Many scleractinian corals only spawn once a year, so opportunities for collecting their gametes are limited. Consequently, the induction of spawning in coral would be useful, not only for studies on the mechanisms of coral reproduction, but also for stock enhancement. A spawning-induction method using hydrogen peroxide (H2O2) has already been developed for coral, but most adult corals died after exposure

Larvae of Auxis rochei and Auxis thazard are commonly found in tropical to temperate waters around the world; however, their identification is difficult due to their similar morphological characteristics. In order to determine the morphological differences between larvae of these two species, we identified larvae of 192 A. rochei and 119 A. thazard using species-specific genetic markers and compared

The neurotoxin domoic acid (DA) is produced by Pseudo-nitzschia spp. during harmful algal blooms and is linked to amnesic shellfish poisoning. This toxin is particularly problematic in the culture of bivalves for human consumption. In this study, we exposed bay scallops to 20, 40, and 60 ng/ml DA and examined toxin accumulation and stress response at 3, 6, 12, 24, 36, and 48 h of exposure. Oxidative

Cytochrome P450 1A (Cyp1a) catabolizes polycyclic organic compounds. In this study, we sequenced the cyp1a gene from two Javanese medaka Oryzias javanicus strains and examined gene expression in response to two organic pollutants, phenanthrene and pyrene. Sequence comparisons among the two strains identified several single-nucleotide polymorphisms (SNPs), two of which resulted in amino acid substitutions

We investigated the effects of different heating conditions on the texture and extractive compounds of meat derived from each part of the yellowtail Seriola quinqueradiata fish. Heating conditions had a tendency to affect the hardness and sample thickness of the dorsal ordinary muscle (OM) and dark muscle (DM). Heating did not significantly affect the inosine monophosphate level in OM. However, lo

Predicting the outbreak of disease is essential when managing shrimp farms. Acute hepatopancreatic necrosis disease (AHPND) caused by Vibrio parahaemolyticus is a serious disease in shrimp. It is essential that shrimp farmers on the east coast of the Mekong Delta detect the disease as early as possible, because the mortality rate can reach 100%. Here, we used machine learning to predict AHPND development

We investigated the free amino acid (FAA) composition, glycogen content, and body index of 31 brands of oyster Crassostrea gigas to evaluate their taste graphically using a three-dimensional (3D) graph. Taurine was the most abundant FAA, followed by glutamic acid, glycine, alanine, and proline. Based on the sensory evaluation, oysters with a higher glycogen content were more often evaluated as “sweet”

The suitability of fermented products of Ulva fronds as diets for juvenile asari clams was tested. Ulva fronds were transformed by fermentation into a single-cell product (Ulva marine silage; UMS) of suitable size for ingestion by the clams. No dietary effect was seen in clams fed UMS alone. Furthermore, combined feeding with UMS and Chaetoceros calcitrans, which is considered a suitable diet for clams

Chondroitin sulfate synthase-1 (ChSy-1) plays an important role in the synthesis and chain extension of chondroitin sulfate (CS). CS, a linear polysaccharide with high structural diversity, plays crucial roles in cell adhesion, morphogenesis and cell division in response to viral and bacterial infections. However, the role of ChSy-1 in the immune response remains unknown. In the present study, ChSy-1

The activity of proteases may be lost during microquantification because of their nonspecific binding to tubes and pipette tips. In this study, the effects of blocking reagents (blockers) in dilutions of digestive proteases of yellowtail, Seriola quinqueradiata, were compared. EzBlock Chemi (EBC; protein free), Western BLoT Blocking Buffer (WBB; protein free), casein-based blocker, and bovine serum

Fermentation of kamaboko in koji with wheat (KW), rice (KR), brown rice (KB), or soybean (KS) was performed by simulation of tofuyo processing. Moisture and protein content decreased with fermentation, while other detected compounds increased significantly. Ash content increased from 12.9 g/100 g in kamaboko to 17.9–20.2 g/100 g (KW, KR, and KB) and 26.8 g/100 g (KS) after 4 weeks of fermentation.

