Population Structure Of Species Research Articles

Insights Into Sea Turtle Population Composition Obtained With Stereo-Video Cameras in situ Across Nearshore Habitats in the Northeastern Gulf of Mexico

Population size estimates are key parameters used in assessments to evaluate and determine a species’ conservation status. Typically, sea turtle population estimates are made from nesting beach surveys which capture only hatchling and adult female life stages and can display trends opposite of the full population. As such, in-water studies are critical to improve our understanding of sea turtle population dynamics as they can target a broader range of life stages – though they are more logistically and financially challenging to execute compared to beach-based surveys. Stereo-video camera systems (SVCS) hold promise for improving in-water assessments by removing the need to physically capture individuals and instead extract 3D measurements from video footage, thereby simplifying monitoring logistics and improving safety for the animals and surveyors. To demonstrate this potential, snorkel surveys were conducted at artificial habitats in the northeastern Gulf of Mexico (neGOM) to collect size and photo-identification data on sea turtles in situ using a SVCS. Over 29.86 survey hours, 35 sea turtles were observed across three species (Caretta caretta, Chelonia mydas, and Lepidochelys kempii) and all neritic life stages (juvenile, sub-adult, and adult) utilizing different habitats, including artificial reefs, jetties, and fishing piers. Greens straight carapace length ranged from 28.55 to 66.96 cm (n = 23, mean 43.07 cm ± 11.26 cm standard deviation; SD) and loggerheads ranged from 59.71 to 91.77 cm (n = 10, mean 74.50 cm ± 11.35 cm SD), and Kemp’s ridleys ranged from 42.23 cm to 44.98 cm (mean 43.61 cm ± 1.94 cm SD). Using a linear mixed model, we found that species and habitat type were the most important predictors of sea turtle body length distribution. Overall, this case study demonstrates the potential of SVCS surveys to enhance our understanding of the population structure of sea turtle species within the neGOM and elsewhere.

Genetic diversity and population structure of the rare species Artemisia hololeuca detected by AFLP analysis

ISHS VIII International Scientific and Practical Conference on Biotechnology as an Instrument for Plant Biodiversity Conservation (Physiological, Biochemical, Embryological, Genetic and Legal Aspects) Genetic diversity and population structure of the rare species Artemisia hololeuca detected by AFLP analysis

Phylogeography of the smooth greensnake, Opheodrys vernalis (Squamata: Colubridae): divergent lineages and variable demographics in a widely distributed yet enigmatic species

Abstract Phylogeographic studies can uncover robust details about the population structure, demographics, and diversity of species. The smooth greensnake, Opheodrys vernalis, is a small, cryptic snake occupying mesic grassland and sparsely wooded habitats. Although O. vernalis has a wide geographical range, many metapopulations are patchy and some are declining. We used mitochondrial DNA and double digest restriction-site associated DNA sequencing to construct the first phylogeographic assessment of O. vernalis. Genomic analysis of 119 individuals (mitochondrial DNA) and a subset of another 45 smooth greensnakes (nuclear DNA; N = 3031 single nucleotide polymorphisms) strongly supports two longitudinally separated lineages, with admixture in the Great Lakes region. Post-Pleistocene secondary contact best explains admixture from populations advancing northwards. Overall, populations expressed low heterozygosity, variable inbreeding rates, and moderate to high differentiation. Disjunct populations in the Rocky Mountains and central Great Plains regions might be contracting relicts, whereas northerly populations in more continuous mesic habitats (e.g., Prairie Pothole region, southern Canada) had signals of population expansion. Broadly, conservation management efforts should be focused on local populations, because habitat connectivity may facilitate gene flow and genetic diversity.

