Artificial light plays an important role in commercial light fisheries as a means to attract fish, such as the Pacific saury and squid. To gain an insight into the optimal allocation of light-emitting diode (LED) fishing lamps in the Pacific saury fishery, we present a mathematical illumination model to describe the illumination characteristics of LED modules installed at different angles. The validity

Invertebrates change the metabolite concentrations in their bodies to adapt to environmental salinity. The kuruma shrimp Marsupenaeus japonicus is one such invertebrate. It lives in coastal areas and is also known to change free amino acid concentrations depending on environmental salinity. To examine the relationship between the concentrations of metabolites, including amino acids, in the kuruma shrimp

A correction to this paper has been published: https://doi.org/10.1007/s12562-021-01502-z

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Outbreaks of bacterial cold-water disease (BCWD), caused by Flavobacterium psychrophilum, are widespread in Japan, especially among ayu Plecoglossus altivelis. There are few investigations of F. psychrophilum in river water, and its seasonal distribution has not been clarified. We aimed to identify the spatiotemporal dynamics of F. psychrophilum and ayu to provide information that is useful for establishing

China (herein referred as China’s mainland, and excluding Hong Kong, Macau and Taiwan) is the largest contributor to global seafood production. While China’s marine fisheries have been extensively documented, there is a gap in systematically quantifying production of its marine fisheries and the different challenges confronting them at the provincial level. We addressed this gap in spatial detail by

Accurately predicting the price of exported fishery products is an important task for fisheries because it will enable market trends to be determined, leading to the development of high-quality fishery products. In this study, we predicted prices in selected base periods (2, 3, 6, and 12 months) to investigate how historical data influenced the Vietnamese export price. A dataset (from May 1995 to May

A correction to this paper has been published: https://doi.org/10.1007/s12562-021-01506-9

The amphipod Sunamphitoe namhaensis grazes on seedlings of Sargassum horneri in culture. To exterminate S. namhaensis, we immersed them in seawater with dissolved carbon dioxide—a treatment used previously to remove copepods in cultures of abalone and sea cucumber. Experiments were conducted under different CO2 (aq) concentrations and for different lengths of time. Amphipod mortality was 100% following

Understanding the role different habitats play in the life histories of fishes is important for the development of holistic aquatic ecosystem management plans. We used otolith trace element analysis to reconstruct the life history of estuarine triplefin Forsterygion nigripenne and infer its habitat use. Analysis of otoliths using laser ablation inductively coupled plasma mass spectrometry showed an

The Silond catfish Silonia silondia, locally known as Nga Myin Yinn, is a commercially important fish in Myanmar; however, fundamental knowledge of its population structure is insufficient. Specimens caught in different regions of the Ayeyarwady River, the basin of which is the country’s largest, from 2017 to 2019 were used to sequence two mitochondrial (mt)DNA genes, cytochrome b and ATPase 6/8, for

Here, we investigated the effect of dietary cysteic acid on the growth performance, sulfur amino acid content, and gene expression levels of taurine-synthesizing enzymes, growth hormone (GH), and insulin-like growth factor 1 (IGF-1) in Japanese flounder Paralichthys olivaceus. Juvenile flounder (0.9 g) were fed one of four diets for 30 days: with 0.25, 0.5, or 1.0% cysteic acid (C0.25, C0.5, C1.0)

We compared the shapes and catches of two trawl nets having differing headrope and groundrope configurations based on paired tow data collected by two research vessels (Yoko Maru and Kumamoto Maru) in the East China Sea. According to the paired data, the vertical opening of the net was significantly higher on the Yoko Maru, which employed a headrope kite, than the Kumamoto Maru, which uses floats on

Hemicentrotus pulcherrimus in the Tohoku area is not utilized as a fishery product because the ovaries have a bitter taste almost all year. To discover the cause, we compared the annual reproductive cycles and ovarian accumulation of a bitter amino acid, pulcherrimine, in H. pulcherrimus collected at Mikuni (Fukui Prefecture), where it is fished in summer, and Iwaki (Fukushima Prefecture), where it

Temperate eels are well known for partial migration where contingents may remain settled in marine habitats or move between seawater and brackish and freshwater habitats during their sub-adult life. This behaviour is less described in tropical Anguillid eels, particularly as it relates to salinity preference, habitat selection, and growth. In this study, glass eels Anguilla marmorata were collected

Seasonal changes in habitat use in terms of depth and temperature were estimated for Japanese flounder Paralichthys olivaceus from the Pacific coast of northeastern Japan from 2006 to 2008, using data from trawl and gillnet fisheries logbooks, to which we assigned monthly estimates of bottom temperature. Estimated distributions of flounder for depth and temperature were validated by actual depth and

