H. Motomura and K. Matsuura (eds) Fishes of Yaku-shima Island
National Museum of Nature and Science, Tokyo, 10 March 2010Freshwater fishes of Yaku-shima Island,
Kagoshima Prefecture, southern Japan
Toshihiko Yonezawa1*, Akihiko Shinomiya2 and Hiroyuki Motomura3
1

Foundation of Kagoshima Environmental Research & Service, 1-1-5 Nanatsujima, Kagoshima 891-0132, Japan
Faculty of Fisheries, Kagoshima University, 4-50-20 Shimoarata, Kagoshima 890-0056, Japan
3
Kagoshima University Museum, 1-21-30 Korimoto, Kagoshima 890-0065, Japan*
Corresponding author: e-mail: yonezawa@kagoshima-env.or.jp
2

Abstract An annotated checklist of freshwater fishes of Yaku-shima Island, Kagoshima Prefecture,southern Japan, was compiled from field and literature surveys. A total of 32 species (22 genera, 11families, 7 orders) are listed with citation of literature, registration numbers, sizes, localities in theisland, ecological notes, and color photographs if available.
Key words: Freshwater fishes, checklist, Yaku-shima Island, Kagoshima, Japan.

Introduction
Yaku-shima Island has well-developed mountains, including the highest peak in Kyushu, Mt.
Miyanoura, at 1936 m. Annual precipitation ishigh, 2,400–5,000 mm in lowland areas and
5,000–7,400 mm in the mountains (Takahara andMatsumoto, 2002). Therefore, the island’s rivers
are well developed, especially the Ambo River,which is more than 10 km long. In addition, theisland has very limited flatlands and in its entirety
appears as one large, steep mountain, with themountain slope continuing under the sea. Thus,
the estuaries are poorly developed, and the rapid
mountain streams flow directly into the sea without any obvious estuarine area.
The water temperature in the larger rivers of
the lowland areas drops below 10°C in the winterseason because the headwaters of these rivers are
fed by snowmelt. On the other hand, the watertemperature in some small-scale rivers with hot
springs exceeds 15°C even in winter.
The freshwater ichthyofauna of Yaku-shimaIsland is poorly known, with only a few faunal
studies published (e.g., Jordan and Starks, 1906;
Kuroiwa, 1927; Ogawa, 1937). During recent
surveys of freshwater fishes of Yaku-shima Islandby the first author, a gobiid, Stiphodon surrufus,

was discovered from a small river with a hot
spring (Yonezawa and Iwata, 2001) and the species is currently known only from the island inJapan. However, no other survey results (except
for Yonezawa, 2002; Yonezawa and Shinomiya,2002) have been published.
This paper provides a list of 32 species offreshwater fishes occurring in the upper and middle reaches of rivers on Yaku-shima Island on thebasis of published papers, collected specimens,
and underwater photographs and observations
during the surveys.
Materials and methods
The systematic arrangement of families follows Nelson (2006). Species in families are arranged in alphabetical order of species name.
Standard Japanese names generally follow Nakabo (2002), and are transliterated using the Hepburn system. Each species record was compiled
from voucher specimens and literature sources
related to freshwater fishes recorded from the upper and middle reaches of the island’s rivers. Each
voucher specimen includes registration number,number of specimens registered if more than one,standard length (abbreviated as SL), and locality
on Yaku-shima Island (Fig. 1). Nishi and Imai249

T. Yonezawa et al.

Fig. 2. Anguilla japonica. USNM 53542, 247.1 mm SL,
Miyanoura River (preserved specimen).

Fig. 1. Map of Yaku-shima Island, with major rivers.
Names of places and rivers given in this map are usedin text.

(1969) listed 11 species from Yaku-shima Island.
However, these fishes are not listed in this study
because some or most species might be collectedfrom estuaries of the Isso River.
Specimens used in this paper have been deposited at the following collections: Biological
Laboratory, Imperial Household, Tokyo (BLIP);
Kagoshima University Museum, Kagoshima(KAUM); National Museum of Nature and Science, Tokyo (NSMT); and Museum Support
Center of the Smithsonian Institution National
Museum of Natural History, Suitland (USNM).

Anguilla marmorata Quoy and Gaimard, 1824
[Japanese name: Ounagi] (Fig. 3)
Kuroiwa (1927); Ogawa (1937); Sakai et al.
(2001); Mizuno and Nagasawa (2009).
Remarks. In small streams at Yaku-shimaIsland, the species occurs from the headwaters toriver mouths. The population of A. marmorata islarger than that of A. japonica at Yaku-shima Island.

Fig. 3. Anguilla marmorata. Isso River, 0.5 m, 16 Oct.
1999, T. Yonezawa.

List of freshwater fishes
ORDER ANGUILLIFORMESFAMILY ANGUILLIDAE
Anguilla japonica Temminck and Schlegel, 1846
[Japanese name: Unagi] (Fig. 2)
USNM 53542, 2 specimens, 247.1–256.5 mm
SL, Miyanoura River.
Jordan and Starks (1906); Kuroiwa (1927);
Ogawa (1937); Sakai et al. (2001).
Remarks. The species usually inhabits gently
flowing rivers and is relatively rare at Yaku-shimaIsland. Classified as ‘data deficient (DD)’ in the2007 Red List by the Ministry of Environment,
Japan.

