Morisita Index Research Articles

Pemantauan Kepadatan Megabentos Target Pada Terumbu Karang di Perairan Leato Selatan Kecamatan Dumbo Raya Provinsi Gorontalo

Megabenthos target associated with coral reefs include spiny starfish, blue starfish, sea urchins, sea cucumber, clams, Drupella spp., trocha snail, and lobsters which is ecologically used as an indicator for monitoring the healt condition of coral reefs and is benefical for the community’s economy.The aim of this research is to determine the density level and distribution pattern of megabenthos target on coral reefs in the waters of South Leato, Dumbo Raya Subdistrict, Gorontalo Province. Method used in collecting megabenthos data is with Bentos Belt Transect. Observation results show that the megabenthos target found in South Leato waters were seven types consisting of sea cucumber, clams, trocha snail, spiny starfish, Drupella spp., sea urchins, and blue starfish. The megabenthos target density range values obtained are 0,007 – 0,435 ind/m2, and for morisita index values ranging 0 - 0,6655 id with the distribution pattern of the megabenthos target found all being unifom.

Study of The Distribution of Amorphophallus beccarii Engl in The Hiking Trail of Mount Singgalang Nature Park

Amorphophallus beccarii is one of the endemic plant of Sumatra, which has the characteristic of compound flowers, and emits a pungent odour that can attract insects such as flies and beetles to pollinate. Amorphophallu beccarii is found growing around the hiking trail of Mount Singgalang Nature Tourism Park, in connection with Mount Singgalang has been used as a Nature Tourism Park, it is feared that it will cause disruption of Amorphophallus beccarii habitat, in addition to the many human activities that carry out climbing activities, its interesting morphological shape is also the reason for the reduced population of Amorphophallus beccarii because it is collected as an ornamental plant. In conservation efforts, research has been carried out on Amorphophallus beccarii Engl Distribution Study in the Mount Singgalang Nature Tourism Park Hiking Trail. This research was conducted in February-March 2024. The research method used was stratified random sampling where sampling was carried out at an altitude of 1000-2000 mdpl along the hiking trail. Data were processed using the morisita index. The results showed that the distribution pattern of Amorphophallus beccarii on the Mount Singgalang hiking trail was clustered.

Density and Distribution Patterns of Bellucia pentamera Naudin in the Rehabilitation Zone of Gunung Palung National Park, Ketapang Regency

Jambu tangkalak is a tree-shaped invasive alien plant belonging to the Melastomataceae family. Jambu tangkalak (Bellucia pentamera) affects forests that are being rehabilitated and must be quickly controlled because it inhibits the growth of other plants. This study aimed to determine the density and distribution pattern of B. pentamera in the Rehabilitation Zone of Gunung Palung National Park. The data were collected from May to June 2023 using a survey method with single plot measuring 100 x 100 m in which there were sub-plots measuring 10 x 10 m. The data were analyzed by using density equations and standardized Morisita Index distribution patterns. The density of B. pentamera seedling stratum was 1485 individuals/ha with a relative density of 42.2%, sapling stratum was 2017 individuals/ha with a relative density of 57.4%, and tree stratum was 14 individuals/ha with a relative density of 0.4%. The standard value of the degree of morisita of B. pentamera nown to be 0,52. Based on this, the distribution pattern of B. pentamera is clustered with the density at the sapling stratum being more dominant than the seedling and tree strata.

Population structure and distribution pattern of endangered species, Dillenia pentagyna, in Indonesian natural reserve forest

Regeneration strategy of endangered species is crucial for maintaining ecosystem sustainability in its endemic habitat. Dillenia pentagyna is a deciduous tree species with many potential benefits for medical use, silkworms’ fodder, and furniture, and is considered as an endangered tree species in Indonesia due to over exploitation in 1980s. The species is an important asset for Gunung Abang Natural Reserve Forest (GANRF) due to essential historical functions for flora, fauna, and local communities. We conducted an initial research to observe the population structure and distribution pattern of D.pentagyna in its native habitat to understand the growth- and population behavior. Using a random sampling method, we built 157 plots to identify the number of seedlings, saplings, poles, and trees followed by measurement of height and diameter-breast-height. We only found fifteen poles, six saplings, five trees, and no seedlings in the plots with dominant distribution in the center of GANRF area. The distribution pattern was random according to Morisita index (Iδ= 0.011 equal to 0), which explains that D.pentagyna grows randomly in nature independent to canopy gaps and slopes. Findings suggested that low population needs to be recovered by seedling initiation growth in the nursery before sowing in the field to avoid high mortality.

