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Anchialine caves are characterized by high levels of endemism and extreme conditions. However, few ecological studies have been conducted in these ecosystems. This study integrates biotic and abiotic parameters of two sets of cave systems with contrasting high and low species richness. Seven ecological patterns are used to explain the expected species richness and density in an anchialine cave. In addition, the population size for conspicuous macrofauna was estimated. The high impact that single-events have on anchialine fauna are also reported. These findings reinforce the conclusions of previous studies of the high extinction risk of anchialine cave fauna, and substantiate the necessity of ad hoc conservation strategies for anchialine caves. [ABSTRACT FROM AUTHOR]

Marine lakes are small bodies of landlocked seawater that are isolated from the open sea and have been shown to house numerous rare and unique taxa. The environmental conditions of the lakes are also characterised by lower pH and salinity and higher temperatures than generally found in the open sea. In the present study, we used a 16S rRNA gene barcoded pyrosequencing approach and a predictive metagenomic approach (PICRUSt) to examine bacterial composition and function in three distinct biotopes (sediment, water and the sponge species Biemna fortis) in three habitats (two marine lakes and the open sea) of the Berau reef system, Indonesia. Both biotope and habitat were significant predictors of higher taxon abundance and compositional variation. Most of the variation in operational taxonomic unit (OTU) composition was related to the biotope (42% for biotope alone versus 9% for habitat alone and 15% combined). Most OTUs were also restricted to a single biotope (1047 for B. fortis, 6120 for sediment and 471 for water). Only 98 OTUs were shared across all three biotopes. Bacterial communities from B. fortis, sediment and water samples were, however, also distinct in marine lake and open sea habitats. This was evident in the abundance of higher bacterial taxa. For example, the phylum Cyanobacteria was significantly more abundant in samples from marine lakes than from the open sea. This difference was most pronounced in the sponge B. fortis. In line with the compositional differences, there were pronounced differences in predicted relative gene count abundance among biotopes and habitats. Of particular interest was the predicted enrichment in B. fortis from the marine lakes for pathways including DNA replication and repair and the glutathione metabolism. This may facilitate adaptation of host and microbes to life in ‘stressful’ low pH, low salinity and/or high temperature environments such as those encountered in marine lakes. [ABSTRACT FROM AUTHOR]

The anchialine fauna from the Yucatan Peninsula has been extensively studied since the 1980's. "Sea spiders" or Pycnogonida, have never been found in these systems before. A record for Anoplodactylus batangensis (Helfer, 1938) from a cenote (sinkhole) in the Yucatan Peninsula, Mexico is presented herein. The pycnogonid was found in waters of the cenote Nohoch Nah Chich, part of the Sac Actun anchialine system, in the State of Quintana Roo. This species was already reported from the northeastern shore of the Yucatan Peninsula, however the record we present herein constitutes the first time a pycnogonid is reported from an anchialine habitat. A brief description of the female A. batangensis is presented for the first time. [ABSTRACT FROM AUTHOR]

We isolated the human pathogen Wallemia mellicola from the class Wallemiomycetes for the first time in Poland. The fungus was isolated from indoor dust in Cracow. The strain belonged to the genus Wallemia, as confirmed by molecular methods (i.e., ITS1-5.8S-ITS2 nrDNA sequencing). We compared the halotolerance and chaotolerance of W. mellicola to other those of halotolerant fungi (Talaromyces diversus and Aureobasidium pullulans) isolated from an anchialine cave. The W. mellicola strain tolerated up to 20% NaCl and up to 15% MgCl2. As the concentration of NaCl in the culture medium increased, the colony diameter of W. mellicola decreased slightly. Dose-response curves for the two reference fungi T. diversus and A. pullulans revealed much lower tolerance of these fungi to increasing concentrations of NaCl. Our results indicated that W. mellicola is an advanced kosmotrope that is distinctly adapted to saline environments. [ABSTRACT FROM AUTHOR]

Surveys of the anchialine crustacean fauna of the Yucatan Peninsula (YP), Mexico, have revealed the occurrence of calanoid copepods. The genus Stephos Scott, 1892, belonging to the family Stephidae is among the most frequent and widely distributed groups in anchialine caves but has not been hitherto recorded from the YP. Recent collections from an anchialine cave in an island off the northern coast of the YP yielded many specimens of a new species of Stephos. The new taxon, S. fernandoi sp. n., is described here based on male and female specimens. The new species is clearly distinguished from its congeners by the following characters: male left fifth leg with three terminal lamellae plus subdistal process, right leg with distal row of peg-like elements; female fifth leg with single long, acute apical process; genital double-somite with two rows each of 4 long spinules adjacent to operculum; legs 2-4 with articulated setae. The diversity of the genus shows regional differences; the Australia-Western Pacific region is the most diverse (eleven species), followed by the Mediterranean (seven species) and the Northeastern Atlantic (six species); only four species are known from the Northwestern Tropical Atlantic (NWTA). The morphology of the female fifth leg was examined to explore possible biogeographic trends in the genus; patterns suggest multiple colonization events in the highly diverse regions and a relatively recent radiation in the NWTA, characterized by anchialine forms. The introduction of stephid copepods in the region may be a relatively recent event derived from colonization of benthopelagic ancestral forms and subsequent invasion onto cave habitats. The new species appears to be linked to the strictly anchialine Miostephos. [ABSTRACT FROM AUTHOR]