Evidence of shape variation in wild Tor Mahseer (Tor tor) from Indian Rivers

AbstractIt has been hypothesized that geographical isolation between river ecosystems often resulted in phenotypic variation and ultimately change in the population structure of aquatic species. To test the hypothesis, 471 individuals of Tor Mahseer, Tor tor, were collected across its distribution range from 18 locations on 10 Indian Rivers covering the Ganges, Narmada, and Godavari River basins to assess the population‐level inter‐ and intra‐basin shape variation through landmark‐based “geometric morphometrics.” Overall, multivariate analysis of variance (MANOVA) showed significant differences (F = 3.33, p < .001) in shape across wild populations. The Mahalanobis and Procrustes distances extracted from canonical variate analysis (CVA) were found to be significant (p < .001) between basins and nonsignificant (p > .001) within basin except Banas and Kali Sindh Rivers in the Ganges River basin. The results indicated that Tor Mahseer in Indian Rivers were represented by four heterogeneous phenotypic stocks (1: the Ganges River basin except Banas and Kali Sindh River; 2: the Banas and Kali Sindh River; 3: the Narmada River basin, and 4: the Godavari River basin) based on their shape. The wireframes depicted variation mainly in the head region, body depth, and the caudal peduncle area between four phenotypic stocks. The population‐level shape variation between the basins might be due to geographical isolation between the basins and within the Ganges basin because of river fragmentation due to habitat alteration, which restricts the movement of fishes. This study is useful for resolving the “phenotypic stock” complexity in order to develop a suitable stock management plan with the aim of conserving and restoring populations of Tor Mahseer in Indian Rivers.

Phenotypic variability in the Old World bollworm, Helicoverpa armigera (Hübner) populations in India

AbstractHelicoverpa armigera (Hübner) is one of the most prominent polyphagous species of the Heliothinae pest complex that inflicts severe damage to a wide range of crops in India. Knowledge regarding the population structure of the pest species, whether morphological or genetic, is considered as an essential tool in making effective management decisions. Thus here, we performed the phenotypic characterization of H. armigera populations collected from varied geographic locations across India. Studied populations differed significantly for several external morphometric traits studied at larval, pupal and adult stages. Significant differences were also observed with respect to the intensity of black pigmentation on larval body as well as adult eye and forewing colour patterns. Besides external phenotypic traits, the length of genital organs like aedeagus and valva in males, and bursa copulatrix and bursa seminalis in females also differed significantly amongst populations. The dendrogram based on selected traits showed clear cut differentiation of studied populations into two major groups, one including all the South Zone populations and the other having populations from North and Central Zones. Differences based on phenotyping in the present study indicate the possibility of the existence of different subspecies within the Indian populations of H. armigera.

Different evolutionary trends form the twilight zone of the bacterial pan-genome.

The pan-genome is defined as the combined set of all genes in the gene pool of a species. Pan-genome analyses have been very useful in helping to understand different evolutionary dynamics of bacterial species: an open pan-genome often indicates a free-living lifestyle with metabolic versatility, while closed pan-genomes are linked to host-restricted, ecologically specialized bacteria. A detailed understanding of the species pan-genome has also been instrumental in tracking the phylodynamics of emerging drug resistance mechanisms and drug-resistant pathogens. However, current approaches to analyse a species’ pan-genome do not take the species population structure into account, nor do they account for the uneven sampling of different lineages, as is commonplace due to over-sampling of clinically relevant representatives. Here we present the application of a population structure-aware approach for classifying genes in a pan-genome based on within-species distribution. We demonstrate our approach on a collection of 7500 Escherichia coli genomes, one of the most-studied bacterial species and used as a model for an open pan-genome. We reveal clearly distinct groups of genes, clustered by different underlying evolutionary dynamics, and provide a more biologically informed and accurate description of the species’ pan-genome.

An Integrated Approach to Determine the Stock Structure of Spinyhead Croaker Collichthys lucidus (Sciaenidae) in Chinese Coastal Waters

An integrated approach including analyses of different biological traits is a proven and powerful tool used to assess the population structures of fish species, which is vital for fishery stock conservation and management of wild resources. This study evaluates the use of three natural tags (i.e., microsatellites, parasites, and otolith nucleus chemistry) in order to describe the population structure of the spinyhead croaker, Collichthys lucidus, in the coastal waters of China, on evolutionary and ecological time scales. Spinyhead croaker was assigned with 86% accuracy to its regional origin (northern China vs. southern China) using all three natural tags. Accuracy decreased when incorporating only one type of natural tag (genetics: 19–69%; parasites: 30–60%; otolith chemistry: 51–86%) or when assigning the fish to a fine scale (sea areas: 44–64%; sampled estuaries: 19–66%). However, the overall accuracy assignment improved slightly compared with otolith chemistry (estuaries: 55 vs. 51%; sea areas: 66 vs. 64%; regions: 86 vs. 86%). Three natural tags and integrated results show that C. lucidus in Chinese coastal waters can be separated into distinct northern and southern Chinese stocks. Finally, this information should promote the development of effective conservation strategies and integrated fisheries management plans for this commercially important species.

