Cranial and mandibular morphometry in Leontopithecus lesson, 1840 (Callitrichidae,Primates)

In this paper, we report on a craniometric analysis comparing the species of lion tamarins, Leontopithecus Lesson, 1840. Seventeen cranial and mandibular measures were taken on skulls of 59 adult crania: 20 L. rosalia (14 females and 6 males); 13 L. chrysomelas (6 females and 7 males); 23 L. chrysopygus (8 females and 15 males), and 3 L. caissara (1 female and 2 males). All specimens were from the Rio de Janeiro Primate Center (CPRJ‐FEEMA, Brazil), except the specimens of L. caissara. Statistical treatment involved a one‐way analysis of variance (the Bonferroni test) and discriminant analysis, comparing cranium and mandibles separately to determine variables which best distinguished groups and to group the specimens, using size corrected methods. The Mahalanobis distance was computed from the centroids of each group. Seven measures distinguished females of L. chrysopygus with L. rosalia, six to L. rosalia with L. chrysomelas, and L. chrysopygus with L. chrysomelas. In males, the numbers of measures statistically different were 5, 4, and 3 of the pairwise comparisons above mentioned. Cranial base length and orbital breadth were the only measures that were significantly different in all three dyads, considering both sexes. For the cranium, function 1 of the Discriminant Analysis accounted for 52.4% of the variance and function 2 accounted for 40.3%. Both functions exhibited a significant value for Wilks' lambda (P<0.0001) and 96.6% of specimens were correctly classified. For the mandible, the first two functions provided a significant discrimination 51.1% and 44.9%, respectively, and 69.5% of the correct classification. Orbital breadth and cranial base length contributed most in the cranial analysis, while mandibular length and mandibular body height to mandibular ones. The analyses performed in this study (univariate and multivariate) demonstrated that cranial and mandibular morphology is significantly different among species of Leontopithecus. Despite of sample size, L. caissara shows morphological distances to L. chrysopygus in cranial analysis. However, other investigations are necessary to confirm this. Am. J. Primatol. 48:185–196, 1999. © 1999 Wiley‐Liss, Inc.     

Density and shell-size variation of Nodilittorina lineolata (Orbigny, 1840) in the intertidal region in southeastern Brazil

Nodilittorina lineolata is a small littorinid characteristic of the supralittoral of rocky shores but extends its vertical range to the lower midlittoral. Shell-size and density of Nodilittorina were measured at two different levels, the supralittoral and barnacle zones, in six sites along the south-eastern Brazilian coast. The sites studied varied in the degree of wave exposure. Densities were lower in the supralittoral, and higher overall values occurred on the most exposed shores. Shell size increased significantly in an upshore direction at five of the six sites. However, mean-size and the magnitude of the difference between levels varied according to the site studied. The shell-size gradient can be explained by larval recruitment in the barnacle zone and subsequent ascending migration to the supralittoral zone, where the larger individuals were found. Reciprocal transfer experiments revealed that differential mortality of large individuals in the lower levels, possibly due to lack of refuges, may also influence the size-distribution. It was also shown that some individuals can be passively transported to upper levels of the shore by wave action during storms.     

Morphological variations of the cranium within the genusLeontopithecus

Multivariate analysis methods were applied to the cranial measurements ofLeontopithecus. InLeontopithecus chrysomelas, the face is generally narrow and the cranial shape is relatively unique. Especially, the male has extremely narrow face and quite unique cranial shape amongLeontopithecus. Leontopithecus rosalia has the broad face compared with the other species. The cranial size ofL. rosalia is as large as that ofL. chrysomelas. Male ofLeontopithecus chrysopygus is the largest in overall size of the cranium, and has the widest braincase.     

Distribution, diversity and ecology of aerobic CO-oxidizing bacteria

Numerous studies indicate that carbon monoxide (CO) participates in a broader range of processes than any other single molecule, ranging from subcellular to planetary scales. Despite its toxicity to many organisms, a diverse group of bacteria that span multiple phylogenetic lineages metabolize CO. These bacteria are globally distributed and include pathogens, plant symbionts and biogeochemically important lineages in soils and the oceans. New molecular and isolation techniques, as well as genome sequencing, have greatly expanded our knowledge of the diversity of CO oxidizers. Here, we present a newly emerging picture of the distribution, diversity and ecology of aerobic CO-oxidizing bacteria.     

