富山県で栽培されているジャノヒゲ(クサスギカズラ科) の染色体数

ジャノヒゲ（Ophiopogon japonicus）は，わが国では本州以南に自生しており，園芸植物または薬用植物として栽培もされている。ジャノヒゲの染色体数には，2n= 36, 67, 68, 70,72 が知られている。栽培されているジャノヒゲでは日光植物園において2n= 36 (Satô 1942)が，2n=67は東京都，神奈川県，石川県，岐阜県，滋賀県，大阪府，奈良県，和歌山県，福岡県，佐賀県，熊本県の栽培株で報告されていた （Nagamatsu and Noda 1971）。本研究では，富山県内の民家，公園，寺院・神社，合わせて26カ所で栽培されていた82株のジャノヒゲの染色体数を調査した。その結果77株（94%）は2n=68，５株（6%）は2n=67であった。富山県内で栽培されているジャノヒゲは報告されている他の地域の栽培ジャノヒゲとは異なり，2n=68が一般的であることが判った

PCNA Protein Expression during Spermatogenesis of the Japanese Eel (Anguilla japonica)

Spermatogenesis can be initiated by a single injection of human chorionic gonadotropin (hCG) into the cultivated Japanese eel, which produces only spermatogonia in the testis. To isolate the genes responsible for regulating spermatogenesis, we performed a differential mRNA display using poly (A)+ RNA extracted from the testes at different time points after hCG injection. Among several cDNA clones, the expression of which was initiated before the onset of meiosis, one clone has high homology with the proliferating cell nuclear antigen (PCNA). In this study, we investigated the protein expression of eel PCNA and found for the first time in any species that two forms (32-kDa and 36-kDa) of PCNA are present in the testis. Although the 36-kDa form existed in both the testis and spleen, the 32-kDa form was specifically expressed in the testis. In contrast to the appearance of 36-kDa PCNA 1 day after the hCG treatment, the 32-kDa PCNA appeared only 9 days after the hCG treatment, at which time active spermatogonial proliferation occurred in the testis. Both the 32- and 36-kDa forms were recognized by antibodies raised against different epitopes of PCNA, and their N-terminal amino acid sequences were identical. The 36-kDa form, but not the 32-kDa form, was recognized by antibodies against phosphoamino acids. These results suggest that the two PCNA proteins are the same molecule with different chemical modifications, including phosphorylation. We discuss the roles of these two forms of PCNA in the spermatogenesis of the Japanese eel

Production of Specific Polyclonal Antibody against the Larvae of Corallivorous Gastropod Drupella fragum for Prediction of Outbreaks

The term corallivorous gastropod refers to a group of snails that feeds on coral and inhabits coral communities worldwide. Outbreaks of these species cause serious damage to coral communities. There are various reasons behind the outbreaks; however, further clarifications are needed. It may be possible to predict outbreaks by measuring the number of floating larvae of corallivorous gastropods in seawater. Drupella fragum is the most damaging species in Japan, so we produced antibodies against D. fragum larvae in order to easily detect this species in the field. Antibody specificity analysis in aquarium-hatched corallivorous gastropods showed a higher specificity against D. fragum compared to D. cornus. A field study using the antibody showed that many D. fragum larvae were detected from June to November at all stations. The larvae at the Shirigai station were collected in June and July in large numbers compared to the other stations. Large groups of D. fragum were collected around the sampling point in Shirigai in September 2016. Our results imply that there is a possibility that outbreaks could be predicted using this antibody

Replacement of Fish Meal by Defatted Yellow Mealworm (Tenebrio molitor) Larvae in Diet Improves Growth Performance and Disease Resistance in Red Seabream (Pargus major)

Yellow mealworm (Tenebrio molitor) larvae are a potential alternative animal protein source for sustainable aquaculture. However, reports on the successful complete substitution of fish meal with yellow mealworm larvae in an aquaculture diet have been limited. In this study, we conducted a feeding trial with red seabream (Pagrus major) being fed diets with partial or complete replacement of fish meal with yellow mealworm larvae defatted with a hexane–ethanol solution. Feed intake in red seabream increased in accordance with yellow mealworm larvae inclusion, and diets including 65% defatted mealworm larvae (complete replacement of fish meal) showed significant growth promotion. The addition of the oil fraction from mealworm larvae to diets resulted in growth reduction, despite meeting the nutritional requirements of red seabream. Moreover, the survival rate of red seabreams fed diets with partial replacement of fish meal with mealworm larvae was significantly higher in a challenge test with pathogenic Edwardsiella tarda bacteria. The present study demonstrated that yellow mealworm larvae are not merely an alternative animal protein, but have potential as functional feed ingredients for aquaculture production