Discover the most talked about and latest scientific content & concepts.

Concept: Roe


Concentrations of Zn, Cu and Mn were examined in caviar and muscle of the Persian sturgeon (Acipenser persicus) collected from coastal waters of south Caspian Sea during March and April, 2011. Mean Zn, Cu and Mn concentrations in caviar samples were 21.48, 2.05 and 1.66 μg g(-1) wet weight basis, respectively. The mean Zn, Cu and Mn concentrations in muscle tissues were 7.49, 1.00 and 0.34 μg g(-1) wet weight basis, respectively. The mean concentrations of Zn and Cu in caviar and muscle samples were under the permissible limits proposed by the United Kingdom’s Ministry of Agriculture, Fisheries and Food (2000).

Concepts: Iran, Sturgeon, Caspian Sea, Acipenseriformes, Caviar, Persian sturgeon, Acipenser, Roe


A new group of arsenolipids based on cell-membrane phosphatidylcholines has been discovered in herring caviar (fish roe). A combination of HPLC with elemental and molecular mass spectrometry was used to identify five arsenic-containing phosphatidylcholines; the same technique applied to salmon caviar identified an arsenic-containing phosphatidylethanolamine. The arsenic group in these membrane lipids might impart particular properties to the molecules not displayed by their non-arsenic analogues. Additionally, the new compounds have human health implications according to recent results showing high cytotoxicity for some arsenolipids.

Concepts: Health, Molecule, Salmon, Atomic mass unit, Lecithin, Caviar, Roe, Sushi


This data article reports the chemical properties (moisture, pH, salinity, and soluble solid content) and colors of fermenting materials in salmon fish sauce products. The fish sauce was produced by mixing salt with differing proportions of raw salmon materials and fermenting for three months; the salmon materials comprised flesh, viscera, an inedible portion, and soft roe. Chemical properties and colors of the unrefined fish sauce (moromi), and the refined fish sauce, were analyzed at one, two, and three months following the start of fermentation. Data determined for all products are provided in table format.

Concepts: Carbon dioxide, Chemistry, Chemical substance, Salmon, TheStart, Fermentation, Roe


The aim of the present study was to investigate the effects of single or combined administration of dietary fermentable fiber (Vitacel®) and probiotic PrimaLac® on mucosal immune parameters, digestive enzyme activity, gut microbiota and growth performance of Caspian white fish (Rutilus frisii kutum) fingerlings. Fish were transferred to laboratory, acclimatized for two weeks and then fish (0.56 ± 0.026 g) were allocated into 12 tanks (30 fish per tank). Triplicate groups were fed a basal diet (Control) or basal diet supplemented with fermentable fiber [Vitacel®] (FF), probiotic [PrimaLac®] (P) and combined fermentable fiber and probiotic (FF + P). At the end of feeding trial, growth performance and feed utilization parameters were significantly (P < 0.05) improved in FF, P and FF + P treatments compared control group. Evaluation of digestive enzyme activity revealed significant (P < 0.05) increase of lipase activity in fish fed supplemented diet. However, amylase, protease and alkaline phosphatase were significantly higher (P < 0.05) only in P and FF + P treatments. Furthermore, total autochthonous intestinal microbiota and autochthonous LAB levels significantly increased in fish fed supplemented diet (P < 0.05). Also, inclusion of FF, P and FF + P in Caspian white fish diet remarkably increased skin mucus immune parameters compared control group (P < 0.05). These results indicate that singular or combined administration of FF and P can be considered as a beneficial dietary supplement for early stages of Caspian white fish (Rutilus fresii kutumn) culture.

Concepts: Bacteria, Gut flora, Nutrition, Enzyme, Caspian Sea, Roe, Rutilus, Kutum


Anaphylaxis and immediate-type fish roe allergies have been reported worldwide, and, in Japan, fish roe is the sixth most common food allergen. No oral food challenges (OFCs) have used pollock roe (PR), which is reported to have high cross-reactivity with salmon roe (SR). Therefore, we administered an OFC using cooked PR to evaluate PR- and SR-specific immunoglobulin E (IgE) levels and allergic reactions in patients with PR sensitivity.

Concepts: Immune system, Asthma, Immunoglobulin E, Allergy, Mast cell, Food allergy, Roe


Ram suspension-feeding fishes swim with an open mouth to force water through the oral cavity and extract prey items that are too small to be pursued individually. Recent research has indicated that, rather than using a dead-end mechanical sieve, American paddlefish (Polyodon spathula Walbaum) employ vortical cross-step filtration. In this filtration mechanism, vortical flow that is generated posterior to the branchial arches organizes crossflow filtration processes into a spatial structure across the gill rakers. Despite the known impact of locomotor kinematics on fluid flow around the bodies of swimming fish, the effects of locomotor kinematics on filtration mechanisms in ram suspension feeders are unknown. Potential temporal organization of filtration mechanisms in ram suspension-feeding fish has not been studied previously. We investigated the effects of locomotor kinematics associated with undulatory swimming on intra-oral flow patterns and food particle transport. A mechanized model of the oral cavity was used to simulate the swimming kinematics of suspension-feeding paddlefish. We recorded fluctuations of flow speed and pressure within the model, which occurred at a frequency that corresponded with the frequency of the model’s strides. Using the mechanized model in a flow tank seeded with Artemia cysts, we also showed that swimming kinematics aided the transport of this simulated food to the posterior margins of the gill slots, although the time scale of this transport is expected to vary with prey parameters such as size and concentration. Dye stream experiments revealed that, while stable vortical flow formed due to flow separation downstream of backward-facing steps in control trials, vortical flow structures in mechanized trials repeatedly formed and shed. These findings suggest strong integration between locomotor and feeding systems in ram suspension-feeding fishes.

