The malacologicalsocietymalacological society ofJapanof Japan fige YENUS (Jap. Jour. Malac.) Vel. 45, Ne. 3 C19S6): 169-176 -? tsgOlijEze< . Rzl<rk7 Jl- 7"* if' -i･ ncN ,ji Mlr N ee ([llkJit#mp\zzwu'tsfireimbeecuant) Freshwater and Brackish Water Neritid Fauna in Taiwan (Republic of China)" Shigemi KoMATsu (Mukaishima Marine Biological Station of Hiroshima University, Mukaishima-cho, Hiroshima-ken 722) Abstract: The present paper deals with freshwater or brackish water neritid fauna in northern and central Taiwan. Twelve species in three genera (eight subgenera) were colleeted, of which five species are new reeords from Taiwan, and all of them are also distributed in Japan. There is a high zoogeographical aMnity between Taiwanese and Japanese neritid fauna. Matsuda (1924a, b), Herikawa (1935a, b), Kuroda (1941) and Pace (1973) have previously reperted on neritid fauna in Taiwan (Republic of China). Kureda listed 26 species in five genera, of which the freshwater or brackish water neritids are composed of one speeies in the genus Nerita, three in the genus Clithen, four in the genus Neritina and one in the genus Septaria. Pace made a detailed review on the Taiwanese freshwater snails among which he dealt with four species of Clithon, four of Neritina and one of Septaria. As a part of the taxonomie study ef Japanese neritids, the comparison ef the Japa- nese speeies with the Taiwanese speeies is made in order to elucidate a faunal relationships within Neritidae and to eontribute new knowledge on freshwater neritid fauna in Taiwan. Materials Specimens used in this study were eolleeted at the rivers of northern or central Taiwan in April, 1985. Their localities are as follows (Map 1) : 1. Tungkang, I-lan (Lanyang Hsi). 2. Taichung (Tachia Hsi). 3. Takangko. ttt t tttt t tt t * Contribution from the Mukaishirna Marine Biological Station, No. 273; Aceepted: May 12, 1986 NII-Electronic Library Service The malacologicalsocietymalacological society of Japan 170 VENUS: Vol. 45, No. 3 (1986) gtianLiaochiav mfo benghub Islants e KHohs Map L Collecting localities. tweeJa±l,E,, 1, Tungkang, I-lan (Lanyang Hsi). Mas, :A:carii (whuzpt) 2, Taichung (Tachia Hsi). kgbi+i (]krpec) 3. Takangko, Jknsn Results Genus Ceithon Montfort, 1810 Subgenus Clithon s. str. 1. CZithon (CZithon) oorona (Linnaeus, 1758). (Fig. 1) Localities oncl habitats: Takangko, 8 specimens; Tachia Hsi, 39 specimens. Many snails were found attached on stones in the estuaries. These loealities are the new distributional records in the central Taiwan. Distribution in Tai2van: Kuroda (1941) reported this speeies enly from Keelung. Paee (1973) has also eited Kuroda's record and showed that a form from the Philippines was C. c. angutosa. 2. (;Zithon ((;Zithon) retropictus (v. Martens, 1879). (Fig. 2) Localities and habitats: Tachia Hsi, 1 specimen. It inhabited the same area as C. corona. This locality is a new distributional record in the central Taiwan, Distribution in Taiwan: Hsinchu (Horikawa, 1935a, b) ; Keelung, Tanshui, Tali, Santiaochiao (Kuroda, 1941); I-lan, Taipei (Pace, 1973). 3. ()tithon (crithon) faba (Sowerby, 1836). (Fig. 3) Loeatities and habitats: Lanyang Hsi, 1 specimen; Taehia Hsi, 9 speeimens. This species inhabited the same areas as C. corona, Distribution in Taiwan: Tanshui (Martens, 1879; Pace, 1973); Liuchiu Yu (Matsuda, 1924a). NII-Electronic Library Service The malaoologloalmalacological societysoolety of Japan Komatsu ： Freshwater Neritid Fauna in Taiwan ． 