Red Snow Crab Research Articles

Embryonic development of the red snow crab Chionoecetes japonicus (Decapoda: Oregoniidae), inhabiting the meso and bathypelagic zones of the Sea of Japan

ABSTRACT This study investigated the seasonal changes in embryonic development of the red snow crabs inhabiting the deep sea using wild and captive ovigerous females. The embryonic stages were categorised into 14 groups based on their external morphology. Females with recently spawned eggs (between stage 1 and early stage 3), those with the eggs at the midterm stage (mainly stages 7 and 8), and those with eggs just before hatching (stage 14) were observed simultaneously from January to March indicating a 2-year reproductive cycle. These findings aid in understanding and identifying the spawning years of the red snow crabs sampled from their natural habitats.

Variations in vertical distribution of developing snow crab Chionoecetes opilio and red snow crab Chionoecetes japonicus (Crustacea, Decapoda, Majoidea) larvae in experimental temperature gradients

ABSTRACT In the Sea of Japan, field studies have found snow crab and red snow crab larvae occur between the surface and depths of up to 550 m and 1100 m, respectively. In this region, snow crab larvae hatch at depths of 240–260 m and red snow crab larvae hatch at 1000–1500 m. To understand their vertical distribution during the larval period, we investigated the upward swimming speed of newly hatched larvae (first-stage zoea) and the behaviour of all larval stages (first and second zoeal and megalopal stages) in a temperature gradient under laboratory conditions. Our results showed that the larvae have the potential to reach the surface within a few days of hatching. As the larvae developed, they preferred greater depth and lower temperatures; although they temporarily rose to higher levels immediately after each moult. The zoeae and megalopae of both species did not occur beyond the 16 and 6°C temperature layers, respectively. The preferred position of the larvae in the gradient temperature did not differ between the two species. The present study suggests that Chionoecetes larvae transported to unsuitable temperatures may not die, but could escape from low temperatures by upward swimming and from high temperatures by sinking.

Preparation and Taste Profiling of the Enzymatic Protein Hydrolysate from a by-Product of Red Snow Crab Processing as a Natural Seasoning Compound.

The red snow crab (Chionoecetes japonicus) is the most industrially processed in the Republic of Korea, and the meat is very popular, owing to its savory taste and flavor. Its body meat production comprises a two-step separation to increase meat yield. However, during the secondary separation, broken shell debris is occasionally entrained in the meat products, which is a concern for manufacturers. As the residues from first separation contain 39.9% protein, it can be utilized as an enzymatic protein hydrolysate (FPH) rich in free amino acids (FAAs). A combination of flavourzyme and alcalase (1:1) superiorly hydrolyzed the protein of the residues, and the best hydrolysis condition was suggested at 60 °C for 15 h with fourfold water and 2% enzyme addition, achieving a 57.4% degree of hydrolysis. The EPH was mostly composed of FAAs containing most essential amino acids; however, bitter-tasting amino acids accounted for 46.4% of the FAAs. To reduce the bitter taste, different nonvolatile organic acids were considered as masking agents, and citric and malic acids were effective, though the umami taste is slightly decreased. In conclusion, the crab processing residues can be utilized as an FAA-based natural seasoning compound through enzymatic hydrolysis and organic acid treatment.

Changes in phototaxis, geotaxis, and sinking velocity in relation to larval development of snow crab (Chionoecetes opilio) and red snow crab (Chionoecetes japonicus) under laboratory conditions

Changes in phototaxis, geotaxis, and sinking velocity in relation to larval development of snow crab (Chionoecetes opilio) and red snow crab (Chionoecetes japonicus) under laboratory conditions

Effect of temperature on red snow crab Chionoecetes japonicus (Crustacea, Decapoda, Majoidea) larval survival, development, and growth under laboratory conditions

