Rock Fish Research Articles

Artificial Light at Night (ALAN) causes size-dependent effects on intertidal fish decision-making

Artificial Light at Night (ALAN) alters cycles of day and night, potentially modifying species' behavior. We assessed whether exposure to ALAN influences decision-making (directional swimming) in an intertidal rockfish (Girella laevisifrons) from the Southeastern Pacific. Using a Y-maze, we examined if exposure to ALAN or natural day/night conditions for one week affected the number of visits and time spent in three Y-maze compartments: dark and lit arms (“safe” and “risky” conditions, respectively) and a neutral “non-decision” area. The results showed that fish maintained in natural day/night conditions visited and spent more time in the dark arm, regardless of size. Instead, fish exposed to ALAN visited and spent more time in the non-decision area and their response was size-dependent. Hence, prior ALAN exposure seemed to disorient or reduce the ability of rock fish to choose dark conditions, deemed the safest for small fish facing predators or other potential threats.

Effect of Ultra-High-Pressure Homogenization Processing on the Microbiological, Physicochemical, and Sensory Characteristics of Fish Broth.

The effect of ultra-high-pressure homogenization (UHPH) treatments at 300 MPa at inlet temperatures (Ti) between 45 and 75 °C on the microbiological, physical, and sensorial characteristics of fish broth was evaluated. Before the application of UHPH treatments, different fish broth formulations were tested, selecting the formula with the best organoleptic and nutritional characteristics and the lowest cost, containing 45% monkfish heads and rock fish in the same proportion. The microbiological shelf-life of fish broth during cold storage at 4 and 8 °C was extended by a minimum of 20 days by applying UHPH treatments at inlet temperatures (Ti) between 45 and 65 °C. Fish broth UHPH-treated at Ti = 75 °C was microbiologically sterile during storage at 4 °C, 8 °C, and room temperature. Fish broth UHPH-treated was physically stable, significantly reducing the particle size. Color showed higher luminosity and lower yellowness as the inlet temperature increased. In fish broth UHPH-treated at Ti = 75 °C, selected for its microbiological stability, no differences were observed in the nutritional composition, antioxidant activity, and sensorial perception compared to untreated fish broth. Hence, UHPH treatments showed to be an alternative to preserving fish broth with an improved microbiological shelf-life and good sensorial characteristics.

Barren environment damages cognitive abilities in fish: Behavioral and transcriptome mechanisms

The surrounding environments that animals inhabit shape their behavioral phenotypes, physiological status and molecular processes. As one of the driving forces for the adaptation and evolution of marine animals, environmental complexity has been shown to affect several behavioral characteristics in fish. However, little is known about the effects of environmental complexity on fish spatial cognition and about the relevant regulatory mechanisms. To address this theoretical gap, black rockfish Sebastes schlegelii, which is a typical rock fish species, were exposed to laboratory-based small-scale contrasting environments (i.e., spatially complex environment vs. spatially barren environment) for seven weeks. Subsequently, the spatial cognitive abilities and behavioral performance during captive period were determined, and transcriptome sequencing and analyses for fish telencephalon were conducted. In general, the fish from barren environment had significantly lower spatial learning and memory abilities compared with the fish from complex environment (i.e., the complex fish exited the maze faster). During the whole captive period, the frequency of aggressive behavior among barren fish was significantly higher than complex fish. And meanwhile, the group dispersion index of barren group was also significantly higher than complex group, which indicated that complex fish tended to distribute in a more homogeneous pattern than barren fish. Through transcriptomic analyses, a series of differentially expressed genes and pathways which may underpin the damaged effects of barren environment on fish spatial cognition were identified, and these genes mainly related to stress response, metabolism, organism systems and neural plasticity. However, no significant differences in growth performance, locomotor activity (indicated by swimming behavior and rotatory behavior) between treatments were detected. Based on these results, mechanisms in the levels of behavior and molecule were proposed to explain the environmental effects on fish cognition. This study may provide fundamental information for deeply understanding the environmental effects on marine animals.