A new species of Teinostoma (Tornidae) is described from an under-investigated section of the anchialine cave system Cenote Crustacea, situated on the northeastern coast of the Yucatán Peninsula. Teinostoma brankovitsi n. sp. is the first anchialine gastropod reported from the Yucatán Peninsula and the first record of the family from an anchialine cave. Specimens were found in chalky sediments riddled with orange bacterial patches, c. 450 m from the inland entrance pool, in complete darkness. Teinostoma brankovitsi has a circular, multispiral operculum with a central nucleus and does not have tentacles on the foot or opercular lobe. Specimens possess a taenioglossate radula with a central tooth broadly V-shaped and a serrated cutting area with two basal denticles. The diagnosis of Teinostoma is emended based on these new findings. [ABSTRACT FROM AUTHOR]

Anchialine ecosystems are groundwater-fed brackish coastal habitats that contain high percentages of endemic fauna and are at risk from anthropogenic stressors, introduced species, and sea level rise. Data on endemic species distribution, habitat condition, and species/habitat interactions in this ecosystem are scarce across large spatial scales. This study offers the most thorough regional perspective on anchialine pool habitat characteristics along the western and southern coastlines of the island of Hawaii since the 1970s. Daytime surveys of 398 anchialine pools documented the widespread distribution of two dominant endemic shrimp Halocaridina rubra and Metabetaeus lohena in a wide range of habitats. Introduced fishes (tilapia, poeciliids) were present in about 25% of pools. Generalized additive models were used to determine the relationship between shrimp occurrence and pool characteristics, invasive species, water properties, and land use. Introduced fishes had a strong negative effect on the occurrence of H. rubra and M. lohena. High benthic silt cover and adjacent development also had significant negative relationships with shrimp occurrence. Our results indicate that conservation efforts should include controlling introduced fishes, preventing new introductions, minimizing siltation, and protecting groundwater resources and low-lying coastal areas. [ABSTRACT FROM AUTHOR]

Marrack, L., 2015. Incorporating groundwater levels into sea-level detection models for Hawaiian anchialine pool ecosystems. As sea levels rise, the distribution and community structure of coastal ecosystems are expected to change. In many coastal aquifers, fresher groundwater floats on top of denser saltwater and will rise with sea level. Under these conditions, ecosystems dependent on groundwater may shift inland as a result of inundation, changes in salinity, or both. Groundwater-fed anchialine pool habitats existing in porous coastal substrates around the world have not been assessed for sea-level rise impacts. As a first step toward examining ecosystem response to rising water levels, geospatial models were developed to detect anchialine pools on the island of Hawai'i at current water levels and models were validated with known pool locations. Specifically, the objectives were to determine whether accounting for groundwater levels in the model improved pool detection, to identify the model that most accurately detected known pools, and to identify which pool features make some pools more likely to be detected than others. Six water level models were validated with the test data set of actual pool locations to determine how well they detected known anchialine pools. Water surface models that included groundwater levels were up to 37% better at detecting anchialine pools than corresponding models without groundwater levels. The model that included groundwater levels at mean higher high water was applied to 42 km of coastline where it correctly detected 62% of known pools. A generalized linear model showed that pools with surface areas greater than 5 m2 and pools without canopy were the most likely to be detected. Future predictive modeling of anchialine pool response to sea-level rise should include groundwater levels. Furthermore, geospatial models aimed at predicting ecosystem shifts due to sea level rise may be improved by including groundwater as a factor and should be validated using current ecosystem conditions. [ABSTRACT FROM AUTHOR]

New records for 17 species of crustaceans from anchialine systems in the Yucatan Peninsula, Mexico, are presented. The records come from explorations in Dzilam de Bravo, Yucatan, and from Puerto Aventuras and the Nohoch Nah Chich and Ox Bel Ha cave systems near Tulum in Quintana Roo, Mexico. For five of the 17 species dealt with here, the records presented constitute the second time those species are reported after their original descriptions. For the alpheid shrimp Yagerocaris cozumel, we present the first record of the species for continental Yucatan and for the atyid shrimp Jonga serrei, the second record from Mexico. Depth data are provided for all species. [ABSTRACT FROM AUTHOR]

We report on opportunistic sampling and/or observations of the fauna of five submarine and six associated anchialine caves in Christmas Island conducted over a total of five weeks from 2010 to 2012. The surveys were conducted mainly via hand picking, overturning of coral rubble, baited fish traps (using baitfish and fish food pellets) and with the use of clove oil. A total of 54 species of cnidarian, gastropod, crustacean, echinoderm, enteropneusta and teleost fish were observed or obtained, with some uncommon species; and interesting taxa including Neoliomera cerasinus, Palinurellus wieneckii, Enoplometopus voigtmanni, Carupa ohashii, Carupa tenuipes, Pagurixus nomurai, and cave Paguridae species. [ABSTRACT FROM AUTHOR]

