Adult Pattern Of Distribution Research Articles

Verification of the gene and protein expression of the aquaglyceroporin AQP3 in the mammalian lens

Transport of water is critical for maintaining the transparency of the avascular lens, and the lens is known to express at least five distinctly different water channels from the Aquaporin (AQP) family of proteins. In this study we report on the identification of a sixth lens AQP, AQP3 an aquaglyceroporin, which in addition to water also transports glycerol and H2O2. AQP3 was identified at the transcript level and protein levels using RT-PCR and Western blotting, respectively, in the mouse, rat, bovine and human lens, showing that its expression is conserved in the mammalian lens. Western blotting showed AQP3 in the lens exists as 25 kDa non-glycosylated and 37 kDa glycosylated monomeric forms in all lens species. To identify the regions in the lens where AQP3 is expressed Western blotting was repeated using epithelial, outer cortical and inner cortical/core fractions isolated from the mouse lens. AQP3 was found in all lens regions, with the highest signal of non-glycosylated AQP3 being found in the epithelium. While in the inner cortex/core region AQP3 signal was not only lower but was predominately from the glycosylated form of AQP3. Immunolabelling of lens sections with AQP3 antibodies confirmed that AQP3 is found in all regions of the adult mouse, and also revealed that the subcellular distribution of AQP3 changes as a function of fiber cell differentiation. In epithelial and peripheral fiber cells of the outer cortex AQP3 labelling was predominately associated with membrane vesicles in the cytoplasm, but in the deeper regions of the lens AQP3 labelling was associated with the plasma membranes of fiber cells located in the inner cortex and core of the lens. To determine how this adult pattern of AQP3 subcellular distribution was established, immunolabelling for AQP3 was performed on embryonic and postnatal lenses. AQP3 expression was first detected on embryonic day (E) 11 in the membranes of primary fiber cells that have started to elongate and fill the lumen of the lens vesicle, while later at E16 the AQP3 labelling in the primary fiber cells had shifted to a predominately cytoplasmic location. In the following postnatal (P) stages of lens growth at P3 and P6, AQP3 labelling remained cytoplasmic across all regions of the lens and it was not until P15 when the pattern of localisation of AQP3 changed to an adult distribution with cytoplasmic labelling detected in the outer cortex and membrane localisation detected in the inner cortex and core of the lens. Comparison of the AQP3 labelling pattern to those obtained previously for AQP0 and AQP5 showed that the subcellular distribution was more similar to AQP5 than AQP0, but there were still significant differences that suggest AQP3 may have unique roles in the maintenance of lens transparency.

Encroachment drives facilitation at alpine shrublines

Ongoing encroachment is driving recent alpine shrubline dynamics globally, but the role of shrub-shrub interactions in shaping shrublines and their relationships with stem density changes remain poorly understood. Here, the size and age of shrubs from 26 Salix shrubline populations along a 900-km latitudinal gradient (30°–38° N) were measured and mapped across the eastern Tibetan Plateau. Point pattern analyses were used to quantify the spatial distribution patterns of juveniles and adults, and to assess spatial associations between them. Mean intensity of univariate and bivariate spatial patterns was related to biotic and abiotic variables. Bivariate mark correlation functions with a quantitative mark (shrub height, basal stem diameter, crown width) were also employed to investigate the spatial relationships between shrub traits of juveniles and adults. Structural equation models were used to explore the relationships among conspecific interactions, patterns, shrub traits and recruitment dynamics under climate change. Most shrublines showed clustered patterns, suggesting the existence of conspecific facilitation. Clustered patterns of juveniles and conspecific interactions (potentially facilitation) tended to intensify with increasing soil moisture stress. Summer warming before 2010 triggered positive effects on population interactions and spatial patterns via increased shrub recruitment. However, summer warming after 2010 triggered negative effects on interactions through reduced shrub recruitment. Therefore, shrub recruitment shifts under rapid climate change could impact spatial patterns, alter conspecific interactions and modify the direction and degree of shrublines responses to climate. These changes would have profound implications for the stability of alpine woody ecosystems.

