Bray-Curtis Similarity Index Research Articles

Relationship between environmental factors and zooplankton diversity in the Gulf of Bandırma (the Sea of Marmara)

Zooplankton community and its relationship to environmental variables were investigated seasonally between autumn 2006 and summer 2008 in the Gulf of Bandirma (the Sea of Marmara). In the Gulf, we identified nine Copepoda, three Cladocera, one Hydrozoa, one Cydippida, Appendicularia, Bivalvia, Chaetognatha, Cirripedia, Decapoda, Echinodermata, Gastropoda, Polychaeta, Pisces larvae, and Pisces eggs at three sampling stations. Shannon-Weaver diversity index and Pielou’s evenness value ranged between 0.00–2.72 and 0.00–1.00, respectively. The first two components of the redundancy analysis (RDA) explained 81.9% of the variance as the main factors (generally the longest arrows) affecting the spatial and temporal distributions of zooplankton in the Gulf of Bandirma, with dissolved oxygen (DO), nitrite+nitrate (NO3 + NO2-N) and phosphate (PO4-P). Liriope tetraphylla, Oithona nana, Paracalanus parvus, Penilia avirostris, Appendicularia and veliger larvae (Gastropoda) were positively related to DO and salinity, and negatively correlated with temperature, chlorophyll-a (Chl-a), Trophic State Index (Trix), PO4-P, and NO3 + NO2-N. According to Spearman’s rank correlation analysis, there was a strong positive correlation between the number of zooplankton individuals and temperature, and the number of zooplankton individuals negatively correlated with salinity and Chl-a. In order to determine similarities among seasons in the samples, the Bray-Curtis similarity index was calculated using species diversity and abundance values, while Euclidean distances were calculated using ecological parameters. Overall, the diversity of zooplankton in the Gulf of Bandirma was higher in the first sampling year and decreased due to the effect of mucilage in the second sampling year.

Species Composition and Distribution of Tropical Marine Macroalgae In The Pari Island Reef Cluster, Jakarta

The objective of this study was to analyze the species composition and distribution of marine macroalgae at Pari Island reef cluster-Seribu Islands reef system Jakarta based on specimen information available in Reference Collection of Research Center for Oceanography (RCO-LIPI). The Macroalgae specimens were collected irregularly by researchers during marine expedition projects from 1973 until 2014. Taxonomic identification of specimens was conducted in 2014, validation of species names was updated in May 2020 through www.macroalgaebase.org. The floristic composition value of macroalgae was analyzed using the C/P, R/P, and (R+C)/P ratio. Bray-Curtis similarity index analyzes were performed to visualize differences in macroalgae species from the different islands. We recorded a total of 41 species from 25 genus and 18 families. Rhodophyta represented the most significant number of taxa with 20 species (49%), followed by Chlorophyta with 11 species (27%) and Phaeophyta with ten species (24%). In this study, we found that Sargassum polycystum, Gracilaria salicornia, Amphiroa fragilisima, and Halimeda opuntia are dominant species in the study area. The highest macroalgae diversity found in Kongsi Island with 33 species, while the lower diversity found in Pari Island with five species. Bray-Curtis Similarity index showed that Kongsi Island and Burung Island have the highest similarity value with 29,26%, while Tikus Island and Pari Island have the lowest similarity value with 11,76%. The macroalgae distribution in the Pari island reef cluster influenced by the difference of substrate profile and environmental pressure derived from human activities. Proper management of macroalgae resources is necessary to preserve the sustainability of the macroalgae ecosystem. Keywords: macroalgae, composition, distribution, Pari Island

Assessment of Romanian circalittoral soft bottom benthic habitats under Danube River influence

