Halacarellus procerus (Viets, 1927)

Halacarellus procerus imageSynonyms: None.

Common names: None.

Order (Scientific): ACARIFORMES.

Family (Scientific): HALACARIDAE.

Taxonomic descriptions: One of 18 species of the subfamily Halacarinae, and one of seven species in the Black Sea. The body is narrow and stretched. Length from 0.475 to 0.580 mm average, width 0.240 mm, Oculars plates well developed and very stretched in length.

Halacarellus procerus arealIUCN Status:
    World level:
    Black Sea Regional level:
    Subregion level: EN (Ukrainian shelf)


Habitats type, Critical habitats, Limiting factors: The species is encountered in the Black Sea and the North Sea. In north-western part of the Black Sea it was discovered in 1973. It is a typical representative of the interstitial meiofauna of the sandy beaches. The only habitat is the pseudolitoral (mediolitoral) and supralitoral zones on beaches with coarse sand. Size of sand grants, pollution of the sea's edge, man-made changes in the granulometric composition of sand.

Biology: As all Halacaridae, H. procerus is a creeping animal and is distributed by water currents. It feeds on liquid food.

Population trends: A sharp decline in population numbers (80-90%) since the 1980s has been observed.

Threats: Pollution of the pseudolitoral (mediolitoral) zone and changes in the granulometric composition of sand

Conservation measures taken: None.

Conservation measures proposed: Entry in the Black Sea Red Data Book and prohibition of pollution of the edge of the sea.


  1. Sokolov, I.I., 1952. Paukoobraznye (Arachnida). In: Fauna SSSR, 5, 5. Moscow: AN SSSR Publ., 200p. (in Russian).

Compiled by: L.Vorobyova.