The microbial abundances, including bacteria, viruses, and heterotrophic nanoflagellates, were determined for two anchialine caves located on the Island of Mljet (Adriatic Sea): Bjejajka Cave and Lenga Pit. Both caves are situated approximately 100 m from the coast with extensive subterranean connections to the sea, resulting in noticeable marine and terrestrial, influences. Because of the shallow settings of the studied caves, they represent habitats with a minimal light or complete darkness where photosynthesis is minimal or not possible. Thus, during the surveys there was no evidence of cyanobacterial cells in either caves, but the presence of bacteria, viruses and heterotrophic nanoflagellates (HNF) was established. Further, bacterial abundance was higher in caves in comparison to surrounding open seawater. In the surrounding seawater the predominance of the LNA group over HNA is determined, which also indicates the differences in relation to the studied caves. In fact, the dominance of HNA group of bacteria in caves together with higher total bacterial abundance indicates that the caves are of higher trophic level than the surrounding seawater. With regard to bacterial diversity, both caves had a unique makeup of bacterial populations and low diversity, with the chemolithoautotrophic Epsilonproteobacteria representing the most abundant taxonomic group. To examine the mechanisms regulating bacterial abundance in these habitats, we observed the relationship between bacteria and heterotrophic nanoflagellates (HNF) and between bacteria and viruses. The importance of predation in controlling bacteria (top down control) and, consequently, the domination of bottom up control of HNF were observed in both caves [ABSTRACT FROM AUTHOR]

Globally, introductions of alien species are increasingly common, with invasive predators potentially having detrimental effects via predation on native species. However, native prey may avoid predation by adopting new behaviors. To determine whether invasive fish populations consume endemic shrimp in invaded Hawaiian anchialine habitats or if adopted patterns of diel migration prevents predation as previously hypothesized, a total of 183 invasive poeciliids (158 Gambusia affinis and 25 Poecilia reticulata) were collected for gut content analyses from four anchialine sites during wet and dry seasons on the islands of Hawai'i and Maui. Predation on shrimp was not detected in habitats where they retreat exclusively into the underlying aquifer diurnally and only emerge nocturnally. However, low levels of predation were detected (7/65 fishes, only by Gambusia affinis) at Waianapanapa Cave, Maui, where shrimp retreat into both the aquifer and a cave during the day. Thus, adopted behavioral responses to invasive fishes generally, though not universally, prevent predation on endemic Hawaiian anchialine shrimps. However, non-consumptive effects resulting from behavioral modification of shrimps may have appreciable impacts on the Hawaiian anchialine ecosystem and warrant further study. [ABSTRACT FROM AUTHOR]

Archipelagos of the Indo-West Pacific are considered to be among the richest in the world in biodiversity, and phylogeographic studies generally support either the center of origin or the center of accumulation hypothesis to explain this pattern. To differentiate between these competing hypotheses for organisms from the Indo-West Pacific anchialine ecosystem, defined as coastal bodies of mixohaline water fluctuating with the tides but having no direct oceanic connections, we investigated the genetic variation, population structure, and evolutionary history of three caridean shrimp species (Antecaridina lauensis, Halocaridinides trigonophthalma, and Metabetaeus minutus) in the Ryukyu Archipelago, Japan. We used two mitochondrial genes--cytochrome c oxidase subunit I (COI) and large ribosomal subunit (16S-rDNA)--complemented with genetic examination of available specimens from the same or closely related species from the Indian and Pacific Oceans. In the Ryukyus, each species encompassed 2-3 divergent (9.52%-19.2% COI p-distance) lineages, each having significant population structure and varying geographic distributions. Phylogenetically, the A. lauensis and M. minutus lineages in the Ryukyus were more closely related to ones from outside the archipelago than to one another. These results, when interpreted in the context of Pacific oceanographic currents and geologic history of the Ryukyus, imply multiple colonizations of the archipelago by the three species, consistent with the center of accumulation hypothesis. While this study contributes toward understanding the biodiversity, ecology, and evolution of organisms in the Ryukyus and the Indo-West Pacific, it also has potential utility in establishing conservation strategies for anchialine fauna of the Pacific Basin in general. [ABSTRACT FROM AUTHOR]

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Ingolfiella arganoi sp. n. from Abd al Kuri Island in the Arabian Sea is described from two specimens, a male and a female. The western shore of the Indian Ocean was hitherto a vacant spot in the distribution of circumtropical shallow marine interstitial ingolfiellids and therefore the location of the new species fills a meaningful gap in the geography of the family. Morphologically, the new species shows close affinities with I. xarifae from the Maldives. [ABSTRACT FROM AUTHOR]

