著者

岩崎 敬二 木村 妙子 木下 今日子 山口 寿之 西川 輝昭 西 栄二郎 山西 良平 林 育夫 大越 健嗣 小菅 丈治 鈴木 孝男 逸見 泰久 風呂田 利夫 向井 宏

出版者

JAPANESE ASSOCIATION OF BENTHOLOGY

雑誌

日本ベントス学会誌 = Japanese journal of benthology (ISSN:1345112X)

巻号頁・発行日

vol.59, pp.22-44, 2004-07-28

被引用文献数

24 26

---

To investigate the invasion history and recent geographic distribution of marine organisms introduced to Japan or transferred domestically to non-native regions, a questionnaire survey on their occurrence in the field, including both published and unpublished records, was conducted in 2002-2003. A total of 105 taxa was reported by 94 respondents. According to three criteria, viz. known or unknown geographic origin, established invasion history, and presumed dispersal mechanisms associated with human activities, 42 taxa were designated as non-indigenous species introduced to Japan through human activities, 26 taxa as indigenous species that are distributed both in Japan and other countries but are introduced from abroad to Japan for fisheries or as fish bait, 20 taxa as cryptogenic species which are not demonstrably native or introduced, two taxa as non-indigenous species that have extended their range to Japan through natural dispersion, and one taxon as an indigenous species. The remaining 14 taxa were considered to have been transferred domestically to new areas. Analysis of the years of first record of 42 non-indigenous species suggests that the rate of invasion has increased over the past century, with seven or eight species being introduced per decade after 1960. Data on temporal change in geographic distribution revealed that many non-indigenous species have become widespread recently, from the Pacific coasts of central Japan to the coasts of the Sea of Japan or northward. However, the species listed in the present study are not exhaustive, and more extensive investigations covering all taxa and all presumed dispersal mechanisms are urgently needed before consideration of legislative management of introduced marine organisms.

著者

熊川 真二 中田 和義 川井 唯史

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.66, no.1, pp.26-32, 2011-10-15 (Released:2012-10-11)

参考文献数

20

被引用文献数

1 1

---

Official documents and archives suggest that the alien crayfish Pacifastacus leniusculus (Dana, 1852) was introduced into Japan from North America on five occasions from 1926 to 1930, and populations have survived in Hokkaido, Nagano, and Shiga Prefectures. The chemical conditions and biological environment of an established habitat near their original a release point in Akashina, Azumino City, Nagano Prefecture, were surveyed on four occasions in 1998 and 1999. Water quality (pH, DO, BOD) and WT were recorded seasonally at each of eight stations, and crayfish and other aquatic macro-organisms were collected. Some predatory fishes (Oncorhynchus mykiss, Anguilla japonica, and Lepomis macrochirus) that might actively eat juveniles of P. leniusculus were recorded. Individual density of P. leniusculus was relatively low compared to its other habitats in Japan. Only 52 crayfish were collected during this study, on 19 of 32 sampling occasions (eight sites, four times each). The shape of the acumen and the species composition of ectosymbiotic crayfish worms (Annelida: Clitellata: Branchiobdellidae) can be used as tools to trace the origin of introduced of P. leniusculus in Japan. The present crayfish from Nagano Prefecture have a relatively short acumen, different from those of specimens from Shiga and Hokkaido Prefectures. Furthermore, the crayfish worm Xironogiton victoriensis occurs only on crayfish from Akashina, Nagano Prefecture. The dates of introduction of P. leniusculus in Nagano (1926, 1929) also differ from those for Hokkaido (1930) and Shiga Prefecture (1926). These findings suggest that the regional population of P. leniusculus in Nagano has a different origin than those in Shiga and Hokkaido, having originated from crayfish that were introduced independently from North America.