ABSTRACT In the Sea of Japan, the mature red snow crab Chionoecetes japonicus is distributed at a depth of 500–2,700 m. However, its planktonic larvae occur at depths shallower than 300 m. To better understand the factors influencing larval dispersal and settlement of the red snow crab in its natural habitat, we tested the effects of temperatures ranging from 1°C to 18°C on the survival, developmental period, and growth of red snow crab zoeal and megalopal larvae. The mean number of days from hatching to second zoeae and megalopae and from megalopae to the first crab instar was significantly shorter at warmer temperatures. Moreover, the relationships between mean temperatures and larval periods were well described by heat summation theory equations and a nonlinear thermodynamic Sharpe-Schoolfield-Ikemoto (SSI) model. The higher survival rate, intrinsic optimum temperatures in the SSI model, and larger carapace width suggested that the optimum temperatures for the development of zoeal and megalopal stages of the red snow crab are 9–10°C and 7–8°C, respectively. A lower optimum temperature in the megalopal stage than in the zoeal stages was considered an adaptation to facilitate deeper vertical distributions in the megalopal stage.

Metamorphosis season from megalopa to the first crab stage in snow crab Chionoecetes opilio and red snow crab C. japonicus (Crustacea, Decapoda, Majoidea) in the Sea of Japan, estimated from captive culture

ABSTRACTMetamorphosis season of megalopae to the first crab stage in snow crab Chionoecetes opilio and red snow crab C. japonicus was inferred by culturing wild-born megalopae collected from the Sea of Japan. Metamorphosis occurred from late June to late July (mainly in July) in snow crab, and from early July to early October (mainly from August to September) in red snow crab. The number of days required from the time of collection to metamorphosis was less than the intermoult period previously reported for snow crab megalopae. However, the developmental period of the megalopae was estimated as substantially longer in red snow crab than in snow crab. Previous studies have shown that the hatching season and the period of the zoeal stage in both two species are similar. These results suggest that a different metamorphosis season between the two species would be due to a difference in their megalopal intermoult period.

Concentrations of total mercury and methylmercury in red snow crabs (Chionoecetes japonicus) caught off the coast of Japan

The total mercury (T-Hg) and methylmercury (MeHg) concentrations in red snow crabs (Chionoecetes japonicus) caught off the coast of Japan were analyzed. The T-Hg concentration ranged from 0.03 to 0.56 mg/kg (mean: 0.21 mg/kg) in the raw muscle, and 0.02 to 0.74 mg/kg (mean: 0.27 mg/kg) in the boiled muscle. The MeHg concentration ranged from 0.04 to 0.54 mg/kg (mean: 0.20 mg/kg) in the raw muscle. The mean ratio of MeHg to T-Hg was 0.88. The crab body weight was found to significantly correlate with the concentrations of T-Hg (r = 0.488) and MeHg (r = 0.490) (p ≤ 0.01). For the general population in Japan, the intake of MeHg from eating red snow crab was estimated to be lower than 0.013 mg/week, which was less than one-sixth of the tolerable MeHg intake (0.08 mg/week).

Effects of crab shell extract as a coagulant on the textural and sensorial properties of tofu (soybean curd).

To find an economic use of red snow crab (Chionoecetes japonicus) shell waste, we focused on its high mineral content. To evaluate its usability as a coagulant for tofu making, the effects of the crab shell extracts on the textural and sensorial properties of the tofu samples were investigated. The crab shell powder (CSP) and ash (CSA) were used for their extract preparation, and 1%–5% acetic acid treatment led to an abundance of calcium in the resulting extracts. The tofu yields of all the acetic acid extracts were comparable with those of the commercial coagulants MgCl2 and glucono‐δ‐lactone (GDL). Furthermore, the results for the textural attributes and sensorial acceptability demonstrated that either the extract from CSP prepared with 3% acetic acid or the extracts from CSA prepared with 1% or 3% acetic acid could be used as coagulants, because all the values of the extracts were statistically equivalent to those of the MgCl2 and GDL (p < 0.05).

