Quantitative trait loci for morphometric traits in multiple families of common carp(Cyprinus carpio)

Quantitative trait locus(QTL) mapping is frequently used to understand the genetic architecture of quantitative traits.Herein,we performed a genome scanfor QTL affecting the morphometric characters in eight full-sib families containing 522 individuals using different statistical methods(Sib-pair and half-sib model).A total of 194 QTLs were detected in 25 different regions on 10 linkage groups(LGs).Among them,37 QTLs on five LGs(eight,13,24,40 and 45) were significant(5%genome-wide level),while the remaining 40(1%chromosome-wide level) and 117(5%chromosome-wide level) indicated suggestive effect on those traits.Heritabilities for most morphometric traits were moderate to high,ranging from 0.21 to 0.66,with generally strong phenotypic and genetic correlations between the traits.A large number of QTLs for morphometric traits were co-located,consistent with their high correlations,and may reflect pleiotropic effect on the same genes.Biological pathways were mapped for possible candidate genes on QTL regions.One significantly enriched pathway was identified onLG45,which had a P-value of 0.04 and corresponded to the "regulation of actin cytoskeleton pathway".The results are expected to be useful in marker-assisted selection(MAS) and provide valuable information for the study of gene pathway for morphometric and growth traits of the common carp.

Genetic Diversity and Interrelationship Among Mulberry Genotypes

Fourteen morphometric traits were used to examine the genetic divergence of 25 mulberry （Morus spp.） genotypes from varied agroclimatic conditions of India. Wide variation was observed for all the traits. The genotypes irrespective of their place of collection were grouped into 10 different clusters. Seven accessions, that is, Baragura-2, Gorabandha-2, Kalimpong, Herbertpur, Kollegal, Resham majri-7, and UP-14 each a cluster of unique entries will be of useful for genetic resources. Nevertheless, the correlation and path analysis suggest the direct selection of lamina length, fresh leaf weight, leaf area, and single leaf weight will be rewarding for mulberry leaf yield improvement.

Multivariate morphometric investigation to delineate species diversity and stock structure of mud crab Scylla sp. along the coastal regions of Bangladesh

Despite the importance of mud crab species(genus Scylla)in both coastal aquaculture and artisanal fisheries,knowledge of the species diversity and stock structure of mud crab population for their sustainable management across the coastal region of Bangladesh remains obscure.Therefore,the present study was conducted to delineate the diversity and stock structure of mud crab species based on the 24 morphometric length measurements and 27 morphometric ratios data collected from the three coastal regions(Chittagong,Cox’s Bazar and Bagerhat)of Bangladesh.Based on the taxonomic keys,majority of the species(about 82.4%)were identified as S.olivacea,while the remaining(about 17.6%)was S.serrata.In consistent to our preliminary analysis,both the univariate proportion and multivariate analysis of the collected morphometric lengths and ratios data also distinctly divided the mud crabs population into two multivariate spaces as S.serrata and S.olivacea.For the further analysis of the stock structure of these two species,data were subjected to the univariate ANOVA,multivariate ANOVA,Canonical Variate Analysis(CVA),and Principal Component Analysis(PCA)according to their collection sites.Scatter plots of CVA scores between CV1 and CV2 and PCA scores between PC1 and PC2 showed that the individuals of both species clearly made clusters into three multivariate spaces with minimum overlaps according to their collection sites.In morphometric traits Linear Discriminant Function Analysis(LDFA),the average percentage of correctly classified(PCC)into the original groups of the S.olivacea and S.serrata was 100%.For stock discrimination,the average PCC into their original groups of collection sites were 100%and 99%for the S.olivacea and S.serrata,respectively.Finally,dendrogram based on the Euclidean distances consistently separated S.olivacea and S.serrata and stock structures similar to other multivariate analyses.In conclusion,our study shows that S.olivacea is the dominant mud crab species and S.serrata is the minor one,and the stock discrimination of each species should be considered in the management and conservation policy of these species along the coastal region of Bangladesh.

Morphological characters of Botia lohachata

Objective:To provide complete and informative description on morphometric characters i.e.,relationships between length-weight(LWRs)and length-length and meristic characters of Botia lohachata from the Ganges River,Northwestern Bangladesh.Methods:Samples were collected occasionally using different fishing gears from July 2015 to June 2016.For each individual,total 15 lengths were taken using digital slide calipers and body weight was measured using an electronic balance with 0.01 cm and 0.01 g accuracy,respectively.The LWRs was estimated using the formula:W=a×L^(b),where W was the body weight(g);L was the length(cm)and,a and b were LWRs parameter.The meristic data were counted using magnifying glass.Results:A sum of 110 individuals of Botia lohachata were hardly collected.Total length was varied from 3.70-6.80 cm and body weight was ranged from 0.55 to 2.80 g.The LWRs were highly correlated(P<0.001)with r^(2)values greater than 0.961.The calculated overall allometric coefficient(b)indicated negative allometric growth pattern(b<3.00,P<0.001).In addition,all length-length relationships were highly significant(P<0.001)and most of the r^(2)values were greater than 0.950.The fin formula was-dorsal,D.10-11(2-3/8);pectoral,P_(c).8-10(4-6/4);pelvic,P_(v).8(2-3/5-6);anal,A_(n).6-7(2/4-5);and caudal,C_(a).20-22(6-8/14-16).Conclusions:The findings of the present study will keep a crucial contribution to fisheries scientist in favor of identification of this fish,stock assessment and sustainable conservation in the Ganges River of Bangladesh and adjoining countries.Also,these results will impart valuable information for the FishBase,as well as provide an important baseline for further studies.