Diversification of shrimp farming with marine finfish in a farmer participatory research model was attempted. The study is intended to find an economically viable finfish culture during the fallow period of shrimp farms. The Silver pompano, Trachinotus blochi i intercropped with Pacific white shrimp, Litopenaeus vannamei culture in coastal shrimp ponds was assessed for growth, survival, and economic viability. During the grow-out period of 100 days, fishes grew from 40.23 ± 1.40 g to 256.56 ± 1.08 g in weight and 12.83 ± 0.19 cm to 25.11 ± 0.09 cm in length. The daily weight gain (DWG) and daily length gain (DLG) were 2.16 g/day and 0.12 cm/day, respectively. Relative growth rate (RGR) and specific growth rate (SGR) recorded for weight was 537.80% in 100 days and 1.85% per day, respectively. Pompano has exhibited its sturdiness and adaptability to the land-based culture system as evidenced by an overall survival percentage of 89.8% including nursery and grow-out phases. The realized feed conversion ratio was 1.94. The culture period of 100 days is found to be enough to attain a desirable harvest size of 250 g. The projected production potential of the experimental demonstration farm of 4500 m 2 water spread area for culture was 16.2 tonnes/cycle with a benefit-cost ratio (BCR) of 1.34 over operational cost. The present participatory trial empirically proved the viability of Silver pompano as an intercrop in coastal shrimp ponds. Thus, the introduction of Pompano in shrimp ponds is recommended and can be promoted for sustainable intercropping with shrimp farming along the Indian coast for improving people’s livelihoods.

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Mud spiny lobsters, Panulirus polyphagus (Herbst, 1793), were reared at four different stocking sizes and stocking densities in open sea cages to evaluate their effects on growth performance. To evaluate the effect of stocking size on the growth performance, the lobsters were segregated into four different treatment groups according to size and were stocked at a density of 300 animals per cage. To evaluate the effect of stocking density on the growth performance, lobsters of 81-100 g were stocked in four different stocking densities, i.e. 16/m 2 , 24/m 2 , 32/m 2 and 40/m 2 . The results showed that the growth rate of (60-80 g) size group, was significantly higher compared to the size groups, i.e. 101-120 g and 121-140 g comprising of larger individuals. The final body weight, though significantly higher in 81-100 g as compared to 60-80 g, the growth performance (i.e. weight gain percentage (WG %) and specific growth rate (SGR)) were not significantly different. The density-dependent influence on growth performance was evident in this study. The WG % and SGR during 90 days' culture period was significantly higher in 24/m 2 compared to other groups.This study provides crucial information about the appropriate stocking density and stocking size of lobsters at the field level, which would help to promote sustainable lobster cage farming by maximizing the production potential of the system. K E Y W O R D S capture-based aquaculture, mud spiny lobster, open sea cages, specific growth, weight gain 1 | INTRODUCTION Aquaculture of spiny lobsters has been viewed as one of the most suitable ways to relieve fishing pressure on lobster populations. However, hatchery rearing attempts have been largely unsuccessful due to the long, complex and delicate larval phases of the lobster (Cox & Johnston, 2003). The long whiskered rock lobster, Panulirus polyphagus, is a marine demersal carnivorous, gregarious crustacean species seen in the rocky bottom of murky marine waters (Booth & Kittaka, 2000). The cage farming of panulirid lobsters in Vietnam is one of the profitable industry and considered as a key economic activity of the country (FAO, 2016). This industry is expanding for the last 15 years with more than 25,000 number of sea cages utilized for P. ornatus fattening. However, fragmented information is available on the scientific cage farming of the species P. polyphagus. Environmental and water quality parameters, farming conditions and food availability are the main factors that affect lobster growth (Hazell, Cockcroft, Mayfield & Noffke, 2001; Johnston, Roy, Blair & Bruce, 2008). There are a few studies in India that provide information on the feasibility and growth of rock lobsters in open sea net cages (Radhakrishnan, 1995; Rahman