수산식품산업의 산업조직론적 분석 : 경상북도 주요 수산가공업을 중심으로

The purpose of this study is to examine how the basic condition(supply of raw material, consumer demand) of seafood processing industry influences on market structure, market behavior and market performance from the view point of industrial organization theory. This study surveyed seafood processing company(red snow crab, alaska pollock, seasoned squid and salted mackerel) in Gyeongsangbuk-do, Korea. The result of study are as follow. First, The material supply structure influences on competitive structure and entry barriers. Second, The change of raw material supply environment influences on market performance. The decrease of raw material supply leads to increase of material price and it leads to decrease in sales & profit. Third, The change of demand influences on market structure. The market with increasing demand leads to the entry of new companies. Forth, The change of demand influences on market behavior(purchase of raw material, production strategy) and it leads to market performance.

Rapid and simple identification of two closely-related snow crabs (Chionoecetes opilio and C. japonicus) by direct triplex PCR

The snow crab (Chionoecetes opilio) and red snow crab (C. japonicus) are commercially valuable in South Korea, and C. opilio has a higher economic value. However, the similar morphological traits of these two species are often exploited for seafood fraud. In this study, sensitive primer sets specific to C. opilio and C. japonicus were designed, and a species-specific PCR was optimized to identify each crab species in various types of processed food. The specificity of the species-specific PCR was tested using twenty eukaryotic species, and no cross-reactivity was observed. The sensitivity of the PCR assays was found to be 0.005 ng/μL. Additionally, a direct triplex PCR method, in which rapid DNA extraction was combined with the species-specific PCR, was developed and utilized to differentiate between snow crab and red snow crab from forty-one commercial crab products. This cost-effective and rapid method can be efficiently utilized in various areas, including rapid screening, quality control, and regulatory monitoring, which are important for the food manufacturing industry and regulatory authorities.

South-North Korea, Japan Red Snow Crab Industry Cooperation

South-North Korea, Japan Red Snow Crab Industry Cooperation

Effects of a freeze-thaw-pressing muscle separation on the biochemical quality and self-stability of leg meat from red snow crab (Chionoecetes japonicus)

To evaluate the product quality of leg meat from red snow crab (Chionoecetes japonicus) prepared with a novel freeze-thaw-pressing muscle separation (FTPS), the biochemical properties were compared with those of two thermal muscle separations (boiling; BS or steaming; SS). Among the muscle separations, the yield from merus part was the highest with the FTPS (22.0 ± 2.1 g), followed by SS (20.3 ± 1.4 g) and BS (17.5 ± 1.8 g). The proximate compositions in the three leg meats were similar, but the quantitative analyses for the water extractive components (free amino acids, minerals, organic acids and ATP-related compounds) revealed that all the contents were notably higher in the leg meat with FTPS (LM-FTPS) than that with BS or SS. The sensorial acceptability test demonstrated the storable day limits of the LM-FTPS at −20 °C, 0 °C or 10 °C, but it was suggested only in storage either at 0 °C (3 days) or 10 °C (1 day), the day limits corresponded to 30 mg% of the VBN value and 5 log CFU g−1 of the total viable cell count. In the case of −20 °C storage, the storable day limit suggested within 5 days, based on the VBN value.

Визуальная оценка жизнеспособности камчатского краба и краба-стригуна опилио в ходе транспортировки

Визуальная оценка жизнеспособности камчатского краба и краба-стригуна опилио в ходе транспортировки

Molecular Cloning and Phylogenetic Analysis of a Chitin Deacetylase Isolated from the Epidermis of the Red Snow Crab &amp;lt;i&amp;gt;Chionoecetes japonicas&amp;lt;/i&amp;gt;

Chitin deacetylase (CDA; EC 3. 5. 1. 41) catalyzes the deacetylation of chitin. In this study, we successfully cloned and sequenced a chitin deacetylase gene from the red snow crab Chionoecetes japonicas. By using reverse transcription-polymerase chain reaction (RT-PCR) and 5' and 3' rapid amplification of cDNA ends, we obtained a 2141-bp amplicon containing a chitin deacetylase gene (CjCDA) from the epidermis of C. japonicas. The amplicon contains a 1575-bp open reading frame that is predicted to encode a 525-amino acid protein. The structure predicted from the deduced amino acid sequence included an N-terminal signal peptide, chitin-binding domain (CBD), low-density lipoprotein receptor class A domain (LDL-A), and catalytic domain. Comparative analysis of the deduced amino acid sequence of CjCDA revealed the highest homology (74%) to gastrolith protein 59 of Cherax quadricarinatus. We used RT-PCR to evaluate the expression of CjCDA in various tissues of C. japonicas, and we observed that CjCDA was expressed only in the epidermis. A phylogenetic analysis, using the amino acid sequences of CjCDA and other known chitin deacetylases, showed that CjCDA belonged to a group of crustacean chitin deacetylases. To our knowledge, this is the first study reporting the cDNA cloning of a chitin deacetylase from a crab.