The residence and movement patterns of the marbled flounder Pseudopleuronectes yokohamae were investigated around a spawning ground located off the coast of Nagasaki point, southern Suo Nada, Seto Inland Sea, Japan. Twenty marbled flounder (9 females and 11 males) tagged with ultrasonic transmitters were released on November 29, 2017, before the peak spawning season (peak spawning season: mid–late

With a decrease in the domestic catches of Ruditapes philippinarum, suspended culture is a potential approach to increase its production. We investigated the establishment of suspended clam culture in Suttsu fishing port, Hokkaido. Cages accommodating 100 clams (mean shell length 28 mm) were suspended in the “stocking area” at the back of the port and the “fairway area” at the center of the port. Rearing

Green tides caused by Ulvales group macroalgae have been reported from many eutrophic waters around the world. The asari clam Ruditapes philippinarum is an important fisheries resource in Japan and co-exists in coastal waters with Ulvales macroalgae. This study examined a possible impact of fresh Ulva fronds on the growth of juvenile, adult, and spat asari clams by conducting rearing experiments. Significant

To investigate the influence of parasitism of the copepod Pennella sp., which belongs to the family Pennellidae, on mortality in the Pacific saury Cololabis saira, we examined the seasonal changes in the following indices: prevalence (%; no. of infected fish × 100/no. of examined fish), mean intensity (total no. of infected Pennella sp./no. of infected fish), relative intensity (total no. of infected

The Japanese eel Anguilla japonica is a prominent and highly valued species in the aquaculture industry in Japan. Sex determination and sex differentiation in eels are significantly affected by environmental factors; however, the molecular mechanisms involved in sex differentiation in eels are largely unknown. In this study, to investigate the gonadal expression profiles of sex-specific genes during

Sepioteuthis lessoniana is a crucial squid species in fisheries and plays a critical role in marine ecosystems. At least two taxa of the squid species have been identified in the waters around Japan; however, the basic biological information of these taxa is limited. In this study, the taxa composition of Sepioteuthis was examined using molecular evidence, and the life-history traits and statolith

To explore the gillnet selectivity for swimming crab Portunus trituberculatus, six mesh sizes (100, 110, 120, 130, 140 and 150 mm) were tested to determine the optimal mesh size for swimming crab. The experiments were conducted in the traditional area for fishing crab in the East China Sea from 25 to 29 July 2018. Four kinds of selectivity curves were used for fitting, and the maximum likelihood method

In this study, the interannual variations of ichthyoplankton assemblages in the Taiwan Strait (TS) during the winters of 2007–2013 were determined. The cold China Coastal Current (CCC) and Mixed China Coastal Water (MCCW) intruded into the TS and impinged with the warm Kuroshio Branch Current (KBC) with annual variations. Consequently, the ichthyoplankton community in the TS was mainly structured into

To elucidate the dynamics of oxidative stress in fish, it is necessary to know the concentration of superoxide anions as a precursor to various reactive oxygen species in the living body. Superoxides are unstable radicals, disappearing within a few seconds, which makes it challenging to measure them using conventional methods. We describe herein the development of a biosensor that can rapidly quantify

Estrogenic endocrine-disrupting chemicals are an increasing social concern, as they can reduce the reproductive activity of wildlife. The present study aimed to clarify the long-term effects of estradiol-17β (E2) on male reproductive activity in goldfish. Sexually mature male goldfish were implanted with a silicone capsule containing E2, and kept for 14 weeks or 15 weeks. The reproductive activity

Our ultimate aim is to establish a small-bodied surrogate broodstock (e.g., mackerel) that produces functional gametes of the Pacific bluefin tuna Thunnus orientalis using xenogeneic germ cell transplantation. To accomplish this goal, we need to be able to sequentially trace transplanted donor cells in recipients. Here we succeeded in identifying two monoclonal antibodies that could specifically recognize

The solitary European sea squirt Ascidiella aspersa was introduced to northern Japan, causing dense coverage of the aquacultured Japanese scallop Mizuhopecten yessoensis. There are concerns that allelopathy by the sea squirt will suppress the growth of the scallop. Herein, we studied the allelopathic and defensive potential of A. aspersa using hemolytic assay. An alkyl sulfate, viz. 3,7,11,15-tetramethyl-hexadecan-1

The cleavage pattern of a vertebrate’s embryo is either holoblastic (complete) or meroblastic (partial). Sturgeon and other basal bony fishes represent a transition of the cleavage pattern. To understand the transition, it is essential to develop an effective technique for the inhibition of specific blastomere cleavage. So far, various studies have demonstrated that diatom-derived polyunsaturated aldehyde

We examined the effects of tank color and stocking density on the growth of spotted halibut (Verasper variegatus) under a green light-emitting diode (LED). Fish reared for 40 days under a green LED (10 μmol m–2 s–1 at the water surface) grew faster than those reared under a white LED, irrespective of tank color (white or black). Green light promoted higher growth than indoor room light when fish were