著者

風呂田 利夫 木下 今日子

出版者

JAPANESE ASSOCIATION OF BENTHOLOGY

雑誌

日本ベントス学会誌 = Japanese journal of benthology (ISSN:1345112X)

巻号頁・発行日

vol.59, pp.96-104, 2004-07-28

参考文献数

27

被引用文献数

3 2

---

Two introduced crab species, Pyromaia tuberculata and Carcinus aestuarii, occur abundantly in organically polluted waters in Japan. Population studies of these crabs have been conducted in Tokyo Bay, in which summer hypoxia causes destruction of the benthic animal populations on the bottom of the innerhalf of the bay. In fall, a population of P. tuberculata quickly recolonizes that bottom, which has recovered from the hypoxia, by settlement of larvae. Settled crabs reach maturity by the next spring, then release larvae until the subsequent summer hypoxia. Released larvae disperse to the outerhalf of the bay, resulting in recruitment of juveniles into the local population. These recruits reach maturity before the fall under the normoxic conditions prevailing there, then release larvae for recolonization of the innerhalf of the bay. Carcinus aestuarii grows along the shores of river-mouths and in a lagoon of the inner bay, but migrates out onto the bay bottom during fall to spring, when it releases larvae. Released larvae settle along the shores during the spring. Settled crabs grow on the shores with adult crabs that had returned from the bay bottom. Thus the crabs on the shores avoid encountering the bottom hypoxia. These results suggest that the main factor that has allowed the establishment of the new introduced populations in Tokyo Bay is complementarity between the life cycle of these crabs, including adult migration or larval dispersal, and the seasonal availability of a habitat that is recovering from hypoxia.

著者

松尾 匡敏 首藤 宏幸 東 幹夫 近藤 寛 玉置 昭夫

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.62, pp.17-33, 2007-07-25 (Released:2010-02-05)

参考文献数

88

被引用文献数

1 1

---

In April, 1997, construction of a dike in the inner part of Ariake Sound to close off the innermost area of Isahaya Bay was completed. In June of both 1991 and 2002, benthic surveys were conducted using a Smith-McIntyre grab sampler at 88 stations over the entire sublittoral area of Ariake Sound. The structure of the gammaridean amphipod assemblage was compared between 1997 and 2002 with regard to any change in grain-size composition of the substrates and dissolved oxygen concentration of the bottom waters. No noticeable changes were observed in the distribution of the median particle diameter and silt-clay content, nor in the spatial arrangement of the sediment types of the substrates. Hypoxic water masses were observed in the bottom waters in 1997 in and around Isahaya Bay and in the southern part of Ariake Sound. Other studies also recorded hypoxic water masses in the former area in 1999 and 2001. For the amphipod assemblage, a total of 12, 434 individuals of 94 species belonging to 24 families was collected in 1997; the most dominant species was Photis longicaudata (family Isaeidae). In 2002, those values had changed to 37, 649 individuals, 89 species, and 27 families, with the most dominant species being Corophium sp. A (family Corophiidae). In both years, the amphipod assemblage was dominated by six families, including Isaeidae, Ampeliscidae, Corophiidae, Priscomilitaridae, Melitidae, and Aoridae, although the dominance order changed partially. The amphipod assemblage in both years inclusive was divided into eight groups using group-averaged clustering and non-metric multidimensional scaling. The group with the highest number of stations occupied the largest bottom area, composed of poorly-sorted medium to coarse sand along the longitudinal axis of Ariake Sound; the number of stations in this group increased from 41 in 1997 to 57 in 2002. Increase in individual density and expansion of distribution range of seven species of the superfamily Corophioidea (Corophiidae, Isaeidae, Priscomilitaridae), which occurred around the two hypoxic areas, contributed most to the range extension. For the above-mentioned six most dominant families, density of individuals and proportional composition of number of individuals in each of the two hypoxic areas and other, non-hypoxic areas were compared between the two years. In particular, both values remarkably increased for several members of the Corophiidae, including Corophium sp. A and C. crassicorne, in 2002; the exception was the value for density of individuals in the southern hypoxic area. The Shannon-Wiener species diversity index values were lower in 2002 for both the two hypoxic areas and the combined non-hypoxic areas, and for the three main groups of the amphipod assemblage.

