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Mariculture, a sustainable and rapidly growing aquaculture sub-sector, meets global seafood demand while reducing strain on wild fish stocks and continues to expand worldwide. However, rising feed and seed costs pose significant challenges, overshadowing other farming expenses. Climate change exacerbates the profitability of sea cage farming, increasing volatility. The surge in fishmeal costs has a detrimental impact on operational expenditure (Opex) and continues to be a threat. Consequently, sea cage farming in India is at a critical juncture, needing a balance between technological advancements and stakeholders' fiscal needs. In this context, this study examines peer-reviewed synthesized data by employing metrics to evaluate the implications of feed and seed costs in Asian Seabass (Lates calcarifer) sea cage farming over a 10-year horizon. The total sales revenue over the 10-year period was US $100,848, with a net profit of US $55,198.89. A 30% increase in feed and seed prices significantly altered the economic dynamics of the enterprise, leading to an 8.8 and 9.2% rise in the respective break-even points. There was also a significant effect on the Benefit–Cost Ratio (BCR), with a 30% increase in each factor resulting in a 10 and 18% change in the projected BCR, respectively. Therefore, the significance of feed and seed cost has been established, necessitating an inevitable shift from low-value fish to formulated feed adaption for sustainable mariculture development. The study suggests improvements to existing practices to maximize efficiency and minimize production costs. [ABSTRACT FROM AUTHOR]

Orange-spotted grouper, ideal finfish for mariculture, is constrained by the non-availability of sufficient seeds due to lower inconsistent larval survival. The present study attempted to establish a reliable larval rearing technique. Larvae fed with un-enriched or enriched rotifers (screened or unscreened) did not survive beyond 13 days post-hatch (DPH). Subsequently, copepod (Parvocalanus crassirostris) nauplii were supplemented at 0, 1, 2, 3 and 4 ml-1, in addition to enriched and screened rotifers, with live feed density of 12 ml-1, and this resulted in significantly improved survival at first feeding. Significantly higher (39.2%) larval survival on 16 DPH, with minimal size heterogeneity (13.13%), was observed in the group fed a combination of 2 copepod nauplii and 10 rotifers ml-1. However, mass mortality was observed between 18 and 21 DPH; and consequently, adult P. crassirostris were supplemented at 0, 0.25, 0.5, 0.75 and 1 ml-1 from 16 DPH along with rotifers, Artemia nauplii and artificial feed. Significantly higher larval survival on metamorphosis (40 DPH) was observed in the groups fed with 0.75 (17.71%) and 1 ml-1 (19.50%) P. crassirostris. Larval rearing protocol, with an average survival and length up to metamorphosis of 18.14% and 29.83 mm, respectively, during eleven cycles was developed. With consistent enhanced larval survival, the present study would facilitate mass scale seed production. [ABSTRACT FROM AUTHOR]

Copepods of genus Acartia are considered as efficient live feeds for marine fish larviculture. A few reports are already there on production and storage for eggs of few temperate species of Acartia. Present study evaluated the storage potential of eggs of a tropical calanoid copepod, A. tropica. Different conditions examined were higher salinity storage (40–200 ppt) at room temperature, cold storage (4ºC) at different salinities (15–200 ppt), cryoprotectant solutions (methanol, glycerol) and antibiotic solutions (kanamycin, oxytetracycline). Results showed that higher salinity storage (50–200 ppt) could not retain egg viability under cold storage, as well as normal temperature conditions. The eggs exposed to cold storage and lower salinities (15–40 ppt) for 24 h survived with highest egg‐hatching success (EHS, %) recorded at 15 ppt (69.44 ± 8.12). The condition was not efficient to retain egg viability beyond 24 h. The addition of certain cryoprotectants and antibiotics to the storage media significantly improved the survival of A. tropica eggs after 48 h storage. In the cryoprotectant treatments highest EHS after 48 h storage was recorded at 1M Glycerol (41.27 ± 6.34). Amongst the antibiotic treatments highest EHS after 48 and 72 h of storage were recorded at 100 ppm Kanamycin (46.79 ± 10.33, 2.67 ± 0.35) and 50ppm Kanamycin (43.86 ± 12.81, 1.73 ± 0.27), respectively. A drastic reduction in egg viability was recorded after 48 h and the antibiotics and cryoprotectants examined were not efficient to retain egg viability beyond 72 h. Hence the conditions examined in the present study could retain the viability of A. tropica eggs maximum up to 72 h and were not sufficient to induce long term quiescence in A. tropica eggs. [ABSTRACT FROM AUTHOR]

