First record of water bears (Tardigrada) from sponges (Porifera)

Abstract

Aquatic species of Tardigrada usually inhabit submerged plants or sediment but they are also known as associated with other animals, like barnacles (Crustacea: Cirripedia) or sea cucumbers (Echinodermata: Holothuroidea). In sponges collected from Lake Ohrid (Macedonia) we found individuals of two tardigrade taxa: Isohypsibius sp. and Dactylobiotus sp. This paper provides the first record of Tardigrada from Macedonia (Lake Ohrid) and is the first report of these animals on sponges.