著者

小川 晟人 自見 直人 蛭田 眞平 小林 元樹 清家 弘治 野牧 秀隆

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.75, pp.65-70, 2020-12-25 (Released:2020-12-24)

参考文献数

4

著者

堤 裕昭

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.76, pp.103-127, 2021-12-25 (Released:2022-02-11)

参考文献数

137

被引用文献数

2

---

Ariake Bay, located in the western coast of Kyushu, Japan, has been praised as “fertile sea” due to its extremely high production of various sea foods. However, since the late 1990s, red tide has occurred about twice as frequently as before, although the total nutrient discharge from the lands surrounding the bay has even decreased slightly since the 1970s. The increase of organic load on the sea floor by the frequent occurrence of red tide has caused seasonal hypoxia in the bottom water, and brought mass mortality of benthic animals in a wide area of the inner parts of the bay. These phenomena have occurred commonly in the enclosed coastal seas that have been suffering from eutrophication throughout the world. In this review, I collected various information on the occurrence of red tide, nutrient discharge, water conditions when red tide occurred, characteristics of the tidal current, etc., in Ariake Bay from the previous studies, and tried to clarify the mechanism how the red tide have occurred frequently, which is the most responsible for the recent marked decline of the benthic ecosystem in the bay. I focus on the impacts of the closure of the dike in a reclamation project conducted in the inner part of Isahaya Bay (an inner bay of Ariake Bay located in its western side of the middle part of the bay) in April 1997 not only on the tidal current in Isahaya Bay, but also the anticlockwise residual current that originally dominates in Ariake Bay.

著者

松村 貴晴 岡本 俊治 黒田 伸郎 浜口 昌巳

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.56, pp.1-8, 2001-07-15 (Released:2009-08-07)

参考文献数

39

被引用文献数

15 11

---

The clam Ruditapes philippinarum (Adams) is one of Japan's most important fisheries resources; recently, however, the anuual catch of this clam has declined to less than one quarter of its previous maximum. In order to implement more effective management of this resource, studies on early life stages, particularly the recruitment process that regulates subsequent population dynamics, are essential. To date, the recruitment dynamics of R. Philippinarum have been poorly understood due to a lack of basic information resulting from difficulties in identifying the larvae. To remedy this lack, we studied the recruitment process of R. philippinarum from April, 1998, to March, 1999, in Mikawa Bay, central Japan, using a new monoclonal antibody method. Our study revealed that R. philippinarum produces larvae from April to November in Mikawa Bay, in two discrete periods. An early spawning period occurred from April to July, with the peak abundance of larvae moving from the north-west to the eastern part of the bay. A later spawning period was observed in a relatively limited season from August to November. The distribution of larvae was basically controlled by the current system of the bay, although the larvae tended to become dispersed as they matured. The new monoclonal antibody identification method, applied for the first time in a study of a natural population, was found to be useful for studying R. philippinarum. It also proved to be an effective procedure for rapidly processing a large number of samples.

著者

山崎 大志

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.76, pp.141-142, 2021-12-25 (Released:2022-02-11)

著者

金谷 弦 多留 聖典 柚原 剛 海上 智央 三浦 収 中井 静子 伊藤 萌 鈴木 孝男

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.73, no.2, pp.84-101, 2019-03-31 (Released:2019-05-22)

参考文献数

45

被引用文献数

3 2

---

To assess macrozoobenthic diversity and habitat conditions following the 2011 tsunamis, we conducted a series of field surveys in the Samegawa and Momiya River estuaries (Fukushima and Ibaraki Prefectures, respectively). We compared measured parameters with existing published datasets for 10 sites along the northeastern Honshu coast. Faunal diversity was higher at the Samegawa site (140 taxa in total, of which 31 were endangered and 51 were endemic; the faunal list included stenohaline marine taxa), likely because of the high habitat diversity at this location and seawater discharge from the thermal power plant. Cluster analysis differentiated distinct faunal community groupings associated with two habitat types: (i) marine-dominated sites, including the Samegawa Lagoon, Mangoku-ura, and Matsushima Bay and (ii) sites with riverine influence, including the mouths of the Samegawa and Momiya Rivers and brackish lagoons along Sendai Bay. The population size of the dominant mud snail Batillaria attramentaria in the Samegawa Lagoon declined steeply after the tsunamis but gradually recovered within five years. Microsatellite DNA analysis showed that the genetic diversity of this population did not significantly change following the tsunamis. After 2016, ongoing restoration work caused drastic habitat degradation at the Samegawa site, resulting in mass mortalities of polyhaline and stenohaline marine taxa and overall reductions in faunal diversity.

