Search

The population structure of Japanese sardinella Sardinella zunasi around Japan was examined based on complete nucleotide sequences of the mitochondrial control region. Phylogenetic analyses revealed four major lineages (A–D). The frequency of lineage A was higher on the Pacific coast, in the Seto Inland Sea, and on the Sea of Japan coast of Kyushu, while the frequency of lineage B was higher on the Sea of Japan coast of Honshu and in Ariake Sound. The frequency of lineage C was much lower than that of lineages A and B at all nine localities in Japan. Lineage D was detected only in Ariake Sound and the Seto Inland Sea, being considered to be a continental relict. The current distribution pattern of S. zunasi was indicated to be constructed by secondary contact among those four lineages, each having different evolutionary history. Hierarchical analyses of molecular variance indicated S. zunasi around Japan to be structured into three units: (1) the group of the coast of Kyushu, including Ariake Sound, and the Pacific coast south of the Izu Peninsula, including the Seto Inland Sea, (2) the Pacific coast north of the Izu Peninsula, and (3) the Sea of Japan coast of Honshu.

The amount of interspecific and ontogenetic variation in otolith shape among clupeid fishes from Japan was investigated to create a key to identify otoliths of these species found in the stomach contents of piscivorous predators, fossiliferous beds, and archaeological sites. The interspecific comparison with 12 species (Clupea pallasii, Etrumeus micropus, Herklotsichthys quadrimaculatus, Ilisha elongata, Konosirus punctatus, Nematalosa come, Nematalosa japonica, Sardinella aurita, Sardinella melanura, Sardinella zunasi, Sardinops melanostictus, and Spratelloides gracilis) revealed morphological variation in otolith shape, OL:OH and AL:RL ratios, rostrum, marginal structures, and features of the crista superior. Intraspecific changes were analyzed in two species (E. micropus and S. melanostictus), revealing ontogenetic changes in OL:OH ratio and consequently otolith shape as well as changes in marginal features. Overall, this study shows that the key morphological features can be used as diagnostic features for identification of clupeid otoliths.

The complete mitogenome of Sardinella zunasi was determined by next-generation sequencing. The S. zunasi mitogenome was a circular 16,307 bp molecule that contained 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and one control region (D-loop). The gene arrangement was consistent with other Sardinella mitogenomes. The phylogenetic relationships of 29 Clupeoidei species based on 13 protein-coding genes from the available mitogenomes were analyzed. Sardinella zunasi clustered with Sardinella among Clupeidae, suggesting a closer relationship with this genus. These results will be useful for understanding the phylogenetic relationships, taxonomic classification, and phylogeography of the genus Sardinella relative to other genera of Clupeoidei.

Sardinella zunasi Bleeker, an edible and medicinal marine fish, is largely distributed in tropical oceans. However, the chemical composition and nutritional properties of this species have not yet been investigated. In the present study, proximate composition, fatty acids, amino acids, taurine, and minerals of S. zunasi Bleeker were characterized, and the immunostimulatory properties of its glycoprotein were evaluated. The results indicated the presence of crude protein (19.66%), crude lipid (6.29%) and carbohydrate (0.74%) in S. zunasi Bleeker; monounsaturated fatty acids and polyunsaturated fatty acids in the fatty acid composition of S. zunasi Bleeker were 25.00% and 31.01%, respectively; S. zunasi Bleeker was rich in taurine (219 mg/100 g) and essential amino acids (5.57 g/100 g). In addition, the glycoprotein of S. zunasi consisted of protein and sugars, with a total content of 34.25% and 16.27%, respectively. The glycoprotein showed significant effects on promoting NO, TNF-α and IL-6 in a dose-dependent manner in RAW264.7 macrophage cells. Thus, these findings provide a scientific basis for the further utilization of glycoprotein from S. zunasi Bleeker.