Kepadatan Megabentos pada Wilayah Konservasi Perairan di Sekitar Kabupaten Kupang, Nusa Tenggara Timur, Indonesia

The Sawu Sea National Marine Park is a marine conservation area in East Nusa Tenggara Province that is known for its high marine biodiversity. The coral reef ecosystem in this conservation area is home to ecologically and economically important megabenthic organisms. Megabenthos are important regulators of marine ecosystems, acting as indicators of coral reef health. However, information on the types and densities of megabenthos in this conservation area is scarce. Research on megabenthos is critical for assessing coral reef health and informing conservation strategies. The aim of this study is to collect baseline data on megabenthos in the Sawu Sea National Marine Park waters surrounding West Kupang and Semau. The Benthic Belt Transect method was used to collect data at six locations throughout the marine park. The information was examined for species composition and density. To assess differences and relationships between locations and megabenthic categories, statistical tests such as Kruskal-Wallis and Pearson's correlation, as well as the Morisita index, were used. Four of the eight target megabenthic categories were identified in the study, with blue starfish and giant clams being the most abundant. There was no statistically significant difference in megabenthic density across locations or ecological and economic categories. The research uncovered potential habitat preferences among various megabenthic categories. The presence and distribution of megabenthos in the waters of this marine park provide important information about the health of coral ecosystems. These findings can help guide conservation efforts.

Qualitative Analysis of Sanitation Management in Residential Area around Gampong Jawa Landfill in 2021 Based on Fly Distribution Pattern

Abstract Aim: Residents are concerned about the presence of flies, especially in areas near landfills, so it is important to study the distribution patterns of fly communities and community responses to the presence of flies. This study focuses on two main topics: fly distribution in various zones and people’s perspectives on fly prevention initiatives. Materials and Methods: Data were collected by dividing the sampling location into four clusters and collecting data three times per day (morning, noon, and afternoon). Flypaper was used to collect the insects, which were then separated based on their morphology. The data were tabulated and analyzed using the Shannon-Wiener equation for the diversity index, and the Morisita index equation for the distribution pattern. The observation was then continued by asking people about the existence of the fly community. Results: Cluster 4 has the strongest dynamics with varying absolute density. The morning has the highest absolute density, with an average of 26.56. The findings of the relative density analysis suggest that Musca domestica has the highest percentage, with an average percentage of 74.36%. Only 45% of respondents took actions to combat the presence of flies. The study’s findings also revealed that 97% of the population had never been socialized about sanitary management and attempts to control fly communities. Conclusions: Community sanitation, the prevalence of trash, and the presence of insects are not successfully regulated. The residential sector of the Gampong Jawa Community, which has the most direct access to the landfill, is at a higher risk of getting affected by hazardous diseases conveyed by flies.

Perbandingan Struktur Komunitas Cacing Tanah Megadrilli pada Ekosistem Alami dan Ekosistem Buatan

Earthworms are an important component of soil ecosystems. The presence of earthworms in a habitat can enhance the quality of the soil, both in its physical, chemical, and biological properties. This research has the purpose to analyze the comparison of earthworm density found in natural ecosystems and artificial ecosystems. The determination of location points is done using the Cluster Sampling method, which includes both natural and artificial ecosystems. Sampling is conducted using the line transect method along a 100-meter length in 20 plots. The earthworm collection method involves the use of square and hand sorting methods. Data analysis includes density values, frequency, diversity index, and the Morisita index, as well as statistical analysis using an independent sample T-Test to determine the significance of the difference in earthworm abundance between the two locations. Five species of megadrillic earthworms were identified, classified into two ecological categories: epigeic and endogeic. In the natural ecosystem, there were five species, namely Pheretima capensis (epigeic), P. corethururus (endogeic), Pheretima sp.1 (epigeic), Megascolex sp. (endogeic), and Pheretima sp.2 (epigeic). Meanwhile, in the artificial ecosystem, three species were found, which are P. capensis (epigeic), P. corethururus (endogeic), and Pheretima sp.2 (epigeic). The density of megadrillic earthworms in the natural ecosystem (567.8 individuals/m2) is significantly higher compared to the artificial ecosystem (242.5 individuals/m2). The relative frequency of earthworms in the natural ecosystem is divided into 3 categories: Rare (Assesory), Common (Constant), and Very Common (Absolute), whereas in the artificial ecosystem, there are 2 categories: Common (Constant) and Very Common (Absolute). The diversity index of earthworms in the natural ecosystem tends to be higher (H' = 1.236) than in the artificial ecosystem (H' = 0.885). The distribution pattern of megadrillic earthworms in the natural ecosystem is clustered, while in the artificial ecosystem, it is random.

