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Females of Scylla serrata attained sexual maturity after reaching 80 mm carapace width and above. Fifty per cent of females at size range 91-100 mm carapace width were sexually mature. The growth rate of abdomen width or length with respect to either carapace width or length was generally at much higher side in mature females than in the immature specimens. A sharp transition at 80 mm carapace width indicated the morphological changes accompanied with the sexual maturity. The relationship between abdomen allometry and carapace measurements was highly significant (P

Rajasree chakraborty, priya prasad, Shantanu Kundu, inderjeet tyagi & Kailash chandra the complete mitochondrial genome of Lyrognathus crotalus is sequenced, annotated and compared with other spider mitogenomes. It is 13,865 bp long and featured by 22 transfer RNA genes (tRNAs), and two ribosomal RNA genes (rRNAs), 13 protein-coding genes (PCGs), and a control region (CR). Most of the pcGs used Atn start codon except cox3, and nad4 with ttG. comparative studies indicated the use of ttG, ttA, ttt, GtG, ctG, ctA as start codons by few pcGs. Most of the tRnAs were truncated and do not fold into the typical cloverleaf structure. further, the motif (cAtAtA) was detected in cR of nine species including L. crotalus. the gene arrangement of L. crotalus compared with ancestral arthropod showed the transposition of five tRNAs and one tandem duplication random loss (TDRL) event. Five plesiomophic gene blocks (A-E) were identified, of which, four (A, B, D, E) retained in all taxa except family Salticidae. However, block c was retained in Mygalomorphae and two families of Araneomorphae (Hypochilidae and Pholcidae). Out of 146 derived gene boundaries in all taxa, 15 synapomorphic gene boundaries were identified. TreeREx analysis also revealed the transposition of trnI, which makes three derived boundaries and congruent with the result of the gene boundary mapping. Maximum likelihood and Bayesian inference showed similar topologies and congruent with morphology, and previously reported multi-gene phylogeny. However, the Gene-Order based phylogeny showed sister relationship of L. crotalus with two Araneomorphae family members (Hypochilidae and pholcidae) and other Mygalomorphae species. The order Araneae is classified into two infra-orders Mesothelae (primitive spiders) and Opisthothelae (modern spiders). The infra-order Opisthothelae is further classified into two suborders Mygalomorphae and Araneomorphae with 117 families. The family Theraphosidae belongs to suborder Mygalomorphae of infra-order Opisthothelae with 992 species. Out of 992 species, 52 species are known from India 1. The members of family Theraphosidae are commonly known as tarantulas or giant spiders for their huge body size. These giant spiders play an important role in controlling the insects 2 and also predators on vertebrates and invertebrates 3. The venom of these tarantulas is the main source of pharmacological research 3. The Pet trade of tarantulas across the globe is in great demand due to their body size, attractiveness, longitivity and for economic point of view 4. So far, 13 species in three genera (Poecilotheria, Thrigmopoeus and Lyrognathus) from India have been reported in the pet trade 4. The species Lyrognathus crotalus is endemic to India restricted to northeast region and frequently traded. The correct identification of these tarantulas is the basic need due to their economical and medicinal values and involvement in the pet trade. However, identification of species in the absence of well-preserved specimens is not possible through morphology ...

Spiders are mega diverse arthropods and play an important role in the ecosystem. Identification of this group is challenging due to their cryptic behavior, sexual dimorphism, and unavailability of taxonomic keys for juveniles. To overcome these obstacles, DNA barcoding plays a pivotal role in spider identification throughout the globe. This study is the first large scale attempt on DNA barcoding of spiders from India with 101 morphospecies of 72 genera under 21 families, including five endemic species and holotypes of three species. A total of 489 barcodes was generated and analyzed, among them 85 novel barcodes of 22 morphospecies were contributed to the global database. The estimated delimitation threshold of the Indian spiders was 2.6% to 3.7% K2P corrected pairwise distance. The multiple species delimitation methods (BIN, ABGD, GMYC and PTP) revealed a total of 107 molecular operational taxonomic units (MOTUs) for 101 morphospecies. We detected more than one MOTU in 11 morphospecies with discrepancies in genetic distances and tree topologies. Cryptic diversity was detected in Pardosa pusiola, Cyclosa spirifera, and Heteropoda venatoria. The intraspecies distances which were as large as our proposed delimitation threshold were observed in Pardosa sumatrana, Thiania bhamoensis, and Cheiracanthium triviale. Further, shallow genetic distances were detected in Cyrtophora cicatrosa, Hersilia savignyi, Argiope versicolor, Phintella vittata, and Oxyopes birmanicus. Two morphologically distinguished species (Plexippus paykulli and Plexippus petersi) showed intra-individual variation within their DNA barcode data. Additionally, we reinstate the original combination for Linyphia sikkimensis based on both morphology and DNA barcoding. These data show that DNA barcoding is a valuable tool for specimen identification and species discovery of Indian spiders.

A new species – Theridion odisha sp.n. – is described from Odisha state, India. An updated checklist of Theridion species known from India with taxonomic remarks is enlisted and mapped. Two new combinations are also proposed, Nihonhimea indicum (Tikader, 1977) comb.n., ex Theridion and Nihonhimea tikaderi (Patel, 1973) comb.n., ex Theridion. Nihonhimea indicum (Tikader, 1977) is considered a senior synonym of Parasteatoda brookesiana (Barrion & Litsinger, 1995).