Species of the genus Placospongia are common within the tropical Indo-West Pacific, demonstrating a wide variety of colors and either branching or encrusting growth forms. A revision of Indo-West Pacific Placospongia was undertaken based on a redescription of the holotypes of species of Placospongia from the Indian Ocean and Western Pacific and an examination of an additional 103 specimens of Placospongia ssp. collected from Indonesia (including Vosmaer and Vernhout 1902 material), Seychelles, India, Singapore and Micronesia. One mitochondrial (COI) and one nuclear (ITS) marker were subsequently used to differentiate species. All Placospongia species are characterized by selenasters and tylostyles in two size classes. The combination of microsclere diversity and morphology as well as megasclere size were shown to be informative morphometric characters, supported by molecular evidence. Live coloration and growth form is shown to be unreliable for diagnoses. The study of holotypes found that P. mixta is a valid species and that two genus transfers are necessary: Geodinella anthosigma is a Placospongia and P. labyrinthica is a Geodia. A new species is also described from an anchialine pool in Indonesia, Placospongia santodomingoae sp. n.; bringing the total fauna of Placospongia species in the Indo-West Pacific to five: Placospongia anthosigma, Placospongia carinata, Placospongia mixta, Placospongia melobesioides, and Placospongia santodomingoae sp. n. An identification key is given. Two additional species, possibly morphologically cryptic, have been identified by molecular markers. [ABSTRACT FROM AUTHOR]

A new smirnovipinid copepod has been found in a shallow coastal cave located between the villages of Bagnara and Palmi on the Calabria coast. The new species belongs to genusGinesiaJaume and Boxshall, but this name is already taken byGinesiaFernández Yépez, a genus of freshwater fish from South America. The nameCostanzoiais proposed as replacement andCostanzoia longicaudata,new combination, is the type of species by original designation. The new speciesCostanzoia longisetais characterized by the extraordinary length of the apical seta on the fifth leg, which extends as far as the distal margin of third urosomal somite of the female, and by the length of seta II on the caudal rami.C. longisetasp. nov. is very similar to shallow water hyperbenthic forms such asCyclopinoides, Oromiina,andSmirnovipina, which also belong to family Smirnovipinidae. The discovery ofC. longisetasp. nov. confirms the presence and spread of this genus in anchialine caves of the Central Mediterranean Sea. In the cave the new species co-occurred with other cyclopoid species such asEuryte longicaudaandEupolymniphilussp. [ABSTRACT FROM AUTHOR]

Jewfish Sink is a former anchialine karst feature located in the Gulf of Mexico off the coast of West Central Florida. Freshwater flowed from the feature until 1962 and it is now an anoxic marine basin. The current biodiversity within Jewfish Sink was examined in terms of Bacteria, Archaea, and Eukaryota using a combination of 16S and 18S ribosomal RNA analysis from environmental samples. Analysis of 16S rRNA sequences from microbial mats in the anoxic zones revealed a broad diversity of bacteria (265 clones) and archaea (392 clones), many of which had previously been identified in anoxic environmental samples and are likely to be involved with sulfur, nitrogen, and methane metabolism. Sequence analysis of 785 18S clones revealed that fungi and dinoflagellate sequences dominate the eukaryote sequences. Because Jewfish Sink water is anoxic and high in sulfide, we investigated the effect of Jewfish Sink on the nearby shallow benthic environment. We compared the shallow benthic macrofauna near Jewfish Sink with that near Crystal Beach Spring, an active submarine spring. We found significantly greater species richness, abundance, and diversity of benthic fauna near the Jewfish Sink site than near Crystal Beach Spring. This comparison suggests that greater submarine groundwater discharge in an area with active submarine springs is a significant factor reducing the richness and diversity of the benthic community structure in the nearshore, shallow marine environment. [ABSTRACT FROM AUTHOR]

Despite iodine being one of the most abundant of the minor elements in oxic seawater, the principal processes controlling its interconversion from iodate to iodide and vice versa, are still either elusive or largely unknown. The two major hypotheses for iodate reduction involve either phytoplankton growth in primary production, or bacteria during regeneration. An earlier study intended to exploit the unusual nature of anchialine environments revealed that iodide is oxidised to iodate in the bottom of such caves, whereas reduction of iodate occurs in the shallower parts of the water column. This investigation was made on the hypothesis that study of the nitrogen and phosphorus nutrient systems within the caves might offer a bridge between the iodine chemistry and the marine bacteria which are assumed to be the agent of change of the iodine in the caves. Accordingly, the hydrography, the nutrient chemistry, and some further iodine studies were made of two anchialine caves on the east coast of the Adriatic Sea in Croatia. Iodate and iodide were determined by differential pulse voltammetry and cathodic stripping square-wave voltammetry, respectively. Total iodine was determined indirectly, as iodate, after oxidation of reduced iodine species with UV irradiation and strong chemical oxidants. Nutrient concentrations were measured by spectrophotometry. Nutrient profiles within the well stratified water columns indicate a relatively short-lived surface source of nitrate and phosphate to the caves, with a more conventional, mid-water, nutrient regeneration system. The latter involves nitrite and ammonium at the bottom of the halocline, suggestive of both autotrophic and heterotrophic microbial activity. High iodate/low iodide deep water, and conservative behaviour of total inorganic iodine were confirmed in both systems. Iodate is reduced to iodide in the hypoxic region where nutrient regeneration occurs. The concentrations of organic iodine were surprisingly high in both systems, generally increasing toward the surface, where it comprised almost 80% of total iodine. As with alkalinity and silica, the results suggest that this refractive iodine component is liberated during dissolution of the surrounding karst rock. A major, natural flushing of one of the caves with fresh water was confirmed, showing that the cave systems offer the opportunity to re-start investigations periodically. [ABSTRACT FROM AUTHOR]

