Lajeiltaan

Lajeiltaan is a Finnish adverb that means “by species” or “in terms of species.” It describes a dimension or perspective that focuses on the species composition of a group, rather than other criteria such as age, size, or region. The term is most often found in biological, ecological and biodiversity contexts, where data or observations are broken down according to species.

The form is derived from the noun laji, meaning species, with a suffix pattern that yields an adverbial expression indicating a particular dimension or mode of classification. In practice, lajeiltaan is used to convey that a statement or measurement concerns the arrangement, distribution or characteristics of organisms at the species level. It can appear in sentences such as a population or catch being reported lajeiltaan eriteltynä (broken down by species), or in descriptions like saalis lajeiltaan monipuolinen (the catch is diverse in species).

Usage notes: lajeiltaan is common in scientific writing, field reports and ecological surveys. It complements other dimension-based terms such as lajittain (by species), ikä- ja koko-jakaumista (by age and size), or alueellisesti (regionally). While related terms exist to express species-focused breakdowns, lajeiltaan specifically signals the species dimension and is understood as a concise way to frame analysis along those lines.

See also: laji, lajittain, lajikohtaisesti. The choice among these forms depends on the precision of the intended focus and the conventional style of the text.