Bugün öğrendim ki: iktiyolojide (balık bilimi), farklı balık türlerini ayırt etmek için yüzgeçlerin ve pulların sayısını sayan meristik adı verilen bir alan vardır.

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**Meristics** is an area of [ichthyology](/wiki/Ichthyology "Ichthyology") which relates to counting quantitative features of [fish](/wiki/Fish "Fish"), such as the number of fins or scales. A **meristic** (countable trait) can be used to describe a particular [species](/wiki/Species "Species") of fish, or used to identify an unknown species. Meristic traits are often described in a shorthand notation called a _meristic formula_. Meristic characters are the countable structures occurring in series (eg [myomeres](/wiki/Myomere "Myomere")), [vertebrae](/wiki/Vertebrae "Vertebrae"), [fin rays](/wiki/Fin_ray "Fin ray" )) in fish. These characters are among the characters most commonly used for [differentiation](https://en.wiktionary.org/wiki/differentiation "wikt:differentiation") of [species](/wiki/Species "Species") and [populations] (/wiki/Populations "Populations"). In the [salmonids](/wiki/Salmonids "Salmonids"), scale counts have been most widely used for the differentiation of populations within species. In [rainbow](/wiki/Rainbow_trout "Rainbow trout") and [steelhead](/wiki/Steelhead_trout "Steelhead trout") [trout](/wiki/Trout "Trout") the most notable among populations occur in counts of scales. Meristic characters are used in many other fields, such as in [botany](/wiki/Botany "Botany") or in [zoology](/wiki/Zoology "Zoology"). Meristic comparison is used in [phenetic](/wiki/Phenetic "Phenetic") and [cladistic](/wiki/Cladistic "Cladistic") analysis.