In order to study the effects of carbon source addition on the bacterial community, water quality and shrimp growth in the recirculating aquaculture system of Litopenaeus vannamei, sucrose with 50% of the daily feed was added daily to the system from the middle stage of culture. The bacterial communities in biofilters, aquaculture waters and shrimp intestines were measured using an Illumina MiSeq platform

To investigate the species composition and genetic characteristics of Far Eastern daces, genus Tribolodon, in the Tama River, Japan, partial DNA sequences of the mitochondrial DNA control region were compared among specimens from the whole river system. Specimens of Tribolodon hakonensis (n = 257) and Tribolodon brandtii maruta (n = 193) were examined in this study. Inconsistencies in species identification

Koji is commonly used in manufacturing Japanese fermented products and promotes enzymatic degradation. In recent years, a seaweed koji has been developed by culturing Aspergillus oryzae on nori Pyropia yezoensis. In the present study, we prepared nori koji by culturing A. oryzae on high- and low-quality noris and then mixing this preparation with additional dried nori. Suitable fermentation conditions

The objective of this study is to determine the lipid content and fatty acid composition of Anguilla japonica caught in South Korea. Seventy-nine eels caught at four different locations in different seasons were analyzed. Lipid content (1.3–30.0% of muscle weight) was more affected by season than by the location where the fish were caught, being the highest among the eels caught in May. Lipid content

Amino acids can act as signaling molecules in protein synthesis and animal growth by regulating several genes in the target of rapamycin (TOR) pathway. An 8-week feeding trial was conducted to examine the effects of dietary proline on growth performance, body composition, amino acid profiles, blood-biochemistry and expression of TOR pathway-related genes in juvenile Nibea diacanthus. Fish (450 juvenile

The article “Bio‑economic analysis of super‑intensive closed shrimp farming and improvement of management plans: a case study in Japan”, written by Junpei Shinji, Setsuo Nohara, Nobuyuki Yagi and Marcy Wilder was originally published electronically on the publisher’s internet portal on 17 September 2019 without open access.

The article “Geographical variation in spawning histories of age‑1 Pacific saury Cololabis saira in the North Pacific Ocean during June and July”, written by Satoshi Suyama, Hitomi Ozawa, Yasutoki Shibata, Taiki Fuji, Masayasu Nakagami and Akio Shimizu was originally published electronically on the publisher’s internet portal on 27 March 2019 without open access.

The article “Development of an efficient bioreactor system for delivering foreign proteins secreted from liver into eggs with a vitellogenin

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The microbiological properties of Myanmar traditional fermented products were characterized using four different brands of bottled shrimp sauce products sold frequently at a large grocery market. Viable cells of these products were detected at various levels (102–105 cfu/ml) using de Man, Rogosa and Sharpe (MRS) agar medium containing 10% NaCl, and all isolates from the product samples were identified

The environmental DNA (eDNA) technique is a convenient and powerful tool to detect rare species. Knowledge of the degradation rate of eDNA in water is important for understanding how degradation influences the presence and/or estimate biomass of aquatic animals. We developed a new set of species-specific primers and probe to detect eDNA of Japanese eel Anguilla japonica, which is a commercially important

The interaction between cortisol and aromatase may be a critical factor in sex determination or sex changes in teleost species. High cortisol concentrations inhibit transcription of the aromatase gene, resulting in masculinization. Anemonefish (Amphiprion spp.) are socially controlled, protandrous sex-changing fish, with a monogamous mating system. Females are the largest and most dominant members

Kisspeptin is an endogenous ligand that modulates gonadotropin-releasing hormone (GnRH) secretion and plays an essential role in the reproduction of mammals. In fish, two subtypes of kiss genes (kiss1 and kiss2), which encode kisspeptins, have been reported. Our previous study showed that kisspeptin 2 receptor (KissR2) is highly expressed in the vicinity of GnRH1 neurons, and that centrally administered

Fishery-independent surveys using sea surface trawl nets for Pacific saury Cololabis saira in the western North Pacific since 2003 have enabled the investigation of their annual distribution patterns and total biomass during June and July, prior to the main fishing season in Japan. We compared biomass estimates and their associated variances derived based on five different post-stratification approaches

The present study established an age determination technique and analyzed growth patterns in three sculpins, Myoxocephalus jaok, Enophrys diceraus, and Gymnocanthus herzensteini, which are major components of demersal fish assemblages in the subarctic Pacific. In all three species, only two or three otolith opaque zones were detected by surface observations, but numerous opaque zones were observed

Aquaculture faces substantial challenges in mitigating the detrimental environmental impacts of intensive farming. Traditional methods have given rise to serious concerns, leading to the search for alternative approaches using probiotics. An indigenously isolated photosynthetic purple bacterium, Rhodovulum sulfidophilum, was introduced into a marine integrated multitrophic aquaculture system cultivating

The catch state in Mytilus anterior byssus retractor muscle is regulated by phosphorylation and dephosphorylation of twitchin, a member of the titin/connectin superfamily, and involves two serine residues, Ser-1075 (D1) and Ser-4316 (D2). This study was undertaken to examine whether isoforms of twitchin were expressed in various muscles of the mussel Mytilus galloprovincialis by reverse transcription-polymerase