Exposure of polystyrene microplastics induces oxidative stress and physiological defects in Drosophila melanogaster

Background: Microplastics are emerging contaminants in aquatic and terrestrial environments. Here, we used the fruit fly (Drosophila melanogaster) as model organism to study the adverse effects of polystyrene microplastics (PS-MPs). Methods: The computational study of styrene-protein interactome revealed enrichment of oxidative stress related pathways. Therefore, we tested the in-silico data by analysing the toxicity of PS-MPs via dietary exposures to 5g/l and 10 g/l doses on Drosophila melanogaster. Results: At both of these doses there was significant increase in oxidative stress as revealed by lipid peroxidase assay. Furthermore, PS-MPs significantly reduced climbing ability of adult flies and distribution pattern of pupal positioning during development. Conclusion: Overall, dietary exposures of PS-MPs caused toxicity in the fruit flies. This study establishes a baseline understanding of the impacts of PS-MPs to the fruit fly and motivates the need for further work focusing on naturally weathered plastic debris.

N equals two (times five). Exploring the effects of horse rewilding on five congeneric adult butterflies

Rewilding incomplete ecosystems by using ungulate megaherbivores represents a significant potential for sustainable management of habitats of declining species. Two xeric grasslands patches in the Podyjí National Park, Czech Republic, were rewilded by a feral horse breed, the Exmoor pony, in 2018. Before this in 2017, demography, mobility, and adult habitat use of five congeneric Melitaea butterflies co-occurring at the grasslands were investigated (Vodickova et al., J. Nature Conserv. 2019). In 2021, four seasons after the rewilding, we replicated the survey to assess the effects of the horse on the butterflies. Here, we compare the results of the two surveys and investigate changes in spatial patterns of adult distribution using Ripley’s K-functions.Total numbers of captures, and estimated population sizes, were consistently lower in 2021, with the largest drop for spring-flying M. cinxia. We cannot discern whether this was due to the cold 2021 spring, or due to reduction of grasses by the horse, possibly contributing to desiccation of M. cinxia host plants. Demographic parameters such as residency/longevity and capture probability changed only little. Mobility ranking among species remained identical, but within species, some mobility characteristics changed among years. Among early summer species, M. britomartis, second most abundant in 2017, switched to the first position with M. aurelia, and these two species displayed the most notable shift in adult habitat use between the two seasons. Short thorny shrubs avoided by the horse protect M. britomartis host plants; this threatened butterfly thus did not suffer from horse presence. M. athalia, a species of woodland edges, profited from decay of conifers caused by a series of dry years; and M. didyma, forming multiple generations, from increase of its host plant. Contrary to expectations, spatial distribution of most butterflies became more aggregated within rewilded pastures, probably due to regularities in home ranges use by the horses, which restructured the vegetation in a zonal, rather than patchy, way. A considerably larger areas should be rewilded by the herbivores to fully achieve the desired beneficial effects.

Spatio-temporal distribution and mass-trapping of leopard moth, Zeuzera pyrina in walnut orchards

Leopard moth Zeuzera pyrina L. (Lepidoptera: Cossidae) is a serious pest of walnut orchards in Iran. This study was conducted during two growing seasons, 2019 and 2020 in walnut orchards located in Ajabshir County, East Azarbaijan Province of Iran. At the beginning of the growing season, pheromone delta sticky traps (baited with female sex pheromone) were placed in the canopy of the treatment trees at 6 m above the ground (16 traps per hectare). The traps were checked weekly and the captured insects were counted and removed. Geostatistics was used to determine the spatial distribution pattern of male adults captured by pheromone traps. At the end of the growing season, damage of leopard moth larvae was assessed in 60 trees chosen from the control and treatment plots. Eight terminal branches were taken from each tree stratified in four cardinal directions (N, E, S, and W) and two canopy levels (upper and lower halves of the tree crown). The number of larval galleries in each sample was counted. The male trapping effect was not significant in the first year of the study, but it reduced leopard moth damage significantly in the second year (p < 0.01). Effects of cardinal direction, canopy level and their interactions were not significant on leopard moth damage (p > 0.05). The geostatistical analysis indicated that leopard moth male adults had random distribution at low populations, and were aggregated during flight peak with moderate to strong spatial autocorrelation. It can be concluded that distribution maps, prepared for spatially autocorrelated datasets, can be used for precision mass-trapping during the flight peak of leopard moth, as a safe method for the environment and natural enemies.

