The hard-shelled mussel (Mytilus coruscus) is an economically important shellfish, which has been cultivated for the last decade. Due to over-exploitation, most mussel stocks have dramatically declined. Efforts to study this species' natural distribution, genetics, breeding and cultivation have been hindered by the lack of a high-quality reference genome. To address this, we produced a hybrid high-quality reference genome of M. coruscus using a long-read platform to assemble the genome and short-reads, high-quality technology to accurately correct for sequence errors. The genome was assembled into 10,484 scaffolds, a total length of 1.90 Gb and a scaffold N50 of 898 kb. Ab initio annotation of the M. coruscus genome assembly identified a total of 42,684 genes. This accurate, reference genome of M. coruscus provides an essential resource with the advantage of enabling the genome-scale selective breeding of M. coruscus. More importantly it will also help the deciphering of the speciation and local adaptation of the Mytilus species.

Three salinities (4‰, 12‰ and 25‰) were selected to determine the effects of different salinities on the growth, survival, nutrition and energy metabolism of Scylla paramamosain during indoor overwintering. Growth performance (survival rate, condition factor, hepatopancreatic index, weight gain rate and specific growth rate), nutrient composition (ash, moisture, crude fat, crude protein and total nitrogen), fatty acids, energy metabolites (glycogen, glucose, triglycerides, cholesterol and lactic acid) and energy metabolic enzymes (hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase) were measured and calculated. The results showed that S. paramamosain exhibited the best growth and survival at 25‰ and worst at 4‰ after overwintering. In addition to consuming crude fat, excess protein was also broken down to provide energy in the 4‰ and 12‰ groups. The content of unsaturated fatty acids in the 25‰ group was higher after overwintering. Glycogen and glucose consumption and triglycerides, cholesterol and lactic acid production were lowest in the 25‰ group. The activity of hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase was highest in the 4‰ group and lowest in the 25‰ group. The activity of hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase in the hepatopancreas was higher than in the muscle. In conclusion, S. paramamosain uses less energy, has more unsaturated fatty acids and has a higher survival rate at a salinity of 25‰ after overwintering. The results of this study provide helpful information the indoor overwintering S. paramamosain in aquaculture production systems.

By the search for new natural compounds with beneficial health effects, cephalopod ink has been considered as an attempt to develop new drugs and functional foods, which is an especially active field in Asia, where cephalopods are a major fishery catch, for which ink sacs are a bi-product and where homeopathic medicine has deep roots. There is a demand to evaluate the safety and influence to the organism. The specific composition and relative abundance of the gut microbiota, which is potentially a major modulator of host metabolism, drives the interaction between functional foods and host health. We explore the effects of melanin from Sepiella Maindroni, most common cuttlefish in China, on the intestinal microbiome of mice. ICR mice were randomly divided four groups, which were normal group (S), low melanin dose group (D; 120 mg/kg), medium melanin dose group (Z; 240 mg/kg), and high melanin dose group (G; 480 mg/kg). Melanin was delivered for 28 consecutive days. Fecal samples were used to generate 7715 operational taxonomic units (OTUs) via high-throughput sequencing. There were significant shifts in relative abundance of the dominant taxa at the phylum, class, order, family, and genus levels following melanin treatment. MSMI had no significant effect on the structure of intestinal flora in mice. The main effect was in the proportion of dominant bacterial communities. The effect positively correlated with the dose. From a health point of view, the use of melanin does not cause intestinal flora disorder. Our results may have important implications for MSMI as functional food component and potential therapeutic for manipulating gut microbiota.