Parapristipoma Trilineatum Research Articles

Artificial Induction of Spawning in Threeline Grunt, Parapristipoma trilineatum Under Controlled Environmental Conditions

Artificial Induction of Spawning in Threeline Grunt, Parapristipoma trilineatum Under Controlled Environmental Conditions

Genetic diversity and population structure of threeline grunt Parapristipoma trilineatum (Perciformes: Haemulidae) in China and Japan based on mtDNA control region

Parapristipoma trilineatum is an edible and economically important marine fish with high farming potential; however, this fish has not been widely investigated. To understand the germplasm resources of this marine fish, we investigated the range of P. trilineatum from Maizuru, Japan, to Hainan, China. Using the mitochondrial control region as a molecular marker, we analyzed the population structure, genetic diversity, and population history dynamics of P. trilineatum. The control region exhibited high haplotype diversity and nucleotide diversity of 0.996 and 0.016, respectively. The genetic differentiation coefficients indicated low differentiation between Japanese and other populations. Additionally, based on the results of SAMOVA, AMOVA, and genetic differentiation coefficients, P. trilineatum can be divided into two management units in fishery resources management: China and Japan. Populations with high genetic diversity are useful as genetic breeding materials. This study provides a basis for the selection and breeding of P. trilineatum.

First report of a Kudoa lutjanus outbreak in farmed Chicken Grunts Parapristipoma trilineatum.

As part of the National Disease Surveillance Program for Taiwanese Aquaculture, we investigated the causative agent of disease outbreaks in farmed Chicken Grunts Parapristipoma trilineatum. In this study, outbreak cases on two separate farms were noticed in coastal Pingtung County, Taiwan. In total, 50 juvenile fish showing clinical signs (such as emaciation and erratic swimming behavior) and broodstock (two females and two males) from both farms were collected to perform gross lesion assessment, histopathological examination, and molecular identification of the pathogen. Clinical symptoms were infected fish exhibited erratic swimming behavior, such as whirling and floating on the surface of the water. In the following months, cumulative mortality had reached 19% and 24%, respectively. The gross lesions in the infected fish included white oval cysts in the muscle, serosa of the internal organs, sclera of the eyes, and cerebral meninges. After conducting a wet mount examination of cysts using a light microscope, we observed a significant quantity of spores with morphological characteristics, suggesting their affiliation with the Myxosporea group. The spores were semiquadrate, with four tiny suture notches at the periphery; the mean spore length was 7.3 μm (SD = 0.5), and the mean spore width was 8.2 μm (SD = 0.6). The mean length and width of the pyriform polar capsules (nematocysts) were 3.6 μm (SD = 0.5) and 2.2 μm (SD = 0.5), respectively. The 18S and 28S ribosomal RNA sequences of these specimens were identical to those of Kudoa lutjanus. As this was the first time an outbreak of K. lutjanus in Chicken Grunts was confirmed, its reappearance with substantial mortality should serve as a warning to the aquaculture industry.

The relationship between eDNA density distribution and current fields around an artificial reef in the waters of Tateyama Bay, Japan

Monitoring of artificial reefs (ARs) has been conducted through such methods as visual censuses, surveys using fishing gear, and echo sounder. These methods have disadvantages: visual census is not possible at ARs in deeper waters, fishing gear surveys are invasive to fish individuals, and echo sounders have difficulty in species identification. A new AR monitoring method is required to compensate for these disadvantages. While eDNA has become a valid monitoring tool for marine biodiversities, it is influenced by degradation and transport of the molecules that affect information about the spatio-temporal distribution of fish. An understanding of the relationship between current fields and eDNA distribution, particularly in open waters, is critical when using eDNA as an index for fish aggregation at ARs. We investigated the relationship between eDNA distribution and current fields around an AR for four dominant species (Engraulis japonicus, Parapristipoma trilineatum, Scomber spp and Trachurus japonicus) in Tateyama Bay, Japan. The highest density of fish schools is formed directly above or at the upstream side of ARs. If we assume that the center of eDNA originates at these locations at an AR and eDNA is simply transported by currents, a higher density of eDNA would distribute downstream from the AR. However, our results indicate that eDNA distribution is in accord with actual fish distribution, namely eDNA densities are more abundant in the upstream side of ARs. We thus consider that eDNA distribution is more influenced by actual distribution patterns than by the transport processes.