Elevation gradient distribution of indices of tree population in a montane forest: The role of leaf traits and the environment

To disentangle the controls on species distribution in the context of climate change is a central element in proposed strategies to maintain species diversity. However, previous studies have focused mainly on the roles of abiotic factors (e.g., climate and soil properties), with much less attention given to the roles of biotic factors such as functional traits. Here, we measured eight leaf traits for 240 individual trees of 53 species and analyzed the variation in traits and population composition indices and their relationships with soil properties, climate factors, and leaf traits. The tree density, frequency and species importance values of the overall species and saplings significantly increased with increasing elevation, while the same indices (except for species frequency) of adults did not significantly change. The largest percentage of variation of species importance value (greater than 50%) was explained by climate, but leaf traits played a critical role in driving elevation distribution patterns of both saplings and adults; the abundance of saplings significantly increased with elevation, with increased leaf carbon contents, while the abundance of adults did not change in accordance with a nutrient conservation strategy associated with the leaf economic spectrum. Our results suggest that the elevation gradient distribution of woody plant species is dependent on tree size and that local atmospheric humidity and leaf traits cause considerable variation in species distribution along subtropical mountain elevations. We provide evidence of which leaf traits play a key role in the elevation gradient distribution of different sizes of woody tree species.

Body Fat Distribution and Associated Risk of Cardiovascular Disease in Adults With Cerebral Palsy.

Objective: Fat distribution has increasingly been acknowledged as a more significant health parameter than general obesity, in terms of the risk of cardiovascular disease (CVD). We aimed to investigate the regional fat distribution pattern and general body fat characteristics of adults with cerebral palsy (CP), and we explored the risk of CVD in this population.Methods: People aged ≥20 years who were diagnosed with CP were recruited between February 2014 and November 2014. The subjects underwent a structured interview, laboratory studies, and physical examination. The amount and distribution of fat were determined directly by dual-energy X-ray absorptiometry. Laboratory analysis was performed to measure total cholesterol and triglyceride, high-density lipoprotein (HDL), low-density lipoprotein, and fasting plasma glucose levels. The Framingham risk score (FRS) was used to present the 10-year risk for having CVD, and predictors such as sex, age, total cholesterol, HDL, systolic blood pressure, treatment for hypertension, and smoking status were used to calculate the FRS.Results: Ninety-nine adults (58 men, mean age 41.77 ± 8.95 years) with CP were included. The participants consisted of all five levels of the Gross Motor Function Classification System. The mean body mass index (BMI) was 22.52 ± 4.58 kg/m2. According to BMI criteria, 54.9% were overweight and 27.3% were obese. The fat mass index criteria revealed 10.1% excess fat and 7.6% obesity. In univariable regression analysis, age, the timing of physical function deterioration, and android fat percentage were associated with the FRS (p <0.001, p <0.001, and p = 0.007, respectively). In multiple regression analysis, the FRS was associated with age and android fat percentage, based on the following formula: “FRS=−18.549 + 0.410 ∗ Age + 0.577 ∗ Android percent fat (%) (R2=0.528)′′ (p<0.001).Conclusions: Body fat distribution in the android area is significantly associated with future CVD risk in adults with CP.

Dietary Intake Patterns of Community-Dwelling Older Adults After Acute Hospitalization.

Malnutrition and sarcopenia are a growing concern in community-dwelling older adults. Hospitalization increases the risk of malnutrition and leads to a decline in functional and nutritional status at discharge. Persistent malnutrition after hospital discharge may worsen posthospital outcomes, including readmissions. The aim of this study was to determine dietary intakes and nutrient distribution patterns of community-dwelling older adults after acute hospitalization. Participants (65 years and older, n = 85) were enrolled during acute hospitalization and dietary 24-hour recalls were collected weekly for 1 month postdischarge. Analysis included change in dietary intake over recovery timeframe; daily intake of energy, protein, fruit, vegetables, and fluids; comparison of intake to recommendations; distribution of energy and protein across mealtimes; and analysis of most common food choices. Most participants did not meet current recommendations for energy, fruit, vegetables, or fluids. Average protein consumption was significantly higher than the current recommendation of 0.8 g/kg/d; however, only 55% of participants met this goal and less than 18% met the 1.2 g/kg/d proposed optimal protein intake for older adults. The protein distribution throughout the day was skewed and no one met the 0.4 g/meal protein recommendation at all meals. Our findings indicate that community-dwelling older adults did not meet their nutritional needs during recovery after hospitalization. These data highlight the need for better nutritional evaluation and support of geriatric patients recovering from hospitalization.

