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Habitats Worldwide (habitat + worldwide)
Selected AbstractsSeagrassNet monitoring across the Americas: case studies of seagrass declineMARINE ECOLOGY, Issue 4 2006Frederick T. Short Abstract Seagrasses are an important coastal habitat worldwide and are indicative of environmental health at the critical land,sea interface. In many parts of the world, seagrasses are not well known, although they provide crucial functions and values to the world's oceans and to human populations dwelling along the coast. Established in 2001, SeagrassNet, a monitoring program for seagrasses worldwide, uses a standardized protocol for detecting change in seagrass habitat to capture both seagrass parameters and environmental variables. SeagrassNet is designed to statistically detect change over a relatively short time frame (1,2 years) through quarterly monitoring of permanent plots. Currently, SeagrassNet operates in 18 countries at 48 sites; at each site, a permanent transect is established and a team of people from the area collects data which is sent to the SeagrassNet database for analysis. We present five case studies based on SeagrassNet data from across the Americas (two sites in the USA, one in Belize, and two in Brazil) which have a common theme of seagrass decline; the study represents a first latitudinal comparison across a hemisphere using a common methodology. In two cases, rapid loss of seagrass was related to eutrophication, in two cases losses related to climate change, and in one case, the loss is attributed to a complex trophic interaction resulting from the presence of a marine protected area. SeagrassNet results provide documentation of seagrass change over time and allow us to make scientifically supported statements about the status of seagrass habitat and the extent of need for management action. [source] The immune response to Naegleria fowleri amebae and pathogenesis of infectionFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2 2007Francine Marciano-Cabral Abstract The genus Naegleria is comprised of a group of free-living ameboflagellates found in diverse habitats worldwide. Over 30 species have been isolated from soil and water but only Naegleria fowleri (N. fowleri) has been associated with human disease. Naegleria fowleri causes primary amebic meningoencephalitis (PAM), a fatal disease of the central nervous system. The pathogenesis of PAM and the role of host immunity to N. fowleri are poorly understood. Strategies for combating infection are limited because disease progression is rapid and N. fowleri has developed strategies to evade the immune system. The medical significance of these free-living ameboflagellates should not be underestimated, not only because they are agents of human disease, but also because they can serve as reservoirs of pathogenic bacteria. [source] The biology and ecology of lotic rotifers and gastrotrichsFRESHWATER BIOLOGY, Issue 1 2000Claudia Ricci Summary 1The occurrence of Rotifera and Gastrotricha in the meiobenthos of lotic habitats is reviewed. About 150 rotifer and 30 gastrotrich species are reported in such habitats worldwide. 2The two phyla share some morphological and biological features that might account for their presence in the meiofauna. Small-size, a soft and elongate body, adhesive glands on the posterior body end, movement through cilia, relatively short life cycles, parthenogenesis and dormant stages are common characteristics. 3Most species of both taxa inhabiting the superficial sediments in streams and rivers may move downward into the hyporheos in response to both biotic (predation) and abiotic (spates, erosion, desiccation) disturbances. [source] Descriptions of Protospathidium serpens (Kahl, 1930) and P. fraterculum n. sp. (Ciliophora, Haptoria), Two Species Based on Different Resting Cyst MorphologyTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 4 2005KUIDONG XU Abstract. Protospathidium serpens (Kahl, 1930) is frequent in semiterrestrial and terrestrial habitats worldwide. Conventionally, all populations are considered as conspecific because they have very similar overall morphologies and morphometrics. We studied in detail not only the morphology of the vegetative cells but also the resting cysts using live observation, protargol impregnation, and scanning electron microscopy. These revealed a cryptic diversity and biogeographic pattern in details of the dorsal brush and cyst wall morphology. The cyst wall is spiny in the Austrian specimens, while smooth in the South African and Antarctic populations. Accordingly, P. serpens consists of at least two species: P. serpens (with spiny cyst wall) and P. fraterculum n. sp. (with smooth cyst wall); the latter is probably composed of two distinct taxa differing by the absence (South African)/presence (Antarctic) of a monokinetidal bristle tail in brush row 3, the number of dikinetids comprising brush row 1 (seven versus three), and the total number of brush dikinetids (29 versus 17). Protospathidium serpens is neotypified with the new population from Austria. The significance of resting cyst morphology is discussed with respect to alpha-taxonomy and overall ciliate diversity. [source] | ||||||||||