The siphonostomatoid copepod Caligus undulatus Shen & Li, 1959 has been widely reported from plankton samples obtained from neritic and oceanic waters off coasts of the Indo-West Pacific and Atlantic Oceans. Until now, its fish host has remained unknown. This copepod belongs to an intriguing group of congeners that, despite being part of a chiefly parasitic group, are consistently found as zooplankters. Quite unexpectedly, in October 2019, a fish host of C. undulatus was discovered in the Seto Inland Sea, Japan—namely, the Japanese sardinella Sardinella zunasi (Bleeker, 1854). Both juvenile (chalimus) and adult individuals of this caligid were observed as parasites of the fish host. The discovery suggests that the species has an alternative life cycle as previously proposed for other purportedly ‘planktonic’ congeners and might frequently switch hosts during the adult stage. Thus, the C. undulatus group is newly proposed as a species group in the genus, in which five species are known as planktonic. Some hypotheses on the modified life cycle of caligids also briefly discussed.

Summary Length–weight and length–length relationships (LWRs and LLRs) for eight fish species collected quarterly by trawl net in Bohai Bay, China, were estimated in a total of 1,395 specimens from 2012 to 2015. These were Pholis fangi, Setipinna taty, Engraulis japonicus, Larimichthys polyactis, Thryssa kammalensis, Scomberomorus niphonius, Johnius grypotus and Sardinella zunasi. The LWRs for the last two fish species are first reports for FishBase.

【Species composition of the fish in the coastal waters of Jindo was determined using monthly sample collection by a gape net with wings in 2014. Of a total of 41 fishes collected, the dominant species were Engraulis japonicus, Thryssa kammalensis, Sardinella zunasi, Leiognathus nuchalis, Amblychaeturichthys hexanema, Neosalanx anderssoni, Acanthogobius flavimanus. The former three species were the migratory species and the other four species were the resident species. These 7 fishes accounted for 99.6% of the total number of individuals collected. Monthly species composition did not show a clear seasonal trend. The peak number of individuals occurred in May, lowest in November. Fish were divided into four groups by the cluster analysis.】

Based on trawls conducted in Laizhou Bay, China (119°05′–120°00′ E, 37°12′–37°40′ N), in 2010 and 2011, an analysis was made of changes in species composition, dominant species and community diversity of nekton. A total of 85 species were identified, which included 55 fish, 25 crustaceans and 5 cephalopod species. The most species-rich orders were Perciformes (28 species) and Decapoda (24 species). There was obvious seasonal variation in nekton number, mostly influenced by the number of fishes. Sardinella zunasi, Konosirus punctatus and Thryssa kammalensis were the main pelagic fishes in Laizhou Bay, Chaeturichthys stigmatias, Acanthogobius ommaturus and Cynoglossus joyneri were the main bottom fishes, Orgtosaquilla oratoria, Charybdis japonica and Crangon hakodatei were the main crustaceans, while squid (Loliolus sp.) represented the main cephalopods. Loliolus sp., Chaeturichthys stigmatias and Konosirus punctatus were the dominant species in both 2010 and 2011 and the Shannon-Wiener diversity index was highest in summer and lowest in winter. The Shannon-Wiener index was also higher in the north-east area and lower in the south-west. Since the late 538 生 物 多 样 性 Biodiversity Science 第 21卷 1950s, nekton number, especially of fish, has significantly declined due to human activities and climate change impacts. This is particularly true for cartilaginous fish, estuarine species, river-migratory species, large-scale economic fish, flatfish and takifugu. In parallel, dominant species, such as Trichiurus lepturus, Setipinna taty, Engraulis japonicus, Thryssa kammalensis have been replaced by smaller nekton.