Depth gradients drive changes in early successional community composition and associated coral larvae settlement interactions

Depth gradients are known to drive patterns of adult and juvenile coral distribution, but the influence on early successional communities and subsequent interactions with coral larvae settlement are poorly understood. We studied how early successional communities changed across a 40 m depth gradient to test whether patterns of coral larvae settlement could be explained by changes in preferred settlement substrates. Light decreased 83-fold from 3 to 40 m, and coral settlement orientation switched from tile undersides at 3 and 8 m to tile topsides at 25 and 40 m as expected. Regardless of the reduction in light, community composition on the topsides of settlement tiles did not change across depths, being dominated by turf algae (49%), crustose coralline algae (CCA; 29%), and biofilmed tile (12%). In contrast, settlement tile undersides were dominated by coralline and fleshy algae at 3 m, transitioning to ascidians and bryozoans at 8 m and 25 m, and biofilmed tile (80%) at 40 m. Following multiple regression analysis from an initial 21 bio-physical variables (R2 = 0.34), the optimal reduced model for predicting coral settlement included just five variables and explained most of the variability (R2 = 0.29). CCA contributed an R2 of 0.14 to the model and was positively correlated with Acroporidae settlement, biofilmed tile contributed an R2 of 0.09 to the model and was negatively correlated with Acroporidae settlement, while the other predictors explained nominal model variance. As assessed using electivity indices, Acroporidae switched settlement preference from CCA at shallower depths to biofilmed tile in deeper environments. In addition to the influence of light on larval settlement behaviour as described in previous research, our results show that CCA also provide an important facilitator of coral settlement behaviour across depth gradients. However, as in shallow reefs environments, further work is required to elucidate whether changes occurring at a finer taxonomic resolution within the CCA community can help to further explain switches in coral larval settlement behaviour in light-limited environments.

Cellular source of hypothalamic macrophage accumulation in diet-induced obesity

BackgroundObese mice on a high-fat diet (HFD) display signs of inflammation in the hypothalamic arcuate nucleus (ARC), a critical area for controlling systemic energy metabolism. This has been suggested as a key mechanism of obesity-associated hypothalamic dysfunction. We reported earlier that bone marrow-derived macrophages accumulate in the ARC to sustain hypothalamic inflammation upon chronic exposure to an HFD. However, the mechanism underlying hypothalamic macrophage accumulation has remained unclear.MethodsWe investigated whether circulating monocytes or myeloid precursors contribute to hypothalamic macrophage expansion during chronic HFD feeding. To trace circulating myeloid cells, we generated mice that express green fluorescent protein (GFP) in their lysozyme M-expressing myeloid cells (LysMGFP mice). We conducted parabiosis and bone marrow transplantation experiments using these animals. Mice received an HFD for 12 or 30 weeks and were then sacrificed to analyze LysMGFP cells in the hypothalamus. Hypothalamic vascular permeability in the HFD-fed obese mice was also tested by examining the extravascular leakage of Evans blue and fluorescence-labeled albumin. The timing of LysMGFP cell entry to the hypothalamus during development was also evaluated.ResultsOur parabiosis and bone marrow transplantation experiments revealed a significant infiltration of circulating LysMGFP cells into the liver, skeletal muscle, choroid plexus, and leptomeninges but not in the hypothalamic ARC during chronic HFD feeding, despite increased hypothalamic vascular permeability. These results suggested that the recruitment of circulating monocytes is not a major mechanism for maintaining and expanding the hypothalamic macrophage population in diet-induced obesity. We demonstrated instead that LysMGFP cells infiltrate the hypothalamus during its development. LysMGFP cells appeared in the hypothalamic area from the late embryonic period. This cellular pool suddenly increased immediately after birth, peaked at the postnatal second week, and adopted an adult pattern of distribution after weaning.ConclusionsBone marrow-derived macrophages mostly populate the hypothalamus in early postnatal life and may maintain their pool without significant recruitment of circulating monocytes throughout life, even under conditions of chronic HFD feeding.