Although numerous studies have focused on ecological quality status (EQS) assessments in the Black Sea, knowledge regarding the status of the soft bottom benthic habitats under Danube River influence is still lacking. Therefore, we investigated the diversity, distribution and EQS of benthic habitats located in the northern part of the Romanian continental shelf. In 2018, 34 samples were collected to analyse the macrozoobenthic fauna. A total of 71 species and 6 taxa belonging to 16 phyla were recorded. Two broad-scale circalittoral habitats (1 — terrigenous mud with Melinna palmata; 2 — mixed sediments with Dipolydora quadrilobata and biogenic reefs with Mytilus galloprovincialis) were encountered in the area based on Bray–Curtis similarity index. EQS analysis of the investigated habitats using a new approach based on the reconsideration of the ecological status of invasive species, resulting in the classification of D. quadrilobata as disturbance-tolerant (III) rather than second order opportunistic, allowed us to perform a realistic assessment of the ecological status. The good environmental assessment (GES) - non-GES threshold for AMBI, S, H and M-AMBI*(n) was calculated using a reference site dataset from the period 2014-2018. Overall, the EQS of the analysed habitats showed that 70% of the Dipolydora habitat is in GES according to M-AMBI Dipolydora III and M-AMBI*(n). Fifty percent of the Melinna habitat is in GES according to the same indices. In our study, for the first time on the Romanian coast, we documented the presence of the anthozoan species Edwardsia cf. claparedii.

Diversity and Assemblage Structure of Marine Fish Species Collected by Set Net in Korean Peninsula During 2009–2013

Assemblage structure analysis was conducted based on seasonal fish species composition data collected four times a year during 2009–2013 from 10 stations around Korea (except the western coast of Korea) using set nets. A total of 154 fish species were identified, of which Trachurus japonicus (22.1%) was the most dominant, followed by Konosirus punctatus (9.2%) and Scomber japonicus (8.7%). Species richness was highest in Jumunjin (in the mid-eastern coast of Korea) and lowest in Gijang (in the east-southern coast of Korea), and species diversity was highest in Gangjeong (southern Jejudo Island) and lowest in Hanrim (northern Jejudo Island). Based on a Bray-Curtis similarity index value of 38%, the 10 stations were divided into three groups: group A comprised four stations in the eastern coast of Korea, group B comprised four stations in the east-southern coast of Korea and Jejudo Island, and group C comprised two stations in the westsouthern coast of Korea. One-way analysis of similarities showed significant differences among groups (global R: 0.822, p = 0.001). The characteristics of the sea currents (e.g., Tsushima Warm Current, North Korea Cold Current) and water masses (e.g., Yellow Sea Bottom Cold Water) might have influenced this grouping.

Native plant community recovery after Carpobrotus (ice plant) removal on an island — results of a 10‐year project

AbstractQuestionSpecies of the genus Carpobrotus, or ice plant, are succulent mat‐forming perennial herbs often introduced for soil stabilization. They are common in coastal environments and may thus threaten island biodiversity. While their effects are well known on soils, plant communities and associated fauna, the effects of Carpobrotus control on vegetation recovery are poorly documented. The aim of the paper is to describe plant community trajectories after Carpobrotus removal.LocationBagaud: a 58‐ha Mediterranean island, southern France.MethodsCarpobrotus and its litter were removed in 2011–2012. Follow‐up controls of germinations and resprouts were carried out from then on. Plant communities were surveyed every year two years before and seven years after Carpobrotus removal: on two ca. 0.5‐ha sites (one coastal and one inland) and in three native plant communities used as potential references. Differences in resprouts, vegetation parameters, and Bray–Curtis similarity indices between years were tested. Plant community dynamics was studied through a non‐metric multidimensional scaling and two recovery indices.ResultsThe removal of Carpobrotus and its litter led to the recovery of diverse native plant communities. To prevent Carpobrotus return and ensure success, follow‐up controls were necessary for a period of at least seven years, but the amount of work decreased with time. The plant community recovering on the coastal site quickly reached a composition and structure similar to that of non‐invaded coastal vegetation, although some slow‐growing native species remain underrepresented (e.g., Crithmum maritimum and Limonium pseudominutum). The plant community recovering on the inland site was still very different from the surrounding matorral vegetation because of its slow colonization dynamics, particularly in the presence of competitive herbaceous species.ConclusionBoth sites now provide diverse native plant communities with a more diversified composition and structure (plant heights, litter, bare ground patches) than the plant communities which used to be associated with Carpobrotus mats.