Distribution and ecology of dictyostelids in China

Dictyostelid cellular slime molds are a ubiquitous component of most soils, where they feed upon bacteria and other microbes and thus play an essential role in the soil ecosystem. Herein we review the available literature on dictyostelid cellular slime molds in China, especially their diversity and ecology. The patterns of distribution for these organisms in relation to the different habitats with which they are associated are analyzed and discussed. In addition, the assemblages of dictyostelids reported from China and the United States were compared. The CC value obtained (0.48) indicates that China and the United States are perhaps less similar than might be expected. Our data point out the need for further studies to characterize more completely the assemblages of dictyostelids associated with particular vegetation types or particular regions throughout the world.     

Aspects of behavioral ecology of Sotalia guianensis in Sepetiba Bay, southeast Brazil

Boat-based surveys were conducted from August 2002 to July 2003 to study the activity patterns, spatial pattern of area use, and group characteristics of Sotalia guianensis in Sepetiba Bay, southeast Brazil. Predetermined routes covered the entrance and interior of the bay, resulting in 210 dolphin sightings during 3,300 km total effort. Data on activity were collected using scan group sampling with instantaneous recording after 5 min of observation. Dolphins were sighted more frequently in the entrance of the bay, where water is deeper, and salinity and transparency are higher, than in the interior of the bay, where the environment is more influenced by freshwater inputs. Foraging and feeding were the most frequent activities, and occurred predominantly between 0600 and 1000. Foraging and feeding peaked during ebbing, low, and flooding tides, while socializing predominated at high tide. Mean group size was larger in the interior of the bay and when seabirds were present. Large aggregations containing >100 individuals of Sotalia guianensis seen year-round indicate that Sepetiba Bay is an important area for this species in coastal Brazil.     

Distribution and ecology of freshwater sponges in Connecticut

A survey of Connecticut lakes and rivers revealed the presence of 7 species of freshwater sponge: Spongilla lacustris, Ephydatia muelleri, Eunapius fragilis, Anheteromeyenia ryderi, A. argyrosperma, Corvomeyenia carolinensis, and Corvospongilla novaeterrae in order of decreasing frequency of occurrence. Corvomeyenia carolinensis has not been reported previously beyond its type locality in South Carolina. In addition, microscleres of Spongilla lacustris, Anheteromeyenia-like megascleres, Ephydatia muelleri-like megascleres, and smooth megascleres (amphioxeas), which could not be assigned to a particular species, were found in surface sediments from lake cores. Spongilla lacustris inhabiting small rivers produced brown, thick-capsuled gemmules during the summer and yellow, thin-capsuled gemmules during the fall. The thick-capsuled gemmules, but not the thin-capsuled gemmules, are tolerant of desiccation; and populations of Spongilla lacustris and Ephydatia muelleri survived severe drying of their habitats during the summer.     

Distribution,habitat use,and abundance of the endangered franciscana in southeastern and southern Brazil

The franciscana (Pontoporia blainvillei) is endemic to coastal waters from Brazil to Argentina. The species is regarded as one of the most threatened cetaceans in South America due to high bycatch levels. Four management units (FMAs) were defined throughout the species’ range. FMA II includes states along southeastern and southern Brazil, and represents one of the least known units. Recently, genetic analysis proposed that FMA II comprises two distinct populations and its range should be divided into FMA IIa and IIb. In December 2008 and January 2009 aerial surveys were conducted to assess the distribution and to estimate abundance of franciscanas off FMA II. A total of 54 groups were seen (average group size = 2.76, SE = 0.17) in shallow (mean depth = 7.15 m, SE = 7.08) coastal habitats (average distance from the shore = 6.48 km, SE = 6.28). Abundance corrected for perception and availability bias was estimated at 6,827 (CV = 0.26) franciscanas in FMA II, and at 1,915 (CV = 0.32) and 4,353 (CV = 0.24) franciscanas in FMA IIa and FMA IIb, respectively. This study indicates that, at least during the summer, franciscanas aggregate in shallow coastal habitats. Current estimates of incidental mortality in FMA II correspond to 4.4%–7.3% of the estimated stock size, suggesting high, likely unsustainable bycatch.     