In this study, we conducted field surveys to investigate and analyze species and length composition of catch from gape net with wings being set in two areas - Masari, Supomri - located in southern part of Jin-do for understanding fishing characteristics of gape net with wings fishery from March to September of 2011. And with those results, we attempted to propose fishery management strategy to harvest fisheries resources continuously. Catch obtained from field surveys comprised total 78 species, which accounted for 53 species of fish, 20 species of crustacean, 4 species of cephalopod and one of polychaete. As to species composition in weight, it showed that there was 88.5% for pisces, 9.0% for cephalopoda and 2.5% for crustacea. As to catch specifics by area, there was 36 species (596,891 individual, 456,551g) of pisces, 17 species (35,815 individual, 12,909g) of crustacea and 3 species (2,876 individual, 3,004g) of cephalopoda in Masari area. In Supumri area, there was 41 species (396,898 individual, 281,457g) of pisces, 15 species (16,113 individual, 7,772g) of crustacea and 4 species (6,792 individual, 72,329g) of cephalopoda and one polychaeta (36 individual, 11g). Catch of anchovy by month recorded on high level on June, July, September in both areas. When considering size composition by month, it was found that new populations recruit to these fishing grounds on June and September. Most of bycatch species including hairtail (Trichiurus lepturus), dotted gizzard shad (Konosirus punctatus), conger eel (Leptocephalous), Pacific sandlance (Ammodytes personatus), horse mackerel (Trachurus japonicus) were juvenile, and grass puffer (Takifugu niphobles), Kammal thryssa (Thryssa kammalensis), Japanese sardinella (Sardinella zunasi) were also small in size. As a result, it is considered that gape net with wings fishery which is likely to catch juvenile needs to be set fishing prohibit period for conserving above stocks during the period excluding main fishing periods of anchovy or fisheries management such as expanding mesh size for preventing juvenile catch.

Summary Intersexual gonads were detected in three clupeiform species, Sardinops melanostictus, Sardinella zunasi and Englaulis japonicus, collected in Tokyo Bay off Yokohama City, Japan, of which appearance rates were 18.2, 34.6 and 33.9 %, respectively. While spermatogenesis proceeded normally in these individuals, previtellogenic stage oocytes were detected outside of the testes in the hermaphrodites, appearing as a single cell or small clusters. The results suggest that these species are non-functional hermaphrodites. As intersexual gonads have been reported in other clupeiform species collected before significant pollution and/or at sites far from urban influences, such non-functional hermaphrodites may be common occurrence in the order. However, high rates of hermaphrodite appearance also suggest the possibility that the development of these oocytes were induced by environmental estrogens.

To elucidate the species compositions of estuarine and inshore fauna and compare productivities between them, catch were collected by bag nets in the Han River estuary off Ganghwa Island and the inshore waters off Jangbong Island for 24 hours at the spring tide from March to December 2010. Community structures of nekton assemblages were different with area, month, taxonomic groups. Although the diversity of estuarine nekton assemblage was lower than that of inshore nekton assemblage, the productivity of nekton assemblage in estuary was higher than that in the inshore waters. Nekton assemblages were distributed according to habitat environment: the estuarine species, Coilia mystus, Chelon haematocheilus, Collichthys lucidus were prominent in the Han River estuary off Ganghwa Island, and marine species, Thryssa kammalensis, Sardinella zunasi, Portunus trituberculatus were prominent in the inshore waters off Jangbong Island. Palaemon gravieri, Exopalaemon carinicauda, Synechogobius hasta were inhabited in both waters. The health assessment of estuarine ecosystem based on scientific research will be contributed to the effective management of estuary with determination of order and direction in policy.