Species diversity, population structure and conservation status of fishes inhabiting in six different wetlands of Uttar Pradesh

The present study was carried out to investigate the species diversity and population structure of freshwater fishes of six wetlands (also called Bird Sanctuaries) of Uttar Pradesh viz., Patna, Nawabganj, Sandi, Lakh Bahosi, Saman and Sur Sarovar. The sampling was done from three years period 2017 to 2020. The results of present investigation revealed the occurrence of twenty fish species in all the study areas belonging to four orders viz. Cypriniformes, Mastacembeliformes, Perciformes and Siluriformes and 11 families i.e. Cyprinidae, Cobitidae, Nemachilidae, Mastacembelidae, Channidae, Osphronemidae, Heterorpnuestidae, Sisuridae, Bagaridae, Chichlidae and Ambassidae. In all the study wetlands Cyprinidae was found to be dominant (35%), Osphronemidae (20%), Mastacembelidae, (10%), followed by family Cobitidae, Nemacheilidae, Channidae, Sisuridae, Bagaridae, Heterorpnuestidae and Ambassidae showed least contribution of 5% each. The fish diversity indices i.e. Shannon weiner (H) and Evenness (e) at all the six wetlands were 1.31, 0.9084 & 0.5710, 1.2068 & 0.6202, 1.0961 & 0.6117, 1.1552 & 0.4649, 0.9080 & 0.5068, 1.3002 & 0.6682 at wetlands viz, Patna, Nawabganj, Sandi, Lakh Bahosi, Saman and Sur Sarovar respectively. Most of the species recorded in the present study were under 19 Least Concern (95%) and 1 species namely Chagunius chagunio were found to be under Near Threatened Category (5%) of the International Union for Conservation of Nature (IUCN).

COMPARISON ON VEGETATION COMPOSITION AND STRUCTURE OF EXCLOSURES VS. OPEN GRAZING LANDS IN NORTHERN ETHIOPIA

This study was conducted with the objectives of study investigates, compare, and try to describe the floristic composition and structure of the vegetation of exclosures and open grazing lands. A stratified preferential sampling design technique with flexible systematic model was used for data collection. Data on vegetation and environmental parameters were gathered from 120 quadrants (90 from restorations or exclosures of different ages and 30 from adjacent open grazing lands), of 20 m x 20 m (400 m2) size. Species richness and the presence or absence of herbaceous plants were recorded like soil samples in a 2 m x 2 m (4 m2) subplot inside each main quadrant from five points, one at each corner and one at the center. A total of 142 plant species belonging to 118 genera and 52 families were identified. All exclosures displayed higher plant species richness, diversity, and aboveground standing biomass compared to the adjacent open grazing lands. Consideration of edaphic (e.g. soil total nitrogen, available phosphorus, CEC, exchangeable bases, soil pH and soil texture) and site (e.g. Stoniness, Grazing) variables will help to optimize the selection of areas for the establishment of future exclosures. Moreover, our study suggests that with time exclosures may increasingly obtain an important role as refugees and species pool similar to church forests and should be protected and managed in a sustainable manner. However, economic and social impacts of exclosures should be included in feasibility studies before establishing exclosures in the future. Altitude, Grazing and some soil parameters like Mg were the major environmental factors in the division of the vegetation into plant community types. The result of the frequency distribution of woody species showed a high proportion of small-sized individuals in the lower diameter classes indicating good recruitment potential of the forest patches and the rare occurrence of large individuals. Such trend was probably caused by past disturbance of the original vegetation resulting in a succession of secondary vegetation. In addition, the analysis of species population structure indicated that some tree species had abnormal population structure with no or few individuals at lower size classes. Moreover, assessment of regeneration status on the basis of age classes indicated that significant proportion of woody species were represented by few or no seedlings, entailing that they were under threat. Substantial numbers of forest species were found to have irregular population structure and are in reduced regeneration status. To prevent local extinction of these species, present efforts of nursery establishment and plantation of indigenous species in the exclosures should be strengthened and extended.