The Overlap of Skin and Blood T-Cell Clones in Early-Stage Mycosis Fungoides

Introduction: Mycosis fungoides (MF) is the most common subtype of cutaneous T-cell lymphoma that initially starts in the skin but can progress to involve blood with significant mortality in late stages. Even in early stages and in the absence of blood involvement, changes in blood T-cell receptor (TCR) repertoire have been observed in MF patients. While prior work has explored the significance of dominant blood T-cell clones in the prognosis of early MF, the relationship between TCR sequences and T-cell repertoires of blood and skin in early-stage MF patients has not been characterized. Objectives: To determine the relationship of blood and skin T-cell repertories and to reassess the impact of dominant blood T-cell clones on selected outcome endpoints in early-stage MF. Materials and Methods: We used high-throughput sequencing to interrogate TCR sequences in blood and skin of MF patients without blood involvement at the Jefferson Cutaneous Lymphoma Clinic (Adaptive Biotechnologies). ImmunoSEQ Analyzer provided T-cell repertoire overlap metric (Morisita's index) and diversity measure (Simpson's clonality score). Time to systemic treatment (TTST) was calculated as the time from initial diagnosis to initiation of first systemic therapy. Results: 60 MF patients with no blood involvement were enrolled. 28% had a dominant clone in blood; of these, 18% were identical to dominant skin clones and 82% were distinct from the dominant clones identified in skin. We found that MF patients with discordant dominant T-cell clones in blood and skin had a longer TTST when compared to the identical clone cohort (P=0.0057) (Figure 1A). Furthermore, patients with discordant dominant clones had a lower degree of T-cell repertoire overlap between blood and skin (P<0.0001) and higher blood T-cell repertoire diversity scores (P=0.013) when compared to the identical clone group (Figure 1B). In all patients, the degree of T-cell overlap in blood and skin did not significantly change over a period of months to years or among skin biopsies obtained from different anatomical locations. Finally, in a subset of patients with discordant clones, the dominant skin clone did not appear to be detected in blood even at low frequencies. Conclusion: Our data highlight the importance of establishing clonal associations between dominant T-cell clones of the skin and blood in MF. We propose that early-stage MF patients with dominant clones in blood segregate into two cohorts with distinct prognoses and T-cell repertoires based on the identity of their peripheral T-cell clones. In addition, our findings suggest that not all MF patients have reservoirs of malignant T-cell clones readily available in peripheral circulation to seed new lesions in skin. Figure 1: A: Kaplan-Meier analyses of time to systemic treatment (TTST) in skin-limited mycosis fungoides (MF) patients with an identical dominant T-cell clone in blood and skin, a discordant dominant T-cell clone in blood and skin, and no dominant blood clones. NS- not significant (P =0.5274), ** (P =0.0057), *** (P <0.0003). B: Average Morisita's index for blood and skin overlap for patients in indicated groups of I: identical dominant clones in blood and skin, D: discordant dominant clones in blood and skin, and N: no dominant clone in blood. **** (P <0.0001).