We documented the temporal occurrence patterns and habitat use of fish in the Mangyeong River estuary on the western coast of Korea from February to December 2003 based on monthly samples collected with a stow net. A total of 46 fish species were collected during the study period. Chelon haematocheilus, Konosirus punctatus, Neosalanx jordani, Sardinella zunasi, Synechogobius hasta, and Thryssa kammalensis were the predominate species, accounting for 84.4% of the collected fish. We classified the fish as brackish water (BF), coastal migratory (CMF), diadromous (DF), or freshwater (FF) fish. BF such as C. haematocheilus, S. hasta, and Coilia nasus were the most abundant and were collected almost year-round. As water temperatures increased in spring, adult CMF, such as K. punctatus, S. zunasi, T. kammalensis, T. adelae, Johnius grypotus, Miichthys miiuy, and Larimichthys polyactis, entered the estuary. In summer, large numbers of their juvenile offspring were caught, indicating a peak in fish abundance. The juveniles grew in the estuary before moving out to deeper waters for overwintering. Diadromous juveniles, such as those of Anguilla japonica (commonly known as glass eel), were collected in the spring during their upstream migration. FF, such as Carassius cuvieri and Acheilognathus rhombeus, were collected during the rainy season. In terms of the number of species, the number of individuals, and the biomass, the ratio of BF to all other fish type classifications in the Mangyeong Estuary (without a dam) was higher than that in the Geum River estuary (with a dam). The fish assemblage in the Mangyeong Estuary still maintained estuarine characteristics before dike enclosure, providing habitats for BF, nursery grounds for CMF, and migratory pathways for DF.

Seventy-one Sardinella zunasi individuals collected from 5 locations in the Northwest Pacific were used in an AFLP analysis to examine the population genetic structure of S. zunasi . Using 4 selective primer combinations, 414 putative loci were detected, including 340 polymorphic loci (82.13%). Both AMOVA and pairwise F ST analysis detected significant population genetic structure between Chinese and Japanese populations, supporting separate stocks in this species. The UPGMA trees also detected significant spatial structure within S. zunasi . Pleistocene glaciations are hypothesized to be responsible for the genetic differentiation. The significant genetic differentiation found among S. zunasi populations might also be due to geographic isolation, because a pattern of isolation-by-distance was observed. The weaker but significant structures between the Japanese Aichi and Kagawa populations might be impacted by the semi-enclosed coastal topography there. No significant genetic structure was detected among the Chinese populations, perhaps because of S. zunasi ’s migratory behavior and ocean current patterns.

Knowledge of population genetic structure plays an important role in fisheries management. In this research, Inter-Simple-Sequence-Repeat (ISSR) markers were employed to evaluate the genetic structure of Japanese sardinella (Sardinella zunasi) populations in the Northwest Pacific. Eighty seven individuals from 5 locations were screened using 4 highly polymorphic primers. A total of 173 polymorphic loci were detected out of 191 loci amplified. Small but significant genetic differentiation was detected between the Chinese and Japanese populations by both AMOVA and pairwise F ST analyses, which was further supported by cluster analysis. We consider that climate change during glaciations should be responsible for the genetic differentiation. Isolation by geographic distance among populations was observed, indicating that the distance might also lead to the genetic differentiation. However, no genetic structure was found within the populations off both the Chinese and Japanese coasts, indicating a high-level along-coast gene flow, which might result from ocean current transport and common ground for over-wintering.