250

ORDER CYPRINIFORMESFAMILY CYPRINIDAE
Tribolodon hakonensis (Günther, 1877)[Jpn name: Ugui] (Fig. 4)
Yonezawa et al. (2003).
Remarks. An introduced species; released
together with Oncorhynchus masou masou into
the Ambo River in 1971 (T. Oyama, pers. comm.).
The Yaku-shima Island population of the species
is most likely to be landlocked because its spawning has been confirmed from an upstream dam.
Catadromous and landlocked populations are
known for the species.

Freshwater fishes of Yaku-shima Island

Fig. 4. Tribolodon hakonensis. Ara River, 0.5 m, 23 Nov.
2005, K. Morita.

Carassius langsdorfi (Temminck and Schlegel, 1846)[Japanese name: Gimbuna]
Ogawa (1937, as Carassius carassius).
Remarks. No records of the species havebeen reported from Yaku-shima Island since
Ogawa (1937). He reported it as “Funa, C. carassius” without voucher specimens, and provided a
photograph of a fish collected from Okinoerabujima Island (not Yaku-shima Island). If his recordof “Funa” was certain, his fish was probably C.
langsdorfi (rather than C. carassius) because C.
langsdorfi is widely distributed in the islands, including Tanega-shima and Amami-oshima Islands,
and on the mainland of Kagoshima Prefecture.
FAMILY COBITIDAE
Misugumus anguillicaudatus Cantor, 1842
[Japanese name: Dojo]
Kuroiwa (1927); Ogawa (1937).
Remarks. No records of the species havebeen reported from Yaku-shima Island since
Ogawa (1937). This species is probably very rareor extinct on Yaku-shima Island because preferredhabitats of the species, e.g., reservoirs, ponds,
and rice fields with small channels, are limitedon the island. It has been classified as ‘criticallyendangered + endangered (CR+EN)’ in the 2003
Kagoshima Red Data Book by the Environment
and Citizens Affairs Department, Kagoshima Prefectural Office.

ORDER OSMERIFORMESFAMILY OSMERIDAE
Plecoglossus altivelis altivelis Temminck and Schlegel, 1846
[Japanese name: Ayu] (Fig. 5)
KAUM–I. 19101, 146.0 mm SL, Isso River;
KAUM–I. 19102, 83.7 mm SL, Isso River;
KAUM–I. 19103, 100.4 mm SL, Isso River;
KAUM–I. 19104, 80.3 mm SL, Isso River;
KAUM–I. 24679, 93.5 mm SL, Miyanoura River;
KAUM–I. 24680, 84.3 mm SL, Miyanoura River;
KAUM–I. 24681, 84.4 mm SL, Miyanoura River.
Kuroiwa (1927); Ogawa (1937); Sawashi etal. (1993); Sakai et al. (2001); Yonezawa et al.
(2003).
Remarks. Occurs in relatively large rivers on
Yaku-shima Island. The Yaku-shima Island population represents the southernmost distributional
range of P. altivelis altivelis (see Yonezawa et al.,2003). A closely related subspecies, P. altivelis
ryukyuensis, is distributed on Amami-oshimaIsland but has never been recorded from Yakushima Island; this is probably because the survival
rate of juvenile P. a. ryukyuensis is extremely
low when sea water temperature exceeds 20°C
(Kishino et al., 2008) and they usually stay incoastal areas and do not venture offshore (Tsukamoto, 1988). Plecoglossus a. altivelis is classified
as ‘vulnerable (VU)’ in the 2003 Kagoshima Red
Data Book by the Environment and Citizens Affairs Department, Kagoshima Prefectural Office.
ORDER SALMONIFORMESFAMILY SALMONIDAE
Oncorhynchus masou masou (Brevoort, 1856)[Japanese name: Yamame] (Fig. 6)
Kawanabe and Mizuno (1989); Yonezawa etal. (2003).
Remarks. A landlocked population in the
Ambo River; introduced into the upstream area of
the Arakawa Dam in 1971 by the Freshwater Fish
Protection Society in cooperation with the Facultyof Fisheries, Kagoshima University, and Fisheries
Department, Kagoshima Prefectural Office.

251

T. Yonezawa et al.

A

B

C

Fig. 5. Plecoglossus altivelis altivelis. A, Miyanoura River,
0.5 m, 15 Oct. 1999, T. Yonezawa; B, Isso River, 0.5 m,
16 Oct. 1999, T. Yonezawa; C, Isso River, 0.8 m, 23
Dec. 2009, S. Harazaki.