Moss communities of xeric calcareous habitats in the southeastern United States: An assessment of compositional variation and distance decay

Moss floras of xeric calcareous habitats were studied at field sites in Florida, Alabama, Georgia, Tennessee and Kentucky. At each site, one study area was established, including open glade and wooded margin. A species inventory and a community composition investigation were conducted at each study area. Community composition was analyzed for ground-dwelling (soil and rock) and corticolous communities. Ground-dwelling communities were sampled with quadrats, and corticolous communities were sampled by examining trees along the margins. Presence/absence data from the complete species lists from the five sites were used to calculate Jaccard similarity indices among pairs of sites. The frequencies of species occurring in community samples were used to calculate Bray-Curtis similarity indices for ground-dwelling margin and corticolous communities. Jaccard and Bray-Curtis similarities were used in regression analyses to explore their relationship with geographic distance and climatic factors. The total number of species found at each 1 ha study area ranged from 32 to 35. Part of the flora at each site consisted of species common elsewhere in the region, but there were also species commonly associated with calcareous substrates, such as Pleurochaete luteola, Weissia jamaicensis, Orthotrichum strangulatum, Schistidium rivulare and Hyophila involuta. Regression analyses of pairwise similarities and geographic distances showed a strong non-linear correlation between distance and the Jaccard similarities, a somewhat lower correlation between distance and the Bray-Curtis similarities from ground-dwelling margin communities, and little correlation between distance and corticolous community compositions. Multiple regression analyses suggested significant correlations between community variation and temperature and in most cases weaker correlations with precipitation. Our results were notable in that the ground-dwelling community subset exhibited a pronounced distance decay but the corticolous subset did not. This finding suggests that in bryophytes characteristics associated with habitat fragmentation and substrate type have important effects on beta diversity.

Controlled ovarian stimulation and progesterone supplementation affect vaginal and endometrial microbiota in IVF cycles: a pilot study

PurposeDoes controlled ovarian stimulation (COS) and progesterone (P) luteal supplementation modify the vaginal and endometrial microbiota of women undergoing in vitro fertilization?MethodsFifteen women underwent microbiota analysis at two time points: during a mock transfer performed in the luteal phase of the cycle preceding COS, and at the time of fresh embryo transfer (ET). A vaginal swab and the distal extremity of the ET catheter tip were analyzed using next-generation 16SrRNA gene sequencing. Heterogeneity of the bacterial microbiota was assessed according to both the Bray-Curtis similarity index and the Shannon diversity index.ResultsLactobacillus was the most prevalent genus in the vaginal samples, although its relative proportion was reduced by COS plus P supplementation (71.5 ± 40.6% vs. 61.1 ± 44.2%). In the vagina, an increase in pathogenic species was observed, involving Prevotella (3.5 ± 8.9% vs. 12.0 ± 19.4%), and Escherichia coli-Shigella spp. (1.4 ± 5.6% vs. 2.0 ± 7.8%). In the endometrium, the proportion of Lactobacilli slightly decreased (27.4 ± 34.5% vs. 25.0 ± 29.9%); differently, both Prevotella and Atopobium increased (3.4 ± 9.5% vs. 4.7 ± 7.4% and 0.7 ± 1.5% vs. 5.8 ± 12.0%). In both sites, biodiversity was greater after COS (p < 0.05), particularly in the endometrial microbiota, as confirmed by Bray-Curtis analysis of the phylogenetic distance among bacteria genera. Bray-Curtis analysis confirmed significant differences also for the paired endometrium-vagina samples at each time point.ConclusionsOur findings suggest that COS and P supplementation significantly change the composition of vaginal and endometrial microbiota. The greater instability could affect both endometrial receptivity and placentation. If our findings are confirmed, they may provide a further reason to encourage the freeze-all strategy.

