Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

University of the Basque Country researcher provides tool to enable determination of age of anchovies with greater precision

13.03.2008
Biologist Pablo Cermeño Villanueva defended his PhD thesis at the University of the Basque Country (UPV/EHU), providing a tool to determine the age of anchovies with greater accuracy on a monthly or even weekly basis, thus enabling studies of the earliest phases of life to be undertaken.

The European anchovy (Engraulis encrasicolus, Linneaus 1875) is a coastal pelagic species of great importance. Not only does it support an important fishing industry, but it is also fundamental in marine growth chains.

The characteristics of this small fish are: a short life cycle, seasonal migrations, high growth rates, first reproduction at an early stage, a long egg-laying period and schooling behaviour (shoal or group). All this gives rise to considerable inter-annual fluctuations – given the variability of stock replacement by juvenile fish, these being highly vulnerable to environmental conditions.

European anchovy catches have dropped alarmingly over the last few decades, going from 83,615 tons in 1965 to 4,456 tons in 1982 and only 950 tons in 2005.

... more about:
»Basque »Life »PhD »anchovies »anchovy »juvenile

This is what Pablo Cermeño Villanueva focuses on in his PhD, undertaken at the Faculty of Science and Technology of the UPV/EHU, research work that provides a tool to determine the age of anchovies with greater accuracy on a monthly or even weekly basis, as opposed to merely annually, and enabling studies to be undertaken of the earliest phases of life, which are those that most bear on survival and, thereby, recruitment.

The PhD, entitled Analysis of the microstructure of the otoliths for growing and recruitment. Application to the European anchovy (Engraulis encrasicolus) in the Bay of Biscay was led by Doctor Beatriz Morales-Nin of the Institute for Advanced Studies of the Mediterranean (IMEDEA) and developed by the AZTI-Tecnalia Foundation under the leadership of Mr Andrés Uriarte. The PhD was defended at the Department of Zoology and Animal Cell Biology, obtaining summa cum laude.

Pablo Cermeño Villanueva is Doctor in Biology from the University of the Basque Country and President of the Basque AMBAR (Society for the Study and Conservation of Marine Fauna) and works for the World Wildlife Foundation (WWF).

Daily growth techniques

The application of daily growth techniques enables the discovery of aspects about growth and its relationship with the environment. The development of the technique in this current research will enable a clarification of when and how stock replacement by juvenile European anchovy in the Bay of Biscay occurs and understanding of the relationship between growth and mortality in the first phases of the development of the species.

Determining the age in days of the juveniles enables obtaining the distribution of these juveniles or survivors of the larval stage according to their month of birth; comparing this data, not only at an inter-annual level, but also showing the variations produced throughout the year their relation with the oceanographic conditions present at the different periods of the year.

The aim of the PhD thesis was to develop and apply this technique to the study and management of the European anchovy. To this end and by means of a series of experiments using chemical marking during captivity, for the first time the daily formation of growth rings in this species has been validated. The chemical marking was carried out, at least during short periods of captivity, using the soluble complex of calcium that both juvenile and adult anchovies deposit as a daily ring of growth in their otoliths.

The daily growth rings deposited in the otoliths form a complex pattern of daily growth which were analysed using both scanning electron microscopy (SEM) as well as optical microscopy with image analysing. In this way, a reproducible methodology for measuring age in days is proposed and which can serve as a guideline for further or other research. Thus, not only the distribution of survivors over a specific year is obtained, but also - and for the first time ever – a growth curve for the first months of life of the European anchovy.

Irati Kortabitarte | alfa
Further information:
http://www.basqueresearch.com/berria_irakurri.asp?Berri_Kod=1670&hizk=I

Further reports about: Basque Life PhD anchovies anchovy juvenile

More articles from Life Sciences:

nachricht Good preparation is half the digestion
15.11.2018 | Max-Planck-Institut für Stoffwechselforschung

nachricht How the gut ‘talks’ to brown fat
16.11.2018 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

NASA keeps watch over space explosions

16.11.2018 | Physics and Astronomy

UNH scientists help provide first-ever views of elusive energy explosion

16.11.2018 | Physics and Astronomy

How the gut ‘talks’ to brown fat

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>