Female medaka, Oryzias latipes, is known to deposit their eggs on substrates in shallow waters. However, there is a possibility that the eggs will be exposed to the air and dry when the surrounding water level falls. In the present study, we examined the resistance to desiccation of fertilized eggs of medaka. Each egg was placed in a plastic dish filled with water and subjected to one of the following three treatments for one or three days at different times after fertilization: 1) placed on a wet filter paper and exposed to the air (wet group), 2) placed on a dry dish (dry group), and 3) kept in water (control). Most eggs in the control and the wet group hatched, and all the eggs of the dry group died. The results of the wet group indicate that fertilized eggs of medaka have some resistance to desiccation.

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Construction of artificial river and lake banks changes the aquatic environment, and these changes are known to cause decreases of aquatic plants in shallow waters. We conducted experiments to examine the involvement of aquatic plants in spawning behavior of goldfish, Carassius auratus, and cruicuan carp, Carassius buergeri subsp.2. The spawning behavior was induced by injecting prostaglandin F2α into females. Pairs of male and female goldfish or crucian carp were placed in experimental tanks with or without aquatic plants made of acrylic yarn. Both goldfish and crucian carp spawned actively onto the aquatic plants whereas the behavior significantly decreased without the aquatic plants. The present experiments demonstrate that aquatic plants are essential as spawning substrates for performance of spawning behavior of these species. It is critical for conservation of fish species that use aquatic plants as spawning substrates to maintain aquatic plants on river and lake banks.

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Mammal fauna in an isolated green area in a Tokyo suburban residential area was studied. Using a camera-trapping method and interviewing some residents in the area, a total of thirteen mammal species including two temporal visitors were recorded. Among them, breeding of Japanese badgers (Meles anakuma) in a suburban residential area was confirmed for the first time. The RAIs (relative abundance indices) in 2008 and 2018 were compared among medium-sized Carnivores such as badgers, raccoons (Procyon lotor), raccoon dogs (Nyctereutes procyonoides), masked palm civets (Paguma larvata), and domestic cats (Felis catus). In these ten years, raccoons increased drastically, and badgers, raccoon dogs, and cats also increased. Masked palm civets did not show much change. Despite overlapping diet resources, the increase in raccoons did not influence the size of population of other medium-sized mammals.

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北海道にはエゾリスおよびアカネズミが生息しており，オニグルミの堅果を貯食する習性をもっている．これらの動物は大型種子を分散貯蔵する．森林生態系における立枯木や倒木はそれ自身が主要な資源である．樹木伐採後の残材は，立枯木や倒木と同様な機能をもつと考えられる．本研究では，エゾリスがいくつかの残材堆積物を利用していることを報告し，林床における残材堆積物の重要性を議論することを目的とし，残材堆積物のどの属性がエゾリスの利用に影響しているかを検討した．その結果，エゾリス食痕数に対して残材堆積物のオニグルミ母樹からの距離で負の関係が，残材堆積物を構成する材の本数で正の関係がみられた．エゾリスは残材堆積物を安全な採餌場所として利用していると考えられる．

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東京都町田市にある玉川学園で今まで確認されていなかったニホンアナグマがセンサーカメラで撮影された．撮影回数は7 月中に2 回のみではあるが，微小緑地での生息例があることから今後，玉川学園内にニホンアナグマが定着する可能性が考えられる．

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A supplementary literature survey was conducted on bryophytes reported from Kanagawa Prefecture, Japan. Including infraspecific taxa, a total of 663 species, which were classified into 452 species of mosses, 201 species of liverworts, and 10 species of hornworts, were recorded.

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