History ◽  
Growth Parameters ◽  
Pelagic Fish ◽  
Otolith Microstructure ◽  
Food Items ◽  
Open Sea ◽  
Otolith Microstructure Analysis ◽  
Rational Management ◽  
One Year

This paper on the otolith microstructure analysis of Maurolicus stehmanni presents estimates of the species growth parameters and longevity. The species inhabits the outer shelf and slope of the southern and southeastern Brazilian Exclusive Economic Zone (EEZ). Growth parameters are important for the knowledge of the species' life history and rational management. M. stehmanni constitutes an important link between the initial and final components of the alimentary chain of the open sea ecosystem, being one of the main food items for squids and large pelagic fish. Among the various applied methods those which presented the most coherent values for growth parameters and were best adapted to the von Bertallanfy's equation were: Li= 55mm K= 0.0088/day and to= 5.5 days Maurolicus stehmanni's longevity is of less than one year (around 220 days) and the sagita daily otolith rings are useful for the determination of its age.

scholarly journals Ekološki otisak cestovnog prometa na cresko-lošinjskom arhipelagu

Geoadria ◽  
2017 ◽  
Vol 15 (2) ◽  
pp. 269
Author(s):  
Hrvoje Grofelnik
Keyword(s):  
Seasonal Variations ◽  
Co2 Emission ◽  
Road Traffic ◽  
Dominant Role ◽  
Point Of View ◽  
Co2 Absorption ◽  
Northern Adriatic ◽  
Open Sea ◽  
One Year

Cres-Lošinj Archipelago is the largest insular traffic unit in Northern Adriatic. The archipelago consists of two large islands, Cres and Lošinj, and 27 smaller islands located among Kvarner, Kvarnerić, Rijeka Bay and open sea. From the point of view of traffic, this area gravitates mostly toward Rijeka traffic node. Traffic development of the islands was determined in the second half of the 20th century with the development of ferry traffic and road traffic on the islands. Today, the Archipelago is characterized by prominent seasonal variations of road traffic intensity due to dominant role of tourism in space valorisation. This research included partial determination of Ecological Footprint of road traffic on the islands on the basis of CO2 emission and capacity of insular surfaces to absorb CO2 .The author also created a model for calculating road mileage on the islands and indirectly calculated CO2 emission. The results indicated significant seasonal variations of CO2  emission on the islands, which are closely related to tourist valorisation of space and the number of non-residential vehicles on the islands. The paper also provides the ratio between residential and non-residential vehicles on the island, which influence the emission in accordance with their energy efficiency. The research showed that the capacity of CO2  absorption on Cres-Lošinj Archipelago is approximately 40 times greater than CO2 emission from road traffic during one year. 

Revisiting daily age determination in juvenile anchoveta Engraulis ringens

2019 ◽  
Vol 70 (8) ◽  
pp. 1143
Author(s):  
Guido Plaza ◽  
Steven E. Campana ◽  
Francisco Cerna ◽  
Akinori Takasuka ◽  
Camilo Rodríguez-Valentino ◽  
...  
Keyword(s):  
Stock Assessment ◽  
Age Determination ◽  
Pelagic Fish ◽  
Juvenile Stage ◽  
Otolith Microstructure ◽  
Double Blind ◽  
Traditional Age ◽  
Otolith Microstructure Analysis ◽  
Engraulis Ringens ◽  
Newly Hatched Larvae

Recent studies using otolith microstructure analysis have suggested that the duration of the juvenile stage in anchoveta (Engraulis ringens) is shorter than previously suspected, which suggests that the ages being entered into the traditional age-based stock assessment are incorrect. However, the interpretation of young pelagic fish otoliths remains problematic. To clarify the age interpretation of larval and juvenile E. ringens, newly hatched larvae were reared in a quasi-natural environment for periods of up to 103 days. The sagittal otoliths were subsequently examined and measured by international otolith experts in a double-blind workshop study. The young anchovy could be aged both accurately and precisely using otolith microstructure, after measures were taken to correct for unresolvable increments formed immediately after hatch. The presence of a fast-growth transition zone characterised by either considerable splitting or subdaily increments or both was confirmed. This study confirms the hypothesis of rapid growth and young age through the juvenile stage for anchoveta, suggesting that a critical appraisal of the annual age determinations used as the basis for anchoveta stock assessment is warranted. The otolith interpretation principles outlined in this study may apply broadly across many small pelagic fish species.