ORDER BELONIFORMESFAMILY ADRIANICHTHYOIDAE
Oryzias latipes (Temminck and Schlegel, 1846)[Japanese name: Medaka]
Sakai et al. (2001).
Remarks. This species is probably very rareor extinct on Yaku-shima Island because preferredhabitats of the species, e.g., reservoirs, ponds, andrice fields with small channels, are limited on theisland. There are three distinct genetic populations of O. latipes (Satsuma, Osumi, and Ryukyu
populations) in Kagoshima Prefecture (Sakaizumi,1997). Oryzias latipes at Yaku-shima Island ismost likely to be the Ryukyu population. The species is classified as ‘critically endangered + endangered (CR+EN)’ in the 2003 Kagoshima Red
Data Book by the Environment and Citizens Affairs Department, Kagoshima Prefectural Office,and as ‘vulnerable (VU)’ in the 2007 Red List by
the Ministry of Environment, Japan.
ORDER SYGNATHIFORMESFAMILY SYNGNATHIDAE
Microphis leiaspis (Bleeker, 1853)[Japanese name: Issen-yoji]
Sakai et al. (2001).
Remarks. At Yaku-shima Island, the species
apparently disappears during winter.
ORDER PERCIFORMESFAMILY KUHLIIDAE
Kuhlia marginata (Cuvier, 1829)[Japanese name: Yugoi] (Fig. 7)
KAUM–I. 17823, 47.3 mm SL, a stream at
Kusugawa; KAUM–I. 17833, 46.9 mm SL, astream at Kusugawa; KAUM–I. 17858, 32.3 mm
SL, Isso River; KAUM–I. 25049, 78.4 mm SL,
Ambo River.
Ogawa (1937); Sakai et al. (2001).
Remarks. Common at Yaku-shima Island.

Fig. 6. Oncorhynchus masou masou. Ara River, 0.5 m, 23
Nov. 2005, K. Morita.

Fig. 7. Kuhlia marginata. KAUM–I. 17833, 46.9 mm SL, astream at Kusugawa (preserved specimen).

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Freshwater fishes of Yaku-shima Island

Kuhlia munda (De Vis, 1884)[Japanese name: Togenagayugoi]
Kawanabe and Mizuno (1989); Sakai et al.
(2001).
Remarks. Extremely rare at Yaku-shima Island. No specimens were confirmed during thisstudy. The species is classified as ‘data deficient(DD)’ in the 2003 Kagoshima Red Data Book by
the Environment and Citizens Affairs Department,
Kagoshima Prefectural Office, and as ‘endangered(EN)’ in the 2007 Red List by the Ministry of Environment, Japan. Sato et al. (2004) synonymized
K. boninensis (Fowler, 1907) with K. munda.
Kuhlia rupestris (Lacepède, 1802)[Japanese name: Okuchiyugoi] (Fig. 8)
KAUM–I. 19094, 79.5 mm SL, Hide River.
Kuroiwa (1927); Ogawa (1937); Sakai et al.
(2001).
Remarks. Often occurs with Kuhlia marginata at Yaku-shima Island. The population of K.
rupestris is much smaller than that of K. marginata at the island. The species apparently disappears
during winter at Yaku-shima Island and adults
have never been observed.

at Yaku-shima Island, possibility of reproduction
at the island is relatively low. The northernmost
recorded range of the species is probably Yakushima Island. The species is classified as ‘criticallyendangered + endangered (CR+EN)’ in the 2003
Kagoshima Red Data Book by the Environment
and Citizens Affairs Department, Kagoshima Prefectural Office, and as ‘endangered (CR)’ in the2007 Red List by the Ministry of Environment,
Japan.

A

B

C

Fig. 8. Kuhlia rupestris. KAUM–I. 19094, 79.5 mm SL,
Hide River (preserved specimen).

FAMILY RHYACICHTHYDAE
Rhyacichthys aspro (Valenciennes, 1837)[Japanese name: Tsubasahaze] (Fig. 9)
BLIP 1999194, 24.9 mm SL, Okawa River;
BLIP 1999195, 24.5 mm SL, Nagata River.
Yonezawa et al. (2003); Suzuki and Shibukawa (2004).
Remarks. Rare at Yaku-shima Island; havebeen observed at small waterfalls near mouths ofsmall rivers. Although the species can overwinterFig. 9. Rhyacichthys aspro. A, Nagata River, 0.3 m, 14 Oct.
1999, T. Yonezawa; B and C, a stream at Onoaida, 0.5m, 25 Dec. 1999, T. Yonezawa.

FAMILY ELEOTRIDAE
Eleotris fusca (Forster, 1801)[Japanese name: Tenjikukawaanago] (Fig. 10)
Remarks. Occurs in the lower portions of the
middle reaches of small-scale rivers; relatively
rare at Yaku-shima Island. The species cannot
overwinter at the island and dead individuals canbe observed on the bottom of rivers in winter.

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T. Yonezawa et al.

Fig. 12. Awaous ocellaris. Nagata River, 0.5 m, 14 Oct.
1999, T. Yonezawa.
Fig. 10. Eleotris fusca. A stream at Onoaida, 0.3 m, 25
Dec. 1999, T. Yonezawa.

Ophieleotris sp.
[Japanese name: Tametomohaze] (Fig. 11)
Akihito et al. (2002); Yonezawa and Shinomiya (2002); Suzuki and Shibukawa (2004).
Remarks. Occurs in the lower potions of the
middle reaches of small-scale rivers; very rareat Yaku-shima Island. The individuals found at
Yaku-shima Island are probably transported by
the Kuroshio Current from the south. The species
is classified as ‘critically endangered + endangered (CR+EN)’ in the 2003 Kagoshima Red Data
Book by the Environment and Citizens Affairs
Department, Kagoshima Prefectural Office, andas ‘endangered (EN)’ in the 2007 Red List by the
Ministry of Environment, Japan.

