The complete mitochondrial genome of freshwater gammarid (Crustacea: Amphipoda: Gammaridae).

This study presents the complete mitochondrial genome sequence of , a freshwater crustacean found in the western regions of Honshu, Shikoku and Kyushu in Japan. The entire genome is 16,429 bp in length, encoding a standard set of 13 protein-coding genes, two ribosomal RNA genes and 22 transfer RNA genes, as well as the putative control regions. The mitochondrial genome of is characterized by a high concentration of A and T nucleotides (67.

Preliminary assessment of genetic variation in the Japanese endemic freshwater crab, , based on mitochondrial DNA sequences.

, a freshwater crab species endemic to Japan, has the largest distribution range amongst the 19 known species in the country. Due to its low dispersal capability and restricted habitat to freshwater, it serves as an excellent model for understanding gene flow between geographically isolated populations. In this study, we analysed the genetic relationships of 26 populations collected from different locations in the Japanese archipelago using two mitochondrial DNA regions - cytochrome oxidase subunit I ( and cytochrome b ().

Effect of Intertidal Elevation at Tsuyazaki Cove, Fukuoka, Japan on Survival Rate of Horseshoe Crab Eggs.

Physical factors affecting the survival of eggs were investigated by translocating their eggs between the high intertidal zone and the low intertidal zone of a known spawning site. The mean egg survival rates per day were highest in the mid intertidal zone (45.1%±25.

Genetic diversification of the Kanehira bitterling Acheilognathus rhombeus inferred from mitochondrial DNA, with comments on the phylogenetic relationship with its sister species Acheilognathus barbatulus.

The Kanehira bitterling, Acheilognathus rhombeus, is a freshwater fish, discontinuously distributed in western Japan and the Korean Peninsula. Unusually among bitterling it is an autumn-spawning species and shows developmental diapause. Consequently, the characterization of its evolutionary history is significant not only in the context of the fish assemblage of East Asia, but also for understanding life-history evolution.

A global-scale screening of non-native aquatic organisms to identify potentially invasive species under current and future climate conditions.

The threat posed by invasive non-native species worldwide requires a global approach to identify which introduced species are likely to pose an elevated risk of impact to native species and ecosystems. To inform policy, stakeholders and management decisions on global threats to aquatic ecosystems, 195 assessors representing 120 risk assessment areas across all six inhabited continents screened 819 non-native species from 15 groups of aquatic organisms (freshwater, brackish, marine plants and animals) using the Aquatic Species Invasiveness Screening Kit. This multi-lingual decision-support tool for the risk screening of aquatic organisms provides assessors with risk scores for a species under current and future climate change conditions that, following a statistically based calibration, permits the accurate classification of species into high-, medium- and low-risk categories under current and predicted climate conditions.

Habitat suitability maps for juvenile tri-spine horseshoe crabs in Japanese intertidal zones: A model approach using unmanned aerial vehicles and the Structure from Motion technique.

The tri-spine horseshoe crab, Tachypleus tridentatus, is a threatened species that inhabits coastal areas from South to East Asia. A Conservation management system is urgently required for managing its nursery habitats, i.e.

Photo images, 3D/CT data and mtDNA of the freshwater mussels (Bivalvia: Unionidae) in the Kyushu and Ryukyu Islands, Japan, with SEM/EDS analysis of the shell.

Background: Freshwater mussels (Bivalvia: Unionidae), which are keystone species of freshwater ecosystems, are in global decline. In addition to ecological/genetic studies, morphological examinations are needed to help provide information for the development of additional freshwater mussel studies and eventually conservation efforts for freshwater ecosystems.The microscopic structure, which can be obtained by scanning electron microscopy (SEM) and elemental composition, which can be obtained with energy dispersive X-ray spectrometry (EDS), of mollusc shells are of interest to malacologists.

A simple SNP genotyping method reveals extreme invasions of non-native haplotypes in pale chub Opsariichthys platypus, a common cyprinid fish in Japan.

Biological invasion by non-native subspecies or populations is one of the most serious threats to ecosystems, because these species might be easily established in the introduced area and can negatively affect native populations through competition and hybridization. Pale chub Opsariichthys platypus, one of the most common fish in East Asia, exhibits clear genetic differentiation among regional populations; however, introgression and subsequent loss of genetic integrity have been occurring throughout Japan due to the artificial introduction of non-native conspecifics. In this study, we developed a simple SNP genotyping method to discriminate between native and non-native mitochondrial DNA (mtDNA) haplotypes in pale chub using real-time PCR assay.

Tributyltin in blood of marine fish collected from a coastal area of northern Kyushu, Japan.

We investigated levels of the pollutant tributyltin (TBT) in blood of pufferfishes (six species), Japanese sea perch, red sea bream, Japanese common goby, Japanese flounder, rockfish, conger eel, and sea mullet collected off the coast of northern Kyushu, Japan. We found considerable levels of TBT (1.4-190 ng/mL) accumulated in the blood of these fish.

Habitat use in irrigation channels by the golden venus chub (Hemigrammocypris rasborella) at different growth stages.

Ecological information on the golden venus chub (Hemigrammocypris rasborella Fowler, 1910) was collected during field surveys and used to analyze habitat use by this species at each growth stage. Surveys were conducted every month for approximately 2 years In an irrigation ditch near the Ushizu River, Kyushu Island, Japan. Based on the characteristic nuptial coloration of males, it was estimated that H.

A screening method for toxicity identification evaluation on an industrial effluent using Chelex-100 resin and chelators for specific metals.

Toxicity of an industrial effluent was characterized using a toxicity identification method established at our research institute. Toxicity was evaluated using the Ceriodaphnia dubia survival test. The industrial effluent chosen in the present study had toxic effects on C.

Expression analysis of sex-specific and 17beta-estradiol-responsive genes in the Japanese medaka, Oryzias latipes, using oligonucleotide microarrays.

Gene profiling of Japanese medaka (Oryzias latipes) was performed using an oligonucleotide DNA microarray representing 22,587 TIGR O. latipes gene indices (OLGIs). The average correlation coefficients for gene expression between individual mature fish were high (>0.

Effects of 17beta-estradiol on survival, growth, sexual development and molting cycles of the marine crustacean mysid shrimp, Americamysis bahia.

A 14-day partial life-cycle test was performed to assess the effects of 17beta-estradiol (E2) on the survival, growth, sexual development and molting cycles of a marine crustacean mysid shrimp (Americamysis bahia). Seven-day-old mysids were exposed to the nominal E2 concentrations of 31.3, 62.

Styrene dimers and trimers affect reproduction of daphnid (Ceriodaphnia dubia).

The endocrine disruptor activity of styrene in humans and other vertebrates appears to be negligible. However, offspring numbers were reduced in Ceriodaphnia dubia bred in polystyrene cups. Styrene dimers and trimers were found to be eluted from the polystyrene cups by hexane and methanol with gas chromatography-mass spectrometry.