Ardavan Farhadi

Climate change is a global issue that requires immediate attention. In order to achieve carbon neutrality as outlined in the Paris Agreement of 2015, in addition to reducing carbon dioxide (CO₂) emissions, promoting blue carbon sinks is equally important. Fishery carbon sink (FCS), especially from bivalve aquaculture, have received increasing attention as bivalves not only store carbon in their flesh and shells, but also promote carbon storage in the aquaculture environment. Unlike previous studies that focused on localized assessments or used outdated carbon budget models, this study was conducted to analyze the trend of fishery carbon sinks from bivalve aquaculture in China (the largest producer of farmed bivalves) over the past two decades using the refined carbon budget model that integrates both carbon removal (flesh and shells) and carbon storage (biodeposits and excretion). In general, the results of this study revealed that the contribution of bivalve aquaculture to FCS has increased significantly with rising bivalve production. Oysters and clams are the most farmed bivalves, with Shandong and Fujian provinces being the largest farmed bivalve producers. From 2004 to 2023, bivalve aquaculture in China contributed to 15 million tonnes of net carbon sink, and is expected to produce over 1 million tonnes of net carbon sink per year from 2024 onwards. The findings of this study not only advance our knowledge of the current trend of FCS in China, but also provide important information to promote the development of carbon trading.

Pontastacus leptodactylus is a freshwater crayfish native to the Ponto‐Caspian region, with a distribution across Eastern Europe and Western Asia. This review synthesizes current knowledge on the biology, culture development, and prospects for sustainable aquaculture of P. leptodactylus . Commercial exploitation of P. leptodactylus has a long history in Western Europe and the Ponto‐Caspian region and has relied primarily on capture fisheries. Türkiye served as the principal exporter to international markets until the 1985 outbreak of crayfish plague ( Aphanomyces astaci ), which precipitated widespread stock collapses. In contrast, aquaculture development remained limited for decades and has only recently gained momentum, particularly, in China. Following the first identification of P. leptodactylus in China in 2021, interest in its culture has increased, with pilot‐scale farming trials and localized hatchery activities reported across several provinces. However, production remains limited in scale, and these developments are best regarded as early‐stage or proof‐of‐concept initiatives rather than established commercial aquaculture. Accordingly, this review provides an integrated appraisal of culture practices, including broodstock management, artificial incubation, juvenile feeding, stocking strategies, grow‐out systems, and health and biosecurity protocols. It further synthesizes market dynamics, value‐chain development, and welfare considerations alongside performance benchmarks. Key constraints such as the lack of species‐specific feeds, limited tools for cannibalism mitigation, and the absence of selective breeding programs are identified as major barriers to sustainable scale‐up. This review offers a framework to guide future research, management decisions, and aquaculture development for the sustainable utilization of P. leptodactylus .

Bivalves are an important alternative source of natural dietary source of unsaturated fatty acids for humans. Although many meta-analysis studies have shown that climate change drivers, especially ocean warming and ocean acidification, can affect the lipid nutritional quality of bivalves, very little is known about how changes in oceanic dissolved oxygen (DO), another important driver of climate change, influence the lipid nutritional quality of bivalves. In this context, this study aims to investigate the effects of climate change-induced dissolved oxygen changes on the lipid nutritional quality of bivalves through a meta-analysis. The impact of changing DO on bivalve nutrition varies by region and species. Generally, lower DO levels negatively affect lipid quality in tropical species but can improve it for temperate species. Subtropical species show a mixed response, where a small DO decrease is detrimental but a large one can be beneficial. Oysters are an exception, as their lipid quality declines under low DO in all regions. The findings of this study not only fill the knowledge gap regarding the effects of climate change on the lipid nutritional quality of bivalves but also provide important guidance to bivalve aquaculturists and farm managers in formulating management strategies for both bivalve aquaculture and fisheries.

Human-induced salinity changes are known to affect bivalve lipid quality, yet existing information remains poorly organized. In this context, this study investigates how salinity changes influence lipid quality in bivalves. The results revealed that salinity changes significantly alter bivalve lipid quality, with responses varying by bivalve family and climate zone. In mussels, lipid quality was inversely correlated with salinity shifts in tropical regions but positively correlated in subtropical regions, and unpredictable in temperate regions. In clams, a negative correlation between lipid quality and salinity shifts was observed in both subtropical and temperate regions. For scallops in temperate regions, substantial salinity reductions lead to poor lipid quality. In oysters, tropical species exhibit reduced lipid quality even with minor salinity increases. For cockles, no specific trend was observed. This research offers novel insights into the bivalve family- and region-specific effects of salinity changes on bivalve lipid quality, offering evidence-based guidance for more sustainable aquatic resource management and commercial bivalve aquaculture.

In recent decades, the decapod aquaculture industry has grown significantly in many parts of the world. Despite this progress, production levels still fall short of market demands, indicating a need for further efforts to increase the production. Investigations into the molecular mechanisms underlying embryonic development in decapods provide valuable insights into the complex embryonic development processes of this economically and ecologically important animal group. In this review, we explore the molecular mechanisms underlying decapod embryonic development, focusing on key genes, signaling pathways, and microRNAs (miRNAs) involved in the embryogenesis. Numerous genes have been identified that regulate various aspects of embryogenesis including egg activation, maternal‐to‐zygotic transition (MZT), mesoderm development, segmentation, nervous system development, sex determination, germline development, and exoskeleton formation. We also discuss the pivotal role of signaling pathways such as Hedgehog, Wnt, Notch, MAPK, TGF‐β, Jak‐STAT, VEGF, and Ecdysteroid in the regulation of embryogenesis. Additionally, this review identifies current research gaps in decapod embryogenesis and proposes directions for future investigation. This review is anticipated to be especially beneficial for researchers delving into the molecular mechanisms driving embryonic development in decapods.

Editorial: Sex determination and developmental mechanism of crustaceans and shellfish, volume II