Increased Proliferative Drive of Lymphocytes in Sickle Cell Disease

Introduction Patients with sickle cell disease (SCD) have higher levels of inflammation which plays a prominent role in disease pathogenesis. It is well known that individuals with SCD have a higher erythropoietic drive given the ~20 day life span of their red blood cells. We asked whether this increased proliferative drive also occurred in white blood cells (WBC). To characterize WBC turnover we focused on the longest-lived CD4+ and CD8+ T cells. Methods Peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll gradient from red cell waste products from consented individuals with sickle cell disease and from leukapheresis products of healthy donors. In ten healthy donors and ten donors with SCD, CD4 and CD8 T cells were purified using EasySep Cell Isolation, labeled with eFluor 670 proliferation dye, and cultured in RPMI with 30% FBS for seven days. Samples were collected daily and stained with naïve and memory T cell markers. CountBright beads were added to obtain absolute cell counts and eFluor 780 live/dead dye was used to capture daily snapshots of cell death. Flow cytometric analysis was performed to track absolute cell numbers, cell division and indirectly monitor cell death. B cells, NK, macrophages, and dendritic cells were similarly tracked. To further probe T cell turnover, T cell receptor (TCR) sequencing was performed on twelve separate aliquots from purified CD4+ T cells at two different timepoints in healthy donors and individuals with SCD. Turnover of clonal sequences was analyzed using the Morisita index. Results CD4+ and CD8+ lymphocytes from individuals with SCD experienced more death in culture by day 7 compared to healthy donor controls. In addition, T lymphocytes from donors with SCD were observed to undergo 15-fold more proliferation compared to healthy donors (p=0.0002, unpaired t-test). Immunophenotyping performed on the CD4 and CD8 T lymphocytes showed a propensity for memory cells to undergo proliferation. We also found individuals with SCD had higher turnover in TCR sequences in two timepoints compared to healthy donors (p=0.05, Chi-square). Notably, we also saw increased proliferation of B cells, NK cells, macrophages, and dendritic cells in individuals with SCD. Conclusion Our data suggest that T lymphocytes and other PBMCs undergo faster turnover in SCD than in healthy donors, suggesting a stronger hematopoietic drive. Our findings may have important implications for gene therapy since an increased proliferative drive may contribute to an increased risk of developing leukemia in SCD.

Pteridophytes Diversity and Distribution Along The Elevational Gradient of Mount Penanggungan's Hiking Trail, East Java, Indonesia

Pteridophytes (ferns) are a fundamental element of tropical rainforests, which provide excellent microhabitats for their development. In addition, the sensitivity of pteridophytes to shifts in microclimate and anthropogenic disturbances makes them excellent environmental bioindicators. The purpose of this study was to determine the diversity and distribution of pteridophytes along the elevational gradient of two well-known hiking trails of Mount Penanggungan, East Java, Indonesia. Using a 10x10 m2 plot and transect line, we examined the composition, species diversity using Shannon-Wiener diversity index (H'), relative abundance, and distribution pattern using Morisita index of dispersion (Id) of ferns along an elevational gradient (700–1500 m above sea level) on the hiking trails of Mount Penanggungan, i.e., Tamiajeng and Kunjorowesi. As many as 14 species from 7 families living in both terrestrial and arboreal types were identified. Species composition along the elevation gradient revealed a pattern of predominating species. The Shannon-Wiener diversity index (H') indicated a moderate level of diversity, where many pteridophytes species are found on the altitude gradient between (700-900 m dpl), and the Morisita index of dispersion (Id) indicated a clustered distribution pattern for most of the species. This pattern of diversity and distribution can be explained by changes in biotic and abiotic factors.

Sebaran Bellucia pentamera Naudin Di Kawasan Objek Wisata Kapalo Banda Taram Kabupaten Lima Puluh Kota

Kapalo Banda Taram Tourism Area, Lima Puluh Kota Regency is one of the tropical rain forest areas in West Sumatra which has a high level of biodiversity that can be disturbed due to the presence of invasive plants, one of which is Bellucia pentamera. The purpose of this study was to determine the distribution of B. pentamera, to determine the effect of the number of Bellucian on the number of non-Bellucian and to determine the effect of distance from the river and light intensity on the distribution of B. pentamera. The research using the belt transect with a plot size of 20x50 m2. Data analysis using the Morisita Index and Simple Linear Regression formulas. The distribution of B. pentamera was quite large with the distribution pattern of B. pentamera sapling strata is clustered, while the tree strata had a uniform distribution pattern. The number of Bellucian individuals affects the presence of non-Bellucian individuals as indicated by a negative effect on species diversity, a decrease in the number of species, high dominance and habitat colonization which will limit resources and space for the growth of other species. The distance from the river affects the distribution of B. pentamera where the closer the distance from the river tends to increase the presence of B. pentamera, while the light intensity does not affect the presence of B. pentamera.