Prey tell: what quillback rockfish early life history traits reveal about their survival in encounters with juvenile coho salmon

2020 ◽  
Vol 650 ◽  
pp. 7-18 ◽  
Author(s):  
HW Fennie ◽  
S Sponaugle ◽  
EA Daly ◽  
RD Brodeur
Keyword(s):  
Life History ◽  
Early Life ◽  
Life History Traits ◽  
Direct Evidence ◽  
Coho Salmon ◽  
Larval Fish ◽  
Early Life History ◽  
In The Wild ◽  
Otolith Microstructure Analysis ◽  
Pelagic Juvenile

Predation is a major source of mortality in the early life stages of fishes and a driving force in shaping fish populations. Theoretical, modeling, and laboratory studies have generated hypotheses that larval fish size, age, growth rate, and development rate affect their susceptibility to predation. Empirical data on predator selection in the wild are challenging to obtain, and most selective mortality studies must repeatedly sample populations of survivors to indirectly examine survivorship. While valuable on a population scale, these approaches can obscure selection by particular predators. In May 2018, along the coast of Washington, USA, we simultaneously collected juvenile quillback rockfish Sebastes maliger from both the environment and the stomachs of juvenile coho salmon Oncorhynchus kisutch. We used otolith microstructure analysis to examine whether juvenile coho salmon were age-, size-, and/or growth-selective predators of juvenile quillback rockfish. Our results indicate that juvenile rockfish consumed by salmon were significantly smaller, slower growing at capture, and younger than surviving (unconsumed) juvenile rockfish, providing direct evidence that juvenile coho salmon are selective predators on juvenile quillback rockfish. These differences in early life history traits between consumed and surviving rockfish are related to timing of parturition and the environmental conditions larval rockfish experienced, suggesting that maternal effects may substantially influence survival at this stage. Our results demonstrate that variability in timing of parturition and sea surface temperature leads to tradeoffs in early life history traits between growth in the larval stage and survival when encountering predators in the pelagic juvenile stage.

DETERMINATION OF AFTER-RIPENING PERIOD AND HORMONAL RESPONSE OF OROBANCHE SOLMSII C.D. CLARKE SEEDS

1970 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Bista ◽  
G. B. Khattri ◽  
B. D. Acharya ◽  
S. C. Srivastava
Keyword(s):  
Growth Hormone ◽  
Seed Germination ◽  
Key Words ◽  
Incubation Period ◽  
Seed Set ◽  
Summer Season ◽  
Conditioning Period ◽  
Root Parasite ◽  
One Year

To find out the ability of Orobanche seeds to germinate immediately after seed set, seeds were germinated periodically at an interval of three months for one year in GR24. Some Orobanche seeds were capable of germination immediately after seed set but most required about nine months as after ripening or incubation period to be able to germinate. The phenomenon of after ripening in Orobanche seeds could be taken as an ecological measure to dormant over following unfavorable wet summer season. The growth hormone studies on Orobanche seed germination have shown that GA3 at a concentration of 100 ppm substantially enhanced seed germination when applied during pre-conditioning period. NAA showed some stimulatory effect at 0.5 - 1.0 ppm when applied during post-conditioning period but the hormone if applied during pre-conditioning period inhibited the germination. Kinetin failed to stimulate the germination at all the concentrations tested. Key words: Germination, root-parasite, hormone. Ecoprint Vol.11(1) 2004.

scholarly journals Quantitative determination of selenium in the most common food items sold in Egypt

2020 ◽  
Vol 95 (1) ◽  
Author(s):  
Fawzya Moatkhef ◽  
Hanaa Ismail ◽  
Neveen Agamy ◽  
Samar Aborhyem
Keyword(s):  
Quantitative Determination ◽  
Food Items ◽  
Common Food
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