The geologic history of a region can significantly impact the development of its flora and fauna, with past events shaping community patterns and evolutionary trajectories of species. In this context, islands are excellent 'natural laboratories' for studying the fundamental processes of evolution due to their discrete geographical nature and dynamic geologic histories. An island system meeting these criteria is the Hawaiian Archipelago, which is ideal for testing how island geologic history influences the processes leading to population genetic variation and differentiation. One Hawaiian endemic whose evolutionary history is closely tied to the geology of the islands is the anchialine atyid shrimp Halocaridina, whose mitochondrial cytochrome oxidase I (COI) gene is hypothesized to be evolving at the rate of 20% per million years. To validate this rapid evolutionary rate, time since divergence estimates between geographically close, yet genetically distinct, populations were calculated for Halocaridina from anchialine habitats on the islands of Hawai'i, Maui, and O'ahu. On the younger (i.e., <1.5 million years) islands of Hawai'i and Maui, where all anchialine habitats occur in basalt, application of the Halocaridina molecular clock identified a strong correlation between levels of genetic divergence and the geologic age of the region inhabited by those populations. In contrast, this relationship weakened when similar analyses were conducted for Halocaridina from limestone anchialine habitats on the older (i.e., >2.75 million years) island of O'ahu. These results suggest geologic age, basin origin and/or composition are important factors that should be taken into consideration when conducting molecular clock analyses on anchialine flora and fauna as well as island populations in general. [ABSTRACT FROM AUTHOR]

Anchialine caves in coastal locations develop in two ways: by pseudokarst processes that form talus caves, sea caves, tafoni, fissure caves and lava tubes, and by karst dissolutional processes that form stream caves, flank margin caves, and blue holes. Pseudokarst caves are of minor importance in anchialine cave habitat development, with some lava tubes being notable exceptions. Dissolution caves provide the most extensive, variable, and long-term environments for anchialine habitats. The Carbonate Island Karst Model (CIKM) allows dissolutional cave development in carbonate coasts to be understood as the interplay between freshwater and marine water mixing, sea-level change, rock maturity, and interaction with adjacent non-carbonate rocks. Glacioeustatic sea-level changes of the Quaternary have moved all coastal anchialine cave environments repeatedly through a vertical range of over 100 m, and modern anchialine environments could not develop at their current elevations until ~4,000 years ago when sea level reached its present position. Blue holes form by a variety of mechanisms, but the most common is upward stoping and collapse from deep dissolutional voids. As a result, they provide vertical connection between different levels of horizontal cave development produced by a variety of earlier sea-level positions. Blue holes are overprinted by successive sea-level fluctuations; each sea-level event adds complexity to the habitats within blue holes and the cave systems they connect. Blue holes can reach depths below the deepest glacioeustatic sea-level lowstand, and thereby provide a refugia for anchialine species when cave passages above are drained by Quaternary sea-level fall. Blue holes represent the most significant anchialine cave environment in the world, and may provide clues to anchialine cave species colonization and speciation events. [ABSTRACT FROM AUTHOR]

Recent investigations of anchialine caves and sinkholes have identified complex food webs dependent on detrital and, in some cases, chemosynthetically produced organic matter. Chemosynthetic microbes in anchialine systems obtain energy from reduced compounds produced during organic matter degradation (e.g., sulfide, ammonium, and methane), similar to what occurs in deep ocean cold seeps and mud volcanoes, but distinct from dominant processes operating at hydrothermal vents and sulfurous mineral caves where the primary energy source is mantle derived. This review includes case studies from both anchialine and non-anchialine habitats, where evidence for in situ chemosynthetic production of organic matter and its subsequent transfer to higher trophic level metazoans is documented. The energy sources and pathways identified are synthesized to develop conceptual models for elemental cycles and energy cascades that occur within oligotrophic and eutrophic anchialine caves. Strategies and techniques for testing the hypothesis of chemosynthesis as an active process in anchialine caves are also suggested. [ABSTRACT FROM AUTHOR]

