Age determination of recent cave deposits using excess \u3csup\u3e210\u3c/sup\u3ePb - A new technique

Cave deposits have been widely used as proxy recorders in deciphering palaeoclimate during the last glacial/interglacial maxima (∼ 120 ka) [Harmon et al., 1975; Atkinson et al., 1978; Goede and Harmon, 1983; Ayliffe and Veeh, 1989]. Palaeoclimatic studies of cave deposits for the past 1–1000 yr time scale require a precise dating technique, that until now has been lacking. Due to the multiple sources of carbon in speleothems, 14C dates obtained for recently deposited calcite are highly variable and thus, 14C dating techniques are not suitable to obtain speleothem ages for the past 1–1000 years. Here, we show for the first time that speleothems contain high concentrations of excess 210Pb and that this 210Pb excess can be successfully employed to obtain growth rates of speleothems deposited during the last 100 years. Of two specimens analyzed, a tubular “soda straw” stalactite yielded a longitudinal growth rate of 1.1 mm/yr, while a normal icicle-shaped stalactite had a lateral growth rate of 0.028 mm/yr. The mass growth rates of these two speleothems (149 and 78 mg/yr respectively) are comparable within a factor of two. Studies of fine-scale variations in the isotopic composition of recent speleothems will help to corroborate the validity of palaeoclimate records obtained using longer lived isotopes and extending back into Pleistocene

The status of Bogidiella Balearica Dancau, 1973, a stygobiont amphipod from Mallorca

[spa] Se presenta la redescripción de Bogidiella balearica Dancau, 1973, un anfípodo estigobionte de las cuevas anquihalinas de Mallorca. Queda demostrado que se trata de una buena especie, clasificable dentro del subgénero Bogidiella s. str., y que se puede diferenciar fácilmente de Bogidiella chappuisi Ruffo, 1952 (con la cual se intentó sinonimizar con anterioridad), perteneciente a otro subgénero, Medigidiella.[eng] Redescription of Bogidiella balearica Dancau, 1973, a stygobiont amphipod from anchihaline caves in Mallorca. It proves to be a good species, to be classified with the subgenus Bogidiella s. str., and it is well-distinguished from Bogidiella chappuisi Ruffo, 1952 (with which it was tentatively synonyrnized in the past), belonging to a different suhgenus, Medigidiella

New Species of Amphipod Crustaceans in the Genera Tegano and Melita (Hadzioidea : Melitidae) From Subterranean Groundwaters in Guam, Palau, and the Philippines

Three new species of Tegano are described, two from caves on Panglao Island, Bohol, Philippines, and one from a cave on Peleliu Island, Palau. Sriha vagabunda from Sri Lanka is reassigned to the genus Tegano based primarily on the high degree of similarity between Sriha vagabunda and species of Tegano and the fact that these species exhibit a great deal of variation in the reduction of the mandibular palp. A new species of Melita with characters intermediate between those defining the genera Abludomelita, Melita, and Paraniphargus is described from a spring on Guam. The characters of the new species and studies by previous authors suggest that Abludomelita may not be as distinct from Melita as previously believed. The troglomorphic genus Paraniphargus from the Andaman Islands and Java is reevaluated and synonymized with Melita

Diving investigations of Bermuda’s deep water caves

Mixed gas rebreathers allowed divers to explore the shelf edge of the Bermuda sea mount at depths from 60 to 136 m to search for potential refugia of anchialine taxa during Pleistocene periods of sea level regression. Divers discovered karst and sea level features including a remnant natural bridge cave, drowned coral reefs, wave-cut notches and high relief escarpments

Serotonin immunoreactive interneurons in the brain of the Remipedia: new insights into the phylogenetic affinities of an enigmatic crustacean taxon