著者

伊野波 佳介 TAN Ee Suan 和泉 遼太郎 武方 宏樹 竹村 明洋 磯村 尚子

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.76, pp.59-72, 2021

---

<p>Corals are known to synchronously undergo gonadal development during a period of 1 year and release gametes simultaneously during the spawning season. Synchronization of reproduction may be caused by changes in the external environment; particularly, the effects of light on reproduction have been extensively reported. In this study, we specifically focused on the type of wavelength, with the intention to elucidate whether there are wavelengths that promote reproduction in two <i>Acropora</i>. We exposed coral colonies to four types of light-emitting diode conditions with wavelengths suitable for keeping coral: "Coral," "Reef," "Fresh," and "Sunset," and monitored gamete maturation every 3 months, as well as the number of released gametes during the spawning season. In <i>A. intermedia</i>, "Sunset" conditions promoted gamete maturation; however, there was no spawning observed. In contrast, in <i>A. muricata</i>, the same conditions promoted a series of processes ranging from gamete maturation to gamete release. In "Fresh" and "Coral" conditions, gamete maturation was also promoted. "Sunset" condition is characterized by longer wavelengths within the red-light visible spectrum, which is relatively predominant in the shallow waters where the two target species live. Therefore, this indicates that these longer wavelengths represent a light stimulus that promotes reproduction. By contrast, gamete maturation was promoted by even shorter wavelengths in <i>A. muricata</i>; therefore, further experiments considering different light sensitivities among species and growth promotion through the photosynthesis of zooxanthellae are recommended. It is also suggested that, in addition to wavelength type, spawning may be affected by water temperature increase after winter season.</p>

著者

大越 健嗣

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.59, pp.74-82, 2004-07-28 (Released:2010-02-05)

参考文献数

30

被引用文献数

30 30

---

The clam Ruditapes philippinarum is a commercially important fishery resource in Japan. Because the amount of production has been decreasing gradually in Japan, the clam has been imported from China and Korea in recent years to provide seed for aquaculture and also for recreational shellfish gathering. The object of this study is to confirm whether alien species are being introduced together with the clam and to obtain information on their distribution in Japanese waters. Three species of mollusk-eating moon snail, Euspira fortunei, Glossaulax didyma, and Glossaulax reiniana, were collected from sacks filled with R. philippinarum imported from China. Seven other gastropod species, nine species of bivalves including Meretrix pethechialis, the purse crab Phiiyra pisum, and a brachiopod, Lingula unguis, were also collected from the sacks. Almost all the unintentionally introduced animals were living and were directly released with commercially introduced clams into Mangoku-ura Inlet, Miyagi Prefecture, by a fishermen's cooperative. Although the snail Euspira fortunei is not indigenous to the eastern and northern coasts of Japan, relatively large populations of it occur in the clam production areas of Lake Hamana (Shizuoka), the estuary of the Obitsu River (Chiba), and Mangoku-ura Inlet. I believe that a population of this invasive snail has already been established at least in Mangoku-ura Inlet and is becoming a new, strong predator of the clam stocks. Prevention of further spread and estimation of the rate of predation are important to the clam culture. Among the 22 alien species recorded in this survey, seven were also found in the native communities. The effect of the alien population on the preexisting population is also important problem to be solved.