The present study provides the complete report on the embryonic and larval development of pink ear emperor, Lethrinus lentjan (Lacepede, 1802). Eggs were obtained from captive‐reared broodstock of pink ear emperors from 1‐year of age maintained in a 10‐tonne recirculating aquaculture system (RAS). The brood fishes spawned throughout the year without hormonal induction. Fertilized eggs (692.65 ± 6.67 µm) were pelagic, transparent, non‐adhesive and with a single oil globule measuring 146.63 ± 3.51 μm. Description of the different phases of embryogenesis, namely the zygote, cleavage, blastula, gastrula, segmentation of the fish is provided. Additionally, the developments during larval development period after hatching, which extends till the completion of yolk‐sac absorption (pre‐larvae) and the end of metamorphosis (post‐larval) are also included in the present study. The embryonic development was completed within 14 h 40 min after fertilization. The newly hatched larvae had an average body length of 1.39 ± 0.08 mm, with a yolk sac measuring 787.67 ± 42.65 µm. The mouth opening was observed at 2 days post‐hatch (dph). The yolk sac was completely absorbed by 2 dph, and the preflexion stage began, and it continued till 14 dph. Notochord flexion began by 15 dph and extended to 20 dph. The appearance of the typical adult colouration and scale formation started by 22 dph and by 35 dph the larvae reached the juvenile stage. The data on the embryonic and larval development will help to standardize the larval rearing techniques for the species. [ABSTRACT FROM AUTHOR]

Keywords: compensatory growth; Snubnose pompano; stunting; Trachinotus blochii EN compensatory growth Snubnose pompano stunting Trachinotus blochii 403 409 7 12/23/20 20210101 NES 210101 Compensatory growth has been reported in stunted fish by several researchers, and the same has been applied at field level for enhancing the fish production. During stunting phase, the size variation was more prominent in stunted fish than normal fish, whereas it registered a reverse trend during post-stunting phase wherein the size variation was lesser in stunted fish than normal fish. The 90 days stunting study reveals that the growth retarded fish could fully regain the growth when adequately fed, since the final weight and SGR/day % at the end of the poststunting rearing were higher in stunted fish than the normal fish. The FCR at the end of the experiment was slightly higher in the case of 30 days stunted fish, whereas in 60 days stunted fish, it was slightly lower and in 90 days stunted fish it was only half of normal fish (Tables 2-4). [Extracted from the article]

Lobsters are one of the premium ocean resources and a highly sought-after seafood commodity globally. The increasing demand for spiny lobsters in both domestic and international markets has led to a growing interest in mariculture as a means of meeting demand. Capture-based mariculture (CBM) by the coastal communities is the only way to cater the existing demand. However, there is scant published information and continued ambiguity on the viability of spiny lobster aquaculture in the Indian subcontinent and a similar gap exists in countries engaged in lobster fattening. Thus, to bridge the gap between the viability information and CBM stakeholders, we examined the profitability and economic performance of mud spiny lobster, Panulirus polyphagus , production in open sea farming systems, specifically sea cages. Our analysis focused on economic indicators such as input costs and return value. We found that the estimated annual revenue for a single operation was USD $3605.04, with an internal rate of return (IRR) of 33% and a net present value (NPV) of USD $1226.17, demonstrating profitability. Despite this, certain bottlenecks such as limited seedstock and feed availability and cost concerns, disease management issues, regulatory complexities, market demand fluctuations limit the expansion of the industry beyond a certain threshold. This study provides useful information for enterprise building and developing better strategies for building food security and supporting traditional communities-oriented commercial lobster farming in India, and potentially in other lobster farming nations as well. • Growing demand for spiny lobsters drives interest in mariculture as a solution. • The revisited economic indicators showed annual revenue of USD $ 3605.04 with net profit USD $ 1226.17. • Wild seed limitations for larger-scale mariculture impede business growth. • Lobster marine cage farming shows potential for profitability and sustainable livelihood. • Study bridges technological gap between the economic sustainability of lobster farming and stakeholder. [ABSTRACT FROM AUTHOR]

Spawning and successful rearing of larvae of honeycomb grouper Epinephelus merra Bloch 1793 upto juvenile stage was accomplished at the finfish hatchery of Mandapam Regional Centre of Central Marine Fisheries Research Institute during 2004. The fertilized eggs were free, spherical and buoyant with size ranging from 710 to 730 μm. Complete early embryonic development took place within 24-27 h and hatching occurred. The hatchlings measured 1.5 mm. Mouth opening (115 μm) appeared at 72 h when the larvae were 2.2 mm in size. Pectoral fin developed on the fifth day. Complete metamorphosis took place and by the 60th day the larvae transformed into juveniles (45 mm) and attained skin colouration and honeycomb pattern. [ABSTRACT FROM AUTHOR]

The blue economy, encompassing sustainable utilization of coastal and oceanic resources, has gained global significance in the context of the developing discourse on economic growth and environmental conservation in ocean-based economies. This article delves into the multifaceted realm of India's fisheries and coastal aquaculture sectors, exploring their status, challenges and prospects through the lens of the 'blue growth' narrative. Various enabling factors, such as technological advancements, governance improvements, market and policy incentives, and investment strategies are discussed that can catalyse a smooth transition of India's marine capture fisheries and aquaculture to align with the blue developmental agenda. [ABSTRACT FROM AUTHOR]