First record of the littoral genus Alismobates (Acari: Oribatida) from the Atlantic ocean, with a redefinition of the family Fortuyniidae based on adult and juvenile morphology

Abstract

Alismobates inexpectatus sp.n., found on rocky shores of the archipelago of Bermuda is described from larva to adult. Addi-tionally a detailed description of the immatures of Fortuynia atlantica, also known from Bermuda, is given. Based on adult andjuvenile morphology the position of the genus Alismobates within the family of Fortuyniidae is clearly confirmed. Furthermorethe definition of the family Fortuyniidae is revised and the classification of its members is discussed. The Fortuyniidae are bestcharacterized by the presence of a “van der Hammen’s Organ”, whereas the configuration of cuticular channels differs remark-ably between the genera Fortuynia and Alismobates. The juveniles of A. inexpectatus and F. atlantica Krisper et Schuster, 2008exhibit conformity in most aspects, whereas porose areas associated with notogastral setae and singular pores in the lateral andposterior ventral folds leading into fine tracheal tubes are documented for the first time in fortuyniid immatures. These poresare part of a complex plastron system expressed in immatures to withstand tidal inundation. The present discovery of Alismo-bates inexpectatus is the first record of a member of this genus from Atlantic coasts and therefore represents a considerable extension of the geographic distribution of this taxon.

Juvenile morphology of seven intertidal mite species (Acari, Oribatida, Ameronothroidea) from the East Asian region

“…Another important study using the juvenile morphology of these families for phylogenetic considerations, was that of Behan-Pelletier ( 1997 ), where she provided strong arguments supporting a relationship among Tegeocranellidae, Fortuyniidae and Selenoribatidae. This relationship was further corroborated by Pfingstl and Schuster ( 2012 ) using new data on fortuyniid juveniles. With the knowledge of these important studies, it was easier for experts to identify juveniles contained in a sample and to make the correct adult-juvenile association, which resulted in a relatively high number of described juveniles in Fortuyniidae and Selenoribatidae.…”

Resistance to fresh and salt water in intertidal mites (Acari: Oribatida): implications for ecology and hydrochorous dispersal

“…This ocean current originates in the Caribbean and flows along the Central American and the southern North American shoreline with an average speed of 1.8 m per second before reaching the Bermudas. The intertidal oribatid mites of this archipelago are assumed to be derived from Caribbean and Central American shores (Pfingstl and Schuster 2012a, b), approximately 3,000 km away. This assumption is further supported by unpublished records of congeners in the Caribbean area (Fig.…”

“…The geological age of this archipelago is supposed to be approximately 30 million years, but terrestrial life on Bermuda is presumable relatively young as this volcanic landmass definitely rose above sea level 900,000 years ago (Thomas 2004). Recently it was shown that Bermuda harbours a high diversity of intertidal fortuyniid and selenoribatid mites (Pfingstl and Schuster 2012a, b). The biogeographical origin of these animals is unknown and presently only a matter of conjecture, but congeners have been found in Central America and the Caribbean (Schuster 1989, Pfingstl unpubl.).…”

“…They feed on intertidal algae and dwell exclusively in the eulittoral zone of the intertidal fringe (Krisper and Schuster 2008). Although these mites are primarily terrestrial animals, they have plastron mechanisms (Pugh et al 1990; Pfingstl and Schuster 2012a, b) and spend nearly half of their lives submerged in seawater and thus are daily exposed to wave and tidal action. In order to assess the possibility of hydrochorous dispersal of these organisms to and from this archipelago, I tested the ability of three local species, Alismobates inexpectatus Pfingstl and Schuster, 2012, Fortuynia atlantica Krisper and Schuster, 2008 and Carinozetes bermudensis Pfingstl and Schuster, 2012, to survive continued submersion in salt water.…”

Ontogeny of South African intertidal oribatid mite species (Acari, Oribatida, Ameronothroidea) and supplements to adult morphology.

“…The morphology of most Fortuynia juveniles is similar in habitus and development of setation, except for the juveniles of F. arabica and F. taiwanica (Bayartogtokh et al 2009), which may be attributed to several factors (see Pfingstl et al 2021b). For the other 10 species, the main differences lie in the length and morphology of setae (Pfingstl and Schuster 2012a) and other minor characteristics such as ontogeny of certain leg setae, especially on the femora. One characteristic of the larva of F. elamellata micromorpha that is distinctly different is the strongly barbed rostral setae.…”