Early mortality and freshwater forage fish recruitment: nonnative alewife and native rainbow smelt interactions in Lake Champlain

We studied the consequences of a nonnative species introduction and changes in temperature on early mortality and recruitment of native rainbow smelt (Osmerus mordax) and nonnative alewife (Alosa pseudoharengus) in Lake Champlain using a simulation model. Distribution patterns of adults and young-of-the-year (YOY) fish were predicted using a model based on observed distribution of different age groups as a function of temperature and light profiles simulated on a daily basis. Mortality rates averaged over the growing season were calculated as a function of fish densities and overlap between adults and YOY. Survival of YOY rainbow smelt and alewife depended on which predator was most abundant. Rainbow smelt YOY mortality rates are highest when rainbow smelt adults are abundant, and alewife YOY mortality rates are highest when alewife adults are abundant, potentially allowing coexistence. August and September mortality rates were higher in the climate change scenario because of increased overlap of adults and YOY of both species. These results indicate that accounting for spatiotemporal fish distribution patterns can be important when forecasting the interacting effects of climate change and aquatic invasive species on fish recruitment.

Spatial analysis to identify invasion colonization strategies and management priorities in riparian ecosystems

Abstract Exotic species have different strategies to invade a new area. Invasive species limited by establishment have a wide dispersion range and high seedling mortality rate. Riparian forests are harsh environments for the establishment of plants. In this sense, we tested the hypothesis that the invasive process of G. triacanthos is limited by establishment in a riparian forest of the Uruguay River and that it begins in the fluvial bank at the transition zone between forest and grassland and moves towards the shore border. We expected that: (1) the distribution pattern of adults of G. triacanthos would be decoupled from the distribution pattern of seedlings and saplings (pre-reproductive stages); (2) the population would have a cluster distribution pattern related to the occurrence of punctual events that favoured the development to adult stages; and (3) the abundance of seedlings, saplings and adults would be higher in the transition zone (between forest and grassland) than in the shore border of the fluvial bank. The spatial pattern of G. triacanthos along the Uruguay River was analyzed using spatial point pattern analysis: autocorrelation indexes, hot spots and wavelet analysis. The effect of the fluvial bank position on the abundance of G. triacanthos was evaluated using non-metric multidimensional scaling (NMDS). This methodology allowed us to detect a primary invasion area, an invasion focus and the dispersal area. This pattern corresponded to an infiltration invasion pattern limited by establishment. It did not seem to be affected by position in the fluvial bank. This information could be relevant to establish correct decision-making in the control of an invasive process and provide an applicable methodology for any other invasion process, especially in riparian ecosystems.

English

Knowledge of the dispersion of adults and nymphs of Edessa meditabunda in soybean model is needed to determine the control actions and thus enable proper use of strategies to avoid losses in production. This research aimed to conduct probabilistic analysis of the spatial distribution patterns of adults and nymphs of E. meditabunda in two regions in soybean Bt and non-Bt. For the evaluations, the method of cloth-to- beat was used, where one sample per plot was collected randomly from each experimental area. Evaluations were performed at 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91 and 98 days after emergence. For data analysis, the rates of dispersion (variance/average Morisita index and exponent k Negative Binomial Distribution) and theoretical frequency distributions (Poisson, Binomial and Negative Binomial Positive) at 5% probability were calculated. The peak population of adults and nymphs of E. meditabunda was observed in the reproductive stage of soybean Bt and non-Bt in Dourados and Douradina. From the results obtained, it can be concluded that the Bt technology had the spatial arrangement of adults and nymphs of E. meditabunda, and is set in probabilistic arrangements with negative binomial distribution (aggregate) in the two regions surveyed. In non-Bt soybeans for adults and nymphs of E. meditabunda, spatial arrangements had set in probabilistic arrangements of positive and negative binomial distribution (uniform), as the days after emergence, for the region of Dourados and Douradina. Key words: Glycine max L., damage, horizontal dispersion, spatial arrangement.

Seaweed beds support more juvenile reef fish than seagrass beds in a south-western Atlantic tropical seascape