This study tests the ecological and physico-chemical effect of sharp density boundaries of meromictic lakes. The investigation was carried out in Nohoch Hol, an anchialine meromictic cenote situated 2.0 km inland from the Caribbean coast of the Yucatan Peninsula, Mexico. In situ physico-chemical parameters were recorded with a water quality datalogger at depth intervals of 0.5 m. In addition, seven water samples for determination of nutrients, bacterioplankton and phytoplankton in the water column were obtained using SCUBA. Bacterioplankton and phytoplankton densities are low, with concentrations consistent with the oligo- to ultraoligotrophic status of Nohoch Hol indicated by the low nutrient concentrations. The phytoplankton was dominated by the chlorophyte Scenedesmus. Maximum concentrations of bacterio- and phytoplankton were found at 10.0 m depth, the top of the chemolimnion. The similarity analysis clustered the samples in three defined groups: (a) the mixolimnion, (b) the mid- and bottom of the chemolimnion and the monimolimnion, and (c) the top of the chemolimnion. The principal component analysis explained over 85% of the total variance in two components (PC). PC1 was related to turbidity and the aggregation of the chlorophytes at the top of the chemolimnion. PC2 was related to dissolved oxygen and the accumulation of filamentous and total bacteria also at the top of the chemolimnion. The top of the chemolimnion acts as a boundary within the water column to the exchange of dissolved and particulate matter between the mixo and the monimolimnion and as an ecological zone with a crucial role in the biogeochemistry of Nohoch Hol. [ABSTRACT FROM AUTHOR]

In this article, the variability of physical settings of anchialine systems in Indonesia is discussed together with the consequences these settings have for the environment and biota within the systems. Exploration in two karstic areas (Berau, East Kalimantan and Raja Ampat, West Papua) has resulted in the discovery of 20 previously unknown anchialine systems in Indonesia. Based on parameters such as bathymetry, size, coastline, salinity, water temperature, pH, degree of connection to the sea, and the presence-absence of selected key taxa we distinguish three types of (non-cave) anchialine systems in the Indo-Pacific: (1) Marine lakes with large and deep basins containing brackish to almost fully marine waters. Marine lakes show a range in the degree of connection to the sea with the result that the higher the connection the more the lake resembles a lagoon in both water chemistry and biota, while the more isolated lakes have brackish water and contain unique species that are rarely found in the adjacent sea. (2) Anchialine pools with small and shallow basins containing brackish water and low diversity of macrofauna. (3) Blue pools in chasms that contain water with a clear halocline and are possibly connected to anchialine caves. Study of the many unique features of anchialine systems will enhance our understanding of the physical and ecological processes responsible for diversification in tropical shallow marine environments. [ABSTRACT FROM AUTHOR]

The mid-Atlantic islands of Bermuda harbor one of the richest and most diverse anchialine communities known from anywhere on Earth. However, all known anchialine caves in Bermuda (maximum depth-26 m) were dry during the last glacial period extending from approximately 9,000 to 115,000 years ago when glacial sea levels were as much as 127 m lower. Since it is highly unlikely that Bermuda's endemic cave species evolved since the caves were flooded by sea level rise, alternate deeper habitats must have existed to shelter anchiane fauna for prolonged periods of lower sea level during the Pleistocene. In order to systematically search for such now deep water cave habitats, high-resolution multibeam sonar and remotely operated vehicles were used to map and explore the seafloor off Bermuda in 60-200 m depths along the outer shelf break edge of the submarine escarpment surrounding the Bermuda Platform and an adjacent seamount. Specific goals were to discover deep water cave and/or crevicular habitats and to characterize the nature, geological stratification and composition, and sea level history of the platform margin, in particular focusing on features directly relating to Pleistocene low sea stand events. During this sea floor survey, clearly defined paleo-shoreline features generated by wave and current erosion were found to encircle the Bermuda seamount and Challenger Bank at 60 and 120 m depths. [ABSTRACT FROM AUTHOR]

Inland blue holes of the Bahamas are anchialine ecosystems with distinct fresh and salt water layers, and anoxic or microoxic conditions at depth. Scientific cave diving and geomicrobiology exploration of blue holes are providing a first glimpse of the geochemistry and microbial life in these vertically stratified karst features. We hypothesized that two geographically adjacent, sunlit blue holes on Abaco Island would have comparable biogeochemistry and microbial life. Water samples were analyzed using in situ multiparameter dataloggers and field and laboratory tests, and diver-retrieved microbial samples were analyzed using nucleic acid analysis. Microbial 16S rRNA genes were dominated by members of the anoxygenic phototroph clade Chlorobi, with smaller numbers of Deltaproteobacteria, in both blue holes. However, spatial distributions of microbial biomass and species present within these major clades were significantly different. We also found that differences in the intensity of solar insolation, terrestrial and marine inputs, water residence time, depth to the halo/chemocline, and cave passage geometry strongly influence geochemical changes with depth. The biogeochemical diversity of inland blue holes in the Bahamas make them valuable as natural laboratories, repositories of microbial diversity, and analogs for stratified and sulfidic oceans present early in Earth's history. [ABSTRACT FROM AUTHOR]

