Intertidal Mite Research Articles

A taxonomist‘s nightmare – Cryptic diversity in Caribbean intertidal arthropods (Arachnida, Acari, Oribatida)

There has been a long controversy about what defines a species and how to delimitate them which resulted in the existence of more than two dozen different species concepts. Recent research on so-called “cryptic species” heated up this debate as some scientists argue that these cryptic species are only a result of incompatible species concepts. While this may be true, we should keep in mind that all concepts are nothing more than human constructs and that the phenomenon of high phenotypic similarity despite reproductive isolation is real. To investigate and understand this phenomenon it is important to classify and name cryptic species as it allows to communicate them with other fields of science that use Linnaean binomials. To provide a common framework for the description of cryptic species, we propose a possible protocol of how to formally name and describe these taxa in practice. The most important point of this protocol is to explain which species concept was used to delimitate the cryptic taxon. As a model, we present the case of the allegedly widespread Caribbean intertidal mite Thalassozetes barbara, which in fact consists of seven phenotypically very similar but genetically distinct species. All species are island or short-range endemics with poor dispersal abilities that have evolved in geographic isolation. Stabilizing selection caused by the extreme conditions of the intertidal environment is suggested to be responsible for the morphological stasis of this cryptic species complex.

<p class="Body"><strong>First record of intertidal oribatid mites (Acari, Oribatida) from the Canaries – a new species and its complete ontogeny</strong></p>

A new species of intertidal oribatid mites from Tenerife is described and its full ontogenetic development is given in detail. Thalassozetes canariensis sp. nov. can easily be distinguished from its congeners by its characteristic notogastral cuticular pattern showing loosely distributed irregular elevations, and its rectangular median sternal cavity. Based on morphology, Thalassozetes canariensis sp. nov. is most closely related to the Mediterranean T. riparius; both species share a small transversal band-like notogastral light spot and the longitudinal orientation of lyrifissure iad. The juvenile morphology of T. canariensis sp. nov. conforms basically to those of known Thalassozetes juveniles but there are discrepancies in certain aspects that require further research into all known species. This report of T. canariensis sp. nov. from Tenerife is the first record of an intertidal mite for the Canaries, and also for the Eastern Atlantic area. Further records of this species within the area may be expected.

Get a grip-evolution of claw shape in relation to microhabitat use in intertidal arthropods (Acari, Oribatida).

Claws may be the most common biological attachment devices in animals but relatively few studies have examined the ecological and evolutionary significance of their morphology. We performed the first geometric morphometric investigation of arthropod claws using 15 intertidal oribatid mite species from two different families living in three different habitat types to determine if claw shape is correlated with ecology. Our results show that species living on rocky shores show remarkably high and strongly curved claws while species from mangrove habitats show significantly lower and less curved claws. Euryoecious species are able to dwell in a wide range of habitats and show an intermediate claw type. These results indicate a strong relationship between claw shape and microhabitat and the best predictors of microhabitat use seem to be claw height and curvature. Claw length varied to some degree among the species but without any noticeable ecological pattern. A comparison with terrestrial and freshwater aquatic oribatid mite species, on the other hand, confirms that their claws are only half as long as that of intertidal mites and it is suggested that tidal flooding and wave action strongly selects for long claws. In this microarthropod group which occupies a vast array of microhabitats, claw morphology may play an important role in niche separation and hence demonstrate the importance of ecomorphological studies.

Phylogeographic patterns of intertidal arthropods (Acari, Oribatida) from southern Japanese islands reflect paleoclimatic events

The Japanese islands represent one of the world’s biodiversity hotspots. Their geological history and present geography resulted in a high number of endemic species in nearly all major metazoan clades. We investigated the phylogeography of three different intertidal mite species from the Ryukyu islands and southern mainland by means of morphometry and molecular genetics. None of the species represents an endemic, nearly all show distributions ranging over at least the southern and central Ryukyus. Two species, Fortuynia shibai and F. churaumi sp. n. clearly represent sister species that are derived from a common Eastern ancestor. Molecular genetic results indicate that these species separated approx. 3 Ma before the opening of the Okinawa trough, whereas F. shibai most likely showed an ancestral distribution stretching from the central Ryukyus across the Tokara strait to Japanese mainland, whereas F. churaumi probably evolved somewhere south of the Tokara strait. Phylogenetic data further indicates that long periods of isolation resulted in heterogeneous genetic structure but subsequent low sea level stands during Pleistocene allowed recent expansion and gene flow between island populations. Comparing these patterns with those of other animals, these tiny wingless mites apparently show better dispersal abilities than partially volant terrestrial organism groups.