Gymnogobius petschiliensis (Rendahl, 1924)[Japanese name: Sumiukigori] (Fig. 13)
KAUM–I. 17865, 67.3 mm SL, Isso River;
NSMT–P 29077, 3 specimens, 55.6–73.0 mm
SL, Nagata River; NSMT–P 29082, 45.0 mm
SL, Nagata River; NSMT–P 29091, 4 specimens,
38.3–44.3 mm SL, Nagata River; NSMT–P
29120, 12 specimens, 41.5–63.8 mm SL, Isso
River; NSMT–P 29368, 53.8 mm SL, Yaku-shimaIsland.
Kawanabe and Mizuno (1989); Sakai et al.
(2001); Akihito et al. (2002, as Gymnogobius sp.
1); Yonezawa et al. (2003); Suzuki and Shibukawa(2004).
Remarks. The southernmost recorded rangeof the species in Japan is considered to be Yakushima Island (Suzuki and Shibukawa, 2004).

Fig. 13. Gymnogobius petschiliensis. NSMT–P 29120, 42.5mm SL, Isso River (preserved specimen).

Fig. 11. Ophieleotris sp. A stream at Harumaki, 0.5 m, 14
Oct. 1999, T. Yonezawa.

FAMILY GOBIIDAE
Awaous ocellaris (Broussonet, 1782)[Japanese name: Minamihaze] (Fig. 12)
Suzuki and Shibukawa (2004).
Remarks. This relatively rare species inhabits
the lower portions of the middle reaches of gently
flowing rivers on Yaku-shima Island.

254

Gymnogobius urotaenia (Hilgendorf, 1879)[Japanese name: Ukigori]
Suzuki and Shibukawa (2004).
Remarks. No specimens were confirmed during this study. The southernmost recorded rangeof the species is considered to be Yaku-shima Island (Suzuki and Shibukawa, 2004).
Lentipes armatus Sakai and Nakamura, 1979
[Japanese name: Yoroibozuhaze] (Fig. 14)
BLIP 1999196, 19.2 mm SL, Okawa River.
Yonezawa et al. (2003); Suzuki and Shibukawa (2004).

Freshwater fishes of Yaku-shima Island

Remarks. Rare at Yaku-shima Island; havebeen observed at small waterfalls near mouths ofsmall rivers. Although individuals with nuptial
coloration are observed at Yaku-shima Island,
the possibility of reproduction at the island is unknown. The northernmost recorded range of thespecies is probably Yaku-shima and Tanega-shimaIslands. The species is classified as ‘criticallyendangered + endangered (CR+EN)’ in the 2003
Kagoshima Red Data Book by the Environment
and Citizens Affairs Department, Kagoshima Prefectural Office, and as ‘critically endangered (CR)’in the 2007 Red List by the Ministry of Environment, Japan.

A

19097, 47.4 mm SL, Isso River; NSMT–P. 29045,
5 specimens, 54.2–79.9 mm SL, Nagata River;
NSMT–P 29055, 41.2 mm SL, a stream at Torigoe; NSMT–P 29069, 2 specimens, 39.0–58.6 mm
SL, a stream at Torigoe; NSMT–P 29076, 58.3mm SL, Nagata River; NSMT–P 29081, 2 specimens, 41.2–55.2 mm SL, Nagata River; NSMT–P
29085, 54.4 mm SL, Nagata River; NSMT–P
29090, 4 specimens, 40.9–47.5 mm SL, Nagata
River; NSMT–P 29099, 27 specimens, 47.5–88.9mm SL, Isso River; NSMT–P 29107, 12 specimens, 42.2–72.9 mm SL, Isso River; NSMT–P
29119, 9 specimens, 22.1–75.8 mm SL, Isso
River; NSMT–P 29126, 2 specimens, 39.6–80.8mm SL, Miyanoura River; NSMT–P 29132, 3
specimens, 38.7–47.0 mm SL, Miyanoura River;
NSMT–P 29136, 51.6 mm SL, Miyanoura River.
Kuroiwa (1927); Ogawa (1937).
Remarks. Common at Yaku-shima Island.

B
A

C
B
Fig. 15. Rhinogobius giurinus. A, male, Nagata River,
0.5 m, 14 Oct. 1999, T. Yonezawa; B, female, Nagata
River, 0.5 m, 14 Oct. 1999, T. Yonezawa.
Fig. 14. Lentipes armatus. A, male, a stream at Onoaida,
0.3 m, Oct. 2000, T. Yonezawa; B, female, a stream at
Onoaida, 0.3 m, Oct. 2000, T. Yonezawa; C, juvenile,
Okawa River, 0.5 m, 16 Dec. 1999, T. Yonezawa.

Rhinogobius giurinus (Rutter, 1897)[Japanese name: Gokurakuhaze] (Fig. 15)
KAUM–I. 17818, 39.8 mm SL, a stream at
Kusugawa; KAUM–I. 17819, 42.2 mm SL, astream at Kusugawa; KAUM–I. 17820, 39.0 mm
SL, a stream at Kusugawa; KAUM–I. 17821, 40.5mm SL, a stream at Kusugawa; KAUM–I. 17822,
64.0 mm SL, a stream at Kusugawa; KAUM–I.