Juvenile instars II, IV, and V of the anchialine halocyprid ostracod Danielopolina kornickeri Danielopol, Baltanas & Humphreys, 2000 (Thaumatocyprididae) are described and illustrated. In addition, a supplementary description of the adult male is presented. Specimens had been collected in Bundera Sinkhole, the type locality of the species in Western Australia. Also, juvenile instars I and II of the deep-sea species Thaumatoconcha radiata Kornicker & Sohn, 1976, which is in the same family as members of the genus Danielopolina, are described and illustrated. It is tentatively concluded that during its ontogeny, D. kornickeri has 6 growth stages; morphological characters useful in identifying the stage and sex of juveniles of D. kornickeri are presented. Finally, the hypothesis is proposed for an anchialine cave ancestor to the present-day planktonic Halocyprididae, now widely spread in the oceans. [ABSTRACT FROM AUTHOR]

A new species of anchialine varunid crab of the genus Orcovita Ng & Tomascik, 1994, O. holthuisi new species, is described from Coron Island, Palawan, Philippines. The new species is easily distinguished from its congeners by differences in the form of the carapace, chela, ambulatory legs, and male abdomen. [ABSTRACT FROM AUTHOR]

The morphology and systematic affinities of Danielopolina sp. cf. D. kornickeri from Christmas Island, an isolated seamount in the Indian Ocean, are reassessed with the aid of new material including a juvenile male. The species is formally described as Danielopolina (Humphreysella) baltanasi sp. n., which places the species in a separate subgenus to Danielopolina (Danielopolina) kornickeri from northwest Australia, the only other member of the genus in the Indian Ocean. In addition, the only deep-sea member of the genus, D. carolynae from the mid-Atlantic, a putative colonizer of seamounts, belongs to the subgenus Danielopolina. These findings compound theories on the distribution and dispersal of anchialine faunas. A coherent programme of molecular phylogenetic research and historical biogeographical analysis is needed to further enquiry into the enigmatic distribution of the anchialine faunas of both isolated sea mounts and epicontinental waters. Owing to the scarcity of anchialine fauna and the difficulty of access of their habitat, a global effort will be required to assemble the required specimens. [ABSTRACT FROM AUTHOR]

Community-based management (CBM) has been recognized as an appropriate approach to conservation, assuming that local communities have higher stakes than the state in their natural resources and have better knowledge of local resources and, therefore, can manage them more efficiently. However, the implementation of CBM has not always been successful. The objective of this research was to assess the potential for the implementation of a governmental proposal for community-based management of peccaries (Tayassuidae) in the Impenetrable northern Argentine, through the examination of the reasons why arrangements to avoid overexploitation have not evolved in this region. I used the theory of common pool resources (CPRs) as a framework for this analysis. CPRs theory explains the coeditions under which appropriators of a resource are likely to engage in devising and altering governing arrangements and the conditions under which such arrangements are likely to succeed. Fieldwork was conducted between June 2000 and August 2003 using a mixed methods approach. It was found that most of the condition of the resource and users identified by the CPR theory as associated with an increased likelihood of successful management of natural resources are absent or scarcely developed in the Impenetrable. Thus, the situation in the Impenetrable does not seem appropriate for the implementation of CBM of peccaries. It is first necessary to invest in training and development of local institutions' capacities and social capital. It is also important to increase the flow of relevant information, which will enable institutions to be effective, responsible, and accountable to the community. For the moment, a more appropriate approach will have to include a mixture of protectionism and comanagement of collared peccaries while the propitious conditions for a complete local management of the resource are developed. [ABSTRACT FROM AUTHOR]

The discovery, in the inner coastal plain of Israel, of a deep, secluded subterranean ecosystem, supported by chemosynthetis producing by sulfide-oxidizing bacteria, suggests the existence of a new biome, “Ophel”, with an autonomous energy basis. This biome could provide an ecological and historical basis for explaining the high taxonomic diversity of subterranean faunas, especially of crustaceans. A continuum with the anchialine ecosystems, in which chemoautotrophy is also encountered, as well as with marine hot vents and cold seeps, implies the existence of a second, parallel chemosynthesis-based eukaryotic biosphere. [ABSTRACT FROM AUTHOR]

