Esijäsemete

Esijäsemete is an Estonian term used in comparative anatomy to denote the anterior pair of appendages on arthropods. The word is formed from ees ('front') and jäsemete ('limbs'), literally 'front limbs.' The term is primarily applied to the front-most appendages on the body, and it is contrasted with the posterior or hind limbs (tagajäsemete) in descriptive morphology.

In many crustaceans and other arthropods, esijäsemete can be differentiated by their functions and morphology. They often bear sensory organs or are adapted for feeding, manipulation, or defense, and may be specialized into a variety of forms depending on the group. The exact composition of esijäsemete varies across taxa; the same general concept is used to describe the position rather than a single uniform structure.

Usage and significance: The term is used in anatomical descriptions, taxonomic keys, and developmental studies to specify location on the body. It helps standardize comparisons between species by providing a consistent reference point—front versus back limbs—across diverse arthropod groups.

See also: Jäsemed, antennae, maxillipeds, arthropod appendages.

Notes: Because Estonian terminology can vary by author, esijäsemete may also appear as eesjäsemete or similar forms in some texts.