Rhinogobius sp. DA[Japanese name: Kuroyoshinobori] (Fig. 16)
KAUM–I. 17834, 52.6 mm SL, a stream at
Kusugawa; KAUM–I. 17835, 64.5 mm SL, astream at Kusugawa; KAUM–I. 17836, 63.1 mm
SL, a stream at Kusugawa ; KAUM–I. 17837,
42.7 mm SL, a stream at Kusugawa ; KAUM–
I. 17859, 53.7 mm SL, Isso River; KAUM–I.
17860, 37.5 mm SL, Isso River; KAUM–I. 19098,
48.8 mm SL, Isso River; KAUM–I. 19099, 57.8mm SL, Isso River; KAUM–I. 19100, 59.8 mm
SL, Isso River; KAUM–I. 19648, 49.6 mm SL,
255

T. Yonezawa et al.

Isso River; KAUM–I. 19649, 50.5 mm SL,
Isso River; KAUM–I. 19650, 40.9 mm SL, Isso
River; KAUM–I. 19651, 40.6 mm SL, Isso
River; KAUM–I. 19652, 41.4 mm SL, Isso
River; KAUM–I. 19653, 37.6 mm SL, Isso
River; KAUM–I. 19654, 37.7 mm SL, Isso
River; KAUM–I. 19655, 41.0 mm SL, Isso
River; KAUM–I. 19656, 34.5 mm SL, Isso
River; KAUM–I. 19657, 27.6 mm SL, Isso
River; KAUM–I. 19658, 28.6 mm SL, Isso
River; KAUM–I. 19659, 34.0 mm SL, Isso
River; KAUM–I. 19660, 42.3 mm SL, Isso
River; KAUM–I. 19661, 43.2 mm SL, Isso
River; KAUM–I. 19662, 24.8 mm SL, Isso
River; KAUM–I. 19663, 23.9 mm SL, Isso River;
KAUM–I. 19664, 44.1 mm SL, Isso River;
KAUM–I. 19665, 26.9 mm SL, Isso River;
KAUM–I. 19666, 27.5 mm SL, Isso River;
KAUM–I. 19667, 23.4 mm SL, Isso River;
KAUM–I. 19668, 24.3 mm SL, Isso River;
KAUM–I. 19669, 26.3 mm SL, Isso River;
KAUM–I. 19670, 24.6 mm SL, Isso River;
KAUM–I. 24718, 38.4 mm SL, a stream at Yudomari; KAUM–I. 24719, 46.2 mm SL, Miyanoura
River; KAUM–I. 24720, 25.9 mm SL, Miyanoura
River; NSMT–P 29059, 9 specimens, 43.1–58.7mm SL, a stream at Torigoe.
Sakai et al. (2001).
Remarks. Common at Yaku-shima Island.

A

B

Fig. 16. Rhinogobius sp. DA. A, male, Nagata River, 0.5 m,
14 Dec. 1999, T. Yonezawa; B, male, Tabu River, 2 m,
6 July 2007, S. Harazaki.

256

Rhinogobius sp. DL[Japanese name: Hirayoshinobori] (Fig. 17)
KAUM–I. 24721, 34.7 mm SL, Miyanoura
River; KAUM–I. 24722, 31.7 mm SL, Miyanoura
River; KAUM–I. 24723, 33.8 mm SL, Miyanoura
River; KAUM–I. 24724, 30.1 mm SL, Miyanoura
River; KAUM–I. 24725, 30.0 mm SL, Miyanoura
River; KAUM–I. 24726, 27.6 mm SL, Miyanoura
River; KAUM–I. 24727, 20.6 mm SL, Miyanoura
River.
Sakai et al. (2001); Yonezawa (2002); Suzuki
and Shibukawa (2004).
Remarks. Occurs in the relatively large-scalerivers of Yaku-shima Island. The population of
the species at the island is smaller than that of
Rhinogobius sp. DA. The northernmost distributional range is probably Yaku-shima and Tanegashima Islands. The species is classified as ‘near
threatened (NT)’ in the 2003 Kagoshima Red Data
Book by the Environment and Citizens Affairs
Department, Kagoshima Prefectural Office.

Fig. 17. Rhinogobius sp. DL. Juvenile, Nagata River, 0.5 m,
14 Dec. 1999, T. Yonezawa.

Schismatogobius ampluvinculus Chen, Shao and Fang, 1995
[Japanese name: Shimaesohaze] (Fig. 18)
BLIP 1999191, 2 specimens, 14.8–15.6 mm
SL, Nagata River.
Yonezawa and Shinomiya (2002); Yonezawa
et al. (2003); Suzuki and Shibukawa (2004).
Remarks. Extremely rare at Yaku-shimaIsland. The species is observed in or on sandy
bottoms in the rapids. Although the northernmost
distributional range is probably Yaku-shima andTanega-shima Islands, the species does not reproduce there. The species is classified as ‘criticallyendangered + endangered (CR+EN)’ in the 2003
Kagoshima Red Data Book by the Environment
and Citizens Affairs Department, Kagoshima Pre-

Freshwater fishes of Yaku-shima Island

fectural Office, and as ‘endangered (EN)’ in the2007 Red List by the Ministry of Environment,
Japan.

Sakai et al. (2001).
Remarks. Common at Yaku-shima Island.

A
Fig. 19. Sicyopterus japonicus. KAUM–I. 17856, 56.2 mm
SL, Isso River (preserved specimen).