Structure and Composition Seedling Plant in the Campus Forest of UIN Sulthan Thaha Saifuddin Jambi

Seedlings are the first stands that grow to replace damaged forest vegetation. Seedlings can have a positive impact on the balance of the wider ecosystem, because seedlings are the beginning of an ecosystem regeneration process that is greatly influenced by that ecosystem The purpose of this research to information regarding the structure and composition of seedling in the UIN Sulthan Thaha Saifuddin Jambi Campus Forest. This research was carried out in July 2022 – March 2023. The research location was determined using the Purposive Sampling Method, determining the plot using systematic sampling, and data collection using the quadratic method with a size of 2 m x 2 m. The observation results were analyzed using the Importance Value Index, Shannon-Winner Diversity Index, Morisita Index, and the Evenness Index. The research results found that there were 332 individuals, 84 types of seedlings, belonging to 28 families. The highest Importance Value Index (INP) is Gmelina arborea Roxb (11.19%), the Diversity Index (H') is in the high category (H' 3.94). The evenness index (E) (0.89) is in the high (even) category.

Composition Structure And Distribution Patterns Of Pandanaceae Family Plants In Batang Gadis Resort 7 Sopotinjak National Park, Mandailing Natal District North Sumatra

The Pandanaceae family includes Monocotyledoneae plants that have tree, liana, and shrub habitus. This study aims to determine the types of the Pandanaceae family, diversity index, and distribution patterns of the Pandanaceae family at Resort 7 Sopotinjak Batang Gadis National Park, Batang Natal District, Mandailing Natal Regency, North Sumatra which was carried out in February - April 2022. The method used in this research is a survey method with the technique of making quadrat plots by purposive sampling on 3 research transects, each transect consisting of 8 plots. The results obtained 7 species from the Pandanaceae family, namely Benstonea eatrocarpa (Griff.), Benstonea parva (Ridl.) Callm & Buerki, Benstonea sp., Freycinetia angustifolia Blume, Freycinetia sumatrana Hemsl, Pandanus furcatus Roxb., Pandanus houlettii Carriere. The diversity index of the Pandanacaeae family in Resort 7 Sopotinjak Batang Gadis National Park in transect 1 was 0.397, in transect 2 was 0.637, and in transect 3 was 0.079 which indicated that the level of diversity was low. The morisita index (Id) of the Pandanaceae family in Resort 7 Sopotinjak Batang Gadis National Park is 9.45, which indicates that the distribution pattern is clustered. The Pandanaceae family is found in highland tropical forests with high rainfall and reproduces vegetatively (budding) under favorable environmental conditions.

Peripheral T-Cell Priming and Micrometastatic Disease Control with Metastasis-Directed Therapy: Multidimensional Immunogenomic Profiling of Oligometastatic Prostate Cancer in the EXTEND Trial

Comprehensive metastasis-directed therapy (MDT) for oligometastatic prostate cancer extended progression-free survival (PFS) and time to new lesion formation in the intermittent hormone therapy (HT) basket of EXTEND. To better understand the mechanism of MDT benefit, we pooled the intermittent and continuous HT baskets of EXTEND and tested the hypothesis that adding MDT to HT would program systemic T-cells to control micrometastatic disease. A total of 174 men were randomized to HT with or without MDT to up to 5 sites of metastases. HT was given for 6 months (intermittent basket, n = 87) or indefinitely (continuous basket, n = 87). Peripheral blood samples were drawn at enrollment, at the end of MDT, at 3 months follow-up (3 mo F/U), and at progression and then analyzed by flow cytometry, T-cell receptor (TCR)-β CDR3 variable region sequencing, multiplex cytokine profiling, and next-generation circulating tumor DNA (ctDNA) sequencing. TCR clonal expansion was determined using a published betabinomial model. Repertoire changes were assessed by Morisita's index, and dominant TCR repertoire motifs were characterized with ImmunoMap. Associations between blood markers and PFS were evaluated with Cox regression adjusted hazard ratios (aHR) accounting for randomization arm and stratifying for intermittent vs continuous HT. Randomization to MDT+HT was associated with T-cell activation, proliferation, and clonal expansion. This response was first observed at end-MDT as upregulated expression of T-cell activation and inhibition markers (i.e., ICOS, Tim-3, and LAG-3) and increases in highly proliferative CD4+ and CD8+ Ki67hi T-cells (all P<0.05). TCR sequencing of 7,678,911 T-cells revealed that MDT+HT was associated with TCR clonal expansion, remodeling of the TCR repertoire, and changes in dominant TCR motifs at end-MDT and 3 mo F/U (all P<0.05). Observed T-cell priming could be driven by signaling networks of canonical T-cell stimulatory cytokines (IL-2, IL-12, and IL-15), which were upregulated at end-MDT and persisted at 3 mo F/U (all P<0.05). This modulation of T-cell phenotype, clonotype, and cytokine concentrations was not observed in the HT-monotherapy arm. At end-MDT, systemic T-cell responses were associated with improved PFS, most notably CD8+ T-cell expression of LAG-3 (aHR 0.22, 95% CI 0.03-0.91) and high TCR clonal expansion (aHR 0.13, 95% CI 0.02-0.52). High ctDNA burden at end-MDT correlated with worse PFS (aHR 1.41, 95% CI 1.04-2.54), as did CD8+ T-cell expression of inhibitory receptor TIGIT at 3 mo F/U (aHR 1.03, 95% CI 1.01-1.06). The addition of MDT to HT induced systemic T-cell activation and expansion, which was not observed in the HT-only arm. This systemic immune response was independently associated with improved PFS. In addition to cytoreduction of macroscopic disease, MDT-induced immune education may be an important complementary mechanism of micrometastatic control in oligometastatic prostate cancer.

