Relation to habitat in rotifers

Abstract

Rotifera should be especially suited for an analysis of habitat relations because this group contains such a high number of species, inhabiting diverse environments . Furthermore, rotifers are to a large extent cosmopolitan, implying that ecological barriers, rather than geographical, are decisive of their distribution . In this review a short characterization of the rotifer fauna in different habitats is given, whereby macroenvironments and microenvironments are reported separately . The macroenvironments are classified as follows : `harmonious' lakes and ponds, arctic and antarctic waters, hot springs, hypertrophic-saprobic environments, mires, strongly acidic waters, saline waters, temporary water bodies, subterranean waters, running waters, oceans, terrestrial environments . The following microenvironments are distinguished : macrophytes (housing periphytic rotifers), open water (with planktic forms), minerogenous sediments (with psammon and hyporheos), organogenous sediments, other organisms (i .e . parasites and epizoans) .Many rotifers are more or less euryecious, while relatively few are strongly restricted in their choice of habitat . In extreme environments a low number of species is found, but often a high number of individuals within these species . These rotifers are usually primary consumers, and for natural reasons extreme environments are characterized by a low number of trophic levels .In environments with a high species number the separate species differ very much in their morphology, making it difficult to find common traits which may be interpreted as adaptations to the respective habitats . The most apparent adaptations ought to be found among the planktic rotifers, and these adaptations seem to constitute largely a protection against predators . Rotifers in extreme environments are usually not very apart in a morphological or taxonomical respect, with their most close relatives living in `normal' habitats and sometimes euryecious (an apparent exception from this rule is formed by the class Seisonidea) . Adaptations to deviating chemical and physical environments may develop relatively rapidly (seen from a geological perspective), while the more fundamental changes (occurring during a longer period of time) seem to be a response to biotic factors (e .g ., the development of different types of trophi for facilitating food collection) .

Hot Spring Microbial Community Composition, Morphology, and Carbon Fixation: Implications for Interpreting the Ancient Rock Record

“…Bdelloidea have been found to inhabit hot springs at temperatures up to ∼45 • C (McDermott and Skorupa, 2011) and thus they could be active under the conditions in Sites 1 and 2. However, Bdelloidea can undergo cryptobiosis, a stage of dormancy, in response to extreme environmental conditions (Pejler, 1995). This could explain the recovery of 18S rRNA gene sequences affiliated with Bdelloidea from these sites, especially Site 4 (68.4 • C), where the temperature exceeds their maximum known temperature tolerance (∼45 • C).…”

The diurnal distribution of the zooplankton community of the littoral zone of Lake Wielkowiejskie (Wielkopolski National Park, Poland)

“…In particular, the macrophyte-dominated area within lakes favors a quality and quantity richness of both plant and animal organisms. The littoral communities of zooplankton consist of the same species as the pelagic zone possesses; however, typical littoral forms prevail as a multiciplicity of rotifers and crustaceans are, in evolutionary terms, littoral forms (Pejler 1995). Only some species have managed to adapt to living within the open water; hence both groups are classified as pelagic or littoral forms (Wetzel 1975).…”

Species Composition and Habitat Preference of Rotifera in Ahansar Lake

“…Diversity is often high in the vegetative habitats as compared with pelagic ( Pennak , 1966 ) . Representatives of rotifers are found in aquatic and semi aquatic habitats , but are predominantly fresh water inhabitants ( Pejler ,1995 ) . They contribute to a a very important part of these ecosystems due to extremely fast reproductive rates Rotifera an integral and important component of aquatic food webs have been documented from a wide variety of fresh water bodies of Kashmir .…”