National Institute of Oceanography, India

About: National Institute of Oceanography, India is a facility organization based out in Panjim, Goa, India. It is known for research contribution in the topics: Monsoon & Population. The organization has 4713 authors who have published 6927 publications receiving 174272 citations.

Alloimmune maturation in the coral Stylophora pistillata is achieved through three distinctive stages, 4 months post–metamorphosis

Abstract: Adult colonies of the reef–building coral Stylophora pistillata discriminate precisely between ‘self’ and ‘non–self’ attributes and respond selectively against specific allogeneic challenges. We studied the ontogeny of these allospecific responses on newly settled polyps by establishing allogeneic contacts within groups of 2–6 siblings or non–related offsprings. Interactions were observed for up to 8 months. Three types of responses, depending on the age of the interacting partners, were documented. The first was tissue fusion and the formation of a stable chimera, observed in partners less than 2 months old. The second was observed in contacts of partners 2–4 months old. It started with tissue fusion and transitory chimera since separation of the chimera–partners or polyp death resulted when the oldest partner in the chimera reached the age of 4 months. The third type was the regular histoincompatibility response, as documented in allogeneic interactions of adult colonies, recorded here in all encounters with S. pistillata partners over 4 months old. Maturation of allorecognition in this species was therefore achieved through three time–dependent stages, 4 months following metamorphosis. Combinations of siblings or genetically unrelated partners did not affect the results. We propose that the coral alloimmune maturation system may be used as a new evolutionary model scheme for studying tissue transplantation and tolerance.

Accumulation of sediment, organic matter and trace metals with space and time, in a creek along Mumbai coast, India

Abstract: Two core sediment samples; one from inner part (ManI) and the other closer to the mouth (ManII); were collected from the intertidal regions of Manori, a tidally influenced creek near Mumbai, India. Both the cores were subjected to various geochemical analyses to determine parameters such as pH, sediment components, total organic carbon, total nitrogen, total phosphorus and selected metals viz., Fe, Mn, Cu, Pb, Co, Ni, Zn, Cr, Al, Ca and V. Analysis of 210Pb activity was employed to assess the sediment deposition trend of the area. The data was further processed using factor and cluster analyses. The results indicate that the sediments from site ManI, had finer sediment composition, higher porosity, organic matter and metal contents but exhibited an erratic decline in 210Pb activity downcore. Also ManI showed higher C:N ratio and enrichment factor values as compared to site ManII. The inner area (ManI) probably received a greater input of organic matter from the erosion of terrestrial matter as well as domestic and industrial discharge. Sediments from site ManII had typical marine organic matter composition (lower C:N ratio). The concentration of metals at this site was also low indicating the contents were getting diluted by freshwater and seawater mixing.

Growth enhancement and muscle structure of striped mullet, Mugil cephalus L., fingerlings by feeding algal meal‐based diets

Abstract: This study was conducted to evaluate algae meal as an inexpensive and locally available feed ingredient in the supplementary diet of striped mullet, Mugil cephalus L. Four 40%-protein diets (D1–D4) containing 10, 15, 20 and 25% Ulva meal were tested to determine the proper incorporation level for best growth and utilization. A fifth test diet (E) containing 40% dietary yeast enriched with vitamin E was further investigated. Mullet fingerlings (6.4 ± 0.5 g) were stocked into 12 1 m3 net cages fixed in an earth lined pond, at a rate of 15 fish per cage, and were fed the test diets twice a day at 4% of biomass for 15 weeks. Two cages were used for each dietary treatment, except for the control group, which did not receive any feed. Performance of fish fed the five test diets was evaluated for final mean weight, percent weight gain, specific growth rate, survival, feed conversion ratio, protein efficiency ratio and proximate composition. Results indicated that the best weight gain and feed efficiency were obtained from fish fed the 20% dietary Ulva meal (diet D3), as well as the yeast-based diet enriched with vitamin E (diet E). In addition to growth enhancement, using these feeds (D3 and E) resulted in improved muscle quality and firmness, as shown from the examination of fish muscle ultrastructure by electron microscopy at the end of feeding trial.

Nitrogen-limited mangrove ecosystems conserve N through dissimilatory nitrate reduction to ammonium

Abstract: Earlier observations in mangrove sediments of Goa, India have shown denitrification to be a major pathway for N loss1. However, percentage of total nitrate transformed through complete denitrification accounted for <0–72% of the pore water nitrate reduced. Here, we show that up to 99% of nitrate removal in mangrove sediments is routed through dissimilatory nitrate reduction to ammonium (DNRA). The DNRA process was 2x higher at the relatively pristine site Tuvem compared to the anthropogenically-influenced Divar mangrove ecosystem. In systems receiving low extraneous nutrient inputs, this mechanism effectively conserves and re-circulates N minimizing nutrient loss that would otherwise occur through denitrification. In a global context, the occurrence of DNRA in mangroves has important implications for maintaining N levels and sustaining ecosystem productivity. For the first time, this study also highlights the significance of DNRA in buffering the climate by modulating the production of the greenhouse gas nitrous oxide.