근해 붉은대게 통발어업에서 어로기술개발에 따른 어획성능지수 변화

근해 붉은대게 통발어업에서 어로기술개발에 따른 어획성능지수 변화

Postmortem changes in physiochemical and sensory properties of red snow crab (Chionoecetes japonicus) leg muscle during freeze storage

In order to evaluate the maximal storable period of the raw crab for a non-thermal muscle separation, the quality changes of the leg meat of red snow crab (Chionoecetes japonicus) during freeze storage were investigated. Fresh red snow crabs were stored at −20 °C for 7 weeks, and the leg muscle was separated by a no heating separation (NHS) method every week. During the storage, considerable loss of the leg muscle did not occur and microbiological risk was very low. In contrast, discoloration appeared at 2-week storage on around carapace and the leg muscle turned yellow at storage 3-week. In physiochemical parameters, protein and free amino acids gradually decreased with storage time, expected that proteolytic enzymes still activated at −20 °C. At 4-week storage, the sensory acceptance dropped down below point 4 as low as inedible and notable inflection points in pH and acidity were observed. The volatile base nitrogen was low, though a little increase was recorded. These results suggested that the maximal storable period at −20 °C of the raw material was within 2 weeks and it was depended on external factor such as the discoloration. The present study might be referred as basic data for approaches to solve quality loss occurred in non-thermal muscle separation.

Quality Characteristics of Teriyaki Sauce added with Red Snow Crab Shell based on Pre-treatment Process

Quality Characteristics of Teriyaki Sauce added with Red Snow Crab Shell based on Pre-treatment Process

Quality Characteristics of Teriyaki Sauce added with Red Snow Crab Shell based on Pre-treatment Process

Quality Characteristics of Teriyaki Sauce added with Red Snow Crab Shell based on Pre-treatment Process

Fluctuations in Volatile Compounds of Red Snow Crab Meat Treated by Heating

鳥取県境港で水揚げされたベニズワイ（Chionoecetes japonicus）を試料とし，揮発性成分をガスクロマトグラフ質量分析装置（GC/MS）により分析した．その結果，加熱によって，特にカニミソ（肝膵臓）の揮発性成分の種類が顕著に増加することを確認した．

Lacinutrix chionocetis sp. nov., isolated from gut of a red snow crab.

A Gram-negative, aerobic, non-motile, rod-shaped bacterial strain, designated MAB-07T, was isolated from the gut of a red snow crab. The novel strain grew optimally at 20°C, pH 7.0-8.0, and in the presence of 3% (w/v) NaCl. A phylogenetic analysis based on the 16S rRNA gene sequence indicated that the strain MAB-07T belongs to the type strains of species of the genus Lacinutrix. Strain MAB-07T exhibited 16S rRNA gene sequence similarity values of 95.5-97.8% with the type strains of species of the genus Lacinutrix. The predominant cellular fatty acids of strain MAB-07T were iso-C15:1 G (27.5%) and iso-C15:0 (21.7%). The major respiratory quinine was identified as MK-6. The polar lipids consisted of phosphatidylethanolamine, four unidentified aminolipids, and two unidentified lipids. The genomic DNA G+C content was determined to be 33.3%, and its DNA-DNA relatedness values with the type strains of L. venerupis, L. mariniflava, L. jangbogonensis, L. algicola, and Olleya aquimaris were 28-32%. Based on the data from this polyphasic taxonomic study, strain MAB-07T is considered to represent a novel species of the genus Lacinutrix, for which the name L. chionocetis sp. nov. is proposed. The type strain is MAB-07T (=KCTC 42767T=JCM 30988T).