In the laboratorial and audiometric evaluation, after exclusion of other related causes, we came to the additional diagnosis of otosyphilis. Report: We described the case of a patient, aged 64 years, black, with complaints of slow and progressive diminishing of auditory accuracy since about 12 years ago, associated with tinnitus and occasional unbalances. Objective: The objective of this work was to emphasize the need for etiologic identification for treatment and control of individuals with cochleovestibular symptoms. In the literature, the neurosensorial hearing loss, tinnitus and unbalance have been described in the secondary and tertiary syphilis. Introduction: Both congenital and acquired syphilis may cause cochleovestibular dysfunction.
Presence of con-specifics proved to be an important factor affecting survivorship in seagrass meadows of the Bahamas. gigas density, suggesting that small-scale distribution is greatly influenced by density-dependent phenomena. Mortality showed a strong negative correlation with wild S. Although growth was >0.1 mm d-' at all but 2 stations, juveniles (60 to 80 mm shell length) suffered higher proportional mortality when tethered outside the aggregation (48 to 100 %) than inside (18 to 20 %). gigas growth and, compared with the presence of conspecifics, relatively unimportant predictors in terms of shelter from pre-dation. Seagrass characteristics proved to be poor predictors of habitat suitability in terms of S. Eight stations were selected to represent a gradient from bare sand to high seagrass biomass and a transect through the aggregation (inside density = 0.40 to 0.56 juveniles m-' outside density 50.08 juveniles m-'). Enclosure and tether experiments were conducted in and around a juvenile aggregation located in the middle of a tidal flow field in the Bahamas which occupied ca 21 ha. The relative roles of habitat quality and predation were examined to test the hypothesis that survivorship in a marine gastropod, Strombus gigast is enhanced by living in aggregations when young. e that the queen conch aggregation occupied only a portion ity over a site however, predation rates are probably * The ecological significance of aggregations should be considered in fisheries management and stock enhancement programs with queen conch. Gregariousness, observed in translo-cation experiments, may provide an active mechanism for maintaining aggregated distribution and reducing mortality in conch nurseries. Aggregations could be maintained by differential mortal-density-dependent. Our results suggest of the habitat that is optimal for feeding and growth. A tethering experiment confirmed the hypothesis that predator-induced mortality is significantly higher outside than inside the conch aggregation.
Tagged juveniles transplanted to zones outside the aggregation had high growth rates but suffered higher losses than individuals transplanted to the aggregation center. In areas of high population density within the aggregation, several mass migrations of juveniles (20 to 99 conch m-') occurred in early 1990. Surveys conducted every 2 mo showed that conch density in the aggregation center remained constant while all other zones had lower densities which varied with time. The aggregation formed an ellipse, with longitudinal axis parallel to the main axis of the tidal current. At the beginning of the study in August 1989, the conch population occupied 16.7 ha, with densities >0.2 juvenile conch m-2. To examine the structure of a juvenile aggregation and to determine the underlying mechanisms which affect juvenile conch distribution, we examined density, size composition, growth, survivorship, and movement patterns within a typical tidal-flow field nursery over a 14mo period (August 1989 to September 1990). Juvenile queen conch (Stronzbus gigus L.) occur in discrete aggregations within seemingly uniform sea-grass beds throughout the Exuma Cays, Bahamas, suggesting that the aggregations occupy ecologically unique sectors of the habitat or that conch gain fitness by aggre-gated distribution.
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