• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.708-715
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• 2023

Hybridization is a major production method used to combine beneficial traits from two different species to obtain a potentially dominant trait. In China, Takifugu obscurus and T. rubripes were artificially crossed, and the resulting hybrids had an average body weight 38.06-8.93% higher than that of the parental species, which enabled the hybrids to be grown in freshwater. This study aimed to provide the basic data necessary for the classification of T. obscurus♀×T. rubripes♂ hybrids in terms of economic value and market potential. Morphological comparing the morphology of hybrids and parental species, we discovered that the hybrids had intermediate traits of the parental species. In morphometrics, the hybrid index (HI) value of head length against standard length was close to the trait of T. rubripes, and the HI values of preanal length and predorsal length were close to those of T. obscurus; however, the HI values of nasal length, snout length, length of anal fin, length of pectoral fin, caudal peduncle depth and caudal peduncle length were found to be unique characteristics of the hybrids. Regarding molecular analysis, a 99.8% nucleotide sequence similarity was found between the hybrid and T. obscurus.

• Development and Reproduction
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• v.1 no.1
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• pp.29-36
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• 1997

Experiments were performed to study the effects of diluents, cryoprotectant, equilibration time, thawing temperature and addition of BSA and egg yolk. Among the various diluents, Alsever's solution was the best for sperm cryopreservation. A combination of Alsever's solution and 15% ethylene glycol showed the better results than others did. Sperm activity indection and survival rate gradually decreased with the equilibration time. The appropriate thawing temperature was 30 ${\pm}1^{\circ}$C. These results indicate that sperm cryopreservation methods can be developed in tiger puffer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.6
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• pp.447-453
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• 2006

Toxicity of two species of puffer fish, Takifugu porphyreus and Takifugu rubripes, collected from coastal regions of Korea, was determined using a mouse bioassay, In T. porphyreus, the proportion of toxic specimens containing ${\ge}$ 10 MU/g was 58.3% for the ovary, 32.6% for the skin, 12.0% for the gallbladder, 11.6% for the liver and intestine, and 9.3% for the fin; no toxicity was detected in the muscle and testis using the mouse bioassay. The highest toxin levels were 531 MU/g in the liver, 253 MU/g in the intestine, 136 MU/g in the gallbladder, 118 MU/g in the skin, 116 MU/g in the ovary, and 108 MU/g in the fin. The skin, which is used for human consumption, showed significantly high toxicity with an average of $11{\pm}3\;(mean{\pm}SE) MU/g$. Takifugu porphyreus toxicity also exhibited remarkable regional variation. In T. rubripes, the proportion of toxic specimens was 25.0% for the ovary, 15.8% for the liver, 11.1% for the gallbladder, and 5.3% for the fin and intestine; no toxicity was detected in the muscle, skin, or testis. Among the organs, the highest toxin levels were 228 MU/g in the ovary, followed by 112 MU/g in the liver, 28 MU/g in the gallbladder, 18 MU/g in the intestine, 11 MU/g in the fin, and 8 MU/g in the skin. Thus, we found acceptable toxin levels in the edible muscle and skin of T. rubripes and in the muscle of T. porphyreus. However, the skin of T. porphyreus, which showed significantly high toxicity, requires special attention when used for human consumption.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.353-358
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• 1998

Experiments were performed to find out the physico-chemical properties of milt, and morphological changes of cryopreserved spermatozoa in tiger puffer, Takifugu rubripes. The average number of sperm and spermatocrit in milt stripped were $9.81{\pm}0.34{\times}10^{10}/m{\ell}$ and $97.8{\pm}0.8$, respectively. While total lipid concentration from seminal fluid was higher than that from sperm, total protein concentration from sperm was higher than that from seminal fluid, Na and K concentrations in sperm and those in seminal fluid were similar each other, However, glucose from sperm and seminal fluid were not detectable. Spermatozoon of tiger puffer was consisted of head, middle Piece and tail. Size of head showing horseshoe shape was $0.65{\pm}0.10{\mu}m$ in diameter and $1.35{\pm}0.30{\mu}m$ in length. The head fully containing chromatin did not have acrosome. Mitochondrion in middle piece was $0.2{\mu}m$ in average diameter and flagellum showed 9+2 structure. A few of cryopreserved spermatozoa showed morphologically loose or swollen plasma membranes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.4
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• pp.404-410
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• 2018

Takifugu rubripes, T. chinensis, T. pseudommus and an unidentified species were morphologically and genetically studied. Morphology was compared using external morphology and the genetic analysis was conducted using mitochondrial DNA cytochrome oxidase I (COI) and cytochrome b (Cyt b). The morphological characteristics of T. rubripes, T. chinensis and T. pseudommus were confirmed, as reported previously. The unidentified species was confirmed to have the characteristics of T. rubripes and T. chinensis. The COI sequences of the four species were 99-100% similar; genetic distance was d=0.0000 and Cyt b genetic distance was d=0.0000-0.00834. Species in the phylogenetic tree belonging to the same group could not be classified genetically. In conclusion, the unidentified species was considered to be a hybrid between T. rubripes and T. chinensis.