著者

齋藤 暢宏 木下 今日子

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.59, pp.1-7, 2004-07-28 (Released:2009-08-07)

参考文献数

26

被引用文献数

4 4

---

During a faunal survey of the intertidal mud flat of Shinhama Lagoon on the northern coast of Tokyo Bay, parasitic bopyrid isopods, Ione cornuta Spence Bate, were found attached to the inner walls of the branchial chambers of ghost shrimps, Nihonotrypaea japonica (Ortmann). In this isopod, the females are parasites of N. japonica whereas dwarf males attach to conspecific females. To investigate the prevalence of the parasite I. cornuta, sampling of ghost shrimps was conducted every 2 to 4 weeks at the Shinhama Lagoon during the periods from August, 1994, to October, 1995, and January, 1998, to May, 1999. A total of 328 individuals (253 females, 62 males, and 13 of unknown sex) of N. japonica was collected, and 22 individuals among them (6.7%) were infected with I. cornuta. Among the infected shrimps, females accounted for 21 individuals, and only one male was infected. This skewed sex ratio is considered to simply reflect the female-biased sex ratio of this species in the field. In most cases, one individual of the parasite I. cornuta was attached within the left or the right branchial chamber of each host shrimp. No significant relationship was detected between the handedness of the major cheliped of the host shrimps and the attachment position of I. cornuta. A significant positive correlation was found between the size of the host shrimps and the size of mature females (i.e., those with brood chambers) of the parasite; however, the size of immature parasites was not correlated with the size of their host shrimp. In spite of the long sampling periods during this study, no ovigerous shrimp infected by I. cornuta was collected. This strongly suggests that infection by I. cornuta negatively affects the reproduction of the host female shrimps.

著者

成田 光好 関口 秀夫

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.57, pp.1-12, 2002-06-27 (Released:2009-08-07)

参考文献数

37

被引用文献数

4 4

---

Sampling of megabenthos was conducted between 1997 and 1998 in Ise Bay, central Japan to examine the food habits of three dominant species of crabs: Charybdis bimaculata, Paradorippe granulata, Cancer gibbosulus. The degree of gut fullness as well as the frequencies of occurrence and the relative volumes of food items were investigated. In the summer when the oxygen-poor water conditions developed, frequencies of occurrence of food items were low and the degree of the guts fullness in most of crabs collected was <50%; in contrast, these values were high from the winter to spring of the following year, when the oxygen-poor water conditions did not develop. A comparison between frequencies of occurrence and relative volumes of food items in the gut showed that crustaceans, polychaetes, gastropods and bivalves were important foods for the crabs. The main components of the gut contents were different between the three species, though this is probably due to differences in spatial distribution patterns of crabs and their prey items.

著者

岩崎 敬二

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.59, pp.19-21, 2004-07-28 (Released:2009-08-07)

参考文献数

23

被引用文献数

1 1

著者

五嶋 聖治

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.71, no.2, pp.83-89, 2017-03-31 (Released:2018-04-17)

参考文献数

41

被引用文献数

2

---

The occurrence of the ghost crab Ocypode stimpsoni was surveyed at 32 beaches within southern Hokkaido, and Itanki Beach at Muroran was detected as the northernmost edge of its range. The burrow distribution of the ghost crab at Omori Beach, Hakodate, near the northern edge, was investigated from January to December 2014. Burrow opening was initially observed in late June near the upper area of the beach with vegetation. The number of burrows increased in the following months, with their distribution extending down the beach. During mid-summer with high temperature, severe dryness of the sand restricted the upper limit of the burrow digging area to immediately below the high-tide water mark with moist sand. The lower limit was determined by excavation of the sand by rough waves, concentrating the burrow area to a narrow band within the beach. In autumn, the dryness decreased and the burrow area extended upward, becoming wider. Burrow activity halted by the end of October. After October, the ghost crab overwintered in deep burrows within the upper area until late next June. These results suggest that at the northernmost edge of the distributional range, seasonal activity patterns are severely restricted by environmental factors such as extreme temperatures, dryness, and rough waves, which is coincident with the general rule of geographical range pattern of organisms. A possibility that the famous poet Takuboku Ishikawa played with the ghost crab at Omori Beach was discussed based on the findings.

