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There are two possible spawning sites of the tiger puffer Takifugu rubripes near Nanao Bay in the Sea of Japan: one near Hachiro Lagoon, approximately 390 km northeast of Nanao Bay, and another in Wakasa Bay, approximately 170 km west of Nanao Bay. Tagging research suggests that these two spawning sites represent different subpopulations. In the present study, Nanao Bay spawning sites were identified by mitochondrial DNA control region sequencing of eggs collected using a sledge net in May and June of 2009. The spawning sites were distributed in a small region with a sandy bottom at a depth of 17.5-20.5 m (water temperature 13.07-16.56 °C, salinity 33.95-34.12). The population structure of T. rubripes around Nanao Bay was also investigated using DNA analysis of mature adult samples from three locations. Genetic differentiation was not significant among the adults, suggesting the presence of gene flow resulting from broad dispersal of individuals from the three locations. [ABSTRACT FROM AUTHOR]

Vibrio harveyi infection occurred with a moderate mortality in tiger puffer, Takifugu rubripes (Temminck et Schlegel), in autumn 2007, at a mariculture farm in western Japan. The diseased fish showed nodular lesions in the branchial chamber and the inner surface of the operculum. Histopathologically, the lesions comprised granulation tissue containing many suppurative foci allowing propagation of the bacteria and granuloma encapsulating abscesses with a decrease in bacteria. The bacteria were disseminated in visceral organs including the spleen, kidney, liver, and myocardium, resulting in the formation of granulomatous lesions. Two groups of tiger puffer juveniles were artificially infected by an intramuscular injection with an isolate (1.0_108 CFU/fish). During the experimental period, 20% mortality occurred within 4–6 days post-infection (d.p.i). The fish sampled on 4 d.p.i showed abscesses in the lateral musculature at the injection site. The fish sampled 5 d.p.i. displayed the production of granulation tissue containing many suppurative foci, which replaced the necrotic dermis and lateral musculature. Surviving fish (15 d.p.i.) had granulomatous lesions in the lateral musculature at the injection site. Pyogranulomatosis is pathognomonic in V. harveyi infection of tiger puffer. [ABSTRACT FROM AUTHOR]

We identified the optimal location for releasing hatchery-produced juveniles of ocellate puffer (Takifugu rubripes) for stock enhancement by tag and release experiments. The fish were released at four areas, Suruga Bay, Enshu Nada, Ise Bay, and Kumano Nada, along the central coast of Honshu Island in Japan from 2001 to 2005. Approximately 10,000-40,000 cultured puffer fish were released in these areas in 23 groups. Tagged fish were mainly recaptured at age 0 by small-scale trawl net fishing in Ise Bay, and by longline fishing at age one or older in Suruga Bay, Enshu Nada, and Kumano Nada. Overall average recapture rate yielded 13.0% for the Ise Bay release group compared with 2.0%, 2.9%, and 0.7% for the Suruga Bay, Enshu Nada, and Kumano Nada release groups, respectively. Even in the Ise Bay area, significant differences in recapture rates were observed among three release locations. Lower recapture rates were presumably caused by predation, because tagged fish were found in the intestines of Japanese sea bass (Lateolabrax japonicus). It is suggested that release locations should be carefully evaluated and chosen to reduce initial mortality even if cultured ocellate puffer are released in Ise Bay. One of the optimal release locations is specified in shallow areas, such as off Tokoname, which are inhabited by wild juvenile ocellate puffer. [ABSTRACT FROM AUTHOR]