• Korean Journal of Environmental Biology
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• v.39 no.1
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• pp.6-15
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• 2021

Various biometric and geometric measures were used to discriminate between the morphologically similar river puffer, Takifugu obscurus, tiger puffer, T. rubripes, their hybrids, and their triploid hybrids. The hybrids and triploid hybrids had greater anal fin width, nostril width, and snout length than the parental species (p<0.05). However, they had less caudal peduncle depth, inter-orbital width, head length, and head width(p<0.05). The morphometric and meristic characteristics of the hybrids and triploid hybrids were either intermediate between the parental species or more similar to those of one parental species. However, the external morphology of the hybrids and triploid hybrids was predominantly maternal. The triploid hybrids had asymmetry in the fin rays and gill raker numbers. This study identified phenotypic characteristics by distinguishing the morphological variables of river puffer, tiger puffer, their hybrids, and their triploid hybrids.

• Journal of Aquaculture
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• v.10 no.3
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• pp.273-279
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• 1997

Condition for fresh storage of tiger puffer in the liquid state were investigated in several experiments. When marine fish ringer solution and 1% NaCl were used as the diluent for the short-term preservation method, spermatozoa activity index (SAI) and survival rate showed the best result among the various diluents tested. The dilution rate for the shortterm preservation of spermatozoa was suitable between 3 and 5 times with the 1% NaCi diluent. The appropriate range of temperature for the short-term preservation showed between 0 and $5^{\circ}C$. In order to keep high SAI and survival rate of spermatozoa, antibiotic addition (800 ppm neomycin) could be suggested. These results indicated that the short-term preservation method could be employed in tiger puffer spermatozoa.

• Journal of fish pathology
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• v.19 no.2
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• pp.99-108
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• 2006

Diseased tiger puffer (Takijugu rubripes) showed anorexia and severe anemia in the gills. In wet mount preparations Heterobothrium sp. with 4 sets of clamps on the opisthohaptor attached to the gill filaments of the diseased fish. From the drum-shaped filter for filtration of the culturing water and the sediment of aquarium held the diseased fish in the laboratory, their eggs forming long strings through connection of the bipolar filaments could be easily collected. The parasites with 4 pairs of clamps on the opisthohaptor were 2.38mm in length and 0.71 mm in width, but had no isthmus which was separated the opisthohapor from the body proper. The parasites could be easily distinguished from Heterobothrium tetrodonis and H. okamotoi in the absence of distinct isthmus, and resembled H. yamagutii described from the gills of Takifugu xanthopterus in Japan. Their eggs were yellowish spindle in shape and 180-200 x 5-6 Iffil in size, which were pointed at both ends. The eggs were linked to adjacent egg shells like a string of beads by the filaments. Onchomiracidia, ciliated larvae spawned from the eggs were 133 Iffil (120-146 Iffil) x 751ffil (68-80 Iffil) in size. The length of the ciliates was 12 Iffil in the anterior part of the larvae and 14 Iffil in the posterior part. Round or leaf-shaped young parasites attached on the secondary gill lamellae. There was a tendency that most of round smaller parasites without an opisthohaptor were found in the middle part of the gill lamellae while leaf-shaped larger ones with a opisthohaptor attached on the distal part of the gill filaments. Each clamp of mature parasites grasped one secondary gill filament which resulted in bending of the filaments and hyperplasia of the epithelium and mucous cells. In the branchial cavity around the pseudobranch, mature parasites grasped the adjacent ones by means of the clamps, and the epithelia of the branchial cavity around the parasites showed severe irregular hyperplasia and erosion with strongly PAS-positive mucous cells.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.4
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• pp.467-473
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• 2016

Several of our recent studies have focused on mass production of the marine Cladoceran Diaphanosoma celebensis, which can serve as a feed substitute for Artemia nauplii in the culture of larval marine fish. We compared the growth and survival rates of tiger puffer Takifugu rubripes fed D. celebensis with those fed Artemia. The group fed D. celebensis showed an increase in growth from 0.10 g to 1.78 g, while the group fed enriched Artemia had a growth from 0.10 g to 0.92 g. The survival rate of fish fed D. celebensis was 86.7% while that of fish fed enriched Artemia was 51.1%, indicating that the former group was superior to the latter both in growth and survival rate. Fatty acid analysis revealed that D. celebensis fed Nannochloropsis oculata and Schizochytrium sp. had an eicosapentaenoic acid (EPA) content of 16.42% and a docosahexaenoic acid (DHA) content of 3.93%. Meanwhile, juvenile tiger puffer fed D. celebensis had an EPA content of 9.12% and a DHA content of 10.69%. Juvenile tiger puffer fed D. celebensis had a similar n-3 highly unsaturated fatty acid content to that of tiger puffer fed enriched Artemia which had an EPA content of 5.82% and a DHA content of 15.90%, indicating that no additional enrichment was required.

• Journal of fish pathology
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• v.31 no.2
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• pp.87-92
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• 2018

A case of disease was occurred in tiger puffer, Takifugu rubripes, reared in circulated system (water temperature was about $20^{\circ}C$) on land in Korea. Diseased fish showed a unique external sign, the cloudy skin ulcer in various sizes. We investigated the cause of disease, and isolated one pure cultured bacterium, TP01. This had 99.7% homology with Vibrio atlanticus by sequence analysis of the 16S rRNA and rpoA genes. TP01 showed some differences with other reported V. atlanticus strains in the biochemical characteristics as like Voges-Proskauer test and gelatin hydrolysis.