First comprehensive insights into the biogeography of the Caribbean intertidal oribatid mite fauna (Ameronothroidea)

Abstract

A decade ago the Caribbean was almost completely uncharted in terms of intertidal ameronothroid mites. Now the present data show that these organisms are a common component of the fauna of Caribbean shorelines. Two families of Ameronothroidea are present, the Fortuyniidae with three genera and four species and the Selenoribatidae with five genera and nine species. The most common species are the fortuyniid Alismobates inexpectatus and the selenoribatid Carinozetes mangrovi, both taxa were found in the Northern Caribbean, the Greater and Lesser Antilles as well as on Central American coasts. Six species are endemic to the Caribbean, Litoribates bonairensis, L. floridae, Schusteria marina, Thalassozetes balboa, T. barbara and Thasecazetes falcidactylus. Biogeographic patterns suggest that the genera Carinozetes and Litoribates may have evolved and diversified in the Caribbean region and that the Western Atlantic Bermudian intertidal oribatid mite fauna was largely shaped by Caribbean colonizers. Most of the species found in the Caribbean are typical rock dwellers and only a minority is represented by exclusive mangrove specialists. These species are seriously threatened by the significant progressive decline of mangrove ecosystems throughout the Caribbean.

A closer look reveals hidden diversity in the intertidal Caribbean Fortuyniidae (Acari, Oribatida)

“…atlantica populations are closely related to northern Caribbean populations and thus confirm this geographic connection. Moreover, dispersal via the Gulf-Stream is supposed to be mainly responsible for the existence of several mites on Bermuda [ 6 , 53 ] and genetic data now corroborates this hypothesis. The Gulf-Stream passes Florida and the northern Bahamas and flows northeastwards before it reaches Bermuda (see Fig 3 ).…”

“…Where the Bahamian populations originated from is yet unknown but most likely they are derived from ancestral populations from Hispanola and Cuba (Greater Antilles). Fortuynia atlantica is known to occur on the Greater Antilles [ 6 ] but genetic data is lacking so far. Therefore, the present results only provide a first insight into the phylogeography of Caribbean Fortuynia and inferred patterns should only be regarded as preliminary.…”

“…Reports from the Caribbean, on the other hand, were initially scarce and provided only vague information about the occurrence of undetermined Fortuynia species from Barbados and the Dominican Republic [ 5 ]. A recent paper [ 6 ] provided a more comprehensive insight and reported occurrences of a specific Fortuynia species, namely Fortuynia atlantica , from Grenada, Guadeloupe, Florida and the Bahamas. This species was originally discovered on the small and remote archipelago of Bermuda in the western Atlantic and it was the first species of this genus and family showing an obvious sexual dimorphism [ 7 ].…”

“…The recent reports of F . atlantica on the Bahamas and Florida support this theory [ 6 ] and point to a wider Caribbean distribution of this species but molecular genetic data linking all these populations is yet missing.…”

“…atlantica , were found to be widespread on Caribbean coasts whereas a molecular genetic investigation revealed them to consist of five distinct genetic lineages, probably representing different species. Furthermore, the allegedly widespread Thalassozetes barbara [ 6 ], another intertidal mite species, was shown to consist of at least seven different species with nearly each representing a Caribbean island endemic [ 14 ].…”