Karyotypic Analysis of Chicken Grunt, Parapristipoma trilimeatum, Small Yellow Croaker, Larimichthys polyactis, and Brown Croaker, Miichthys miiuy.

To clarify the cytogenetic features of the chicken grunt, Parapristipoma trilineatum, small yellow croaker, Larimichthys polyactis, and brown croaker, Miichthys miiuy, in Jeju, Korea, karyotype analysis was performed. The karyotype of chicken grunt and brown croaker consists of 24 pairs of telocentrics [2n=48, fundamental number (FN)=48], and small yellow croaker consists of 3 pairs of submetacentrics and 21 pairs of telocentrics (2n=48, FN=54). No evidence of polymorphism, including aneuploidy or sex-related heteromorphic chromosomes, was found in any specimens examined in this study.

Residence Time and Swimming Depth of Threeline Grunt Parapristipoma trilineatum, Gathering around an Artificial Mound Reef

Residence Time and Swimming Depth of Threeline Grunt Parapristipoma trilineatum, Gathering around an Artificial Mound Reef

Measurement of Diurnal Body Tilt Angle Distributions of Threeline Grunt Parapristipoma trilineatum Using Micro-Acceleration Data Loggers

The body tilt angle of a fish has a large effect on the acoustic target strength. For an accurate estimation of fish abundance using acoustic methods, it is necessary to measure body tilt angles in free-ranging fish. We measured diurnal body tilt angle distributions of threeline grunt (Parapristipoma trilineatum) while swimming in schools in a fish cage. Micro-acceleration data loggers were used to record (for 3 days) swaying and surging accelerations (at 16 Hz intervals) of 10 individuals among 20 forming a school in a fish cage. Time series analysis of 1-h mean body tilt angles revealed significant differences in body tilt angles between day (−7.9 ± 3.28°) and night (0.8 ± 5.89°), which must be taken into account when conducting acoustic surveys. These results will be useful for calculating the average dorsal aspect target strength (TS) of threeline grunt for accurate estimations of fish abundance.

Purification, characterization, and molecular cloning of chitinases from the stomach of the threeline grunt Parapristipoma trilineatum

Two chitinase isozymes, PtChiA and PtChiB, were purified from the stomach of the threeline grunt, Parapristipoma trilineatum. The molecular masses of PtChiA and PtChiB were estimated to be 50 and 60kDa by SDS-PAGE, respectively. Both chitinases were stable at pH 3.0–6.0 (acidic) and showed the optimum pH toward both short and long substrates in the acidic region (pH 2.5–5.0). PtChiA and PtChiB preferentially degraded the second and third glycosidic bonds from the non-reducing end of N-acetylchitooligosaccharides, respectively. PtChiA and PtChiB exhibited wide substrate specificities toward crystalline chitin. Moreover, 2 cDNAs encoding PtChiA and PtChiB, PtChi-1 and PtChi-2, respectively, were cloned. The deduced amino acid sequences of both chitinase cDNAs comprised N-terminal signal peptides, glycoside hydrolase 18 catalytic domains, linker regions, and C-terminal chitin-binding domains. Phylogenetic tree analysis of vertebrate chitinases revealed that fish stomach chitinases including PtChi-1 and PtChi-2 form unique chitinase groups, acidic fish chitinase-1 (AFCase-1) and acidic fish chitinase-2 (AFCase-2), which differ from the acidic mammalian chitinase (AMCase) group. The present results suggest that fish have a chitin-degrading enzymatic system in which 2 different chitinases, AFCase-1 and AFCase-2, with different degradation patterns are expressed in the stomach.

Francisella infections in fish and shellfish

A series of recent reports have implicated bacteria from the family Francisellaceae as the cause of disease in farmed and wild fish and shellfish species such as Atlantic cod, Gadus morhua L., tilapia, Oreochromis spp., Atlantic salmon, Salmo salar L., three-line grunt, Parapristipoma trilineatum (Thunberg), ornamental cichlid species, hybrid striped bass Morone chrysops x M.saxatilis and, recently, a shellfish species, the giant abalone, Haliotisgigantea Gmelin. The range of taxa affected will very probably rise as it is likely that there has been considerable under-reporting to date of these disease agents. In common with other Francisella species, their isolation and culture require specialized solid and liquid media containing cysteine and a source of iron. This likely restricted earlier efforts to identify them correctly as the cause of disease in aquatic animals. The most information to date relates to disease in cod, caused by F.noatunensis and tilapia, caused by F.noatunensis subsp. orientalis (also termed F.asiatica), both causing granulomatous inflammatory reactions. Mortalities in both species can be high and, as the disease can likely be transferred via live fish movements, they pose a significant threat to tilapia and cod aquaculture operations. Although the fish-pathogenic Francisella species are classified in the same genus as the human pathogens F.tularensis, causative agent of tularemia, and F.philomiragia, the risk to humans from the fish and shellfish pathogenic Francisella species is considered very low.