Demographic differentiation among pioneer tree species during secondary succession of a Neotropical rainforest

Abstract Early pioneer species share life histories enabling them to colonize disturbed sites, but how much they differ demographically and how such differentiation determines pioneer species turnover during succession are still open questions. Here, we approached these issues by comparing the demography of dominant pioneer tree species during the secondary succession of tropical rainforest in Southeast Mexico. We assessed changes in population density, population structure, vital rates and intrinsic population growth rate (r) of the pioneer species Trema micrantha, Cecropia peltata and Trichospermum mexicanum during the first 35 years of succession. For this, we combined chronosequence and long‐term (from 2000 to 2018) data from 14 abandoned cornfields with 0.5–35 years fallow age. Trema colonized and disappeared first during succession (<15 years), followed by Cecropia (<28) and Trichospermum (>31). All species exhibited hump‐shaped successional trajectories of population density and biomass with Trema reaching a peak first, followed by Cecropia and later Trichospermum. Species exhibited a fast reduction in r with fallow age, with Trema reaching negative growth rates (r < 0) in the third, Cecropia in the fourth, and Trichospermum in the seventh year of succession. Recruitment, growth and mortality rates of seedlings and juveniles defined the period of population increase and the age of succession at which each species reached maximum density and biomass. The mortality rate in mature stages determined how long each species persisted during succession. An important variation in species replacement occurred among study sites. In some sites, one species was abundant and the others were almost absent, while it was the opposite in other sites. We inferred that priority inhibitory effects operated among species during the field colonization. Synthesis. Although Trema, Cecropia and Trichospermum are considered typical pioneer trees, these species differed importantly in their demographic attributes during succession. The speed at which r declined with age of succession indicated the moment at which each species reached its maximum density and species replacement sequence during succession. However, inter‐specific priority inhibitory effects during field colonization may also be involved in the chance of colonization and replacement between species with similar regeneration strategies.

Phlebotomine sand fly survey in the Republic of Moldova: species composition, distribution and host preferences

BackgroundPhlebotomine sand flies (Diptera: Psychodiae) in the Republic of Moldova have been understudied for decades. Our study provides a first update on their occurrence, species composition and bloodmeal sources after 50 years.MethodsDuring 5 seasons (2013–2017), 58 localities from 20 regions were surveyed for presence of sand flies using CDC light traps and manual aspirators. Species identification was done by a combination of morphological and molecular approaches (DNA barcoding, MALDI-TOF MS protein profiling). In engorged females, host blood was identified by three molecular techniques (RFLP, cytb sequencing and MALDI-TOF peptide mass mapping). Population structure of most abundant species was studied by cox1 haplotyping; phylogenetic analyses of ITS2 and cox1 genetic markers were used to resolve relationships of other detected species.ResultsIn total, 793 sand flies were collected at 30 (51.7%) localities from 12 regions of Moldova. Three species were identified by an integrative morphological and molecular approach: Phlebotomus papatasi, P. perfiliewi and Phlebotomus sp. (Adlerius), the first being the most abundant and widespread, markedly anthropophilic based on bloodmeal analyses, occurring also indoors and showing low population structure with only five haplotypes of cox1 detected. Distinct morphological and molecular characters of Phlebotomus sp. (Adlerius) specimens suggest the presence of a yet undescribed species.ConclusionsOur study revealed the presence of stable sand fly populations of three species in Moldova that represent a biting nuisance as well as a potential threat of pathogen transmission and shall be further studied.Graphical abstract

Genome-wide SNP analysis to assess the genetic population structure and diversity of Acrocomia species.

