AFORO - Shape Analysis of Fish Otoliths





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Otolith database help

> Age: Related to the donnor fish and codified in days. Here, a year contains 365 days. It is possible to use years in the query by clicking on the checkbox. Note that fish maximum age may vary greatly between species.

> All Related Images:  In the individual results page it is possible to obtain a general view of all otolith images related to that species. If clicked a new page opens showing all otoliths ordered by Fish Length.

> Contributors Field that contains general information about the source of information. Usually it contains data on the oceanographic cruise from which the donnor fish was sampled, locality of the collection, the name of scientist who provided the specimen, etc.

> Common name Field refered to the english common name of species as adopted by FAO.

> Date The collected date of the donnor fish. Expressed in mm/dd/yyyy format.

> Donnor Fish: Fish specimen from which the otolith has been extracted.

> Fish ID: Internal database code that identifies a register. When clicked in the Search Results table a new page is openned showing data corresponding to that sample.

> Institute Code: Each Institution that provides samples to this database has an unique code number to its specimens that allows to rapidly locate the otolith specimen. This is a search tool specifically designed for official providers of this database.

> Fish Length: Length of the donnor fish given in milimeters (mm). Note that, in this data base there exist several lengths, please see Type for more details.

> Location: Place where the donnor fish was captured. Location is codified in 10º Marsden Squares numbering system as used in oceanographic data. The system starts with the lower-right (SE) corner of square 1 at the equator and proceeds west from 0° longitude, spiraling up through each zone of latitude to 288 at 70°N, 10°E. Then following a gap in numbering from 289 through 299, it begins again just below the equator with square 300, and proceeds west from 0° longitude down through each zone of latitude to 623 at 90°S, 10°E. Finally, following yet another gap from 624 through 900, it begins again with squares 901 through 936 numbered westward from 0° longitude at 80°N latitude. Each 10º Marsden Square can be subdivided into 4 squares of 5º each, numbered from bottom left to upper right in eastern longitudes and from bottom right to upper left in western longitudes. Examples from Database: 145;2= Marsden Square number 145 and subdivision 2 corresponds to Northeast Atlantic (Galician Coast). 144;3= Marsden Square number 144 and subdivision 3 corresponds to South of Balearic Sea. A world map showing Marsden Squares and examples of subdivisons can be viewed here.

> N/A: No available data.

> Related otoliths: In the individual results page, a list of related otoliths belonging to the same species is given. They are referenced by a pair of number, the second one being in parenthesis. The first number correspond to the Fish ID and the second number is the associated length of the donnor fish. For example a pair, 20(330) indicates Fish ID 20 (Diplodus puntazzo) of 330 mm length. You may clik on it to go to that register.

> Reset: If clicked in search form, all fields will be erased.

> Results: In individual register results page it is possible to download additional information related to the specimen: a full resolution otolith image in TIFF format; otolith contour numerical data based in x/y points; otolith shape analysis including Elliptic Fourier Analysis (EFA) and Wavelets numerical data; and the otolith morphometries and indexes. Otolith Morphometry parameters are:
   > Area (Oa): The total area of the otolith in millimeters (mm).
   > Perimeter (Op): The total length of the perimeter in millimeters (mm).
   > Length (Ol): The length of the otolith longest axis expressed in millimeters (mm).
   > Width (OW): The greatest width of the otolith measured perpendicularly from the longest axis and expressed in millimeters (mm).
Otolith indexes are described below:
   > Aspect ratio= OW/Ol. Is the relationship between otolith width (OW) and otolith length (Ol).
   > Otolith relative length=100*(Ol/Fl). Expresses in percentage the length relationship between otolith and fish.
   > Otolith relative size=0.36 (1000*(Oa/Fl2). Expresses the size (based on otolith area) relationship between otolith and fish.
The results also give graphic information of contour, EFA and Wavelets.
> Scientific name: In this database it is possible to search otoliths using these taxonomic options:
   > Scientific name: using complete genus and species. Results of that query will be related only to that species.
   > Genus: choosing a Genus will generate a search results table related to all species belonging to that genus stored in database.
   > Species: like "scientific name", results will be related only to that species.
   > Family: choosing a Family will generate a search results table related to all species belonging to that family stored in database. For better results, it should be used one of these four search fields. Note that if a wrong combination of taxonomic names is choosen, an error message will appear. (Ex: In Family=Sciaenidae, Genus=Diplodus and Species=puntazzo, no results will be obtained, because, D.puntazzo belongs to Sparidae family).

   > Taxonomic system: Organisms are ordered and classified in a hierarchical system following their suposed natural relationships. Different hierarchical levels receive the name of Taxons. The basic taxon is the scientific (or taxonomic) name in Latin composed of a Genus and a Species (Ex: Diplodus puntazzo). A Genus (Diplodus) can contain more than one species (puntazzo, vulgaris). The next taxonomic level over Genus is Family, every Family have different genus and species (Ex: Diplodus puntazzo belongs to family Sparidae). The taxons are stablished following N.Y.Nelson, 1994, in "Fishes of the World", 3rd Ed. John Wiley & Sons, New York.

> Type: Related to the donnor fish. There are different ways of measuring the fish length, depending on species, sample type, etc. They are internationally accepted and in this database are codifed as: SL =Standard length; TL=Total length; FL=Furca length; PL=Preanal length; HL=Head length. The meaning of each length type is explained in the image below.