著者

北橋 倫 仲村 康秀

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.74, no.2, pp.129-135, 2020-03-31 (Released:2020-04-04)

参考文献数

54

著者

邉見 由美 塩﨑 祐斗 山守 瑠奈 伊谷 行

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.74, no.1, pp.35-40, 2019-08-31 (Released:2019-09-09)

参考文献数

41

被引用文献数

1

---

Pseudopinnixa carinata (Crustacea: Decapoda: Varunidae) is a monotypic rare brachyuran endemic to the Japanese coast. Seventeen specimens of the crab were collected from tidal flats in Yamaguchi and Kochi Prefectures, Japan. The collection from Kochi Prefecture sets a new record from the Pacific coast of Shikoku. A review of P. carinata collection sites and the habitat information revealed that the species is widely distributed in Honshu, Shikoku, and Kyushu, but has never been collected in the Ryukyu Islands and southern Kyushu. This crab inhabits intertidal to subtidal sandy sediments with its deepest record being at 55 m depth. Several studies have shown that the crab was collected from sediments where burrowing invertebrates were abundant. Crabs have been found inside burrows of the echiuran Urechis unicinctus, the gebiidean shrimp Upogebia sakaii, and the axiidean shrimp Nihonotrypaea japonica by digging sediments. In this study, some specimens were pulled out from the burrows of N. japonica and other callianassid shrimp species as well as those of the polychaete Arenicola brasiliensis by yabby pumps.

著者

宮園 章

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.61, pp.45-52, 2006-07-28 (Released:2009-08-07)

参考文献数

30

被引用文献数

3 3

---

Hanging culture of Japanese scallops (Mizuhopecten yessoensis) constitutes the most important fishery in Funka Bay, located in the southeastern part of Hokkaido, Japan. Scallop culture started in the early 1970s and developed into an important industry involving scallop processing and distribution not only as locally important industries, but also as a pillar of the Hokkaido economy. The carrying capacity of scallops cultured in Funka Bay was estimated in 1977-1978 for the first time; after that, however, cultured scallop production continued to increase year by year owing to failure to control on the basis of this estimate. At present, scallop production far exceeds the carrying capacity. The carrying capacity model used to calculate that early estimate was based on the difference between food production and food consumption in the scallop culture area. Controllability of product size and quarity is a marked characteristic of mariculture. I have incorporated the idea into the old 1977-78 model. A new model proposed herein will be useful as educational tools for businesses involved in scallop culture. The huge number of scallops hanging in the coastal area, where their culture areas occupy 19% of the total area of Funka Bay, undoutedly has important ecosystem-level effects in the bay. We need to assess the ecosystem-level effects of the scallop culture and devise a new standard of carrying capacity estimation in order to improve the sustainability of this fishery.

著者

大越 和加 阿部 博和 寺本 航 大野 博正 内海 修平 鈴木 陽大 綾小路 法孝 近藤 智彦 西谷 豪 遠藤 宜成

出版者

日本ベントス学会誌編集委員会

雑誌

日本ベントス学会誌 = Japanese journal of benthology (ISSN:1345112X)

巻号頁・発行日

vol.66, no.2, pp.124-126, 2012-03-27

著者

大高 明史

出版者

日本ベントス学会

雑誌

日本ベントス学会誌 (ISSN:1345112X)

巻号頁・発行日

vol.73, no.1, pp.48-56, 2018-08-31 (Released:2018-10-12)

参考文献数

54

被引用文献数

1

---

Forty taxa of aquatic microdrile oligochaetes (Annelida, Clitellata) that belong to three families were recorded in inundated rice paddies in Japan on the basis of faunistic survey in 81 localities. To our knowledge, three naidine species, Bratislavia dadayi, Dero nivea, and Aulophorus hymanae, are new to Japan. The oligochaete assemblages primarily consisted of widely distributed and thermophile species and were often dominated by desiccation-tolerant species such as Aulodrilus limnobius, Bothrioneurum vejdovskyanum, and Branchiura sowerbyi. The faunal characteristics have been discussed in relation to rice paddy environments.