171 ’ 一 ；i ・・：：： ・ ：ii蘇 ・鵬 謙 難iilii 隙 嫉 li 3 「囁 ミttt 照揮 』 睾緜 痴 肝 §匿 脚・ 噸驫 叢 黙 鑑二認 i ’ ・ ． ： ： 鑑 認 堀 iil7 ，：：：；．蕊ill： 雌難 鑞 嬬鍛 1鑓il ’ ’ ’ げ’ ’ほ：にu ， ，ニ こttU ミt 、t ttt’ r− ’ ・ 臓 ：：：…；1鑞i8i：、：：ili≡欝ii；；： tt ；一 ・：嵩 ン遣遣囁藩 ：溝O ！i鳧t彈tt’til；；｝：淫議 ：： 曽””／SMU ”／遥 ：／ ：tt・tmt・・tttt 簔：， ’tt 訟 ・灘鮒w” tt・t ■ ， 騾 Fig． L Ctithon （Clithon） corona （Linnaeus，1758）． Takangko ． イ ガ カ ノ コ ガ イ （大港 口 産 ） 2． C．（C ．） retropictus （v ， Martens ，1879）． Tachia Hsi ． イ シ マ キ ガ イ （大 甲渓 産） 3． C ，（C ．）faba （Sowerby ，1836）． Tachia Hsi． カ ノ コ ガ イ （大 甲渓産） ハ コ 4． C．（Pictoneritina）chlorostema （Sowerby ，1833）． Takangko ． ナ ガ ス ミ カ ノ ガ イ （大 港 「1産 ） 5 ． Neritina （Neripteron ） auriculata Lamarck ，1816． Lanyang Hsi ソ バ サ カ ノ コ ガ イ （蘭陽 渓産） ． Lanyang Hsi ． ヒ 卩 ク チ カ ノ コ ガ イ 678901 コ N ．（1）ostia ） viotacea （Gmelin ，1791） （蘭陽 渓 産 ） コ N ．（Vittina） turrita （Gmelin ，1791）． Lanyang Hsi ． シ マ カ ノ コ ガ イ （蘭 陽渓 産 ） コ N ，（γ ．） paratlela （R6ding ，1798）． Lanyang Hsi． イ ナ ズ マ カ ノ コ ガ イ （蘭陽渓産） ． Hsi ． ド ン グ U カ ノ コ ガ イ ロ N ，（V ．） plumbea Sowerby ， 1855 Lanyang （蘭 陽 渓産 ） 11 ロ N ．（Vittoida） variegata Lesson ，1830． Takangko ． ム ラ ク モ カ ノ コ ガ イ （大 港 口 産 ） ロ Septaria（Septaria） porcellana（Linnaeus．1758）． Takangko ． フ ネ ア マ ガ イ （大 港 口 産 ） ー ベ コ フ ・ 口 12． S．（Navicetla）lineata（Lamarck ，1816）．Takangko ． ッ ウ ネ ア ガ イ （大 港 産 ） ． Scale＝1mm ． 一 NII-ElectronicN 工 工 Eleotronlo LibraryLlbrary Service The malacologicalsocietymalacological society of Japan 172 VENUS: VoL 45, No.3(1986) Remarks: Martens considered that NeritinQ faba Sowerby, N. avetlana R6cluz and N. sotoerbiana Recluz are distinct species and that the latter two are distributed in Taiwan. Furthermore, he regarded N. pulchetta Recluz as a synonym of IV. sowerbiatna and N. interTupta Recluz as that of N. avellana. How- ever, Tryon (1888) eonsidered that pulchetla, avellana and faba are all probable synonyms of sozverbiana and that interrztpta pessesses all the characters of N. nucleolus Morelet, 1857. Hirase (1934) applied Theodoxus (Ctithon) sower- bianus and T. (C.) faba to Japanese species, but Hirase and Taki (1954) identi- fied C. fthba with C. sowerbianu$. Thereafter, Japanese workers allocated Japanese species into Clithon sowerbianus. On the other hand, Benthem Jutting (1956, 1963) used the names C. faba to Javanese species and C. sowerbianza to New Guinean one. Paee pointed out that the most commonly used name for these snails was Ctithon so2verbianus (R/6cluz) and stated that for the sake of stability it would be worthwhile to appeal to the International Commission en Zoological Nomenclature to preserve this name. In examining the syntype speci- mens of Neritina･ sowerbiana R/ecluz, 1842 (Museum d'Histoire Naturelle, Geneve and Museum National d'Histeire Naturelle, Paris) and N. faba Sowerby, 1836 (British Museum), the present author confirmed that these species were identi- cal and considered it inadequate that Hirase and Taki used sozverbianus to Japanese species. Therefore, Clithon faba (Sowerby) should be used for this specles. Pace assigned this species to the subgenus Vittoctithon by the characters that the shell was covered by a smooth periostracum and the co]or pattern was quite variable. However, I consider it inadequate to use these characters as diagnoses of the subgenus and could not distinguish them from the subgenus Clithon s. str. by the shell, opercular and radular characters. Subgenus Pictoneritina Iredale, 1936. 