Carved in Stone: What Yangtze Rock Fish Tell of China’s Climate

Carved in Stone: What Yangtze Rock Fish Tell of China’s Climate

Severe Historical Droughts Carved on Rock in the Yangtze

AbstractThe White Crane Ridge (WCR) Rock Fish, now submerged under the backwater of the Three Gorges Reservoir in the Yangtze River, are affirmed as one of the earliest hydrologic observations ever made in any large river in the world. The usually in-water monument provides highly valuable historical records of severe droughts in the upper Yangtze over the last 1,200 years. This article updated the historical drought chronology previously developed based on the WCR inscriptions, which can be applied in assessment of extreme climatic and hydrological risks, and also made a preliminary analysis of changes of the severe drought frequency during the last thousand years in the upper Yangtze. The analysis shows that the severe droughts occurred more frequently during the Medieval Climate Anomaly (MCA), relatively less so during the Little Ice Age (LIA), and once again more often under the background of modern global warming. It was suggested that a generally warmer Euro-Asian continent during the MCA was in favor of the stronger East Asian summer monsoon, and the resulting less precipitation and more severe droughts of the Yangtze and the lower water level at the Three Gorges area on the centennial scale, and vice versa for the period of the LIA. The results would help in understanding the causes and mechanisms of the regional climate change and variability, and also in taking measures in the fields of the watershed management to cope with the long-term change in climatic and hydrologic droughts.

Shorelines in the Desert: Mapping Fish Trap Features along the Southwest Coast of Ancient Lake Cahuilla, California

ABSTRACTIn the desert of southeastern California, the geological and archaeological remnants of a once massive lake, Lake Cahuilla, are still visible. One of the most distinctive features marking Lake Cahuilla's relic shorelines is a series of rock fish trap features that, in some cases, stretch across thousands of square meters. These fish traps are severely understudied, and systematic archaeological survey can help scientists reconstruct the dynamic human-environmental history of the region. The large number of fish traps along with the rocky desert terrain, however, make traditional pedestrian archaeological surveys both difficult and inefficient. We used unmanned aerial vehicle (UAV) technology along with traditional archaeological methods to conduct surveys and identify patterning in the shapes, orientations, and frequencies of fish traps. Our study demonstrates the potential of emerging archaeological field technology to better understand the nature of human-environmental ecodynamics through time and space.

Molecular Characterization of Megalocytiviruses from Diseased Fishes in Korean Aquatic Farms from 2013 to 2017

We identified structural and non-structural gene regions encoding major capsid protein (MCP) and DNA polymerase (DPOL) of megalocytiviruses collected from infected cultured fishes in RBIVD outbreak farms in 2013-2017 in Korea. With the two PCRs using 1-F/1-R and 4-F/4-R primer sets of the Manual of Diagnosis Tests for Aquatic Animals of the World Organization for Animal Health (OIE), amplicons were generated from the spleen and kidney tissue from approxmately ~30 fishes, including rock bream (Oplegnathus fasciatus), red sea bream (Pagrus major), and rock fish (Sebastes schlegeli), from 15 outbreak regions in the aquatic farms of the South Sea and Jeju Island. In phylogenetic analysis, complete MCP and partial DPOL genes belonged to RSIV type-subgroup2. Interestingly, these genes formed a cluster indicating closer relatedness to GSIV-K1, RIE12-1, and RBIV-C1, which were previously isolated from Japan and China, than with RBIV-KOR-TY1 isolated from Korea. However, the nucleotide sequence identities of the MCP and DPOL genes of these viruses were high, at 99.8% and 99.7%, respectively, compared with RBIV-KOR-TY1. Comparisons of nucleotide and amino acid sequences showed minimal differences between the obtained strains in the MCP gene, however, one or two nucleotide sequences substitutions of the DPOL gene were detected in nine strains, including a silent mutation detected in five strains. These findings suggest a slow rate of evolution of megalocytiviruses in this region, but the potential for mutations and new pathogenic strains warrants continuous surveillance.

Oxytetracycline의 약욕에 따른 조피볼락 (Sebastes schlegelii) 체내 약물동태학적 특성

Oxytetracycline (OTC) is a tetracycline broad-specturm antibiotic with bacteriostatic action. The pharmacokinetic properties and the residue level of OTC were studied after dipping to cultured rock fish, (283±5 g) Sebastes schlegelii. For pharmacokinetic studies, OTC of 50, 100 and 400ppm were administered at 15±1℃ and OTC concentrations were determined in plasma, muscle and liver by HPLC-DAD. Plasma, muscle and liver samples were taken at 0.5, 1, 3, 6, 12, 24, 48, 168 and 336h post-injection. The kinetic profiles of OTC were analyzed by fitting to a two-compartmental model. The kinetic profile of the OTC was found to be dose dependent. The time for maximum concentration (TSUBmax/SUB) and the maximum concentration (CSUBmax/SUB) of 400ppm OTC were 2.12h at 1.66㎍/㎖ in plasma, 15.25h at 0.95㎍/㎖ in muscle, and 15.3h at 6.29㎍/㎖ in liver. The absorption half-life (tSUB1/2/SUBα) of 400ppm OTC was 1.24h in plasma, 9.43h in muscle, and 10.31h in liver, respectively, whereas the elimination half-life (tSUB1/2/SUBβ) of the drug was 90.28h in plasma, 265.3h in muscle, and 6.93 ×105h in liver. A higher OTC residue level of liver in comparison with muscle and plasma was showed at all time points