Cytokines are low molecular weight glycoproteins involved in the regulation of the immune system, and more than 100 cytokines have hitherto been identified in humans. Cytokines similar to those found in humans have also been found in fish. The innate immune response of fish can be examined by using cytokines as markers. We developed a multiplex reverse transcription–polymerase chain reaction assay

Leptocephalus larvae have transparent bodies with tubular intestines that usually lack identifiable food items when they are collected, so mystery has surrounded efforts to determine what they feed on. Artificially spawned and reared first-feeding larvae were found to be highly selective in what they would eat, but they would consume rotifers and eventually ate specially formulated diets that contained

Snow trout Schizothorax labiatus constitute a significant part of the diet of large human population of colder regions of the Indian Himalayan subcontinent, and are also important for local livelihoods there. In the present study, the hematological and serum biochemical parameters of S. labiatus were examined with respect to sex and season. Hemoglobin (Hb) concentration, red blood cell (RBC) count

Bristle patches on the carapace behind the eyes were found for the first time in both males and females of the four species of mud crab Scylla spp. Electrocardiography revealed that the bristle patches of Scylla paramamosain were sensitive to touch (with a glass capillary) but not to chemical stimulation (with sugarcane juice). To elucidate the function of these touch signals, the courtship behaviour

The medaka Oryzias latipes is a teleost fish with an XX/XY sex determination system similar to that of mammals. However, under high-temperature conditions, XX medaka are masculinized by an elevation of the key teleost glucocorticoid, cortisol. Cortisol inhibits female-type proliferation of germ cells and induces masculinization of XX medaka during gonadal sex differentiation. To identify masculinization

Cocaine- and amphetamine-regulated transcript (CART) is an anorexigenic peptide hormone of fish and other vertebrates. In aquaculture, appetite regulation of fish is important to improve their growth. We cloned five CART genes (cart1b, 2a, 2b, 3a, and 3b) from yellowtail Seriola quinqueradiata, which belong to CART groups 1, 2, and 3 across four CART branches according to phylogenetic analysis. The

Two sediment cores were collected from two sites in Nagatsura-Ura Lagoon, the mouth of which was destroyed in the 2011 Tohoku-oki tsunami. Although sediment conditions differed widely between the central and inner parts of the lagoon, we could identify traces of the 2011 Tohoku-oki tsunami at both, and those of earlier tsunamis in the inner part of the lagoon. Chlorophyll a maxima were observed at

Cold-anesthetization waterless live fish preservation is considered a promising alternative strategy. This work investigates the effects of temperature chilling rates of 2, 4, and 6 °C/h on serum biological parameters and muscular chemical composition of channel catfish Ictalurus punctatus and the influence of waterless preservation time (6, 9, 12, 15, and 18 h) on survival after subjection to three

Intensive commercial harvesting of the wedge clam Donax trunculus and the striped venus Chamelea gallina was conducted along the southern coast of the Marmara Sea using a mechanical dredge (MD) and a hand dredge (HD). The purpose of this study was to characterize and quantify the bycatch and discards of both types of dredge. The dredge tows were performed along sandy bottoms at depths ranging from

Pufferfish belonging to Lagocephalus are composed of several species, some of which have been recognized to be non-toxic. Although fish belonging to this genus inhabit a wide variety of seawaters from temperate to tropical, toxin distribution has remained unclear. The present study was conducted to thoroughly survey the presence of tetrodotoxin (TTX) and its analogs (TTXs) in the extracts from various

This study presents age-based life history information on three small-bodied species targeted in the American Samoan fishery: Chlorurus japanensis palecheek parrotfish/fuga-alosama, Lethrinus rubrioperculatus spotcheek emperor/fiola pa`o`omumu, and Naso lituratus orangespine unicornfish/ili`ilia. Age and reproductive information were derived from sagittal otoliths and gonads. Maximum observed ages

The distribution and early growth of juvenile Pacific bluefin tuna (PBF) Thunnus orientalis were studied based on trawl surveys conducted around Sado Island, eastern Sea of Japan, from late August to early September in 2017 and 2018. Juvenile PBF were mainly collected in an area between the Tsushima Warm Current and land where the surface water (5-m depth) temperature ranged from 22.8 to 27.2 °C. The

The effect of fish freshness on myosin denaturation during the frozen storage of flounder muscle was studied. The muscle of instantaneously killed flounder was immediately stored at − 20 °C (pre-rigor mortis; day 0), or after storage at 0 °C for 2 days (rigor mortis) or 5 days (post-rigor mortis). Myosin denaturation in frozen stored muscle was studied by measuring Ca2+-ATPase activity, myosin solubility