Coastal karst is characterized by special geomorphologic and hydrodynamic conditions as well as by peculiar sedimentary, geochemical, and biospeleological environments. Generally, the more distinctive karstic features produced near the coastline are strongly influenced by sea-level changes, which generate a broad set of interactions between littoral processes and karst development. The glacioeustatic rises and falls of sea level affected the littoral karst in different ways, namely: vertical and horizontal shifts in the shoreline position, changes in elevation of the local water table, and vertical displacements of the halocline. Most eogenetic karsts have been subjected over long time spans to repeated changes of a variety of vertically-zoned geochemical environments: vadose, phreatic meteoric-water, brackish mixing-waters and even marine water. Many coastal caves appear to be passively drowned by Holocene sea-level rise, and to contain glacioeustatic pools of varied size where the current water table intersects formerly air-filled chambers or passages. These coastal phreatic waters are controlled by sea level and fluctuate with tides. Significantly, features such as phreatic speleothems that are able to record ancient sea levels occur closely associated to the surface of the pools. The cave pools are brackish or even marine anchialine environments that contain remarkable communities of troglobitic stygofauna. All of these aspects can be studied in detail along the southern and eastern coast of Mallorca Island owing to the widespread outcrop of Upper Miocene calcarenites, in which the development of eogenetic karst features started approximately 6 Ma ago, at the end of Messinian times. Some outstanding coastal caves result and include the celebrated Coves del Drac (explored by E.A. Martel in 1896), the labyrinthine Cova des Pas de Vallgornera (more than 30 km in length) and he recently explored Cova de sa Gleda (whose submerged passages exceed 10 km, as shown by scuba-diving surveys). Careful observations and detailed mapping of caves in the Upper Miocene reef rocks of Mallorca permit a better understanding of the coastal speleogenetic processes involved in a typical eogenetic karst over time ranges greater than 1 Ma. The role played by recurrent glacioeustatic oscillations of sea level and the subsequent rises and falls of the water table are emphasized in our model. There are two associated mechanisms: the triggering of breakdown by the loss of buoyant support that follows each lowering of sea level (i.e., during glaciations or smaller cold events) and the later underwater solution of boulders and collapse debris (during high sea levels that correspond to interglacial events). Additionally, tidal fluctuations affecting groundwaters would enhance solutional enlargement of caves and vug-porosity connected to the sea, rather than conventional karstic flow through conduits that probably is not as important an agent in eogenetic speleogenesis. [ABSTRACT FROM AUTHOR]

The article focuses on a new Exumella, a fish belonging to the copepod family, from Anchialine waters of the Western Caribbean. Specimens from biological collections were found to belong to an undescribed species of the genus Exumella. The new species of Exumella is distinguished by a combination of characters and by details of the structure of the male and female legs. The new species represents the first record of the family in Mexico.

Four new species of Ostracoda belonging to the tribe Thalassocypridini are described from anchialine cave pools of the Loyalty Islands of New Caledonia: Dolerocypria iliffei n. sp., Paracypria uberis n. sp., Mungava woutersi n. sp., and Mungava xariessa n. sp. Detailed anatomical comparisons with 36 established species test the soundness of the emerging generic classification of thalassocypridines. Mangalocypria and Mungava are well-defined genera with exclusive, key diagnostic traits. Dolerocypria, Paracypria and Thalassocypria are somewhat less coherent. The essential qualities of Pontoparta and Parapontoparta remain elusive because of the heterogeneity of species referred to those nominal genera. Emended diagnoses are offered for the tribe Thalassocypridini and for the genera Dolerocypria, Paracypria, and Mungava. [ABSTRACT FROM AUTHOR]

A new copepod genus and species, Speleohvarella gamulini, collected from the anchialine cave Živa Voda on Hvar Island (Croatia), is described from both sexes. This is the first record of a calanoid copepod found in an Adriatic anchialine cave. The new genus is distinguished from other Stephidae by a combination of the following features: the cephalosome is separate from the first pedigerous somite, and the fourth and fifth pedigerous somites are fused; the female urosome has 4 segments, the genital double-somite is symmetrical and the caudal rami is asymmetrical with the right longer than the left; antennules of both sexes are symmetrical and 24-segmented, with the fusion of ancestral segments II–IV, X–XI and XXVII–XXVIII; the exopod of antenna is 7-segmented; 2 setae are present on the basal exite of maxillule; in the male the right leg 5 is short and 3-segmented, and the left leg elongate and 5-segmented. [ABSTRACT FROM AUTHOR]

Presents taxonomic composition of suspended algae communities in several cenotes and anchialine caves in Quintana Roo, Mexico. Relation of diatoms to species richness; Influence of the distance of the cenote site to the coastline; Presence of marine species at the halocline of the caves.

Anchialine sinkholes provide insight into coastal aquifer systems and coastal mixing processes. Aquifer microbial community function is usually inferred from hydrochemical information, but there are few direct studies of microbial communities in the Floridan Aquifer. Hospital Hole is a 43 m-deep stratified sinkhole under the Weeki Wachee River, FL, with three distinct brackish layers: a hypoxic layer, a chemocline and a sulfidic anoxic layer. Illumina sequencing and bioinformatic tools were used to reconstruct metabolic functions and interactions of microbial communities in each layer. Each layer appears to originate from different parts of the coastal mixing zone and has a distinct microbial community with unique functions, which are influenced by the respective hydrochemistry. Sulfide oxidation and nitrate reduction are the most abundant functions. Syntrophy between methane oxidizers, methanogens and sulfate reducers is present. Similarities between the hydrochemistry and potential connectivity of Hospital Hole and the Floridan Aquifer coastal mixing zone suggest that microbial communities of Hospital Hole could be a surrogate for the coastal mixing zone of the aquifer in the absence of direct studies. Understanding how groundwater microbial communities react to saltwater intrusion and nutrient flux will be useful in predicting how coastal aquifer regions might react to anthropogenic change. [ABSTRACT FROM AUTHOR]

A preface for this issue of "Hydrobiologia," focusing on anchialine ecosystems, is presented.