4. (;lith{m (Pictoneritina) tht(m'astoma (Sowerby, 1833). (Fig. 4) Localities and habitats: Takangko, 3 specimens. On the boulders in the estuary but slight]y closer te the sea than the habitat of C. cerona. This species was originally described on the speeimens from Tahiti (Sowerby, 1833) and is known from Polynesia to Japan. It was newly reported from Taiwan and this the speeies is eharacterized by two black radiating bands on the exterior of operculum. Genus Neritina Lamarek, 1816. Subgenus Neripteron Lesson, 1830. 5. IVeritina (IVieripteron) aesricutata Lamarck, 1816. (Fig. 5) Localities a･nd habitats: Lanyang Hsi, 16 speeimens. On stones on the bank adjacent to the reed field of the estuary. This speeies was newly reported from Taiwan. Subgenus Dost･ia Gray, 1840. NII-Electronic Library Service The malacologicalsocietymalacological society of Japan Komatsu: Freshwater Neritid Fauna in Taiwan. 173 6. IVIeritina (Dastia) violacect (Gmelin, 1791). (Fig. 6) Localities and habitats: Lanyang Hsi, 2 specimens. Collected with N. (2VeripteTon) auricutat-. This was a new locality in the northern Taiwan. Distribntion in Taizvan: Pingtung, Kaohsiung, Anping (Kurbda, 1941). Remarks: Pace (1973) allocated this species to the subgenus Neripteron, sinee no explanatioll was given for the changes in taxonomic position by Kuroda and Habe (1961), However, the subgenus Dostia is characterized by much areuated shells and thieker opercula than in the subgenus Neripteron and trape- zoid eentral teeth of radulae. Therefore, Dostia is aeeeptable as the subgenus of the genus Neritina･. Subgenus Vittina Baker, 1923. 7. IVeritina (Vittina) turrita (Gmelin, 1791). (Fig. 7) Teed Locatities and habitats: Lanyang Hsi, 7 specimens. In the fieldof the estuary; on the mud, stalks of reed or stones on the bank, This species was newly reported from [I]aiwan. 8. IVbritina (Vittina) paralteta (R6ding, 1798). (Fig, 8) Localities and habitats: Lanyang Hsi, 28 specimens, collected with N. (V.) turrita. This species was newly reported from Taiwan. 9. IVbritina (V]ittina) plumbetz Sowerby 1855. (Fig. 9) t Localities and habitats: Lanyang Hsi, 28 specimens, collected with N. CNeripteron) auricueata. Distribution in Taitv(mt: Aoti (Taipei Hsien) (Kuroda, 1941). Subgenus Vittoida BakeT, 1923. 10. IVeritina (Vittoida) variegata Lesson, 1830. (Fig. 10) Localities and habitats: Takangko, 1 specimen. On the muddy bed of the bank. This is a new loeality in the central Taiwan. Distribution in Taiwan: Kaohsiung (Kuroda, 1941). Remarks: As well as the subgenus Dostia, Pace did not aecepted Vittoida as the subgenus of the genus Neritina. However, I admitted a differentiation of Vittoida from Vittina in the shell, opercular and radular eharacters. Thus, I alloeate .this species under the subgenus 7ittoida, Genus Septaria Ferussae, 1807. Subgenus Septaria s. str. 11. Septaria (Septaria) poraellana (Linnaeus, 1758). (Fig. 11) Locatities ana habitats: Takangko, 32 specimens; Tachia Hsi, 29 specimens, collected on stones with Clithon corona.