Transcriptional profiling, molecular cloning, and functional analysis of C1 inhibitor, the main regulator of the complement system in black rockfish, Sebastes schlegelii

C1-inhibitor (C1inh) plays a crucial role in assuring homeostasis and is the central regulator of the complement activation involved in immunity and inflammation. A C1-inhibitor gene from Sebastes schlegelii was identified and designated as SsC1inh. The identified genomic DNA and cDNA sequences were 6837 bp and 2161 bp, respectively. The genomic DNA possessed 11 exons, interrupted by 10 introns. The amino acid sequence possessed two immunoglobulin-like domains and a serpin domain. Multiple sequence alignment revealed that the serpin domain of SsC1inh was highly conserved among analyzed species where the two immunoglobulin-like domains showed divergence. The distinctiveness of teleost C1inh from other homologs was indicated by the phylogenetic analysis, genomic DNA organization, and their extended N-terminal amino acid sequences. Under normal physiological conditions, SsC1inh mRNA was most expressed in the liver, followed by the gills. The involvement of SsC1inh in homeostasis was demonstrated by modulated transcription profiles in the liver and spleen upon pathogenic stress by different immune stimulants. The protease inhibitory potential of recombinant SsC1inh (rSsC1inh) and the potentiation effect of heparin on rSsC1inh was demonstrated against C1esterase and thrombin. For the first time, the anti-protease activity of the teleost C1inh against its natural substrates C1r and C1s was proved in this study. The protease assay conducted with recombinant black rockfish C1r and C1s proteins in the presence or absence of rSsC1inh showed that the activities of both proteases were significantly diminished by rSsC1inh. Taken together, results from the present study indicate that SsC1inh actively plays a significant role in maintaining homeostasis in the immune system of black rock fish.

Helping secondary school students develop a conceptual understanding of refraction

Using real-world examples, ray diagrams, and a cognitive apprenticeship cycle, this paper focuses on developing students’ conceptual (not mathematical) understanding of refraction. Refraction can be a difficult concept for students to comprehend if they do not have well-designed opportunities to practice explaining situations where reflection and refraction occur. The use of ray diagrams can be useful in (a) the teacher modelling a correct explanation to a situation where refraction occurs and (b) for students to create as they practice other examples. This paper includes eight examples of increasing complexity that use a cognitive apprenticeship cycle approach to scaffold student learning. The first examples (rock fish, floating penny) are shown and a solution is modeled using a ray diagram. Three more examples (bent pencil, dropping an item in water, sunrise/sunset) are presented for students to practice, with each becoming more sophisticated. Three assessment exercises are then provided (two dots, three coins, broken tube).

Oxidative stress, neurotoxicity, and metallothionein (MT) gene expression in juvenile rock fish Sebastes schlegelii under the different levels of dietary chromium (Cr6+) exposure

Juvenile Sebastes schlegelii were exposed for 4 weeks with the different levels of dietary chromium (Cr6+) concentration (0, 30, 60, 120 and 200mg/kg). The superoxide dismutase (SOD) activity, glutathione S-transferase (GST) activity, and glutathione (GSH) level of liver and gill were evaluated after 4 weeks exposure. The SOD and GST activity of liver and gill was significantly increased in the concentration of 240mg/kg after 2 weeks and over 120mg/kg after 4 weeks, whereas a considerable decrease in the concentration of 240mg/kg after 2 weeks and over 120mg/kg after 4 weeks was observed in the GSH levels of liver and gill. In neurotoxicity, AChE activity was significatly inhibited in brain in the concentration of 240mg/kg after 2 weeks and over 60mg/kg after 4 weeks and muscle in the concentration of 240mg/kg after 2 weeks and over 120mg/kg after 4 weeks. Metallothionein (MT) gene in liver was considerably increased over 120mg/kg after 2 weeks and at 30, 120, and 240mg/kg after 4 weeks by dietary chromium exposure. The results indicate that dietary Cr exposure over 120mg/kg can induce substantial alterations in antioxidant responses, AChE activity and MT gene expression.