Distribution and association pattern of Keruing (Dipterocarpus sp.) in Tangkahan, Gunung Leuser National Park

Keruing (Dipterocarpus sp.) is a commercially important timber and oil-producing species. Keruing’s wood is of high quality, and its oil is widely used for medicinal purposes. Because of the high price and demand for wood and oil, keruing has become a target for exploitation and causing the population to decrease. Understanding of the keruing population in natural habitats is important for conservation efforts, one of which is in the Gunung Leuser National Park (GLNP) area. The purpose of this study was to analyze the distribution patterns and associations of keruing in the Tangkahan area of GLNP. These are accomplished through the use of a vegetation analysis method with purposefully defined paths based on the presence of keruing. The Ochiai index (Oi), Dice index (Di), and Jackard index (Ji) were calculated for data analysis, while the Morisita index was used to determine the shape of the distribution pattern. The research reveals three keruing species, namely Dipterocarpus haseltii, Dipterocarpus constulatus, and Dipterocarpus elongataus Korth. The keruing distribution showed different patterns at different growth stages. At the seedling and tree stage, the distribution pattern was clustered, while at the sapling and pole stage were uniform. The three keruing species has weak associations with various surrounding species. The species that has the highest association value is Syzygium fastigiatum, which is 0.22.

Population Dynamics of Three Polyplacophora Species from the Aegean Sea (Eastern Mediterranean)

The present study is the first to examine spatio-temporal variations in the densities and morphometrics of three shallow water Polyplacophora species (Rhyssoplax olivacea, Acanthochitona fascicularis and Lepidopleurus cajetanus), native to the eastern Mediterranean, while also estimating several growth parameters. Two intertidal boulder fields located in the Pagasitigos gulf (central Aegean) were sampled monthly with SCUBA diving using quadrant sampling, to compare the spatial and temporal (month, season) effects on their size, population density and dispersion pattern. Region was the most significant factor influencing the abundance and size for all three species, while the temporal scales affected mostly Rhyssoplax olivacea. The effect of a boulder under the surface was only significant for the density of Lepidopleurus cajetanus. The standardized major axis method showed that the three species exhibited different allometric relationships between length, width and weight, while a slope comparison between regions yielded significant, in most cases, results. Using the standardized Morisita index for dispersion, a clustered pattern was observed for all species seasonally, with the exception of Acanthochitona fascicularis in Plakes in autumn and winter. To estimate the growth parameters, a bootstrapped Electronic Frequency Analysis (ELEFAN) utilizing a genetic algorithm was employed on pooled populations. L∞ and K varied among the three species with A. fascicularis exhibiting the highest L∞ and L. cajetanus the lowest K value.