Seascape connectivity is regarded essential for healthy reef fish communities in tropical shallow systems. A number of reef fish species use separate adult and nursery habitats, and hence contribute to nutrient and energy transfer between habitats. Seagrass beds and mangroves often constitute important nursery habitats, with high structural complexity and protection from predation. Here, we investigated if reef fish assemblages in the tropical south-western Atlantic demonstrate ontogenetic habitat connectivity and identify possible nurseries on three reef systems along the eastern Brazilian coast. Fish were surveyed in fore reef, back reef, Halodule wrightii seagrass beds and seaweed beds. Seagrass beds contained lower abundances and species richness of fish than expected, while Sargassum-dominated seaweed beds contained significantly more juveniles than all other habitats (average juvenile fish densities: 32.6 per 40 m2 in Sargassum beds, 11.2 per 40 m2 in back reef, 10.1 per 40 m2 in fore reef, and 5.04 per 40 m2 in seagrass beds), including several species that are found in the reef habitats as adults. Species that in other regions worldwide (e.g. the Caribbean) utilise seagrass beds as nursery habitats were here instead observed in Sargassum beds or back reef habitats. Coral cover was not correlated to adult fish distribution patterns; instead, type of turf was an important variable. Connectivity, and thus pathways of nutrient transfer, seems to function differently in east Brazil compared to many tropical regions. Sargassum-dominated beds might be more important as nurseries for a larger number of fish species than seagrass beds. Due to the low abundance of structurally complex seagrass beds we suggest that seaweed beds might influence adult reef fish abundances, being essential for several keystone species of reef fish in the tropical south-western Atlantic.

Early life history traits and geographical distribution ofParachaenichthys charcoti

AbstractThe geographical distribution of the two species of the genusParachaenichthysis allopatric and restricted to the inner shelves of South Georgia–South Sandwich Islands (P. georgianus) and South Orkney Islands–South Shetland Islands (P. charcoti). To evaluate the consistency between the geographical patterns of adult distribution and early life history traits ofP. charcoti, sagittal otoliths were used to estimate growth rate and pelagic duration in larvae and juveniles of this species collected in the Bransfield Strait in winter and summer, respectively. Individual age was determined through microincrement counts, assuming they were daily increments. The Gompertz model was fitted to age–length estimates, providing a mean growth rate of 0.22 mm day-1estimated for 28–204-day-old individuals. Larval hatching was spread over a relatively wide period, lasting from July throughout September. The pelagic larval duration ofP. charcotiwas about six months based on ageing data of larvae and juveniles, as reported forP. georgianusfrom South Georgia. The strong dependence of larvae on the inshore habitat may hamper their dispersal at large spatial scale limiting the connectivity among distant populations, providing clues to interpret the present geographical distribution of the two species.

Seedling growth responses to phosphorus reflect adult distribution patterns of tropical trees.

Soils influence tropical forest composition at regional scales. In Panama, data on tree communities and underlying soils indicate that species frequently show distributional associations to soil phosphorus. To understand how these associations arise, we combined a pot experiment to measure seedling responses of 15 pioneer species to phosphorus addition with an analysis of the phylogenetic structure of phosphorus associations of the entire tree community. Growth responses of pioneers to phosphorus addition revealed a clear tradeoff: species from high-phosphorus sites grew fastest in the phosphorus-addition treatment, while species from low-phosphorus sites grew fastest in the low-phosphorus treatment. Traits associated with growth performance remain unclear: biomass allocation, phosphatase activity and phosphorus-use efficiency did not correlate with phosphorus associations; however, phosphatase activity was most strongly down-regulated in response to phosphorus addition in species from high-phosphorus sites. Phylogenetic analysis indicated that pioneers occur more frequently in clades where phosphorus associations are overdispersed as compared with the overall tree community, suggesting that selection on phosphorus acquisition and use may be strongest for pioneer species with high phosphorus demand. Our results show that phosphorus-dependent growth rates provide an additional explanation for the regional distribution of tree species in Panama, and possibly elsewhere.

Regional-scale patterns of habitat preference for the seahorse Hippocampus reidi in the tropical estuarine environment

When dealing with species where local information on distribution and habitat preferences is insufficient or lacking (data poor), it is challenging for managers to determine effective measures for conservation. The purpose of this paper was to identify trends in habitat preference for a data-deficient seahorse species, Hippocampus reidi in northeastern Brazil. This is also the first study to use mixed-effect models to compare multiple datasets at a regional level for any seahorse species. Generalized linear mixed-effects models determined that shallow depths, warm temperatures and the number of holdfasts were the most important habitat variables in predicting seahorse presence in tropical estuaries. A log-likelihood ratio *G test found no difference between the proportion of adults and juveniles using various holdfasts, although adults used a greater diversity of holdfasts. The lack of difference in adult and juvenile habitat suggests either that H. reidi may not experience ontogenetic shifts in habitat or that habitat is not determining the distribution patterns of adults and juveniles within estuaries. Alternatively, habitat preference may be coupled with other factors to drive seahorse distribution within estuaries. Due to estuary importance in providing holdfast diversity and other conditions to seahorse use, conservation and management for H. reidi should also consider appropriate protection of estuarine areas, thus safeguarding habitat for both juveniles and adults.