During June, August and October 2006, there were three multi-disciplinary surveys carried out in the Changjiang River estuary and its adjacent waters (122°00′–125°00′E, 27°50′–34°00′N) by R/V Beidou to study the species composition and abundance of ichthyoplankton (including fish eggs, larvae and juveniles), the spatial distribution of fish spawning ground and their relationship with habitat factors. There were 29, 29 and 25 grid stations sampled in the three cruises, respectively. The ichthyoplankton samples were collected by horizontally towing with a macro-plankton net (mouth diameter 80 cm, length 270 cm, mesh size 0.50 mm) at the sea surface, and the towing speed was 3.0 n mile/h at each sampling station. The towing lasted for 10 min. After hauling for each station, habitat factors including temperature and salinity were measured by Sea Bird-25 CTD. Samples were preserved in 5% formaldehyde solution immediately after sampling for analysis in laboratory. Since the trawl speed could not be accurately evaluated due to the effects of ocean currents and wind-induced wave, the amount of ichthyoplankton was evaluated by actual number of the sampling haul in each station. Ichthyoplankton collected were divided into three categories: dominant species, important species and main species by the index of relative importance ( IRI ). There are 71 species (including 1200 fish eggs and 2575 fish larvae and juveniles) collected during 3 cruises and 59 species have been correctly identified to species level, which belongs to 50 genera, 37 families and 9 orders; while 5 species can only be identified to genera level, 1 species only identified to family level and 6 species identified to order level. These 59 species identified to species level and 5 species identified to genera level are divided into three ecological patterns, i.e., brackish water species, neritic water species and coastal water species. Warm water species have 34 species in those 59 species identified to species level, accounting for 57.63%, warm temperature species have 25 species, accounting for 42.37%. According to the analysis of IRI , the dominant species are Engraulis japonicus (in June and August, that is important species in October), Scomber japonicus (in August), and Johnius grypotus (in October) during the survey; important species are Cynoglossus joyneri (in June and August), Trichiurus lepturus (in June, August and October), Gonorhynchus abbreviatus (in August), Stolephorus commersonii (in October), Saurida undosquamis (in October) and Saurida elongate (in October), and main species have 12 species in June, 9 species in August and 10 species in October, respectively. The amount of fish eggs and larvae of the dominant species, important species and main species (28 species) are 97.50% and 97.13% of the total amount of fish eggs and larvae, respectively, which are the important composition of fish eggs and larvae in the Changjiang River estuary and its adjacent waters. In June and August of 2006, if compared with that in corresponding months in 1986, there are great changes in the habitat factors especially for temperature and salinity in the investigating areas: high salinity water from off-shelf is much closer to the coastal areas which results in the dramatic increase of sea surface salinity during all three surveys. Sea surface temperature, on the other hand, decreases distinctively in June, but significantly increases in August. The run-off of the Changjiang River greatly reduced due to the long-term drought in summer 2006, which is responsible for the great changes of habitat factors in the Changjiang River estuary and its adjacent waters. The habitat of the Changjiang River estuary is greatly changed, which consequently has significant influences on the spawning, breeding and the spatial distribution of spawning ground of neritic water species, such as Sardinella zunasi , Thryssa kammalensis , Thryssa mystax , Setipinna taty and S. commersonii ect, and coastal water species, such as Ilisha elongate and Konosirus punctatus ect.

Age, growth and maturity of the Japanese sardinella Sardinella zunasi were estimated from scale readings, observations and measurements of gonads. Specimens were collected by angling and set net as well as from commercial landings. Scale rings were found to be formed once a year from September to October. The matured are at least 9.5 cm in standard length for both sexes and the spawning season extends from June to September and its peak is in August. By applying the maximum likelihood method to the standard length-at-age data, we found that von Bertalanffy's growth equation with seasonal changes is a better fit than any other type of growth model, i.e. SLsub(t)= 12.53[1-exp(-0.6254(F(t)+ 0.534))]F(t) = t-(1/2pi)sin 2pi(t-0.259) for males, and SLsub(t)= 13.42[1-exp(-0.4990(F(t)+ 0.713))]F(t) = t-(1/2pi)sin 2pi(t-0.287) for females, where Ssub(t)Lt is standard length in cm and t is age in year. The growth of females is statistically higher than that of males. SLs at which 50% of specimens attain maturity were estimated by logistic analysis as 10.11 and 10.32 cm for males and females respectively.

Seasonal variation in species composition of fish in the Geum River estuary was determined using monthly samples collected with a bag net from February to December 2003. Of a total of seventy-three species collected, four groups of fishes were distinguished. Estuarine fishes such as Chelon haematocheilus and Synechogobius hasta were collected almost all the seasons and predominated in abundance during cold months. Coastal fish species such as Sardinella zunasi, Konosirus punctatus, Engraulis japonicus, Johnius grypotus and Thryssa kammalensis were dominated from late spring to autumn. Their adults entered into the estuary in spring and a large number of their juveniles were collected in summer and autumn till moving out to deeper waters for over-wintering. A few freshwater fishes were collected when the freshwater was discharged during the rainy season. Anguilla japonica elvers (diadromous fish) and Coilia nasus (amphidromous fish) were collected in spring during their upstream migration. The principal component analysis revealed that the seasonal variation in species composition of fishes was principally determined by water temperature and/or water temperature related factors.