Swordtip squid Uroteuthis edulis is a commercially important species in coastal waters throughout the Northwestern Pacific, including those of Japan and Taiwan. Despite the importance of U. edulis to fisheries, previous studies on the life history traits (growth rate, size at maturity, and fecundity) of its populations in the Northwestern Pacific have been localized and region specific. Thus, we report

We examined phytoplankton productivity in Shido Bay, an active oyster farming area in the eastern Seto Inland Sea, Japan, by an in situ 13C method from March 2016 to January 2017. The depth-integrated daily phytoplankton production ranged from 0.13 to 1.61 g C m−2 day−1, and the estimated annual production was 218 g C m−2 year−1. The daily production peaked in the rainy season and autumn, when phytoplankton

Globally, neonicotinoid contamination in aquatic environments, including estuarine areas, is a prevailing environmental concern. The estuarine resident marine crustacean sand shrimp Crangon uritai was previously found to have a higher tolerance to neonicotinoids than the marine crustaceans kuruma prawn Penaeus japonicus and mysid Americamysis bahia. Based on these findings, we aimed to explore the

Gene expression profiles during the transition from fasting to refeeding were investigated in the gut and liver of Masu salmon Oncorhynchus masou masou. Fish were starved for 3 days and then fed at 3% of body weight. The gut and liver were resected before and after feeding, and the tissues were used for transcriptome analyses. Twenty-nine and 45 genes were more than eightfold differently expressed

Increasing water temperatures and salinity intrusion due to climate change are serious challenges for freshwater aquaculture. In this study, we assessed the combined effects of salinization at 0, 6, and 9‰ and water temperatures of 28, 31, and 34 °C on the survival and growth rates, and feed utilization, of freshwater snakehead Channa striata. We also assessed feed digestibility in snakeheads to explore

Generally, the catch efficiency (CE) of a set net is difficult to evaluate because it is affected by fish behavior. Therefore, to evaluate CE, we proposed a fish school behavior simulation model based on the boid model and applied it to a full-scale set net. The moving path of the fish school around the set net was simulated and visualized via the proposed method. From the moving path, three behaviors

We reviewed the current methodology and practices of the DNA metabarcoding approach using a universal PCR primer pair MiFish, which co-amplifies a short fragment of fish DNA (approx. 170 bp from the mitochondrial 12S rRNA gene) across a wide variety of taxa. This method has mostly been applied to biodiversity monitoring using environmental DNA (eDNA) shed from fish and, coupled with next-generation

Hypo-salinity exposure is a serious concern for bivalve aquaculture, with profound effects on the animals’ physiological condition. The present study aimed to evaluate the influence of low-salinity exposure on the clearance rate, total heterotrophic marine bacteria and total Vibrio count in flesh, as well as the biochemical parameters of hemolymph and heat shock protein (HSP) gene expression, in Pinctada

The proximate composition and nutritional content of oysters define their quality and commercial value. Cultivation site and harvest date may impact these characteristics. We assessed moisture, ash, protein, fat, and glycogen concentrations, mineral and free amino acid content, and free fatty acid composition in oysters Crassostrea gigas from three coastal regions of the Seto Inland Sea, Hiroshima

Although recreational fishing is popular in Japan, few estimates have been made of its economic value to the country. This study aims to (1) evaluate the economic value of recreational fishing in Tango Bay, Kyoto Prefecture using the travel cost method (TCM); and (2) explore the development of related regional economies around Tango Bay. The TCM analysis showed that 150,000 anglers visit Tango Bay

The feeding habits and prey selection of Gymnocypris firmispinatus in the Anning River were investigated with respect to fish size, season and sex. Gut contents of 305 individuals ranging in size from 57 to 193 mm total length were analyzed, and 16.0% of the guts were found to be empty. The vacuity index indicated that the feeding intensity of the fish roughly followed a seasonal trend, with minimum

We examined the sea-entry conditions (i.e., timing and body size) of juvenile chum salmon that improve their survival during their coastal residency. On 25 June 2013, we sampled 365 juvenile chum salmon [57.5–98.6 mm fork length (FL)] off Konbumori, eastern Hokkaido, ⁓ 20 km east of the Kushiro River mouth, which originated from a hatchery in the Kushiro River. Sea-entry conditions of these Konbumori

Gelatin, which is thermally converted from collagen, is widely utilized in the pharmaceutical industry as a raw material for hard and soft capsules. The aim of this study was to produce gelatin from yellowfin tuna skin, the by-product of tuna processing, and determine the optimal concentration for hard capsule production. Capsules were prepared from the skin gelatin. The tuna skin gelatin was characterized

The aquaculture industry is growing rapidly throughout the world, but due to intensification, fish hatcheries are often faced with infestations of parasites, which can lead to economic loss. Among these parasites, the leech Zeylanicobdella arugamensis (Hirudinea: Piscicolidae) has been reported to impact hybrid groupers and other hosts. The objective of this study was to test the antiparasitic potential