B

Fig. 18. Schismatogobius ampluvinculus. A and B, Nagata
River, 0.5 m, 14 Oct. 1999, T. Yonezawa.

Sicyopterus japonicus (Tanaka, 1909)[Japanese name: Bozuhaze] (Fig. 19)
KAUM–I. 17816, 50.9 mm SL, a stream
at Kusugawa; KAUM–I. 17817, 46.0 mm SL,a stream at Kusugawa; KAUM–I. 17855, 65.0mm SL, Isso River; KAUM–I. 17856, 56.2 mm
SL, Isso River; KAUM–I. 17857, 68.0 mm SL,
Isso River; KAUM–I. 19095, 81.1 mm SL, Isso
River; KAUM–I. 19096, 78.5 mm SL, Isso River;
NSMT–P 29057, 4 specimens, 51.1–63.1 mm
SL, a stream at Torigoe; NSMT–P 29063, 53.3mm SL, a stream at Kusugawa; NSMT–P 29071,
2 specimens, 44.3–48.2 mm SL, a stream at Torigoe; NSMT–P 29078, 8 specimens, 43.2–63.0mm SL, Nagata River; NSMT–P 29083, 6 specimens, 36.0–79.6 mm SL, Nagata River; NSMT–P
29109, 2 specimens, 52.3–68.6 mm SL, Isso River; NSMT–P. 29122, 4 specimens, 45.7–65.8 mm
SL, Isso River; NSMT–P 29133, 57.6 mm SL,
Miyanoura River; NSMT–P 29137, 4 specimens,
56.5–81.2 mm SL, Miyanoura River; NSMT–P
29139, 6 specimens, 38.7–62.7 mm SL, Okawa
River.

Sicyopterus lagocephalus (Pallas, 1770)[Japanese name: Ruribozuhaze] (Fig. 20)
BLIP 1999200, 27.7 mm SL, a stream at Onoaida.
Yonezawa et al. (2003); Suzuki and Shibukawa (2004).
Remarks. This rare species appears not to
overwinter at the island. The northernmost distributional range is probably Yaku-shima andTanega-shima Islands. The species is classified
as ‘vulnerable (VU)’ in the 2003 Kagoshima Red
Data Book by the Environment and Citizens Affairs Department, Kagoshima Prefectural Office,and classified as ‘endangered (EN)’ in the 2007
Red List by the Ministry of Environment, Japan.

Fig. 20. Sicyopterus lagocephalus. A stream at Onoaida, 0.3m, Nov. 1996, T. Yonezawa

257

T. Yonezawa et al.

Sicyopus leprurus Sakai and Nakamura, 1979
[Japanese name: Kaeruhaze] (Fig. 21)
BLIP 1999197, 2 specimens, 28.0–32.1 mm
SL, a stream at Onoaida.
Yonezawa et al. (2003); Suzuki and Shibukawa (2004).
Remarks. The species usually inhabits small
waterfalls in the forests and valleys of Yaku-shimaIsland, and appears to overwinter at the island.
Nuptial-colored individuals are observed at theisland. The northernmost distributional range isprobably Yaku-shima Island. The species is classified as ‘critically endangered + endangered(CR+EN)’ in the 2003 Kagoshima Red Data Bookby the Environment and Citizens Affairs Department, Kagoshima Prefectural Office, and as ‘critically endangered (CR)’ in the 2007 Red List by
the Ministry of Environment, Japan.

A

B

Fig. 21. Sicyopus leprurus. A, male, a stream at Onoaida,
0.2 m, 13 Oct. 1999, T. Yonezawa; B, female, a stream
at Onoaida, 0.2 m, 13 Oct. 1999, T. Yonezawa.

Sicyopus zosterophorus (Bleeker, 1857)[Japanese name: Akabozuhaze] (Fig. 22)
BLIP 1999198, 2 specimens, 28.8–33.2 mm
SL, a stream at Onoaida; BLIP 1999199, 7 specimens, 22.0–26.9 mm SL, a stream at Yudomari.
Yonezawa et al. (2003); Suzuki and Shibukawa (2004).
Remarks. The species usually inhabits small
waterfalls in the forests and valleys of Yaku-shima
258

Island, and appears to overwinter at the island.
Nuptial-colored individuals are also observed at
the island. The species often occurs with Sicyopus
leprurus. The northernmost distributional range isprobably Yaku-shima and Tanega-shima Islands.
The species is classified as ‘critically endangered+ endangered (CR+EN)’ in the 2003 Kagoshima
Red Data Book by the Environment and Citizens
Affairs Department, Kagoshima Prefectural Office, and as ‘critically endangered (CR)’ in the2007 Red List by the Ministry of Environment,
Japan.

A

B

Fig. 22. Sicyopus zosterophorus. A, male, a stream at
Onoaida, 0.2 m, Oct. 1996, T. Yonezawa; B, female, astream of Onoaida, 0.2 m, 13 Oct. 1999, T. Yonezawa.