To clarify the feeding habits of tidal mudflat fishes, the gut contents of 29 fish species, collected from unvegetated tidal mudflats in Tokyo Bay, central Honshu, Japan, were examined. Ontogenetic changes in food preference were recognized in 21 species, including several of commercial importance (e.g. Acanthogobius flavimanus, Konosirus punctatus, Mugil cephalus cephalus, Plecoglossus altivelis altivelis, and Sardinella zunasi). In general, larvae and/or juveniles of these species fed mainly on small zooplankton or benthic harpacticoid copepods, later switching to other prey items with growth (e.g. gammaridean amphipods, mysids, polychaetes, detritus, bivalves, and juvenile fishes). A cluster analysis based on dietary overlaps showed that the tidal mudflat fish assemblage comprised six feeding guilds (small benthic and epiphytic crustacean, zooplankton, detritus, mollusc, polychaete, and fish feeders). Of these, small benthic and epiphytic crustacean feeders were the most abundantly represented in the number of species.

Seasonal variation of the fishery resource in the shallow waters of Ganghwado tidal flat was investigated using monthly collected samples with a fence net from June 1998 to May 1999. Thirty-six species were found including 27 fish species, 6 crustaceans, and 3 molluscs. Of the fish, Konosirus punctatus, Sardinella zunasi Liza haematocheila and Synechogobius hasta dominated in the number of individuals and in biomass A few number of resident species, such as L. haematocheila and S. hasta, were collected only during the cold months. As the water temperature increased in the spring, the adult migratory fish such as K. punctatus and S. zunasi, were collected. In the summer, the juvenile fish recruited in the shallow water showing a peak in fish abundance. The data suggested that they grew until late autumn before moving to deeper waters for over-wintering. The principal component analysis showed that the seasonal variation in species composition was principally determined by water temperature and/or water temperature related factors. The species composition of the fish assemblage in the study area suggested that these species are highly adapted to extreme seasonal temperature variation and high water turbidity.

The new polyenzyme method for making gravy fromHarengula zunasi offal involves protein enzymolysis with flavorase after proper alkaline and neutral protease levels were established by orthogonal trials to select the best hydrolytic conditions for processing offal with alkaline and neutral protease. The conditions for the polyenzyme method were pH of 7.0, temperature of 50°C, alkaline and neutral protease concentration of 1.5% respectively, hydrolysis time of 120 min, and flavorase concentration of 2.0%, for 60 min. The new gravy-making technology yields a nutritious and delicious gravy containing 40.3% of total essential amino acids, with delicious amino acids Glu, Asp, Gly, Ala, Pro and Ser comprising 49.5%, total and amino nitrogen being respectively 1.9 and 1.1 g/100 g (amino acid nitrogen being 61.0% of total nitrogen), The polyenzyme method was used to make 14.8% protein gravy fromHarengula zunasi offal. In addition, inorganic elements, the phosphorus content is the highest.

Variation in fish assemblages was investigated to clarify the migration patterns and growth rates of marine, brackish and freshwater species in three adjacent areas with different salinities. In the polyhaline Lake Nakaumi, Japan, benthic fishes and crustaceans were negatively affected by oxygen depletion in the lower water under stratification during the warm seasons. On the other hand, marine and brackish species that once migrated into the Honjo Area, which is isolated from L. Nakaumi and has a homogeneous salinity structure, remained and grew there until winter. In the mesohaline Lake Shinji, two types of fishes were distinguished: one that migrated into the lake during the warmer seasons; and the other which stayed in the lake during winter. Fauna and production in L. Shinji were compared with those of a comprehensive study carried out approximately 35 years ago. For 35 years, Konosirus punctatus and Sardinella zunasi have increased in abundance, while Carassius sp. and Hypomesus nipponensis have decreased. Even with the recent acceleration in eutrophication of the lake, fish production during the warmer seasons has not declined for 35 years, but the fish fauna have drastically changed.