New and cryptic species of intertidal mites (Acari, Oribatida) from the Western Caribbean – an integrative approach

ABSTRACTThe present study highlights the distribution, systematics, morphology, genetics, and ecology of two newly discovered intertidal oribatid mites from the Western Caribbean. The fortuyniid Litoribates floridae sp. nov. represents a cryptic species as it looks nearly identical to L. bonairensis. The two species can be distinguished only by subtle morphological and morphometric characteristics, whereas cytochrome oxidase subunit I gene sequences clearly separate the two taxa. The absence of morphological divergence in these disjunct species may have resulted from stabilizing selection due to the extreme intertidal environment. Litoribates floridae sp. nov. is presently known from the Florida Keys, primarily in mangrove leaf litter. The selenoribatid Thalassozetes balboa sp. nov. can be distinguished from all known congeners by a unique cuticular notogastral pattern, the presence of only two pairs of adanal setae, and two ventral teeth on each leg claw. It is morphologically most similar to T. barbara from the Eastern Caribbean. Thalassozetes balboa sp. nov. was found in Panama and Florida. This species usually occurs on rocky substrate and feeds on the intertidal alga Bostrychia.Litoribates floridaehttp://www.zoobank.org/urn:lsid:zoobank.org:act:A4B830FC-A03F-405D-9DE4-DE4C39DB6211Thalassozetes balboahttp://www.zoobank.org/urn:lsid:zoobank.org:act:EBF8C435-5C07-4B0E-8279-2101DC9E2CD4

Schusteria marina sp. nov. (Acari, Oribatida, Selenoribatidae) an intertidal mite from Caribbean coasts, with remarks on taxonomy, biogeography, and ecology

ABSTRACTSchusteria marina sp. nov. is a newly discovered intertidal mite species found on the Lesser Antillean Islands of Martinique and Grenada. It represents the first record of the genus Schusteria within the Caribbean area. Schusteria marina sp. nov. is very similar to the type species, S. littorea from Brazil, but can be distinguished by its smaller body size, a median sternal dark sclerotized small ridge on epimeron I and a few other less pronounced differences. Both species are closely related and form a Western Atlantic Schusteria clade, which is characterized by the possession of a pair of faint anterior epimeral ridges. Schusteria marina sp. nov. occurs on different littoral substrates, e.g. mangrove roots, anthropogenic concrete structures, but seems to be associated with an intertidal red alga belonging to the genus Bostrychia Montagne, 1842 growing on these substrates.http://zoobank.org/urn:lsid:zoobank.org:pub:C246533E-D108-4F2C-8577-545C059D46CE

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

The resistance to fresh water and seawater in three intertidal oribatid mite species from Bermuda, Alismobates inexpectatus, Fortuynia atlantica and Carinozetes bermudensis, was tested in laboratory experiments. Larvae are more sensitive to fresh and salt water, nymphs and adults showed equal tolerances. Fortuynia atlantica and A. inexpectatus were more resistant to salt water whereas C. bermudensis survived longer in fresh water. Differences in the resistance to fresh and salt water among the three species may be related to their different vertical occurrences in the eulittoral zone but also to the ability of single species to dwell in periodically brackish waters. In all three species half of the specimens survived at least 10 days in fresh water and more than 18 days in salt water. Maximal submersion time in fresh and salt water ranged from 40 to 143 days. Based on median lethal times it could be estimated that each species would be able to survive transport in seawater along the Gulf Stream over a distance of 3,000 km, from Central America to Bermuda. Thus hydrochorous dispersal should be assumed as the most likely mode of dispersal in intertidal fortuyniid and selenoribatid mites.

Diversity and biogeography of southern African intertidal Acari

Abstract Aim The aims were (1) to describe the diversity and geographical distribution of the intertidal mite fauna of southern Africa, and (2) to show how species richness, endemism and geographical patterns of this fauna (comprising taxa of variable terrestrial ancestry) compare with typically marine faunas.Location and methods To assess intertidal mite diversity and endemism, records (published and unpublished) were compiled for a variety of habitats (mainly rocky shores and mangroves), between Swakopmund (Namibia) and Inhambane (Mozambique). The geographical study was based on a dedicated sampling programme from rocky shores, at nine localities between Elandsbaai (on the west coast) and St Lucia (on the east coast).Results Eighty‐two species of marine mite, from thirty‐three genera, are currently known from southern Africa. The majority belong to the earlier marine ancestral Halacaridae (forty‐eight species), with the Ameronothroidea and Hyadesiidae collectively comprising seventeen species. In constituting three faunistic provinces, corresponding with the west (Atlantic), south and east coast (Indian) regions, the mite fauna conforms with trends for the southern African marine fauna in general. Species richness was greatest in the southern province, which deviates from the general pattern of increase from west to east, but is similar to that of some invertebrate taxonomic groups.Conclusions Despite their relatively recent marine connections, marine mites show typical geographical distributions, comparable with those of other rocky‐shore biota in southern Africa. The marine faunistic provinces are ‘insular’ and apparently remain largely intact, across taxonomic groups and with increased taxonomic resolution.