Acrocomia (Arecaceae) is a genus widely distributed in tropical and subtropical America that has been achieving economic interest due to the great potential of oil production of some of its species. In particular A. aculeata, due to its vocation to supply oil with the same productive capacity as the oil palm (Elaeis guineenses) even in areas with water deficit. Although eight species are recognized in the genus, the taxonomic classification based on morphology and geographic distribution is still controversial. Knowledge about the genetic diversity and population structure of the species is limited, which has limited the understanding of the genetic relationships and the orientation of management, conservation, and genetic improvement activities of species of the genus. In the present study, we analyzed the genomic diversity and population structure of Acrocomia genus, including 172 samples from seven species, with a focus on A. aculeata with 117 samples covering a wide geographical area of occurrence of the species, using Single Nucleotide Polymorphism (SNP) markers originated from Genotyping By Sequencing (GBS).The genetic structure of the Acrocomia species were partially congruent with the current taxonomic classification based on morphological characters, recovering the separation of the species A. aculeata, A. totai, A. crispa and A. intumescens as distinct taxonomic groups. However, the species A. media was attributed to the cluster of A. aculeata while A. hassleri and A. glauscescens were grouped together with A. totai. The species that showed the highest and lowest genetic diversity were A. totai and A. media, respectively. When analyzed separately, the species A. aculeata showed a strong genetic structure, forming two genetic groups, the first represented mainly by genotypes from Brazil and the second by accessions from Central and North American countries. Greater genetic diversity was found in Brazil when compared to the other countries. Our results on the genetic diversity of the genus are unprecedented, as is also establishes new insights on the genomic relationships between Acrocomia species. It is also the first study to provide a more global view of the genomic diversity of A. aculeata. We also highlight the applicability of genomic data as a reference for future studies on genetic diversity, taxonomy, evolution and phylogeny of the Acrocomia genus, as well as to support strategies for the conservation, exploration and breeding of Acrocomia species and in particular A. aculeata.

Population genetic structure and connectivity of a riparian selfing herb Caulokaempferia coenobialis at a fine-scale geographic level in subtropical monsoon forest

BackgroundRivers and streams facilitate movement of individuals and their genes across the landscape and are generally recognized as dispersal corridors for riparian plants. Nevertheless, some authors have reported directly contrasting results, which may be attributed to a complex mixture of factors, such as the mating system and dispersal mechanisms of propagules (seed and pollen), that make it difficult to predict the genetic diversity and population structure of riparian species. Here, we investigated a riparian self-fertilizing herb Caulokaempferia coenobialis, which does not use anemochory or zoochory for seed dispersal; such studies could contribute to an improved understanding of the effect of rivers or streams on population genetic diversity and structure in riparian plants. Using polymorphic ISSR and cpDNA loci, we studied the effect at a microgeographic scale of different stream systems (a linear stream, a dendritic stream, and complex transverse hydrological system) in subtropical monsoon forest on the genetic structure and connectivity of C. coenobialis populations across Dinghu Mountain (DH) and Nankun Mountain (NK).ResultsThe results indicate that the most recent haplotypes (DH: H7, H8; NK: h6, h7, h11, h12) are not shared among local populations of C. coenobialis within each stream system. Furthermore, downstream local populations do not accumulate genetic diversity, whether in the linear streamside local populations across DH (H: 0.091 vs 0.136) or the dendritic streamside local populations across NK (H: 0.079 vs 0.112, 0.110). Our results show that the connectivity of local C. coenobialis populations across DH and NK can be attributed to historical gene flows, resulting in a lack of spatial genetic structure, despite self-fertilization. Selfing C. coenobialis can maintain high genetic diversity (H = 0.251; I = 0.382) through genetic differentiation (GST = 0.5915; FST = 0.663), which is intensified by local adaptation and neutral mutation and/or genetic drift in local populations at a microgeographic scale.ConclusionWe suggest that streams are not acting as corridors for dispersal of C. coenobialis, and conservation strategies for maintaining genetic diversity of selfing species should be focused on the protection of all habitat types, especially isolated fragments in ecosystem processes.

Dispersal modeling of octopoda paralarvae in the Gulf of Mexico

AbstractThe dynamics and population structure of octopus species in the Gulf of Mexico (GoM) can be studied by analyzing dispersal paralarvae mechanisms. Accordingly, this study focused on understanding octopus paralarval dispersal using numerical modeling. A Lagrangian approach was implemented using the transport model ICHTHYOP and surface currents from a GoM simulation of the HYbrid Coordinate Ocean Model (HYCOM). We modeled the dispersal of four octopus species from the GoM (Octopus “vulgaris”, Octopus insularis, Macrotritopus defilippi, and Amphioctopus burryi), considering two regions as the source of larvae in the southern GoM, namely the Yucatan shelf and the Veracruz coastal waters. Additionally, an environmental suitability analysis was incorporated using the maximum entropy (MaxEnt) model to establish potential settlement areas under the influence of the water masses’ thermal conditions. The simulation results supported the hypothesis that the abundances recorded in the GoM were influenced by the fertility (egg‐laying) of each species, surface water circulation (the Loop Current, eddies, and wind), and sea surface temperature. Greater dispersal was obtained throughout the GoM for Yucatan species O. “vulgaris”, registering the highest settlement rates. In contrast, in Veracruz, O. insularis dispersed and settled only in the western portion of the GoM. The relevance of the ecological descriptors proposed to influence the dispersal and abundance of octopods throughout the GoM's coastal waters are discussed.