Multiple-locus, variable number of tandem repeat analysis (MLVA) of the fish-pathogen Francisella noatunensis.

BackgroundSince Francisella noatunensis was first isolated from cultured Atlantic cod in 2004, it has emerged as a global fish pathogen causing disease in both warm and cold water species. Outbreaks of francisellosis occur in several important cultured fish species making a correct management of this disease a matter of major importance. Currently there are no vaccines or treatments available. A strain typing system for use in studies of F. noatunensis epizootics would be an important tool for disease management. However, the high genetic similarity within the Francisella spp. makes strain typing difficult, but such typing of the related human pathogen Francisella tullarensis has been performed successfully by targeting loci with higher genetic variation than the traditional signature sequences. These loci are known as Variable Numbers of Tandem Repeat (VNTR). The aim of this study is to identify possible useful VNTRs in the genome of F. noatunensis.ResultsSeven polymorphic VNTR loci were identified in the preliminary genome sequence of F. noatunensis ssp. noatunensis GM2212 isolate. These VNTR-loci were sequenced in F. noatunensis isolates collected from Atlantic cod (Gadus morhua) from Norway (n = 21), Three-line grunt (Parapristipoma trilineatum) from Japan (n = 1), Tilapia (Oreochromis spp.) from Indonesia (n = 3) and Atlantic salmon (Salmo salar) from Chile (n = 1). The Norwegian isolates presented in this study show both nine allelic profiles and clades, and that the majority of the farmed isolates belong in two clades only, while the allelic profiles from wild cod are unique.ConclusionsVNTRs can be used to separate isolates belonging to both subspecies of F. noatunensis. Low allelic diversity in F. noatunensis isolates from outbreaks in cod culture compared to isolates wild cod, indicate that transmission of these isolates may be a result of human activity. The sequence based MLVA system presented in this study should provide a good starting point for further development of a genotyping system that can be used in studies of epizootics and disease management of francisellosis.

Age and Growth of the Threeline Grunt, Parapristipoma trilineatum, in a Coastal Area of Tokushima Prefecture

Age and Growth of the Threeline Grunt, Parapristipoma trilineatum, in a Coastal Area of Tokushima Prefecture

Maturation and Sex Ratio of Three-line Grunt, Parapristipoma trilineatum along the Southwestern Coast of Kii Peninsula, Japan

Maturation and Sex Ratio of Three-line Grunt, Parapristipoma trilineatum along the Southwestern Coast of Kii Peninsula, Japan

Francisella asiatica sp. nov. isolated from farmed tilapia (Oreochromis sp.) and elevation of Francisella philomiragia subsp. noatunensis to species rank as Francisella noatunensis comb. nov., sp. nov.

Bacterial isolates from diseased farmed tilapia (Oreochromis sp.) from Costa Rica (PQ 1104), Atlantic salmon (Salmo salar) from Chile (PQ 1106) and three-line grunt (Parapristipoma trilineatum) from Japan (Ehime-1) were characterized by phenotypic and molecular taxonomic methods. These isolates were Gram-negative, oxidase negative, non-motile, strictly aerobic cocco-bacilli, produced H2S from cysteine supplemented media, which is phenotypically consistent with the genus Francisella. Comparison of 16S rRNA gene sequences and five partial housekeeping gene sequences (groEL, shdA, rpoB, rpoA and pgm) confirmed these isolates to be members of the genus Francisella, with high 16S rRNA similarity (> 99 %) to Francisella philomiragia subsp noatunensis, F. piscicida and Francisella philomiragia subsp philomiragia isolates. Despite the close 16s rRNA relationship with the aforementioned Francisella taxa, isolates PQ 1104 and Ehime-1 form a separate clade on phylogenetic analysis of the 16s rRNA gene and all housekeeping genes investigated, whereas isolate PQ 1106 is highly similar to F. philomiragia subsp noatunensis (NCIMB 14265T) and F. piscicida (DSM 18777T). DNA-DNA hybridization studies revealed mean reassociation values of 60.3 and 72.6 % between isolate PQ 1104 and F. philomiragia subsp noatunensis (NCIMB 14265T) and F. philomiragia subsp philomiragia (ATCC 25015), respectively. Thus, on the basis of molecular genetic evidence, we propose that isolates PQ 1104 and Ehime-1 should be recognised as Francisella asiatica sp. nov. with type strain PQ 1104T (NCIMB and CCUG number not received yet). No separation between F. piscicida and F. philomiragia subsp noatunensis were identified by the same methods and these species constitute heterotypic synonyms for which the epithet noatunensis has priority. However, given the increased evidence of ecological differentiation within the F. philomiragia group and the existence of a specific fish pathogenic clade, we propose that the F. philomiragia subsp noatunensis be elevated to species level as F. noatunensis comb. nov., sp.

