Seasonal abundance and diversity of finfish in a tropical estuary, Karwar, southwest coast of India

The spatial and seasonal variability in finfish availability in the tropical Kali Estuary, in Karwar was studied from January 2017- May 2019 at three stations. A total of 26 species belonging to 9 orders and 20 families were recorded from the Kali Estuary and the order Perciformes with 16 species dominated the group (62%) followed by order Mugilliformes and Pleuronectiformes (8%). Maximum abundance was observed during the pre-monsoon season in all the stations. Excluding Ambassis ambassis which was abundant in all the stations, Caranx ignobilis dominated in all the stations. Truly marine and estuarine species of fishes recorded dominated than the freshwater estuarine ones like Etroplus suratensis, Scatophagus argus, Aplocheilus lineatus. Number of species recorded at each station during the study ranged from 11 to 25 and it was significantly different between stations. The Shannon- Wiener diversity index ranged from 2.0 to 4.6, the minimum in station 1 and maximum in station 3. The seasonal analysis of diversity also showed minimum value during the monsoon season in station 1 and maximum value in station 3. The minimum value (2.2) of Margalef richness index was also recorded in Station 1 during monsoon season and maximum value (4.2) in Station 2. When comparing the relative abundance using Pielou’s evenness index (J’) the values were in the range of 0.92 to 0.99 which was closer to one, indicating evenness in distribution. There was similarity in species composition according to different seasons except for monsoon season in Station 1. The same pattern was also evident in the MDS plot where seasonal aggregation was observed between the stations. In addition to the diversity studies, the surveys also threw light on the abundance and seasonality of candidate species suitable for mariculture like C. ignobilis, Lutjanus spp., Etroplus spp., etc. Judicious exploitation of the species could help brackishwater fish farmers

Abundance of natural fish seed resources prioritized for mariculture in the Kali estuary

Mariculture is a promising fish producing industry in India with cage farming of marine finfish and shellfish becoming popular along the entire coast. Fish seed availability is the need of the hour for sustaining and supporting expansion of cage farming of fishes in India. Capture Based Aquaculture (CBA), can be considered as an economic activity for fishermen communities to practise where by accessing natural fish seed resources for culture, it enhances the fish production, yield and market value

Cobia culture in low volume cages in coastal waters of Uttara Kannada, Karnataka

Cobia, Rachycentron canadum is a marine finfish globally favoured for aquaculture. In India, cage culture of cobia was first reported by ICAR-CMFRI in 2013 with better growth rate recorded under conditions of higher salinities (Philipose et al.2013). The present report is on the growth and production of cobia, Rachycentron canadum in Gangavali estuary (14o 61’ 225’’ N and 74 o35’726’’E) of coastal Karnataka during the period 2018-19

Brief note on infestation of Diplectanum sp. in Asian seabass

Recently open sea cage farming has emerged as an alternative and additional income source for fishermen and fish farmers in India. Asian seabass, Lates calcarifer is widely used in open sea cage culture due to its high market demand. In cage farming, high stocking densities and poor water quality enhance the parasite loads of the cultured fishes. In this study, 47 specimens of Asian seabass collected from cages located in Naganathwada, Sunkeri, Ankola were analysed with the aim of identifying the parasites prevalent among this species. All external and internal organs of each fish were examined separately under microscope for parasites. The collected monogenean parasites were washed in a 0.85% saline solution and fixed in 70% ethanol and identified. Most of the infected fishes had dark coloration of the body and postmortem findings revealed gills with excessive mucus secretion and sticking of the gill tips with greyish coloration

Argulus quadristriatus infestation in cage cultured Asian seabass

In Indian waters, genus Netuma is represented by two species namely N. bilineata and N. thalassina (Order: Siluriformes, Family: Ariidae). Rounded shout, thin lips, inconspicuous median longitudinal groove, and higher anal fin ray count (16-19) are characters of N. bilineata while N. thalassina has conical snout, clearly visible median longitudinal groove and lower anal fin ray count (13-15). Prior to the erection of N. bilineata (earlier considered as synonym of N. thalassina) as valid species, Indian workers had difference of opinion regarding the representation of species under this genus from Indian waters

Report on Amyloodinium spp. cysts infection in clownfish

A study was undertaken to record the occurrence of parasitic infections in ocellaris clownfish, Amphiprion ocellaris. Of a total eight A. ocellaris maintained in hatchery, three were found infected with different developmental stages of Amyloodinium spp. and were kept under observation

A simple and green synthesis of highly functionalized quinoline derivatives using zinc oxide nanoparticles

1548-1554A simple and one pot method has been designed for the synthesis of highly substituted quinoline derivatives using ZnO nanoparticles in aqueous medium by means of three component condensation reaction of aromatic aldehydes, malononitrile and substituted anilines via Knoevenagel condensation followed by Michael addition in water. This new method has many advantages over reported methods like easy work-up, operational simplicity and excellent yields with short reaction time