Guild Composition and Niche Overlap of Insectivorous Birds in Evergreen Rainforest

A guild is a group of species that have similar requirements of resource and foraging behavior. The knowledge of insectivorous guild could explain foraging patterns, niche exploitation, and competition in a tropical forest. This information could help to monitor the forest by understanding the guild composition and their response to the habitat condition. In order to describe the guild composition and niche overlap of insectivorous birds, we observed all of the individual birds found foraging in the evergreen forest, Baluran National Park. Bray-Curtis similarity index and Pianka niche overlap index were used to analyze the data and grouping the birds into a guild. The cluster analysis consists of 27 bird species revealed 4 guilds: ground gleaner, foliage gleaner, aerial sallier, and bark prober. Based on species richness, foliage gleaner dominates the other groups while bark prober had the least species richness in the evergreen forest. The scarcities of feeding substrate affect guild existence and proved that the diversity of habitat substrate could affect the diversity of guild in an area. Ten congeneric species were found in this habitat and most of them are grouped into foliage gleaner. The junglefowl has the highest niche overlap than any other congeneric species. It seemed that the more specific the foraging substrate niche, the higher the competition among sympatric species. The level of congeneric/sympatric species competition could become the indicator to monitor a specific habitat or forest by understanding their niche partitioning, especially if the species is protected by the law.

A systematic comparison between infant formula compositions using the Bray-Curtis Similarity Index.

BackgroundMaking an informed choice between the available infant formulas is challenging, as there is no unbiased tool allowing a systematic comparison between the very long lists of infant formula compositions.AimThe aim is to present the Bray-Curtis Similarity Index (BCSI) as a tool for systematic comparison between standard stage-1 infant formula (SS-1-IF) compositions.MethodsWe obtained the nutrient levels from the packaging labels of 23 SS-1-IFs available in Al-Ahsa, Saudi Arabia, in April 2018. The international legislations that launched infant formula standards endorse targeting the minimum rather than the maximum proposed nutrients levels. Thus, we blindly compared between displayed nutrients levels on each of the 23-studied SS-1-IF and the minimum international proposed nutrient levels via using the BCSI.ResultsThe range of the total displayed components was 38–57. Except for docosahexaenoic acid, all displayed components were within the standard recommended range. The BCSI summarized all displayed nutrients in a single number. The BCSI of the studied SS-1-IF ranged from 0.4141 to 0.79730. We ranked the 23 studied SS-1-IFs based on the higher BCSI is the closer to the minimum proposed nutrient levels. A dendrogram segregated the SS-1-IFs into four clusters based on their BSCI and total numbers of all displayed components.ConclusionsWe think the BCSI is an appropriate tool for a systematic comparison between SS-1-IFs compositions and may help for choosing a SS-1-IF.

Diversity of dragonflies (Insecta: Odonata) in Ujung Kulon National Park

Ujung Kulon National Park is a lowland tropical forest that was still preserved. There was limited information about the diversity of dragonflies in Ujung Kulon National Park. The purpose of this study was to study species diversity of dragonfly in Ujung Kulon. The research was conducted in Ujung Kulon Peninsula, Banten, Indonesia in five locations and three types of aquatic habitats i.e., natural ponds, streams in forests, and rivers. The transect line method is used to collect adult dragonflies. Thirty-one species of dragonflies belong to two anisopteran families and six zygopteran families were reported in this study. Twenty-two species were as new records based on previous publications. There were different species compositions in all habitat types (R = 1, p = 0.0016, one-way ANOSIM with Bray-Curtis similarity index). Natural ponds have the highest anisopteran species richness compared to other habitats. Eight species Anisoptera only were found in natural ponds. Meanwhile, zygopteran species prefer in flowing water habitat.