Stenogobius sp.
[Japanese name: Tanekawahaze]
Suzuki and Shibukawa (2004).
Remarks. The species usually occurs in thelower portions of the middle reaches of gently
flowing rivers and is relatively rare at Yaku-shimaIsland.
Stiphodon atropurpureus (Herre, 1927)[Japanese name: Konteribozuhaze] (Fig. 23)
BLIP 1999201, 24.4 mm SL, a stream at Onoaida.
Yonezawa et al. (2003); Suzuki and Shibukawa (2004).
Remarks. The Yaku-shima Island populationof the species is extremely small. The species
inhabits the same areas as Stiphodon percnopterygionus. The species is classified as ‘criticallyendangered + endangered (CR+EN)’ in the 2003
Kagoshima Red Data Book by the Environment

Freshwater fishes of Yaku-shima Island

and Citizens Affairs Department, Kagoshima Prefectural Office, and as ‘critically endangered (CR)’in the 2007 Red List by the Ministry of Environment, Japan.

A

B

Fig. 23. Stiphodon atropurpureus. Male, Okawa River, 0.5m, 16 Oct. 1999, T. Yonezawa.

Stiphodon percnopterygionus Watson and Chen, 1998
[Japanese name: Nan-yobozuhaze] (Fig. 24)
KAUM–I. 24730, 18.9 mm SL, a stream at
Yudomari; KAUM–I. 24731, 23.4 mm SL, Okawa
River.
Kawanabe and Mizuno (1989); Sakai et al.
(2001); Suzuki and Shibukawa (2004).
Remarks. The species inhabits the middle
reaches of small-scale rivers on Yaku-shima Island. It prefers to stay on stones in full sun, but
swims to deeper water when threatened.
Stiphodon surrufus (Watson, 1995)[Japanese name: Kakiirohimebozuhaze] (Fig. 25)
NSMT–P 61273, 20.0 mm SL, a stream at
Onoaida.
Yonezawa and Iwata (2001); Suzuki and
Shibukawa (2004).
Remarks. Currently known only from a single
Yaku-shima Island specimen from Japan (Yonezawa and Iwata, 2001). The collected specimen wasobserved to occur with Sicyopus leprurus and Sicyopus zosterophorus. The species is classified as‘data deficient (DD)’ in the 2003 Kagoshima Red
Data Book by the Environment and Citizens Affairs Department, Kagoshima Prefectural Office,and as ‘data deficient (DD)’ in the 2007 Red Listby the Ministry of Environment, Japan.

C

Fig. 24. Stiphodon percnopterygionus. A, female, Nagata
River, 0.5 m, 14 Oct. 1999, T. Yonezawa; B, male,
Okawa River, 0.5 m, 16 Oct. 1999, T. Yonezawa; C,
male, Tabu River, 0.5 m, 12 Sept. 2007, S. Harazaki.

A

B

Fig. 25. Stiphodon surrufus. A and B, male (same individual), a stream at Onoaida, 0.3 m, 3 Oct. 2000, T.
Yonezawa.

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T. Yonezawa et al.

Tridentigers kuroiwae Jordan and Tanaka, 1927
[Japanese name: Naganogori] (Fig. 26)
KAUM–I. 17839, 33.3 mm SL, Isso River;
KAUM–I. 17840, 40.1 mm SL, Isso River;
KAUM–I. 24732, 27.3 mm SL, Miyanoura River.
Kuroiwa (1927); Sakai et al. (2001); Suzuki
and Shibukawa (2004).
Remarks. Common in the middle and lower
reaches of the relatively large-scale rivers of
Yaku-shima Island.

Fig. 26. Tridentigers kuroiwae. Miyanoura River, 0.3 m, 15
Oct. 1999, T. Yonezawa.

Conclusion
A total of 32 fish species (22 genera, 11 families, 7 orders) was confirmed from the upper andmiddle reaches of the freshwater rivers of Yakushima Island in this study. Only three species,
Plecoglossus altivelis altivelis, Gymnogobius
petschiliensis, and G. urotaenia, occurring at
Yaku-shima Island represent the southernmost
records for each species. On the other hand, 12
species, Kuhlia boninensis, Rhyacichthys aspro,
Ophieleotris sp., Lentipes armatus, Rhinogobius
sp. DL, Schismatogobius ampluvinculus, Sicyopterus lagocephalus, Sicyopus leprurus, S. zosterophorus, Stiphodon atropurpureus, S. surrufus,
and Tridentigers kuroiwae, represent the northernmost records for each species. This indicates that
the Yaku-shima Island freshwater ichthyofauna isstrongly influenced by southern faunal elements.
No reliable records of two species, Carassius
langsdorfi and Misugumus anguillicaudatus, havebeen reported from Yaku-shima Island for the last
70 years since Ogawa (1937). These species aremost likely to be already extinct or exist only as
an extremely small population on the island. Two
introduced species, Oncorhynchus masou masou
and Tribolodon hakonensis, were confirmed to beestablished at Yaku-shima Island. Interestingly,260

