We examined hemolymph O_2 partial pressure (Po_2), pH, total CO_2 concentration (Tco_2), CO_2 partial pressure (Pco_2), and bicarbonate concentration ([HCO_3^–]) to evaluate the acid–base balance of the winged pearl oyster Pteria penguin under normoxic condition. Hemolymph was collected anaerobically from the adductor muscle. Mean values for hemolymph Po_2, pH and Tco_2 were 73.4 torr, 7.598 and 2.40 mM/L, respectively. Hemolymph Pco_2 was calculated using the rearranged Henderson–Hasselbalch equation, yielding 1.83 torr and a [HCO_3^–] of 2.33 mM/L. The non-bicarbonate buffer value (hemolymph pH–[HCO_3^–] relational expression slope) was 1.99 slykes, higher than that of other marine bivalves. Thus, the winged pearl oyster hemolymph has a comparatively greater nonbicarbonate buffering capacity.

Viral edema of carp (VEC) is a viral disease affecting carp Cyprinus carpio, caused by the carp edema virus (CEV). However, the dynamics of the virus and the levels of viral shedding in diseased and carrier fish remain to be elucidated. In this study, experimental infections with two CEV strains were performed, after which samples were collected chronologically from the rearing water and gills in order to measure viral genome copy numbers (vgcn). The vgcn in the rearing water remained below the detection limit up to 1 day post infection (dpi). However, the presence of the virus was first detected at 3 dpi, reaching a peak at 7 dpi before declining rapidly. As with the rearing water, the vgcn in the gills also began to increase from 3 dpi, peaking at 7 dpi before gradually declining thereafter. Therefore, when koi carp are experimentally infected with CEV, viral replication in the gill tissue begins around 3 dpi, and the rearing water becomes cloudy presumably due to excessive mucus secretion. Around 7 dpi, the viral level in the gill tissue and viral shedding reach their peak, with symptoms such as sunken eyes and recumbency observed. Subsequently, the viral level declines gradually, and the fish dies several days later.

“Ehrlich’s ꞵ granules” refers to different granules identified in two types of leukocytes and is a term that has ambiguity. Among these, the ꞵ granules observed in the neutrophils of rabbits and guinea pigs stain with both acidic and basic dyes (amphophilic) and are now regarded as the granules of “pseudoeosinophils”, a term used for neutrophils in these species. However, it remains uncertain whether Kurloff (1889, 1892), who first introduced the term “pseudoeosinophils”, actually observed amphophilic granules in the cells. This study analysed Kurloff’s original papers and examined the morphological characteristics of the pseudoeosinophils he described. In addition, the papers include accounts of granular cells referred to as nigrosinophils. It also remains unclear which type of white blood cell, as recognised in modern haematology, corresponds to the cells. The results of this study suggest that the pseudoeosinophils observed by Kurloff refer to neutrophils in rabbits and guinea pigs, but their granules were not amphophilic and did not stain with basic dyes. Furthermore, the granules of pseudoeosinophils were assumed to exhibit staining characteristics similar to those of α granules, the specific granules of eosinophils, as demonstrated by triacid staining to confirm neutrophilic properties of granules and by staining with a triglycerine mixture that colours the α granules in the eosin staining properties. These staining results were considered to be due to the high temperature during the heat fixation of the specimens. The nigrosinophils were thought to correspond to basophils.

Totals of 4,193 and 3,000 of larval, juvenile and adolescent fishes representing about 45 and 46 fish species were collected by monthly light–trap sampling respectively on rocky and on sandy shores at the foot of the Gotsu Lighthouse, Shimane Prefecture, Japan after sunset of the high tide during the flood tide from January to December, 1998. A high number of species occurred from January to March on the rocky shore, and from January to May on the sandy shore, respectively. Number of each species in each month sampled from the rocky and sandy shores were analyzed by Hayashi's quantification theory III (multivariate analysis) and cluster analysis (Ward method) for clarifying the characteristics of occurrence patterns of each fish species. Five clusters were defined in the rocky shores as follows： Cottidae, Stichaeidae and Chaenopsidae fish occurred from January to April, Acanthopagrus schlegelii and Girella punctata occurred in May and June, Rhinogobius spp. and Acentrogobius spp. occurred in July and August, Iso sp. and Omobranchus elegans occurred in September and October, few fish species occurred in November and December. Six clusters were defined in the sandy shores as follows： Cottidae, Stichaeidae and Chaenopsidae fish occurred from January to April, Engraulis japonica and G. punctata occurred in May and June, Spratelloides gracilis and Gymnapogon sp. occurred in July and August, S. gracilis, E. japonica and Iso sp. occurred in September and October, S. gracilis and Acanthopagrus latus occurred in November, Plecoglossus altivelis altivelis, Mugil cephalus cephalus and Sebastiscus marmoratus occurred in December. These results indicate that these shores adjoining to the Gonokawa River (Class A river) are utilized as a nursery for various larval, juvenile and adolescent stages of the saltwater and diadromous fish species.