Evaluation of Water Quality Based on Macrozoobenthos as a Bioindicator in the Four Springs of Wana Wiyata Widya Karya Tourism Area, Cowek Village, Purwodadi District, Pasuruan Regency

The purpose of this study was to determine water quality based on the physicochemical of water and biotic indices from macrozoobenthos in four springs in the Wana Wiyata Widya Karya tourism area, Cowek Village, Pasuruan. Identification and calculation of macrozoobenthos were used to determine the macrozoobenthos community structure and some biotic indices (ASPT, FBI, EPT indices, and water quality index) as bioindicators of water quality. Water quality grouping based on physicochemical of water and biotic indices was analyzed using Cluster Analysis, and Biplot. The results showed that several physical-chemical parameters of water observed had values exceeding water quality standards for drinking water raw materials (BOD, DO, temperature and pH), based on Government Regulations No. 82 of 2001. Based on the NSF-Water Quality Index, water quality in four springs in the Wana Wiyata Widya Karya tourism area is in good category (72.77-88.37), which indicates that the waters are not contaminated with organic matter. Water quality based on the macrozoobenthos diversity index value indicates the category of moderate to mild contamination (H value 1.40-1.97). The Bray-Curtis similarity index resulted in a high level of similarity between of Alang-Alang and Sumber Bendo in 86.49%. Keywords : biotic index, macrozoobenthos, springs, Wana Wiyata Widya Karya, water quality

Species composition of mosquito breeding in bamboo stumps in Sikkim, India.

Sikkim is a part of Eastern Himalayan biodiversity hotspot of India rich in bamboo flora harbouring over 30 different bamboo species. The present study was aimed to investigate the larval mosquito diversity in the bamboo stumps of Gangtok, Sikkim. Besides, efforts were also made to evaluate the propensity of particular species of mosquito towards specific bamboo species (if any). A total of 75 bamboo stumps of four genera were surveyed and screened at five different sampling sites of Gangtok from July to October 2017. Mosquito species similarity between the five sampling sites and the four varieties of bamboo species was calculated using the Bray-Curtis similarity index. A total of 216 larvae were collected from 25 different bamboo stumps studied. The species identified were Aedes albopictus, Ae. atlanticus, Ae. aegypti, Orthopodomyia signifera, Oclerotatus japonicus, Oc. taeniorhynchus, Armigeres subalbatus, and Toxorhynchites splendens. The Oc. japonicus (34.5%) was found to be the most abundant species having distribution in Phyllostachys assamica, Dendrocalamus hamiltonii and Bambusa nutans. On the other hand, genus Armigeres subalbatus and Tx. splendens were found to breed only in the stumps of P. assamica. Based on Bray-Curtis similarity index highest species similarity was recorded between D. hamiltonii and P. assamica bamboo species. The study may help to understand the bioecology of the mosquito larvae which may help to devise suitable mosquito control programmes. Future studies including the survey of large number of bamboo stumps both in urban and rural areas of Sikkim may provide better insight into the mosquito diversity in the bamboo stumps of Sikkim.

Sucesión estacional de zooplancton gelatinoso (medusae y ctenophores) del puerto de Mar del Plata, Argentina (Océano Atlántico sudoccidental)

