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A new species of potamid freshwater crab of the genus HimalayapotamonPretzmann 1966 is described here on the basis of several specimens collected from different localities in Poonch district, in Jammu province of Jammu and Kashmir, India. The new species Himalayapotamon jammuensecan be differentiated from its congeners by a suite of carapace (i.e., postorbital cristae) and gonopod (first and second) characters. In addition, molecular evidences derived from two mitochondrial gene (16srRNA and cox1) and one nuclear gene (28srRNA) supported the morphological findings. Genetically, H. jammuenseis sister to clade containing H. robertsianum(Pakistan) and H. koolooense(Punjab) which are found in close proximity to Jammu and Kashmir. Moreover, genetic distance inferred for the gene 16srRNA significantly support the species described in the study as a new species.

The science of cytogenetics deals with the structure and behavior of chromosomes during the mitotic and meiotic division of cells. Chromosomal studies have received significant attention over the past few years, especially in the disciplines of Karyology and Cytogenetics. Animal species provide a vital contribution to the knowledge of chromosome evolution. The species studied during the present investigation possessed 2n = 74 chromosomes and the karyotypic formula of Himalayapotamon emphysetumwas found to be 2n = 46 m + 10sm + 6st + 12t. Meiosis was observed to be normal and thirty-seven bivalents in the form of rings were observed during diakinesis. The individual chromosomes in the Karyotype were identified by using NOR-banding method. The data generated during the present study adds great knowledge to the karyosystematics of the crab species and will help understand interrelationships among the different crab species and also aids in undertaking hybridization programmes. Data related to the karyotypic features is considered a pre-requisite for genomic studies.

The genus Macrobrachium, despite having immense nutritional, medical, and ornamental importance, is least explored cytogenetically. One of its species M. kistnensefrom J&K is an eligible candidate for commercial culturing and can enhance the dietary protein content and economic standard of local inhabitants. There is no previous record of chromosome number and karyotype of this species. Therefore, in the present study, the diploid number and karyotypic characteristics of M. kistnensewere worked out by using conventional Giemsa staining and chromosome banding techniques. The diploid chromosome number was found to be 2n= 74 with karyotypic formula (54m + 14sm + 4st + 2t). The characteristic banding patterns were also obtained after Ag- NOR and G-banding. The present study will aid to solve taxonomic ambiguities within the family Palaemonidae and also in general understanding of the course of evolution in order Decapoda.

In the present investigation, genetic polymorphism and variability in seven natural populations of Himalayan prawn Macrobrachium dayanumwere assessed by polymerase chain reaction (PCR) based two molecular techniques viz., ISSR and RAPD. Genomic DNA of each sample was isolated by Phenol–chloroform method. Genotyping by selective ISSR and RAPD markers revealed high level of genetic variability among seven populations depicted by 86.9% and 96.2% polymorphism respectively. The combined results of two molecular marker assays disclosed that populations of Nagri and Chadwal streams were genetically closest having highest values of Jaccard similarity (0.419) and Nei & Li coefficient (0.591) whereas the populations of Chadwal and Sai streams were genetically least related with lowest values of Jaccard similarity (0.206) and Nei & Li coefficient (0.342). Cluster analysis by UPGMA dendrograms revealed that seven populations of M. dayanumwere distributed into two major groups which were further divided into sub-groups. The principal coordinate analysis was consistent with the UPGMA Clustering of the populations. Overall, the population of Kheri stream was found to be quite distinct from rest of six populations. The findings of present communication will serve for the sustainable conservation program of the Himalayan prawn and selection of its desired populations having higher genetic variability to withstand adverse conditions for future venture of commercial prawn culturing in the rural areas of Himalayas. In addition, the results of current study set a stage to evaluate the reasons for lesser genetic diversity of the studied species in some of the streams of Jammu and the way forward to improve the status of these lotic ecosystems to enhance the genetic polymorphism in M. dayanum.