Temporal variation in the diet of gentoo penguins at the Falkland Islands

Knowledge of diet is critical in interpreting the ecological roles of marine top predators and provides information towards their conservation and management. The Falkland Islands hold the largest number of breeding gentoo penguins. Yet knowledge of gentoo penguin diet at the Falklands is limited to either broad taxonomic divisions of prey items or dietary samples collected only on a single day. This study is the first to investigate gentoo penguin diet at Cow Bay, Falklands, to the species level, over repeated sampling intervals during the breeding period. Through stomach content analysis, we determined diet over a large temporal scale (2002/2003/2004–2011/2012/2013) and between the guard and creche periods of chick rearing. The principle prey item by reconstituted mass was rock cod fish Patagonotothen spp., for all periods (47–78 %) except that of the 2012/2013 creche period (19 %) when Falkland herring Sprattus fugensis made up the bulk of the diet (52 %). Of the cephalopods recovered, Patagonian squid Doryteuthis gahi was prominent (1–24 %), while crustaceans contributed negligibly to gentoo penguin diet. Our findings revealed that gentoo penguins breeding at the Falkland Islands were primarily demersal foragers with an ability for pelagic feeding. Diet choice appears to reflect prey availability.

양식 조피볼락 (Sebastes schlegeli)에서 megalocytivirus의 무증상적 감염과 특성 분석

양식 조피볼락 (Sebastes schlegeli)에서 megalocytivirus의 무증상적 감염과 특성 분석

The lead accumulation and hematological findings in juvenile rock fish Sebastes schlegelii exposed to the dietary lead (II) concentrations

Juvenile rockfish (mean length 14.2±1.9cm, and mean weight 57.3±5.2g) were exposed for 4 weeks with the different levels of dietary lead (Pb2+) at 0, 30, 60, 120 and 240mg/L. The exposure concentration and period of Pb have induced significant amount of it the specific tissues of rockfish. The highest Pb accumulation was observed in the kidney tissue by the dietary lead exposure. The growth rate and hepatosomatic index were considerably inhibited over 120mg/kg. The hematological parameters such as red blood cell (RBC) counts, hematocrit (Ht) value, and hemoglobin (Hb) concentration were significantly decreased over 60mg/kg Pb concentration. In the inorganic components, the values of calcium and magnesium in plasma were significantly decreased. The glucose and cholesterol values were notably increased, whereas total protein was decreased. The enzyme components, glutamic oxalate transaminase (GOT) and glutamic pyruvate transaminase (GPT), were significantly elevated by the dietary lead exposure, but no change was observed in alkaline phosphatase (ALP).

조피볼락, Sebastes schlegeli의 혈액학적 성분변화에 미치는 구리 및 온도의 복합적 영향

) has been widely used to control algae and pathogens in fish culture ponds. However, its toxic effects on fish depend not only on its concentration in water but also on water quality. The susceptibility of the rockfish, Sebastes schlegeli to copper was evaluated at three water-temper-atures (WT; 18, 23 and 28℃) for 4 days. After the exposure of two copper concentrations (100 and 200 μg/L), a hematological effect was exerted on rockfish, by causing changes in red blood cell count and hematocrit value at 28℃. Total protein levels of the fish showed a tendency of co-in-crease with glucose depend on the WT, after copper exposure. However, the plasma calcium and magnesium levels were significantly increased at 200 μg/L copper, regardless of the WT. Enzymes activities including ALT and LDH in serum were also significantly increased depend upon the copper treatment only. This indicates that inorganic components and enzymes activities were sensitive indexes to stress by toxicant such as copper. The cortisol levels were significantly elevated by both WT rising and copper treatment in serum of rock fish. In conclusion, these changes can be seen as an initial response to temperature stress and as a sustaining response to copper exposure. The present findings suggest that a simultaneous stress by temperature change and copper exposure could accelerate an alteration of hematological and plasma biological parameters in the rockfish. Key words: Sebastes schlegeli, Copper, Temperature, Hematology, Serum enzymes, Cortisol

Isolation and expression analysis of FTZ-F1 encoding gene of black rock fish (Sebastes schlegelii)