Abstract: We recently identified approximately 1400 conserved non-coding elements (CNEs) shared by the genomes of fugu (Takifugu rubripes) and human that appear to be associated with developmental regulation in vertebrates [Woolfe, A., Goodson, M., Goode, D.K., Snell, P., McEwen, G.K., Vavouri, T., Smith, S.F., North, P., Callaway, H., Kelly, K., Walter, K., Abnizova, I., Gilks, W., Edwards, Y.J.K., Cooke, J.E., Elgar, G., 2005. Highly conserved non-coding sequences are associated with vertebrate development. PLoS Biol. 3 (1), e7]. This study encompassed a multi-disciplinary approach using bioinformatics, statistical methods and functional assays to identify and characterise the CNEs. Using an in vivo enhancer assay, over 90% of tested CNEs up-regulate tissue-specific GFP expression. Here we review our group''s research in the field of characterising non-coding sequences conserved in vertebrates. We take this opportunity to discuss our research in progress and present some results of new and additional analyses. These include a phylogenomics analysis of CNEs, sequence conservation patterns in vertebrate CNEs and the distribution of human SNPs in the CNEs. We highlight the usefulness of the CNE dataset to help correlate genetic variation in health and disease. We also discuss the functional analysis using the enhancer assay and the enrichment of predicted transcription factor binding sites for two CNEs. Public access to the CNEs plus annotation is now possible and is described. The content of this review was presented by Dr. Y.J.K. Edwards at the TODAI International Symposium on Functional Genomics of the Pufferfish, Tokyo, Japan, 3–6 November 2004. [Copyright &y& Elsevier]

Pathological changes in cultured tiger puffer, Takifugu rubripes , with emaciation disease in Kyushu, Japan were studied histologically. In most cases, diseased fish were heavily infected with at least one of three myxosporeans (Myxidium fugu , Myxidium sp. and Leptotheca fugu ) and two unidentified hyperparasitic microsporeans, attached to, or in, the intestinal epithelium. Myxidium fugu attached to the surface of the epithelium, caused no noticeable effects on the host tissue, irrespective of its infection with the hyperparasite. Myxidium sp., which proliferated in the epithelium, induced severe pathological changes including accumulation of cell debris between the epithelium and lamina propria and resultant detachment of the epithelium. Leptotheca fugu, another histozoic myxosporean, induced degeneration of the epithelium, associated with massive infiltration of macrophages into the epithelium to encapsulate parasites. When L. fugu was infected with its hyperparasitic microsporean, shortened villi were also observed. This is probably because passage of macrophage-parasite aggregates through the basement membrane of the epithelium severely damaged the epithelial structure. It is evident histologically that, unlike epicellular M. fugu , histozoic Myxidium sp. and L. fugu with or without hyperparasitic microsporeans, were highly pathogenic to host fish. This strongly suggests that they are causative agents of the emaciation disease. [ABSTRACT FROM AUTHOR]

The article focuses on the species of piscicolid leech which is found to be parasitic on seaperch Lateolabrx japonicus and on kusafugu Takifugu niphobles in Japan. The species were gathered from bastard halibut Paralichthys olivaceus and Japanese pufferfish Takifugu rubripes which were cultured in the Seto Island. It stated that the 4 fish species were hosts for Limnotrachelobdella okae.

Pufferfish accumulate tetrodotoxin (TTX) at high levels in liver and ovary through the food chain. However, the mechanisms underlying TTX toxification in pufferfish have been poorly understood. In order to search gene candidates involved in TTX accumulation in the torafugu pufferfish Takifugu rubripes, a custom 4x44k oligonucleotide microarray slide was designed by the Agilent eArray program using oligonucleotide probes of 60 bp in length referring to 42,724 predicted transcripts in the publicly available Fugu genome database. DNA microarray analysis was performed with total RNA samples from the livers of two toxic wild specimens in comparison with those from a nontoxic wild specimen and two nontoxic cultured specimens. The mRNA levels of 1108 transcripts were more than 2-fold higher in the toxic specimens than in the nontoxic specimens. The levels of 613 transcripts were remarkably high, and 16 transcripts encoded by 9 genes were up-regulated more than 10-fold. These genes included those encoding forming structural filaments (keratins) and those related to vitamin D metabolism and immunity. It was also noted that the levels of the transcripts encoding serpin peptidase inhibitor clade C member 1, coagulation factor X precursor, complement C2, C3, C5, C8 precursors, and interleukin-6 receptor were high in the toxic liver samples., (Copyright © 2013 Elsevier Ltd. All rights reserved.)