Concepts: Fluid dynamics, Fluid mechanics, Chemical engineering, Filtration, Roe, Paddlefish, American paddlefish, Polyodontidae


In recent years, use of lumpfish (Cyclopterus lumpus L.) as cleaner-fish to remove sea-lice have been chosen by many salmon farmers in Europe and Canada as an alternative to medical treatment, which has led to large scale production of lumpfish. At present, there is limited knowledge of how lumpfish respond upon anaesthesia, which anaesthetics and concentrations that are efficient and conditions for euthanasia. We have therefore tested and developed protocols for bath immersion for three commonly used anaesthetics metacaine (Finquel, buffered tricaine methanesulfonate, MS-222 and Tricaine Pharmaq), benzocaine (Benzoak vet) and isoeugenol (Aqui-S), determined concentration for normal and fast anaesthesia and evaluated safety margin for each condition. Also, a behavioral matrix has been developed. We have examined the effect of fish size (10-20 g, 200-400 g and 600-1300 g) and sea water temperature (6°C and 12°C). We found that 200 mg L-1 metacaine is an efficient dose for deep narcosis independently for fish size and temperature due to good safety margins with regards to both exposure times and doses. However, for many tasks lighter anaesthesia is sufficient, and then 100 mg L-1 metacaine can be used. Benzocaine is less efficient than metacaine, but can be used as anaesthetic of fish < 400 g. The optimal doses of benzocaine were 100-200 mg L-1 for small fish (10-20 g) and 200 mg L-1 for medium sized fish (200-400 g). For larger fish (> 600 g), benzocaine is not suitable. Isoeugenol cannot be recommended for full anesthesia of lumpfish. The conditions for lethal doses varied with chosen anaesthetic, fish size and temperature. For small fish (10-20 g), exposure to 1600 mgL-1 of metacaine in 10 minutes it lethal. Guided protocols for non-lethal anaesthesia will contribute to ensure safe treatment of lumpfish according to an ethical standard for good fish welfare.

Concepts: Fish, Dose, Anesthesia, Ocean, Local anesthetic, Anesthetic, Roe, Lumpsucker


An eight-weeks feeding trial was conducted to investigate the effects of galactooligosaccharide (GOS), on the skin and serum non-specific immune parameters and growth performance of Caspian white fish (Rutilus frisii kutum) fry. Fish (2.07 ± 0.08 g) were fed different levels of GOS (0%, 1%, 2% and 3%). No significant (P > 0.05) difference was observed in mucus protease activity, but inclusion of 1% GOS significantly (P < 0.05) elevated total immunoglobulin (Ig) level and lysozyme activity. Evaluation of serum non-specific immune parameters revealed significant (P < 0.05) increase in serum total Ig and lysozyme activity of fish fed 1% or 2% GOS compared those of fish fed control diet. Furthermore, the serum alternative haemolytic complement activity (ACH50) was significantly (P < 0.05) elevated in all prebiotic groups regardless of inclusion levels. Administration of GOS in diet significantly (P < 0.05) improved growth performance and feed utilisation. The results of the present study revealed that GOS administration is beneficial by improving immune response and growth performance of Caspian white fish.

Concepts: Immune system, Antibody, Complement system, Lysozyme, Caspian Sea, Roe, Rutilus, Kutum


Capelin (Mallotus villosus) is among the most abundant fish species in the Barents Sea, and represents a critical food source for many predators in the area including Atlantic cod and harp seal. In Norway, the fish is of economic importance since whole capelin and roe are valuable export products. Despite its economic and ecological importance, the parasites of Barents Sea capelin are poorly known. However, the presence of parasites in the edible parts may adversely affect product quality and consumer safety. During the main annual catching seasons of 2009-2012, we investigated the diversity and infection dynamics of ascaridoid nematodes in capelin (n = 620) from the southern Barents Sea. Three anisakid species were identified by genetic or molecular methods; Anisakis simplex (s.s.), Contracaecum osculatum sp. B, and Hysterothylacium aduncum, with C. osculatum sp. B as the most prevalent and abundant species. The present findings suggest that the ascaridoid species composition in capelin reflects its trophic position in the Barents Sea ecosystem. There appears to be a link between infection level of the nematode species and the preferred prey organisms of the different developmental phases of capelin. Thus, the higher abundance of C. osculatum sp. B compared to A. simplex (s.s.) and H. aduncum may be related to more extensive feeding on calanoid copepods over a wider ontogenetic size range including adolescence, while the main intermediate hosts of the latter nematode species, i.e. euphausiids and amphipods, appear to be the preferred prey of larger capelin.

Concepts: Ecology, Norway, Abundance, Forage fish, Roe, Atlantic cod, Barents Sea, Capelin


Here we report an autopsy case of asphyxia due to aspiration of a salmon egg (ikura) into the airway. The patient was a 19-month-old girl. During breakfast, she put salmon eggs into her mouth, and began to walk. She slipped, fell down, and collapsed. She was pronounced dead following 2 h of resuscitation. The body was autopsied 28 h after death. The gastric contents consisted of rice, orange sections, and white salmon eggs. The lungs were deeply congested and over-inflated. In the right lung, areas of atelectasis in the upper and middle lobes were seen. A yellow salmon egg (8 mm in diameter) was found in the trachea. Although fish eggs are consumed throughout the world, reports of this sort are limited. The aspiration of fish eggs is under-acknowledged and underreported. The importance of preventive measures needs to be emphasized to parents and caregivers.

Concepts: Death, Pneumonia, Salmon, Meat, Tetrapod, Snake, Roe, Sushi