Elevated carbon dioxide levels in ocean waters, an anthropogenic stressor, can alter the chemical equilibrium of seawater through a process called ocean acidification (OA). The resultant reduction of ...pH can be detrimental during the early developmental stages of the commercially important edible Pacific oyster
Crassostrea gigas
; the ability of larvae to join a population is likely to be compromised by declining ocean pH. Given this threat, it is important to study the molecular mechanisms that these organisms use to overcome OA stress at the gene expression level. Here, we performed transcriptome profiling in oyster larvae following exposure to ambient (8.1) and reduced (7.4) pH during the pre-settlement growth period (i.e., 18 d post fertilization) using RNA-seq with Illumina sequencing technology. In total, 1,808 differentially expressed genes (DEGs) were identified, 1,410 of which were matched by BLAST against the Swiss-Prot database. Gene ontology classification showed that most of these DEGs were related to ribosomal, calcium ion binding, cell adhesion and apoptotic processes. Pathway enrichment analysis revealed that low pH (7.4) enhanced energy production and organelle biogenesis but prominently suppressed several immune response pathways. Moreover, activation of the MAPK signaling pathway was observed along with inhibition of the Wnt, VEGF, and ErbB pathways, highlighting the fact that the initiation of stress responses is given priority over larval development or shell growth when the larvae cope with low pH. In conclusion, our study demonstrated a unique gene expression profiling approach in studying oyster larval responses to OA, which not only provides comprehensive insights into the mechanisms underlying oyster tolerance to CO
2
-driven decreases in ocean pH but also supplies a valuable genomic resource for further studies in this species.
Fisheries and aquaculture have emerged as a promising food production sector at the global level as well as regional levels. Fish and fish products are produced in one region and then are traded ...across various parts of the world. The whole sector is dependent on chains of workers engaged at landing centres, breeding units, processing units, and the trade and export chains. When the pandemic and the subsequent lockdown hit the country, it affected the whole sector and caused a huge decline in the production and trade of fishing products. This article aims to have a glimpse into the aquaculture sector and evaluate the impact of the pandemic on this sector in India. This valuable information can be of great importance to government and aquatic food suppliers so that they can evolve their strategies to withstand ongoing and future pandemics. It also helps them in framing regional and sectorial adjustments to transform investment plans, match market demands, improve monitoring strategies and get prepared for future needs.
•The purpose of this article is to have a glimpse into the aquaculture sector and evaluate the impact of the COVID-19 pandemic on this sector in India.•This valuable information can be of great importance to the government and aquatic food suppliers so that they can evolve their strategies to withstand ongoing and future pandemics.•It also helps them frame regional and sectorial adjustments to transform investment plans, match market demands, improve monitoring strategies and prepare for future needs.•Some of the major challenges the entire fishing community faced during the COVID-19 lockdown are (i)difficulty in hiring truck drivers for transport of cargo.•(ii) Delayed seaweed seed material transportation.•(iii) Total shutdown of shrimp processing unit, forced engagement of minimal labour in shrimp feed, medicine and probiotics industries.•and (iv) Negative impacts on the livelihood of local fishermen due to fishing ban and low demand.•The paper also summarizes the reformations in the aquaculture sector in India to future pandemics.•Outbreak of COVID-19 has stimulated digital transformation across many aquaculture supply chain in India to reduce the dependence on manpower.•Scientific farming practices, the inclusion of technology and decreasing the over-dependency on export (around 90%) can recover the sector and can help take it to a desired level.
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