Distribution and seasonal dynamics of Rhodophyta in the Preto River basin,southeastern Brazil

Distribution and seasonal dynamics of freshwater Rhodophyta were investigated in the Preto River basin, located in northwestern São Paulo State, southeastern Brazil. Twenty-two sites were sampled, six monthly during one year, four bimonthly during two years, and 12 twice (hot-rainy and cool-dry seasons) during the study period (May 1989 through March 1991). Red algal representatives were found in 19 sites (86.4%). Four species occurred in the basin with varying frequencies:Batrachospermum delicatulum (54.5%),Compsopogon coeruleus (36.4%),B. bicudoi (13.6%) andB. virgatum (4.5%). In addition, Chantransia stage of the batrachospermalean species was found in 17 sites (77.3%).B. bicudoi, B. virgatum andC. coeruleus occurred only in large stream segments ( 3-order), generally in the main river, whereasB. delicatulum was more frequent in small streams ( 3-order). The stream variables most closely related to the species distribution in the basin were specific conductance, pH and oxygen.B. bicudoi andB. delicatulum showed a marked seasonality: gametophytes were observed from late fall to early spring, while the Chantransia stage generally occurred throughout the year.C. coeruleus was observed throughout the year in most sites, but the populations were generally more abundant from late fall to early spring. The combination of lower temperature and reduced turbidity resulting in increased illumination to the benthic algae during the dry winter months promotes the gametophytic growth of the batrachospermalean species, whereas current velocity was found to be the most influential stream variable forC. coeruleus. The persistance of the Chantransia stage throughout the year as well as its tolerance to wider environmental conditions are key factors in the efficiency of the batrachospermalean life history strategy in lotic ecosystems.     

Distribution and ecology of anthozoa in the estuarine region of the rivers Rhine,Meuse and Scheldt

Data on the ecology and distribution in the estuarine region of the rivers Rhine, Meuse and Scheldt are given for ten species of Anthozoa. These data have been correlated with several environmental variables, but especially salinity. Communication nr. 142 of the Delta Institute for Hydrobiological Research.     

A complex species complex: The controversial role of ecology and biogeography in the evolutionary history of Syllis gracilis Grube, 1840 (Annelida,Syllidae)

The cryptic diversity in the polychaete Syllis gracilis Grube, 1840, in the Mediterranean Sea was examined with an integrative morpho-molecular approach. Individuals of S. gracilis were collected at eleven Mediterranean localities to provide an insight into the role of brackish environments in inducing cryptic speciation. The examination of morphological features combined with a molecular genetic analysis based on a partial sequence of the 16S rRNA gene highlighted discrepancies between morphological and molecular diversity. Morphological data allowed to identify a morphotype with short appendages occurring in coralline algae communities and another one with long appendages observed in brackish-water environments and Sabellaria reefs. Multivariate analyses showed that sampling localities were the greatest source of morphological divergence, suggesting that phenotypic plasticity may play a role in local adaptations of S. gracilis populations. Molecular data showed the occurrence of four divergent lineages not corresponding to morphological clusters. Different species delimitation tests gave conflicting results, retrieving, however, at least four separated entities. Some lineages occurred in sympatry and were equally distributed in marine and brackish-water environments, excluding a biogeographic or ecological explanation of the observed pattern and suggesting instead ancient separation between lineages and secondary contact. The co-occurrence of different lineages hindered the identification of the lineage corresponding to S. gracilis sensu stricto. The discrepancy between morphological and molecular diversity suggests that different environmental and biogeographic features may interact in a complex and unpredictable way in shaping diversity patterns. An integrative approach is needed to provide a satisfactory insight on evolutionary processes in marine invertebrates.     

Distribution and ecology of myxomycetes in the high-elevation oak forests of Cerro Bellavista, Costa Rica

Myxomycetes associated with a high-elevation (>3000 m) oak forest in the Talamanca Range of Costa Rica were studied for 7 mo. Field collections were supplemented with collections obtained from moist chamber cultures prepared with samples of bark and ground litter of Quercus costaricensis. Various microenvironmental parameters including pH, substrate moisture and diameter, height above the ground and canopy openness were recorded for each field collection, whereas macroenvironmental data for temperature and precipitation were obtained from a meteorological station near the study area. Niche breadth and niche overlap indices were calculated to assess possible resource partitioning by myxomycetes. Thirty-seven species were recorded, including 11 new records for Costa Rica, eight for Central America and one for the neotropics. Both PCA and NMS multivariate analyses indicated that pH and height above the ground explained most of the observed variation, although substrate diameter also seemed to be an important factor. Precipitation showed an inverse correlation with the number of fruitings, confirming its importance as a macroenvironmental factor. Niche overlap values were not higher for closely related species and values for niche breadths were similar for most of the more common species, suggesting that most members of the assemblage of myxomycetes present in the study site are ecological generalists.     