Temporal variation of the population dynamics of the medusae and ctenophores (gelatinous zooplankton) is described over an annual cycle in the Mar del Plata Harbor, Argentina. A total of 18 species were identified, 3 of which were ctenophores (2 of Class Tentaculata and 1 of Nuda) and 15 medusae (14 of Class Hydrozoa and 1 of Scyphozoa). A species of hydromedusae, Annatiara affinis , was observed for the first time in the Argentine Sea. In both groups, species richness and abundances showed the lowest values in the cold period (austral autumn-winter) and the highest values in the warm period (spring-summer). The meroplanktonic medusae Obelia sp. and Eucheilota ventricularis as well as the holoplanktonic Liriope tetraphylla represented 94.2% of the total abundances of this group (classified as dominant). In the ctenophores, the dominant species were Pleurobrachia pileus and Mnemiopsis leidyi , which accounted for 99.3% of the ctenophores. Monthly medusae succession indicated that holoplanktonic species were dominant over practically all the annual cycle in terms of abundance, while considering species richness values, meroplanktonic species showed highest values. Ctenophores (considering abundance values) was displayed alternating periods of approximately three months of dominance between P. pileus and M. leidyi . The Bray-Curtis similarity index performed on medusae identified two groups of seasons with faunal affinity, the 1) cold and 2) warm periods, with the water temperature and non-gelatinous zooplankton abundances as the environmental factors that best explained this variability (BIO-ENV analysis), while for ctenophores, temporal faunal homogeneity was observed and a single group with faunal affinity was identified. https://doi.org/10.25260/EA.19.29.3.0.880

Community composition of Symbiodiniaceae among four scleractinian corals in the eastern Gulf of Thailand

Symbiotic algae in the family Symbiodiniaceae are essential for scleractinian corals’ survival and resilience. Understanding the community composition of Symbiodiniaceae species within coral colonies can provide insight into how corals respond to environmental changes. We examined Symbiodiniaceae community composition in four scleractinian coral hosts, Porites lutea, Platygyra daedalea, Pavona decussata and Pocillopora damicornis at six sites (n = 3-5 colonies/species/site) in the eastern Gulf of Thailand using Denaturing Gradient Gel Electrophoresis (DGGE) to resolve polymorphisms of the Internal Transcribed Spacer-2 (ITS2) DNA. The results showed that the Symbiodiniaceae genus Durusdinium was the most common clade in all coral hosts in all areas, whereas Cladocopium was common in P. lutea. We observed at least five prevalent Symbiodiniaceae species: Cladocopium goreaui (C1); two Cladocopium spp. (C3u and C15, C15v1); and at least two Durusdinium spp. (D1), which include Durusdinium sp. (D1-6 in P. damicornis), and at least one other Durusdinium sp. (D1) in all host coral species. Cladocopium sp. (C15) was highly abundant in P. lutea. Durusdinium spp. (D1) were the dominant species in P. decussata, P. daedalea and P. damicornis. PERMANOVA revealed the effects of site, host coral species and interaction between site and host coral species on the variation of Symbiodiniaceae species composition. Cluster analysis based on Bray–Curtis similarity index suggested four large groups. The first group, consisting of all coral host species (mainly P. daedalea, P. decussata and P. damicornis), had Durusdinium spp. (D1) as dominant species; the second group, consisting of P. lutea, had Cladocopium sp. (C15) as the dominant species; the third group, consisting of P. damicornis had D. glynnii (D1-6) as the dominant species; and the last group, consisting of P. daedalea had Cladocopium sp. (C3u) as the dominant species. Our results suggested complex interactions among Symbiodiniaceae species composition, coral species and environmental conditions.

Impacts of Saltwater Intrusion on the Fish Assemblage in the Middle Part of Shatt Al-Arab River, Iraq

In 2018, a serious changes in the salinity of the Shatt Al-Arab river, as salinity intrusion progressed further to upper reaches of the river due to sharply decline in river flow. Therefore, the fish assemblage structure in the middle of the river, from Sindbad and Abu Al-Khasibs was assessed during the period from January to December 2018. Fish were sampled by gill nets, cast net and electro-fishing from both sites. Salinity fluctuated from 2.0‰ (January) in both sites to 16.2 and 25.0% during August in both sites, respectively. 35 and 44 fish species were collected from both sites, respectively, these included 18 marine species in first site and 28 marine species in second site. Poecilia latipinna, Tenualosa ilisha and Oreochromis aureus were the dominant species in first site, whereas O. aureus, Carassius auratus and P. latipinna in second site. The index of species richness, diversity and evenness each showed a consistent seasonal pattern in both sites. The highest value of Bray-Curtis similarity index of fish species between both sites was noted during the period of low salinity. Findings indicate that the salinity values and the percentages of marine and occasional species were considerably higher than that documented in the previous studies on this part of the  river.Â