Sex related FTZ-F1 is a transcriptional factor regulating the expression of fushi tarazu (a member of the orphan nuclear receptors) gene. In this study, FTZ-F1 gene (FTZ-F1) was isolated from the testis of black rockfish (Sebastes schlegeli) by homology cloning. The full-length cDNA of S. schlegeli FTZ-F1 (ssFTZ-F1) contained a 232bp 5′ UTR, a 1449bp ORF encoding FTZ-F1 (482 amino acid residules in length) with an estimated molecular weight of 5.4kD and a 105bp 3′ UTR. Sequence, tissue distribution and phylogenic analysis showed that ssFTZ-F1 belonged to FTZ group, holding highly conserved regions including I, II and III FTZ-F1 boxes and an AF-2 hexamer. Relatively high expression was observed at different larva stages. In juveniles (105 days old), the transcript of ssFTZ-F1 can be detected in all tissues and the abuncance of the gene transcript in testis, ovary, spleen and brain was higher than that in other tissues. In mature fish, the abundance of gene transcript was higher in testis, ovary, spleen and brain than that in liver (trace amount), and the gene was not transcribed in other tissues. The highest abundance of gene transcript was always observed in gonads of both juvenile and mature fish. In addition, the abundance of gene transcript in male tissues were higher than that in female tissue counterparts (P<0.05).

ECONOMIC RELATIONSHIPS BETWEEN AQUACULTURE AND CAPTURE FISHERIES IN THE REPUBLIC OF KOREA

Wild fish species are becoming scarcer and their market prices significantly increasing due to limited natural resources and increasing demand for sea food. In recent years, the Republic of Korea's (South Korea's) marine aquaculture production of finfish has drastically increased while prices have declined. This study conducts a comparative analysis of the economic relationships between wild-caught and farmed fish species, examining the relationship between fish price and supply resulting from the development of marine aquaculture. Major marine aquaculture species, in particular the most favored sashimi species in Korea, are evaluated. These are: flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagrus major), and grey mullet (Mugil cephalus). This paper illustrates that the prices for both wild-caught and farmed fish declined as the farmed products entered the market and production expanded. However, the magnitude of price changes varied by species depending on if the farmed species has the same value or substitute value as the wild-caught fish and the development of aquaculture technology. The study shows aquaculture seems to play a role in helping to meet the demand for fish and can reduce the pressure on wild-stock fisheries.

Artemia 공급 단계에서 은어(Plecoglossus altivelis), 조피볼락(Sebastes schlegeli ), 감성돔(Acanthopagrus schlegeli ) 및 넙치(Paralichthys olivaeus)의 소화효소 활성

We compared the nutritional requirements of whole larvae of the black seabream Acanthopagrus schlegeli, sweet fish Plecoglossus altivelis, olive flounder Paralichthys olivaeus and rock fish Sebastes schlegeli. The larvae were 20, 30, 14 and 5 DAH (or spawning) of black seabream, sweet fish, olive flounder and rock fish, respectively. Specific <TEX>${\alpha}$</TEX>-amylase activity (mU/mg protein) was highest (8,324.9 mU/mg protein) in rock fish larvae (P<0.05). Specific trypsin-like protease activity was highest (11,330.1 mU/mg protein) in black seabream larvae (P<0.05), which also exhibited the highest activity, 685.5 mU/mg dry weight (P<0.05). The specific activities per mg protein and mg dry weight of black seabream were the highest (187.4 mU/mg protein and 11.3 mU/mg dry weight, respectively) (P<0.05). A/P, P/L and A/L ratios of rock fish were 1.47, 90.3 and 133.1, respectively (P<0.05). We present here basic larval digestive enzymatic nutritional requirement data.