Diversity and population structure of Dipterocarpaceae species in Weh Island Nature Tourism Park, Indonesia

The Dipterocarpaceae family is one of the identified plant groups with high conservation value that exist in Weh Island Nature Tourism Park. However, the data availability on the species diversity and population structure of Dipterocarpaceae in Weh island in particular and Aceh in general is still very limited. Thus, it is necessary to conduct studies on species diversity and population structure of Dipterocarpaceae from Weh Island. This study aims to obtain data on species abundance and diversity, species composition of each stratum, population structure, and stand structure of Dipterocarpaceae in Weh Island Nature Tourism Park. This research utilized transect method with randomly selected plots according to topographic conditions. We found two Dipterocarpaceae species: Shorea sumatrana (Slooten) Desch and Dipterocarpus hasseltii Blume. Shorea sumatrana (Slooten) Desch has the greatest abundance of all types and strata. The diversity of Dipterocarpaceae species in Weh Island Nature Tourism Park is categorized as low because the diversity index value is in the range of H'1. This means that the presence of seedling and sapling strata from each species has a major effect on the survival of the Dipterocarpaceae family in the future. The stand structure of the Dipterocarpaceae family in normal conditions is indicated by an inverted “J” shaped diagram.

Population structure of the European sardine Sardina pilchardus from Atlantic and Mediterranean waters based on otolith shape analysis

The European sardine (Sardina pilchardus) is broadly distributed in the NE Atlantic and the Mediterranean Sea, representing an important fishery resource for several countries. Currently, European sardine stock limits are set administratively, and to design reliable fisheries management regulations it is essential to know the species population structure. The objective of this work was to contribute to the knowledge on the population structure of the European sardine using shape analysis, based on samples from 14 locations in the Northeast Atlantic and the Mediterranean Sea, covering nearly the entire distribution range of the species. A combination of elliptic Fourier descriptors and otolith size parameters were explored by multivariate statistical methods. Five distinct groups were identified: (1) the Cantabrian Sea and the English Channel; (2) the North and Southwestern Portuguese coast; (3) the Mediterranean and the Gulf of Cadiz; (4) Madeira and Azores islands; and (5) Northwest African and South Portugal coasts. Moreover, connectivity between Cantabrian/Galicia and western Portugal was suggested, as well as through the Gibraltar Strait. The results were directly compared with those from previous genetic and morphometric studies conducted on the same individuals, being generally consistent with areas of otolith shape change.

Genome‐wide SNP genotyping reveals hidden population structure of an acroporid species at a subtropical coral island: Implications for coral restoration

Abstract It is essential to consider genetic composition for both conventional coral restoration management and for initiating new interventions to counter the significant global decline in living corals. Population genetic structure at a fine spatial scale should be carefully evaluated before implementing strategies to achieve self‐sustaining ecosystems via coral restoration. This study investigated the population genetic structure of two acroporid species at Kume Island, Okinawa, Japan. There were 140 colonies of Acropora digitifera collected from seven study sites, and 81 colonies of Acropora tenuis from six sites. In total, 384 single nucleotide polymorphism (SNP) loci for A. digitifera and 470 SNPs for A. tenuis were obtained using a comparatively economical technique, Multiplexed ISSR Genotyping by sequencing. Observed heterozygosity was significantly lower than expected heterozygosity at all SNP sites in both acroporid species, suggesting deficient genetic diversity possibly caused by past massive coral bleaching. Even though both species are broadcast spawners, the population structure was different in the two species. No detectable structure was evident in A. digitifera, but two distinct clades were found in A. tenuis. The genetic homogeneity of A. digitifera at Kume Island suggests that this species could be used as a focal species for active restoration in terms of genetic differentiation at this island. By contrast, A. tenuis unexpectedly included two distinct clades with little or no admixture within a small study area, possibly representing two reproductively isolated cryptic species. Thus, when using A. tenuis, it would be prudent to avoid disturbing the genetic composition of wild populations until this question is answered.