Komunitas Burung pada Pegunungan Bawah dan Sub-Pegunungan Di Taman Nasional Gunung Halimun Salak

Bird diversity has been known to be affected by various factors, including elevational gradient. The objective of this study was to describe the bird community trend and its associated habitat conditions on lower mountain and sub-mountain areas. The study was conducted in September-October 2017 in Gunung Halimun Salak National Park, West Java, Indonesia. Bird data were collected using point count method. Data were analyzed by using Shannon-Wiener (H’) diversity index, Margalef’s richness index (D Mg ), and Bray-Curtis similarity index. Birds were grouped into guilds according to their major diet. There were 54 bird species (23 families) in both altitudes, of which 23 species were found in the lower altitude and 33 species were found in the higher altitude. Contrary to most studies elsewhere, the diversity and richness indices were significantly higher at the sub mountain (H’=2.85; D Mg =5.96) than at lower mountain (H'=2.38; D Mg =3.79). Insectivores were dominant in both altitudes, although similarity index was low (5%). Bird diversity was higher in the higher altitude due to habitat condition. Lower montain had a higher anthropogenic disturbance than the sub-mountain.

Polychaetes from Burdwood Bank: “Namuncurá I” Marine Protected Area and slope, SW Atlantic Ocean

Introduction: The first open-sea (non-coastal) Marine Protected Area in Argentina, named “Namuncurá I” (NMPA), was created in 2013 at Burdwood Bank (BB), an undersea plateau located about 200 km south from Malvinas Islands (Falkland Islands) and 150 km east from Staten Island, SW Atlantic Ocean. It comprises three different management areas: the central one (“core”, strict protection, only control and monitoring activities), surrounded by a “buffer” area (authorized activities, e.g. scientific research) and an external “transition” area (productive and extractive activities contemplated in the Management Plan). Beyond the transition area, only the southern shelf-break is protected, after the creation of the “Namuncurá II” MPA in December 2018. Objective: provide the inventory of polychaetes collected during 2016 and 2017 at the core (98 m depth), buffer (128 m depth), transition (133 m-189 m depth) areas of the Namuncurá I MPA, together with slope areas (220 m-798 m depth). Methods: taken with a trawl net used to characterize the faunal assemblages and to compare results with other Magellan areas. Multidimensional Scaling (MDS) and Cluster Analysis (CA) were applied to a Bray-Curtis similarity index to assess polychaete assemblages in the NMPA - BB slope and Magellan region respectively; SIMPER (Similarity Percentage Analyses) and ANOSIM (Analysis of Similarities) were performed. Results: A total of 918 individuals, which correspond to 39 taxa distributed in 22 families, were recorded in samples from NMPA and BB slope, mainly epibenthic or associated with the large corals collected. Ampharete kerguelensis McIntosh, 1885; Hyalinoecia artifex Verrill, 1880; Idanthyrsus macropaleus (Schmarda, 1861); Laetmonice producta Grube, 1877; Onuphis pseudoiridescens Averincev, 1972; Pista mirabilis McIntosh 1885 and Terebellides malvinensis Bremec &amp; Elias, 1999 constitute new records for Burdwood Bank. A similar polychaete assemblage characterized the three areas of NMPA and slope locations, while H. artifex characterized locations at the NW deepest slope of the bank. Conclusions: These results indicate strong connections between the fauna collected at NMPA and the polychaetes assemblage in other Magellan areas dominated by soft bottoms. The biogeographic importance of the BB as connection for benthic polychaete species between South America and the Antarctic Peninsula merits future investigation.

Floral Scent Variation in the Heterostylous Species Gelsemium sempervirens.