Taxonomical study into two new species of Philometra (Nematoda: Philometridae) previously identified as Philometra lateolabracis (Yamaguti, 1935)

Males of the nematode Philometra lateolabracis (Yamaguti, 1935), the type species of the genus Philometra Costa, 1845, were discovered for the first time in gonads of its type host, the Japanese seaperch, Lateolabraxjaponicus (Cuvier). Morphological comparisons carried out between the collected male and female P. lateolabracis with the male and female philometrid nematodes previously reported as P. lateolabracis infecting chicken grunt, Parapristipoma trilineatum (Thunberg), and red sea bream, Pagrus major (Temminck et Schlegel), revealed that the latter represent two new species, Philometra isaki sp. n. and Philometra madai sp. n., respectively. Molecular comparison of ITS2 rDNA between P. lateolabracis and P. madai supported the morphological conclusion that the two nematodes obtained from different fish species should be assigned to different species.

Age and growth of threeline grunt Parapristipoma trilineatum along the south-western coast of Kii Peninsula, Japan

Age and growth were determined for threeline grunt Parapristipoma trilineatum based on otolith readings of 1043 specimens collected along the south-western coast of Kii Peninsula, Japan. Observations of the otolith margin, together with comparisons of ring mark counts with age in artificially reared specimens, verified that such marks were produced once a year. The formation period corresponded approximately to the main spawning season (May–June). Both surface and cross-section methods were used for age determination; the surface method often resulted in underestimations of age for fish older than 2 years. Discrepancies between the two methods became greater with fish growth. The von Bertalanffy growth curve, based on ages inferred from the cross-section method, was FL t=331×{1−exp[−0.283×(t+1.45)]}. No substantial difference was detected between male and female growth parameters. The oldest maximum ages inferred from the cross-section method were 15 and 21 years for females and males, respectively. It seems likely that P. trilineatum grows more slowly and lives longer than previously thought, and the difference is attributed primarily to differences in aging methods used in the present and previous studies.

A Piscirickettsiosis‐like Syndrome in Cultured Nile Tilapia in Latin America with Francisella spp. as the Pathogenic Agent

In 2004, cultured Nile tilapia Oreochromis niloticus in several Latin America farms began to succumb to a disease similar to the piscirickettsiosis-like syndrome previously reported in tilapia in Taiwan and the United States. Mortality increased during 2005; reductions in tilapia biomass ranged from 5% to 80% in individual ponds and averaged 50% overall. All ages of fish have been involved. Clinical signs include lethargy, loss of appetite, petechia, exophthalmia, and abnormal swimming behavior. Gross lesions have included splenomegaly, renomegaly, and numerous white nodules observed in the spleen, kidney, testes, heart, ovaries, and occasionally the liver. A previously unreported black granulomatous lesion was reported in up to 30% of the fillets. Histologically, granulomatous infiltrates were observed in the kidney, spleen, liver, testes, ovary, and choroid gland, and rarely in the brain and heart. A small pleomorphic bacterium was observed in Giemsa-stained blood smears and spleen imprints. The bacterium did not grow on standard microbiological media and has not been isolated in cell culture. We obtained a near-complete 16S ribosomal DNA sequence with high similarity to Francisella spp. sequences previously identified in tilapias Oreochromis spp. (Taiwan), Atlantic cod Gadus morhua (Norway), and three-line grunts Parapristipoma trilineatum (Japan).

