Patterns of copepod -appendicularian distribution were studied along the Mangalore coastal waters (12°50'49" N; 74°48'50" E) of the Arabian Sea to understand the food and feeding relationship existing among these groups. Sampling was conducted during premonsoon, monsoon and post-monsoon extending from January 2009 to December 2010. The copepod and appendicularian community was sampled with a 60 µm net to include the smallest species and their developmental stages. Copepod biomass, especially calanoids, was substantially high throughout the study. Seasonal mean results showed that the small-sized copepods (calanoids, harpacticoida and cyclopoids) dominated in terms of biomass and production. Calanoids found in abundance included Acartia, Centropages, Calanus, Eucalanus and Labidocera. Cyclopoid and Harpacticoid copepods genera dominated included Oithona, Oncaea and Microsetella, Macrosetella. Appendicularian species diversity was represented by Oikopleura fusiformis, O. dioica and its juveniles represented as Oikopleura sp. Total chlorophyll (chlorophyll a) ranging between 10 and 20 mg m -3 indicated the eutrophic state as well as productivity prevailing during the study period. Principal component analysis (PCA) indicated the routine and opportunistic seasonal grazers and establishes a phytoplankton -appendicularia -copepod -fish food chain relationship along Mangalore coast.

DOI: 10.15835/nsb13110862 Cephalopods are ecologically and economically important marine groups in the world. Biodiversity description is essential for sustainable utilization of natural resources and to characterize biological entities for conservation. DNA barcoding is an effective tool used for identification of organisms at species level and is been widely used for delineate several ambiguity species. In this study, partial sequence of mitochondrial cytochrome c oxidase 1 (CO1) gene with a mean size of 680 bp was amplified by universal primers. Totally 13 individuals of Cephalopods comprising of three species, were barcoded and genetic variation was analysed. The maximum A+T content (67.60%) was recorded in Cistopus indicus and minimum (63.70%) in Sepioteuthis lessoniana. The maximum K2P distance (0.268) was found between the genus Cistopus and Sepioteuthis whereas the minimum distance (0.188) was observed between Uroteuthis and Sepia. The neighbour joining tree revealed three distinct clades represents Loligonidae, Sepiidae and Octopodidae with high boot strap values. However, Sepioteuthis lessoniana is showing a bifurcated branch and it may due to the co-occurring of cryptic species and till date this species is treated as Sepioteuthis lessoniana complex.

Morphology of the marine egg bearing cyclopoid copepod Oithona similis occurring along the southwest coast of India [Vizhinjam (8º21'56"N; 76º59'39"E), Neendakara (8º57'29"N; 76º31'13"E), Cochin (9º56'16"N; 76º13'55"E) and Calicut (11º13'33"N; 75º46'30"E)] from January to December 2010 at different seasons (pre monsoon, monsoon and post monsoon) were studied. Detailed comparison of the structure of different appendages of O. similis with those already available for the species from Norway, Japan, China, Spain and Russia revealed minute differences in the armature of appendages, number and arrangement of spines, setae of swimming legs and anal laminae. The total length of the specimen collected from all the four stations in the study ranged from 615 to 650μ. The smallest specimens were obtained from Calicut.

Chitosan is a characteristic polysaccharide, naturally extracted from the crustacean’s shells. The stability and shelf-life of chitosan are affected by a few parameters, basically the moisture content. In this study, three species of shrimps such as Indian white shrimp (Fenneropenaeus indicus), banana shrimp (F. merguensis), and tiger prawn (F. monodon) were utilized for the extraction of chitosan. The extraction strategy included the method of demineralization, deproteinization, and deacetylation. Later the yield and moisture of chitosan were examined from three diverse species. The yield of shell waste ranged between 46% to 50% (on moist weight premise) and the chitosan was between 18.0 to 20.2%. Moisture content always plays a critical part in chitosan shelf life and stability and was between 5.2% to 6.8 %.