저수온기 양식 조피볼락, Sebastes schlegeli 간에 대한 조직병리학적 연구

본 연구에서는 조피볼락의 간의 육안적 색조에 따른 병리조직학적 소견 및 혈액학적 소견에 근거하여 건강상태를 확인하였다. 조피볼락 총 47개체 모두 외부 소견에서는 특기할 이상 소견이 없었으나, 간은 육안적으로 정상간 (42.55%), 황간 (25.53%), 갈변 위축간 (25.53%), 녹간 (4.26%) 및 지방간 (2.13%) 순으로 나타났다. 간의 육안적 소견에 따른 조피볼락의 간의 조직 소견 관찰시, 정상 간 개체는 HE 염색 시 간세포가 밝게 염색되며, 소엽구조가 불명확하게 관찰되었으나, 황간 개체는 황갈색의 과립이 간세포 및 MMC 내에 관찰되었으며, 간세포는 정상 간 개체에 비해 크기가 위축되어 세포질이 짙은 호산성으로 관찰되며, 세포질 내에 핵과 유사한 크기의 황갈색 초자적이 한 개 이상 관찰되었다. 한편, 녹간 개체는 정상 간 개체에 비해 간세포 크기가 위축으로 관찰되며, HE 염색 시 황갈색과 녹색의 초자적이 간세포 및 MMC 내에 관찰되었으며, 담즙색소 동정을 위한 Stein 염색에서 간세포질 내에서 담즙색소로 추정되는 녹색의 초자적이 관찰되었다. 갈변 위축 간 개체는 간세포의 용적이 줄어들어, 중심정맥 및 동양 모세혈관의 이완이 확인되었다. 그리고 갈변 위축 간이 육안적으로 갈색으로 관찰되나 광학현미경적 관찰결과 간세포질 내에 색소과립은 관찰되지 않았으며, 간세포의 경계가 명확하게 나타나지 않았다. 지방간 개체는 지방 소적의 축적으로 간세포에 다양한 크기의 둥근 지방 공포가 광범위하게 관찰되었으며, 지방소적으로 인해서 팽창된 간세포가 관찰되거나, 간세포핵의 변성이 관찰되었다. 본 연구 결과, 간의 육안적 관찰 및 조직학적 관찰 결과가 어체의 임상 질병으로 실질적인 발현을 진행하기 전에 중요한 건강 매개변수로 사용될 수 있을 것으로 판단되었다. This study was aimed to determine the fish physical status according to the gross and histopathological findings of liver in cultured black rock fish, Sebastes schlegeli. All 47 fish submitted had no marked abnormalities in the external findings. 42.55% of fish showed normal liver, 25.53% yellow liver, 25.53% atrophic brown liver, 4.26% yellowish-green liver and 2.13% fatty liver in gross examination. Grossly normal liver showed no remarkable change in lobular structure but many vacuoles were found in hepatic cell. Hepatic cells took normal roundish, polygonal shapes containing spherical nuclei. In group of yellow-brown liver, many brown pigments were seen in hepatic cells, MMCs and brown-colored hyaline droplets within cytoplasm of hepatocytes. Yellowish green pigments were seen in hepatic cells and MMCs of yellow green liver and green colored hyaline droplets within hepatocytes. The dilated central veins are highlighted with atrophy of hepatic cells. Outline of atrophic hepatocyte became ambiguous and nucleus frequently become small and pyknotic. Fatty liver showed prominent vacuolar structures in cells as clear spaces or foamy cytoplasm with degenerative nuclei. From these results, it was strongly suggested that hepatic gross and histological findings could be used as important and critical health parameters of fish prior to progression to substantial manifestation as clinical disease.

Two hepcidin-like antimicrobial peptides in Barramundi Lates calcarifer exhibit differing tissue tropism and are induced in response to lipopolysaccharide

Genes encoding two hepcidin-like antimicrobial peptides were discovered in Barramundi, Lates calcarifer (barramundi, Giant sea perch). Analysis of the coding regions indicated that genes for each hepcidin comprised 3 exons and 2 introns. The deduced amino acid sequences for each molecule resulted in a protein comprising a signal sequence of 24 aa in each case, coupled to a prepropeptide of 75 aa for hepcidin 1 and 78 aa for hepcidin 2. A cleavage site was identified in each prepropetide at amino acid 64 with the cleavage motif – QKR/QS – resulting in mature peptides of 25 and 28 amino acids respectively. Each mature peptide contained 8 conserved cysteine residues and 3 dimensional modeling predicted a β-hairpin and β-sheet structure characteristic of human Liver Expressed Antimicrobial Peptide (LEAP). Analysis of the deduced amino acid sequences by BLAST with phylogenetic supported indicated that hepcidin 1 was a HAMP1-type peptide closely related to hepcidins identified in other Perciformes ( Micropterus and Pseudosciaena), whilst hepcidin 2 was a HAMP2-type peptide most similar to a hepcidin previously identified in black rock fish ( Sebastes schlegeli). Both hepcidin genes were inducible in barramundi following intraperitoneal injection with lipopolysaccharide, with elevated expression detected in liver and head kidney 3 h post IP injection for hepcidin 1 and in liver only for hepcidin 2. The elevated expression was transient with return to normal levels within 24–48 h. No significant expression of either peptide was detected in spleen, skin or gill following IP injection with LPS.