BACKGROUND: Remipedia, a group of homonomously segmented, cave-dwelling, eyeless arthropods have been regarded as basal crustaceans in most early morphological and taxonomic studies. However, molecular sequence information together with the discovery of a highly differentiated brain led to a reconsideration of their phylogenetic position. Various conflicting hypotheses have been proposed including the claim for a basal position of Remipedia up to a close relationship with Malacostraca or Hexapoda. To provide new morphological characters that may allow phylogenetic insights, we have analyzed the architecture of the remipede brain in more detail using immunocytochemistry (serotonin, acetylated α-tubulin, synapsin) combined with confocal laser-scanning microscopy and image reconstruction techniques. This approach allows for a comprehensive neuroanatomical comparison with other crustacean and hexapod taxa. RESULTS: The dominant structures of the brain are the deutocerebral olfactory neuropils, which are linked by the olfactory globular tracts to the protocerebral hemiellipsoid bodies. The olfactory globular tracts form a characteristic chiasm in the center of the brain. In Speleonectes tulumensis, each brain hemisphere contains about 120 serotonin immunoreactive neurons, which are distributed in distinct cell groups supplying fine, profusely branching neurites to 16 neuropilar domains. The olfactory neuropil comprises more than 300 spherical olfactory glomeruli arranged in sublobes. Eight serotonin immunoreactive neurons homogeneously innervate the olfactory glomeruli. In the protocerebrum, serotonin immunoreactivity revealed several structures, which, based on their position and connectivity resemble a central complex comprising a central body, a protocerebral bridge, W-, X-, Y-, Z-tracts, and lateral accessory lobes. CONCLUSIONS: The brain of Remipedia shows several plesiomorphic features shared with other Mandibulata, such as deutocerebral olfactory neuropils with a glomerular organization, innervations by serotonin immunoreactive interneurons, and connections to protocerebral neuropils. Also, we provided tentative evidence for W-, X-, Y-, Z-tracts in the remipedian central complex like in the brain of Malacostraca, and Hexapoda. Furthermore, Remipedia display several synapomorphies with Malacostraca supporting a sister group relationship between both taxa. These homologies include a chiasm of the olfactory globular tract, which connects the olfactory neuropils with the lateral protocerebrum and the presence of hemiellipsoid bodies. Even though a growing number of molecular investigations unites Remipedia and Cephalocarida, our neuroanatomical comparison does not provide support for such a sister group relationship

<i>Xibalbanus cozumelensis</i>, a new species of Remipedia (Crustacea) from Cozumel, Mexico, and a molecular phylogeny of <i>Xibalbanus </i>on the Yucatán Peninsula

A new species belonging to the crustacean class Remipedia is described from an anchialine cave system on the island of Cozumel (Mexico), and is illustrated and compared morphologically and molecularly (CO1 and 16S) with closely related taxa. Xibalbanus cozumelensis sp. nov., the first remipede described from Cozumel, is morphologically similar to Xibalbanus tulumensis (Yager, 1987) from the Yucatán Peninsula, but the two species are genetically separate from each other (about 10% in CO1). A phylogenetic (Bayesian) analysis of Yucatán remipede populations based on CO1 and 16S placed them in a monophyletic Xibalbanus (in Xibalbanidae fam. nov.), with X. cozumelensis as most closely related to X. tulumensis. The Yucatán Peninsula and Cozumel have been separate since approx. early Cenozoic (~65 Ma), which suggests allopatric speciation for X. cozumelensis sp. nov. and X. tulumensis. However, the comparatively low genetic divergence between the two species may indicate that there has been gene flow between ‘mainland’ Yucatán and Cozumel long after the geological separation of the two landmasses, e.g., in cave systems under the sea bed, either continuously or sporadically, for example during the Last Glacial Maximum when the sea level was about 120 m lower than today

A new species of Eupelte (Copepoda: Harpacticoida: Peltidiidae) from Anchialine caves in Bermuda

A new anchialine species of Eupelte (Copepoda: Harpacticoida: Peltidiidae) is described from tidal pools and submerged passages in Bermuda caves. It is the sixth anchialine harpacticoid species known from Bermuda and the first anchialine member worldwide of the family Peltidiidae. The genus Eupelte currently contains 16 valid species, of which five have been found in the Atlantic Ocean, four in the Pacific Ocean, three in the Indian Ocean, two in the Mediterranean Sea, one in arctic waters and the last one in antarctic waters