Global distribution patterns of non‐halacarid marine intertidal mites: implications for their origins in marine habitats

AimWe investigated the taxonomic, ecological and global biogeographical trends of non‐halacarid marine mites with a view to understanding their origins in the marine environment. While halacarid mites are typically marine, numerous other mite taxa occupy littoral habitats, including rocky‐shores, boulder beaches, salt marshes and mangrove forest floors, and occur in most geographical regions.LocationThis study concerns the extant taxa of non‐halacarid marine mite from intertidal zones, worldwide.MethodsA literature survey was undertaken to compile the records for localities and habitats of all the known species of non‐halacarid intertidal mite. Simple analyses were used to determine their taxonomic and geographical trends. A multivariate analysis was used to compare how closely the biogeography of selected faunas conformed with the generally accepted marine biogeographical zones.ResultsAlthough the species records are incomplete because of variable sampling intensities among regions, there is clear indication that these marine mite faunas are species‐poor (only 162 species were recorded in the literature). The records for some groups (ameronothroid and hyadesiid mites), some habitats (rocky‐shores) and some world regions (Eastern Atlantic‐Boreal, Sub‐Antarctic and Southern New Zealand) are apparently representative of actual faunas, whereas those for the mesostigmatid and non‐halacarid prostigmatid mites, and mangrove and salt marsh habitats, are clearly incomplete. The faunas comprise mites from four suborders, the Mesostigmata, Prostigmata, Oribatida and Astigmata. Structuring of the lower taxonomic levels differs markedly among the suborders; mesostigmatid and prostigmatid mites comprise low species to genus and species to family ratios, relative to oribatid and astigmatid mites. These mite groups also differ with respect to ecological and geographical attributes; ameronothroid (oribatid) and hyadesiid (astigmatid) mites exhibit wider generic geographical distributions and stronger marine trophic links.ConclusionsThe emerging trends suggest different geological time‐scales for the evolutionary incursions into the marine environment by the mesostigmatid and prostigmatid mite group and the oribatid and astigmatid mite group. They suggest that members of the latter have had longer associations with marine intertidal systems. The origins of both groups are also likely to differ from those of the typically marine halacarid mites.

Ecophysiology of Two Intertidal Mites at South Georgia

Etude de la tolerance au froid, a la chaleur, a l'anoxie, a la submersion d'Halozetes marinus et d'Hyadesia maxima pour determiner leurs adaptations a l'environnement intertidal de la region sub-antarctique

Short-term changes in activity rhythms in an intertidal arthropod (Acarina: Bdella interrupta Evans).

On a marine saltmarsh, the intertidal mite, Bdella interrupta Evans, is exposed to periods of regular tidal submergence which alternate with periods of tidal emergence. The mite shows well defined day and night peaks of locomotory activity on the soil surface. During periods of tidal submergence the activity peaks showed an apparent periodicity, of around 12.5 h, characteristic of a tidal rhythm. In the presence of non-submerging tides the periodicity of the activity peaks changed to around 11.5 h. It is suggested that this shorter periodicity results either from free-running of the circatidal clock in the absence of entraining tides or from a sequence of transients that are phaseshifting towards a stable relationship with a second zeitgeber. It is further suggested that the alternation between a ca. 12.5 h and a ca. 11.5 h rhythm ensures that an activity peak is maintained in daylight and, also, reduces the possibility of inundation during the first critical floodings during sequences of rising spring tides.

Suberites Domuncula (Olivi): Its Synonymy, Distribution, and Ecology. Notes on Asteroids in the British Museum (Natural History), III and IV. Some Inter-Tidal Mites from South-West England.M. Burton , A. M. Clark , G. O. Evans , E. Browning

<i>Suberites Domuncula (Olivi): Its Synonymy, Distribution, and Ecology. Notes on Asteroids in the British Museum (Natural History), III and IV. Some Inter-Tidal Mites from South-West England.</i>M. Burton , A. M. Clark , G. O. Evans , E. Browning

Some inter-tidal mites from South-west England

Some inter-tidal mites from South-west England