Spatial Distribution of Adults of Triozoida limbata Enderlein, 1918 (Hemiptera: Triozidae) in Guava Orchards

The aim of this study was to carry out probabilistic analyses of the spatial distribution patterns of adults of Triozoida limbata Enderlein, 1918 (Hemiptera: Triozidae) in guava orchards. This study was conducted in four guava orchards in Ivinhema, Mato Grosso do Sul, Brazil. The samplings were conducted every fortnight from April 2012 to March 2014. A sampling area was set up for adult samples, and it consisted of 24 sampling units or plots with 15 plants in each (3 rows × 5 plants). A double-sided adhesive yellow trap was installed, 23 cm in length and 11 cm in width, around the central plant of each sampling unit, approximately 1.5 m from the ground. The dispersion rates (variance/mean ratio, Morisita index and Exponent k of the Negative Binomial Distribution) and the theoretical frequency distributions (Poisson and Negative Binomial) were calculated. Following the analyses, it can be concluded that the adults of T. limbata of the populations studied are randomly distributed in the four areas evaluated, with the sampling data fitting the Poisson distribution model.

Seasonal Migration Behaviors and Distribution of Adult Pacific Lampreys in Unimpounded Reaches of the Snake River Basin

AbstractComplex life histories render anadromous fishes particularly susceptible to environmental and anthropogenic change. Adult Pacific Lampreys Entosphenus tridentatus migrating in the Columbia River and its tributaries must ascend a series of dams to reach interior spawning sites. While considerable research has focused on improving dam passage for lampreys, little is known about adult Pacific Lamprey behavior and distribution patterns within free‐flowing environments, particularly within the interior portions of their distribution. In this 3‐year study, we monitored the movements of 146 adult Pacific Lampreys in the Snake River and its tributaries upstream from Lower Granite Dam, the eighth dam from the Pacific Ocean. Our objectives were to characterize migration and test several hypotheses about adult upstream movement after dam passage. A majority of radio‐tagged adults, released above Lower Granite Dam, migrated upstream after release and many moved hundreds of kilometers upstream into Snake River tributaries. Of those with telemetry records after release, 59–70% were recorded in the Clearwater River, 16–25% were in the Snake River, and 13–16% were in the Salmon River. Lampreys that passed the Snake River–Clearwater River confluence were significantly more likely, in most years, to enter the lower‐discharge Clearwater River. Adults moved primarily at night during the summer–fall migration and did not exhibit a consistent response to changes in water temperature or discharge. These findings highlight the importance of the Clearwater River to Pacific Lampreys in the lower Snake River basin and indicate that adults that successfully pass through the Columbia–Snake hydrosystem can continue upstream migration into many Snake River subbasins. This distribution suggests that improved passage efficiency at dams may increase the number of adult Pacific Lampreys available for spawning within the interior portions of their distribution.Received May 12, 2014; accepted November 5, 2014

Effect of habitat characteristics on the distribution and abundance of damselfish within a Red Sea reef

For coral reef fish with an obligate relationship to their habitat, like Pomacentrid damselfish, choosing a suitable home amongst the reef structure is key to survival. A surprisingly small number of studies have examined patterns in adult damselfish distributions compared to other ontogenetic phases. The aim of this study was to determine which reef and coral colony characteristics explained adult damselfish distribution patterns in a Red Sea reef. The characteristics investigated were reef type (continuous or patchy), coral species (seven species of Acropora), and coral morphology (coral size and branching density). The focal damselfish species were Dascyllus aruanus, D. marginatus, Chromis viridis, and C. flavaxilla. Occupancy (presence or absence of resident damselfish), group size and fish species richness were not significantly different between the seven Acropora species. However, within each coral species, damselfish were more likely to occupy larger coral colonies than smaller coral colonies. Occupancy rates were also higher in patchy reef habitats than in continuous sections of the reef, probably because average coral colony size was greater in patchy reef type. Fish group size increased significantly with coral colony volume and with larger branch spacing. Multi-species groups of fish commonly occurred and were increasingly likely with reduced branching density and increased coral size.