Effect of flow structures on the transport of gametes in broadcast-spawning sea urchin

Broadcasted fertilization for the reproduction of invertebrates is accomplished through a complicated interaction between spawned gametes and the surrounding flows. Most gametes encounter each other in the vicinity of the sea urchin body where unique flow structures develop, and so analysis of local flow characteristics allows us to better understand the effect of flow on the fertilization process. This study applied a Lagrangian framework based on computational fluid dynamics to estimate the fertilization rate of eggs in a range of flow velocities (0.025–0.2 m/s) and the fertilization rate was the highest at U = 0.1 m/s, which is an intermediate flow speed. Among the four classified sub-zones, such as the aboral surface, wake, substrate, and water column, fertilization occurred most frequently in the wake and substrate regions. The relationship between fertilization rate and flow structures was investigated using three parameters: 1) standardized Morisita index to quantify the pattern of gamete distribution, 2) length of the recirculation zone to specify the areas where the eggs are most frequently fertilized, and 3) integral scale to estimate the dimension of vortex structures downstream. The results of this study show that the fertilization rate is higher inside the recirculation zone, especially when strong vortex structures are observed because the flow provides a favorable condition for the gametes to aggregate and collide with each other.

Autecology of &lt;i&gt;Nepenthes&lt;/i&gt; spp. in Peat Swamp and Heath Forest Pematang Gadung, West Kalimantan

Nepenthes occur in various habitat types in West Kalimantan. But some species are categorized as vulnerable on the IUCN red list. Autecological studies of Nepenthes spp. are required for species management and conservation. The study aimed to analyze species diversity, distribution pattern, association, and environmental factors that correlated with Nepenthes spp. at peat swamp and heath forest in Pematang Gadung. Data was collected in September 2021 by purposive sampling on 60 plots measuring 3 x 3 m2 in each habitat type. Species diversity was analyzed based on the presence and abundance of species in the plots. The distribution pattern was determined using a standardized Morisita index (Ip). Meanwhile, the association type was determined based on the Jaccard index (JI). Environmental data were analyzed by Canonical Correspondence Analysis (CCA) using Past Version 4.03. This study found six wild species in a peat swamp and four species in a heath forest. The population of Nepenthes spp. has clumped distribution pattern with Ip&gt;0. Nepenthes spp. are associated with plants such as Barringtonia racemosa, Syzygium sp., Nephrolepis biserrata, and Campnosperma auriculatum. The result of CCA revealed that environmental factors in both habitat types affected the presence of each Nepenthes species. The air temperature, humidity, soil moisture, and light intensity show different influences on different species.

STRUKTUR KOMUNITAS DIPLOPODA TANAH PADA KETINGGIAN BERBEDA DI PERKEBUNAN TEH KABAWETAN BENGKULU

Soil diplopods are an important biotic component in agricultural land ecosystems. Its presence in the soil is an important in the decomposition process of soil organic matter, and plays a role in increasing soil fertility. This study aims to study the community structure of soil Diplopoda at different altitudes in the Bengkulu Kabawetan Tea Plantation. The location of the study used the stratified sampling method which is based on the altitude of 800 m, 900 m and 1000 m above sea level. Soil Diplopods were collected by using the 50x50 cm quadratic method and a 100 m line transect. Data analysis consisted of density, relative density, diversity index, and Morisita index. There were 4 types of soil Diplopods in the Bengkulu Kabawetan Tea Plantation, namely Arthrosphaera sp., Gyrodrepanum sp., Oxidus sp., and Trigoniulus sp. At an altitude of 900 m and 1000 m, 4 species of Diplopoda were found and at an altitude of 800 m consisted of 3 types of Diplopoda. The density of soil diplopods at the three study locations varied, with the highest density at an altitude of 1000 m followed by at an altitude of 800 m and at 900m. The diversity index at the three locations is low and moderate. The distribution of diplopods at the study site was random and uniform.

Changes in the distribution density of locate, Thaisella chocolata (Duclos, 1832) (Gastropoda, Thaididae) as an indicator for predicting their reproductive events

For a population of locate, Thaisella chocolata, in La Rinconada, Chile, on a grid of 39 stations distributed along three 910 m-long transects at depths of 5 to 18.5 m, Moran and Morisita indices were used to evaluate whether density variations along the depth distribution are related to the stratification of larger sizes at the beginning of their reproductive process. Results indicate that before, during, and after forming reproductive aggregations, there is a T. chocolata increase in density in the shallow stratum (5 to 13 m). This finding is corroborated by the Moran index, which showed a greater autocorrelation in January-May, September-October, and January 2010, and by the Morisita index; thus, it is validated as a potentially easy-to-use indicator for assessing the reproductive process of this species. This index could also alert fishermen to the prevalence of reproductive aggregations in an area and that these aggregations should not be exploited as is currently the case to ensure the reproductive success of this species.