Stock structure analysis of the endemic fish, Barbodes carnaticus (Jerdon 1849), for conservation in a biodiversity hotspot.

The population structure of Barbodes carnaticus species was studied using conventional (based on body morphometrics and meristic) and image-based analysis (truss network system) methods. The study was carried out with four stocks, namely Karnataka (KA) and Tamil Nadu (TN) stocks from the River Cauvery, Kerala (KE) stock from the River Chalakudy and farm-reared stock (CI) from Central Institute of Freshwater Aquaculture, Bangalore. A total of 27 morphometric, 9 meristic and 30 truss measurements were used in the study for the stock structure. Fifteen landmarks were used to generate 30 truss distance measurements. The principal component analysis (PCA), factor analysis (FA), discriminant function analysis (DFA) and cluster analysis (CA) were deployed to determine the variation using both the conventional and truss variables. Variations (86.9%) among the morphometric characters were explained by five principal components, while four principal components explain 96.01% of the variation among the truss distances. DFA using conventional method correctly classified 100% of the original grouped classes of the KA, KE and CI and 93.8% of TN stocks. The DFA employed with truss distance was classified into the stocks CI, KA, KE and TN, and the values are 100, 89.1, 8.6 and 6.1%, respectively. Factor analysis based on truss morphometry showed that factor one is related to body shape and factor two is related to head shape. Two clusters were identified in both the conventional and the truss distance analysis. Truss distance-based cluster showed that the KE and CI stocks are similar compared to the TN stock. In contrary, morphometry-based cluster showed the KE and TN stocks are similar compared to CI stock. The multivariate analysis showed that the farm-reared stock (CI) is different from the wild stocks (KA, KE and TN). This study explained that the combination of the conventional and image-based truss network analysis helps to discriminate various stocks of B. carnaticus. Based on the PCA, bilinear data models were generated using R 3.5.3 software for predicting the stock of each individual. Stock discrimination of this species was mainly due to the geographic isolation, river ecology and temperature variations. The stocks of B. carnaticus are highly exploited from the studied rivers, and the species is an important candidate for species diversification to enhance aquaculture production. Within stock variations are found to be minimum in the present morphometric study, hence the gene pool identification and marker study are required for better understanding of the stocks. This stock structure study may help to develop conservation programmes for this endemic species through a more scientific approach.

Genetic structure of Alhagi (Hedysareae, Fabaceae) populations using ISSR data in Iran.

Alhagi Gagnebin (Fabaceae: Hedysareae) is a small genus of shrubs or subshrubs distributed in temperate and tropical regions of Asia, Europe, and Africa. The exact number of Alhagi species in Iran has been disputable. Studies showed that morphology, seed protein, and chromosome characters could not clearly delimitate the species boundaries of the genus. In order to determine species boundaries and the population structure of Alhagi species in Iran, eight labeled inter simple sequence repeat (ISSR) primers were used to screen 22 populations including 110 individuals. STRUCTURE, PCoA and clustering analyses of ISSR data were able to clearly split all populations of Alhagi in Iran into two distinct groups. As the populations A. pseudalhagi and A. maurorum jointly formed a group (A. maurorum complex) segregated from those of Alhagi graecorum. Further analyses of A. maurorum complex showed a significant molecular difference among the studied populations (PhiPT value = 0.213, P = 0.001) as well as a high amount of variability within populations (79%) indicating frequent genetic exchanges. Structure analysis of complex populations (K = 2) showed no distinct genetic pattern related to their geographical distribution. In this study, Alhagi has retrieved the only two species of Alhagi in Iran; A. graecorum and A. maurorum.

Invasion Potential, Impact and Population Structure of Non-native Fish Species, Cyprinus carpio (Linnaeus, 1758) from the Tributary of the Ganga River, Central India

Invasion Potential, Impact and Population Structure of Non-native Fish Species, Cyprinus carpio (Linnaeus, 1758) from the Tributary of the Ganga River, Central India