The concentrations of brominated dioxins which are polybrominated dibenzo-p-dioxins/polybrominated dibenzofurans (PBDD/DFs) and mono-bromo polychlorinated dibenzo-p-dioxins/dibenzofurans, polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) were investigated in a total of 45 fish samples collected from three regions in Japan. In the brominated dioxins, 1,2,3,4,6,7,8-heptabromodibenzofuran (HpBDF) was the most abundant congener, and it was found in seven fish samples at 0.10-25.6 pg/g wet weight (ww). The highest concentration of 1,2,3,4,6,7,8-HpBDF was found in the pike eel. Regarding other congeners, 2,3,7,8-tetrabromodibenzo-p-dioxin was detected in the sea bream at 0.02 pg/g ww, and 2,3,7,8-tetrabromodibenzofuran was detected in the conger eel at 0.03 pg/g ww. 3-Bromo-2,7,8-trichlorodibenzofuran was detected in the Sardinella zunasi and the conger eel at 0.01 pg/g ww and 0.02 pg/g ww, respectively. Using toxic equivalency factors of chlorinated dioxins, we calculated the PBDD/DFs concentrations of these fish samples at 0.001-0.256 pg TEQ/g ww. PBDEs were detected in all of the fish samples. The concentrations of total PBDEs were 0.01-2.88 ng/g ww. The seerfish and the yellowtail containd PBDEs in high concentrations. The most dominant congener in most of the fish was 2,2',4,4'-tetrabromo diphenyl ether. TBBPA was detected in 29 fish samples at 0.01-0.11 ng/g ww. The mean level of TBBPA was about one-tenth or less of the total level of PBDEs. A good correlation was obtained between total PBDEs and fat content. On the other hand, no correlation was obtained between TBBPA and fat content. The daily intakes from fish were estimated to be 0.58 ng/kg body weight (bw)/day for total PBDEs, 0.03 ng/kg bw/day for TBBPA, and 0.01 pg TEQ/kg bw/day for brominated dioxins in the case assuming that the average bw of a Japanese adult person is 50 kg and that the average fish consumption is 82 g/day. For PBDEs, the provisionally calculated value was much less than the lowest observed adverse effect level value (1 mg/kg bw/day). For brominated dioxins, the daily intake was at a very low level compared with the Japanese daily intake of polychlorinated dioxins from fish. Even if the value of PBDD/DFs is added to the amount of chlorinated dioxin exposure, it was estimated that it is less than the tolerable daily intake (4 pg TEQ/kg bw/day) in Japan.

Karyotypes of three species of the subfamily Clupeinae collected from northern Japan were analyzed by in vitro methods and their cellular DNA contents were measured using an integrating microdensitometer.Sardinella zunasi andSardinops melanostictus show very similar karyotypes: 2n = 48, consisting of acrocentric or subtelocentric chromosomes with a gradual decrease in chromosome size, but with differences in cellular DNA of 2.32 and 2.69pg/cell respectively.Clupea pallasii differs from the aforementioned species in karyotype: 2n = 52, consisting of 6 metacentric or submetacentric chromosomes and 46 acrocentric or subtelocentric chromosomes, with a cellular DNA content of 1.96 pg/cell. The results showed two different modes in karyological evolution within the subfamily Clupeinae, i.e. an increase of cellular DNA content without apparent change in karyotype, as shown bySardinella zunasi andSardinops melanostictus, and less change in cellular DNA content but with marked change in karyotype, as shown byClupea pallasii.