The use of stable and radiocarbon isotopes as a method for delineating sources of organic material in anchialine systems

A duel isotope (stable and radiocarbon) investigation of anchialine cave systems in the Yucatan Peninsula compares the food web of a coastal and an inland cenote. Isotopic data demonstrates distinct photosynthetic and chemoautotrophic trophic levels, as well as the ability of fauna within the cave to be selective feeders even within these nutrient poor environments

Multidimensional Geriatric Assessment: Back to the Future Preclinical Disability as a Risk Factor for Falls in Community-Dwelling Older Adults

Background. Falls are common and serious problems in older adults. The goal of this study was to examine whether preclinical disability predicts incident falls in a European population of community-dwelling older adults. Methods. Secondary data analysis was performed on a population-based longitudinal study of 1644 community-dwelling older adults living in London, U.K.; Hamburg, Germany; Solothurn, Switzerland. Data were collected at baseline and 1-year follow-up using a self-administered multidimensional health risk appraisal questionnaire, including validated questions on falls, mobility disability status (high function, preclinical disability, task difficulty), and demographic and health-related characteristics. Associations were evaluated using bivariate and multivariate logistic regression analyses. Results. Overall incidence of falls was 24%, and increased by worsening mobility disability status: high function (17%), preclinical disability (32%), task difficulty (40%), test-of-trend p <.003. In multivariate analysis adjusting for other fall risk factors, preclinical disability (odds ratio [OR] = 1.7, 95% confidence interval [CI], 1.1-2.5), task difficulty (OR = 1.7, 95% CI, 1.1-2.6) and history of falls (OR = 4.7, 95% CI, 3.5-6.3) were the strongest significant predictors of falls. In stratified multivariate analyses, preclinical disability equally predicted falls in participants with (OR = 1.7, 95% CI, 1.0-3.0) and without history of falls (OR = 1.8, 95% CI, 1.1-3.0). Conclusions. This study provides longitudinal evidence that self-reported preclinical disability predicts incident falls at 1-year follow-up independent of other self-reported fall risk factors. Multidimensional geriatric assessment that includes preclinical disability may provide a unique early warning system as well as potential targets for interventio

The Unique Dorsal Brood Pouch of Thermosbaenacea (Crustacea, Malacostraca) and Description of an Advanced Developmental Stage of Tulumella unidens from the Yucatan Peninsula (Mexico), with a Discussion of Mouth Part Homologies to Other Malacostraca

The Thermosbaenacea, a small taxon of crustaceans inhabiting subterranean waters, are unique among malacostracans as they brood their offspring dorsally under the carapace. This habit is of evolutionary interest but the last detailed report on thermosbaenacean development is more than 40 years old. Here we provide new observations on an ovigerous female of Tulumella unidens with advanced developmental stages in its brood chamber collected from an anchialine cave at the Yucatan Peninsula, which is only the third report on developmental stages of Thermosbaenacea and the first for the genus Tulumella. Significant in a wider crustacean context, we report and discuss hitherto unexplored lobate structures inside the brood chamber of the female originating at the first (maxilliped) and second thoracic segments, which are most likely modified epipods, perhaps serving as gills. At the posterior margin of carapace of the female are rows of large spines preventing the developing stages from falling out. The external morphology of the advanced developmental stages is described in much detail, providing information on e.g., carapace formation and early limb morphology. Among the hitherto unknown structures in the advanced developmental stages provided by this study are the presence of an embryonic dorsal organ and rudimentary 'naupliar processes' of the second antennae. Since most hypotheses on crustacean (and malacostracan and peracaridan) relationship rest on external limb morphology, we use early limb bud morphology of Tulumella to better establish thermosbaenacean limb homologies to those of other crustaceans, which is a necessary basis for future morphology based phylogenetic considerations