Distribution patterns of the fish assemblage in the Mamanguape River Estuary,North-eastern Brazil

The Mamanguape River Estuary was studied along a continuum ranging from shallow sandstone reefs adjacent to the river mouth up to the limit of influence of seawater, the upper portions of the estuary. Fish samples were gathered using three types of nets along 17 sample sites, grouped in four regions according to salinity range (reefs and low, middle and upper estuaries), to seasonality (dry and rainy seasons) and to habitat usage (marine visitor, marine estuarine-opportunist, marine estuarine-dependent, estuarine resident and estuarine &; marine). Differences were found in the fish assemblages along the estuarine-reef gradient, with most species (n?=?30) being considered marine, estuarine-opportunists or estuarine-dependent, according to its abundance and distribution. A low number of species (n?=?11) were considered estuarine residents. Some species exhibited significant differences in spatial distribution pattern, in which juveniles and adults predominated in different portions of the estuary, suggesting an ontogenetic migration both in relation to the adjacent reef area and across estuarine regions. Several species were newly recorded in the Mamanguape Estuary: Anchoa spinifer, Halichoeres poeyi, Hyporhamphus roberti, Scomberomorus cavalla, Sphyraena barracuda and Ocgocephalus vesperilio.     

Eggs and larvae of the 'curvina' Plagioscion squamosissimus (Heckel, 1840) (Osteichthyes, Sciaenidae) in the Baia River, Mato Grosso do Sul State, Brazil

The aim of this work was to study the eggs and larvae of the‘curvina’, specifically the examination of spatialand temporal variation, location of spawning and dispersal groundsand verification of the relationship between occurrence andenvironmental variables. Sixteen collection sites were establishedin the Baía River, Brazil, and grouped into four areas.Collections were carried out between February 1999 and April2000. Spatial and temporal variations were analysed using ANOVA.Identification of the spawning and dispersal grounds was carriedout using development stage distribution. The relationship betweenoccurrence and the environmental variables was determined usingPrincipal Components Analysis (PCA) and Pearson correlation.The eggs were found in every area practically every month, almostexclusively in the initial embryo stage, while the larvae occurredin every area mainly between October and April. The correlationbetween PCA scores and organism occurrence demonstrated thatthe highest catches occurred when the values of temperature,water level and rainfall were high and those of dissolved oxygenand pH were low. This specie spawns and develops in lentic areas,and the lotic stretch serves as a dispersal route through whichthe eggs and larvae are transported.     

Distribution and ecology of deep-water benthic foraminifera in the Gulf of Mexico

Bathyal and abyssal foraminifera in the Gulf of Mexico are distributed among thirteen generic predominance facies. Five predominance facies nearly encircle the Gulf basin along the slope and rise; a sixth predominance facies blankets the Sigsbee Plain, and a seventh is restricted to the Mississippi Fan. The remaining eight predominance facies have more restricted distributions. The areal patterns of these predominance facies can be related chiefly to water mass and substrate characteristics; modifications are brought about by calcite dissolution, upwelling, and sill depth. Analysis of ancient generic predominance facies is useful in predicting relative paleobathymetry and other paleoenvironmental properties.     

Distribution and ecology of copepods in mountainous regions of the Eastern Alps

Copepod species richness, patterns of distribution and composition of assemblages were evaluated in high-altitude sites in the Eastern Alps. Diverse habitats were sampled in 160 lentic water bodies from different geologic areas, ranging from acid bog ponds to alkaline karst waters and from small temporary puddles to deep lakes. The altitudinal range comprised all mountainous regions from the montane (1290 m a.s.l.) to the alpine (2886 m a.s.l.) zone. Forty-four species were recorded, with the harpacticoids being the richest group. Although most species occupied a wide altitudinal range, some stenotopic mountain forms were restricted to alpine habitats. The most widespread taxa were Acanthocyclops vernalis, Eucyclops serrulatus, Bryocamptus rhaeticus, Arctodiaptomus alpinus and Cyclops abyssorum tatricus. All species found were listed along with notes on their distribution, ecology and patterns of coexistence. There was both a marked change in species composition and a decline in species richness from hardwater habitats in the Limestone Alps to softwater sites in the Central Alps. Copepod taxocoenoses were most diverse in montane limestone lakes and impoverished with increasing altitude. Copepods and sampling sites were ordinated using canonical correspondence analysis (CCA), and copepod assemblages were defined in relation to physical and chemical parameters, habitat type and presence/absence of planktivorous fish. Planktonic species were largely absent from lakes with introduced fish. Although calanoid associations were common, coexisting diaptomids were rare, suggesting a strong interspecific competition between these predominantly filter feeders. Most copepods found are common eurytopic or cold stenothermal, but some exhibit peculiar disjunct patterns of geographical distribution, and others are apparently restricted to the Alps. Some species are discussed in more detail from a zoogeographical point of view. A complete checklist of copepods recorded to date from high-altitude sites in the Eastern Alps is provided.