Aquatic Francisella-like bacterium associated with mortality of intensively cultured hybrid striped bass Morone chrysops × M. saxatilis

The present study identifies an emerging disease associated with an aquatic Francisella-like bacterium that can cause mortality in hybrid striped bass Morone chrysops x M. saxatilis reared intensively in freshwater. Clinically affected fish were lethargic, had scattered haemorrhagic cutaneous lesions and diffuse gill pallor. The head kidney and spleen were markedly swollen and contained numerous interstitial granulomas; histological examination revealed small, pleomorphic Gram-negative coccobacilli within vacuolated cells. The bacterium could not be cultured from head kidney homogenates either with standard or enriched microbiological media or following inoculation of a Chinook salmon embryo (CHSE)-214 cell line. No amplification product was obtained from head kidney DNA by polymerase chain reaction (PCR) assay using Piscirickettsia salmonis-specific primers. PCR analysis of infected head kidney homogenate with primers designed for the eubacterial 16S rRNA produced a single amplicon. Phylogenetic analysis of this DNA sequence demonstrated that the sequence aligned most closely with members of the genus Francisella, identified from tilapia Oreochromis spp. in Taiwan and an aquatic Francisella species that was recently isolated from the three-line grunt Parapristipoma trilineatum in Japan. This Francisella-like disease was transmitted to naive hybrid striped bass fingerlings by intraperitoneal injection of tissue homogenates prepared from a natural outbreak. All fish developed gross and histological lesions identical to those from natural outbreaks. Intracellular Gram-negative bacteria were observed within the cytoplasm of cells (presumably macrophages) within the granulomas, but bacteria were not recovered. The 16S DNA sequence of the bacterium obtained from tissues of experimentally infected fish was identical to that obtained from the fish used as infected donor tissue.

Identification and Pathogenicity of Intracellular Francisella Bacterium in Three-line Grunt Parapristipoma trilineatum

Bacteriological examination was conducted on the disease of cultured marine fish, three-line grunt Parapristipoma trilineatum (Japanese common name: isaki). The affected fish characteristically showed white spots of granulomas containing an intracellular bacterium in the kidney and spleen. Total DNA was extracted from the kidney of the diseased fish. The coding region of small subunit ribosomal RNA (16S rDNA) of eubacteria was amplified from the DNA by PCR, and nucleotide sequence was determined. The sequenced 16S rDNA revealed high similarity (97.3-98.5%) to those of Francisella species. On the basis of phylogenetic analysis, the closest relative organism was revealed to be Francisella philomiragia. A bacterium was isolated from the spleen of one affected fish using cystine heart agar medium with 1% hemoglobin. The 16S rDNA sequence of the isolated bacterium was consistent with that determined from the kidney tissue of the affected fish. An experimental infection with the isolate exhibited the same disease signs in the injected fish, and the bacterium was reisolated from these fish. These results demonstrate that the intracellular bacterium is pathogenic and is identified to the genus Francisella This is the first report of pathogenic Francisella from marine fish.

Video analysis of fish schooling behavior in finite space using a mathematical model

The schooling behavior of the fish Parapristipoma trilineatum (chicken grunt) was examined for a range of school sizes in a water tank containing a central columnar structure using a mathematical model of fish schooling behavior that was modified from that of Sannomiya and Matuda. The two-dimensional motion of individuals was captured on digital video over about 10 min, and these time-series data were used to tune the model to the experimental conditions. The model parameters were then used to evaluate schooling behavior quantitatively. Comparing force magnitudes between experimental conditions revealed that propulsive force was less in a tank without the central structure than in a tank with the central structure, under all conditions tested. These results indicate that the school was less active under unobstructed conditions. Propulsive force also decreased with increasing school size. Attractive and repulsive forces of the walls were dominant for smaller school sizes; the attractive and repulsive forces of the structure were significant only for the largest school tested (25 individuals). Thus, changes in behavioral patterns caused by the number of individuals or the presence of structures can be expressed using the mathematical model.

Two new species of lepocreadiid trematodes of marine fishes from the Taiwan Straits, China.

Two new species of lepocreadiid trematodes are reported from marine fishes from the Taiwan Straits, China: Diploproctodaeum spinosus n. sp. from the intestine of Takifugu oblongus (= Fugu oblongus) and Preptetos parapristipomae n. sp. from Parapristipoma trilineatum. Diploproctodaeum spinosus differs from the known species of Diploproctodaeum, with 1 spine at the base of the ejaculatory duct. Preptetos parapristipomae is most similar to Preptetos rotto in having an entire ovary but differs from it in the sucker ratio, distribution of the uterus, position of the cirrus sac, and locality.