Hidden invertebrate diversity – phytotelmata in Bromeliaceae from palm houses and florist wholesalers (Poland)

Bromeliads accumulate water in the leaf axils (forming phytotelmata), which may then form a habitat for many animal species of both invertebrates and vertebrates. In temperate regions, bromeliads are commonly displayed in palm houses and distributed by florist wholesalers. Taking into account the fact that global plant trade can be a source of spreading alien species, the phytotelmata that had formed within the bromeliads were examined here in order to study the protists and invertebrates associated with this habitat. In the examined Bromeliaceae micro-reservoirs representatives of testate amoebae (Euglyphida and Arcellinida), Gastrotricha, Nematoda, Rotifera, Polychaeta, Cladocera, Copepoda and mites (Oribatida, Mesostigmata and Heterostigmatina) were found. Additionally, unidentified Nemertea, Turbellaria, Insecta larvae and single representative of Mollusca were also found. Thirty taxa are recorded for the first time from bromeliads micro-reservoirs. Among the identified taxa, the gastrotrich Chaetonotus(Hystricochaetonotus) furcatusKisielewski, 1991 was found, which was previously known only from bromeliads in the natural environment in South America. Nematodes belonging to Clarkus spp. were found in the Bromeliaceae reservoirs for the first time. Additionally, the tropical mite Phthiracarus(Phthiracarus) phoxosNiedbała, 2004, previously known from Cuba in the natural environment and other greenhouses in Poland, was also found in the studied phytotelmata. Steneotarsonemusananas (Tryon, 1898) sensu Beer, 1954 was recorded from Poland for the first time. Some of the mite specimens, e.g., Mesostigmata and Heterostigmatina, had most likely accidentally been caught in the phytotelmatum, which acted like a trap; but others, especially freshwater fauna representatives can be a constant element of the phytotelmata merocenoses. Our study provides comprehensive analysis of fauna living in these exceptional micro-habitats, and it underlines the possibility of passive invertebrate dispersal within bromeliad micro-reservoirs and between different localities, e.g., florist shops and markets as well as greenhouses.