Gelsemium sempervirens (L.) W.T. Aiton, a distylous woody vine of the family Gelsemiaceae, produces sweetly fragrant flowers that are known for the toxic alkaloids they contain. The composition of this plant’s floral scent has not previously been determined. In this study, the scent profiles of 74 flowers obtained from six different wild and cultivated populations of G. sempervirens were measured by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). There were 81 volatile organic compounds identified and characterized as benzenoids, terpenoids, fatty acid derivatives, and yeast associated compounds. The most abundant compound was benzaldehyde (23–80%) followed by ethanol (0.9–17%), benzyl benzoate (2–15%), 4-anisaldehyde (2–11%), (Z)-α-ocimene (0–34%), and α-farnesene (0.1–16%). The impacts of geographic location, population type (wild or cultivated), and style morph (L = long, S = short) on scent profile were investigated. The results showed no relationship between geographic location or population type and volatile organic compounds (VOC) profile, but did show a significant scent profile difference between L and S morphs based on non-metric multidimensional scaling (NMDS) using Bray-Curtis similarity indices. The L morphs contained higher amounts of benzenoids and the S morphs contained higher amounts of terpenoids in their scent profiles. The L morphs also produced a higher total abundance of scent compounds than the S morphs. This study represents the first floral scent determination of G. sempervirens finding significant variation in scent abundance and composition between style morphs.

Biometrical Evaluation of Morphological Traits in Family Cucurbitaceae in Lafia, Nigeria

Biometrical evaluation is a valuable tool for the study of biosystematics of plant taxa. This study assessed morphological variation and phenetic relationship in the Cucurbitaceae species in Lafia, Nasarawa State, Nigeria. Plant specimens were collected by simple random sampling across the municipality and 11 species were identified in the study area. Analysis of variance and multivariate analyses were used to determine the differences and identify variation among morphological characters among the species, respectively. Genetic similarity among the taxa was generated by single linkage algorithm of Bray-Curtis similarity index. Wide variations were observed in the morphological characters; Telfairia occidentalis had the longest pods (46.3 cm) and the longest vines (831.4 cm), while Cucumis sativus had the shortest vines (162.3 cm). All the species had multi-seeded pods; Lagenaria breviflora had 734.7 seeds, which was significantly more than the seeds in other species, Citrullus lanatus had 438.3 seeds and Momordica charantia had the fewest seeds (12.7) per pod. T. occidentalis had significantly (p ≤ 0.05) the heaviest seeds (89.8 g) of the species. Three major clusters were identified; Lagenaria abyssinica and L. rufa had similarity index of 0.9; Cucumeropsis mannii and Citrullus lanatus had index of 0.89. Principal component analysis established close relationship between T. occidentalis and L siceraria; then L. breviflora, Citrullus lanatus; Cucumeropsis mannii, Cucurbita pepo, Cucumis sativus, Lagenaria rufa and Lagenaria abyssinica, Luffa cylindrica and Momordica charantia, indicative of genetic similarity among the taxa. Closely related species are potential materials for interspecific hybridization and improvement of the family.

Diversity of insect pollinators on Citrullus lanatus thunb

The interaction between insect pollinator and crops is a mutualism association, in which plants provide feed for insects and plants to benefit in the pollination process. So that insect pollinators are the biological agents of fruit production. This study aims to analyze the diversity of pollinating insects, and to know their effectiveness in the watermelon production (Citrullus lanatus Thunb.). Observation of visiting insect community was conducted by scan sampling method. Visiting activity of insect pollinator were observed based on lenght of visit per flower and number of flowers visited per minute. The Result showed that 7 species of insects visitors, were pollinator of Citrullus lanatus flower i.e. Amegilla sp, Ceratina sp, Lasioglossum sp, Nomia sp, Cerceris sp, Ischiodon scutellaris and Polistes stigma. The highest abundance i.e. Lasioglossum sp (98 individuals) and Ceratina sp (81 individuals). The highest diversity of insect pollinators was found in the morning (07.00-10.00). The community similarity based Bray-Curtis similarity index was highest between 10.00 - 12.00 and 14.00 - 16.00 o’clock.