however, major introduced species, such as twocentrarchids, Lepomis macrochirus Rafinesque,1819 and Micropterus salmoides (Lacepède,1802) and a poeciliid, Gambusia affinis (Bairdand Girard, 1853), widely distributed elsewhere in
Japan, have never been recorded from Yaku-shimaIsland.
Of the 32 fish species recorded from Yakushima Island, the following 15 are listed on the2003 Kagoshima Red Data Book by the Environment and Citizens Affairs Department, Kagoshima Prefectural Office, and/or the 2007 Red
List by the Ministry of Environment, Japan: Anguilla japonica (— in 2003 Kagoshima Red Data
Book/DD in 2007 Red List), Misugumus anguillicaudatus (CR+EN/—), Plecoglossus altivelis
altivelis (VU/—), Oryzias latipes (CR+EN/VU),
Kuhlia boninensis (DD/EN), Rhyacichthys aspro(CR+EN/CR), Ophieleotris sp. (CR+EN/EN),
Lentipes armatus (CR+EN/CR), Rhinogobius
sp. DL (NT/—), Schismatogobius ampluvinculus(CR+EN/EN), Sicyopterus lagocephalus (VU/
EN), Sicyopus leprurus (CR+EN/CR), Sicyopus
zosterophorus (CR+EN/CR), Stiphodon atropurpureus (CR+EN/CR), and Stiphodon surrufus(DD/DD). In addition to more research of Yakushima Island’s freshwater ichthyofauna, conservation measures are required to protect rare species
and populations from threats such as water pollution and introduced species.
Acknowledgments
We are especially grateful to T. Kishino (Office of River Ecological Research, Kyoto) and N.
Horiki (Fisheries Department, Wakayama Prefectural Office, Wakayama) for their assistancewith collecting fishes from Yaku-shima Island.
We thank K. Morita (Hokkaido National Fisheries
Research Institute, Fisheries Research Agency,
Hokkaido) and S. Harazaki (Diving Service Morito Umi, Kagoshima) for providing photographsof some species, S. Raredon (USNM) for taking
Figure 2, Y. Ikeda and K. Sugiyama (Biological
Laboratory of Imperial Household, Tokyo) for
cataloging some specimens from Yaku-shima Island, K. Kuriiwa and Y. Takata (NSMT) and students of KAUM for curatorial assistance, and G.
Yearsley (Hobart) for reviewing the manuscript.

Freshwater fishes of Yaku-shima Island

Literature cited
Akihito, K. Sakamoto, Y. Ikeda and K. Sugiyama.
2002. Gobioidei. Pages 1139–1310, 1596–1619
in T. Nakabo (ed.). Fishes of Japan with pictorial
keys to the species, English edition. Tokai University Press, Tokyo.
Jordan, D. S. and E. C. Starks. 1906. List of fishes
collected on Tanega and Yaku, offshore islands ofsouthern Japan, by Robert Van Vleck Anderson,with descriptions of seven new species. Proceedings of the United States National Museum,30(1462):695–706.
Kawanabe, H. and N. Mizuno (eds.). 1989. Freshwater fishes of Japan. Yama-kei Publishers Co. Ltd.,Tokyo. 720 pp.
Kishino, T., A. Shinomiya and H. Kotobuki. 2008.
Survival rates of larval Ryukyu-ayu Plecoglossus
altivelis ryukyuensis under differing experimental
conditions of temperature and salinity. Japanese
Journal of Ichthyology, 55(1):1–8.
Kuroiwa, H. 1927. Catalogue of fresh water fishes ofcollected in Riukiu curve, 1912–1925. Zoological
Magazine, 39:355–368.
Mizuno, K. and K. Nagasawa. 2009. The current status of the geographical distribution of the giant
mottled eel Anguilla marmorata (Anguilliformes,
Anguillidae) in Japan. Bulletin of the Biogeographical Society of Japan, 64:79–87.
Nakabo, T. (ed.). 2002. Fishes of Japan with pictorial
keys to the species, English edition. Tokai University Press, Tokyo. lxi + 1749 pp.
Nelson, J. S. 2006. Fishes of the world, fourth edition.
John Wiley & Sons, Inc., New Jersey. xv + 601
pp.
Nishi, G. and S. Imai. 1969. On the juvenile of Anguilla marmorata Quoy et Gaimard in Yakushima(Yaku Island). Its ecology and morphology. Memoirs of the Faculty of Fisheries, Kagoshima University, 18:65–76.
Ogawa, K. 1937. Regional distribution of freshwater
fishes of Kagoshima Prefecture. Natural Science
Association Magazine, Hiroshima University,(5):1–27.
Sakai, H., M. Sato and M. Nakamura. 2001. Annotatedchecklist of the fishes collected from the rivers in
the Ryukyu Archipelago. Bulletin of the National
Science Museum, 27(2):81–139.

Sakaizumi, M. 1997. Genetic characteristics and strain
control of the local populations of freshwater
fishes. Pages 218–227 in Y. Nagata and K. Hosoya (eds.). Circumstance in endangered Japanese
freshwater fishes and their protection. Midorishobo Co. Ltd., Tokyo.
Sato, M., H. Sakai and M. Nakamura. 2004. Kuhlia
boninensis (Fowler, 1907), a junior synonymof Kuhlia munda (De Vis, 1884) (Perciformes:
Kuhliidae). Ichthyological Research, 51(1):70–72.
Sawashi, Y., H. Fujimoto, M. Azuma, S. Nishijima
and M. Nishida. 1993. Genetic and morphologicalcharacteristics and distribution of the ayu Plecoglossus altivelis in the northern Ryukyus. Nippon
Suisan Gakkaishi, 59(2):191–199.
Suzuki, T. and K. Shibukawa. 2004. A photographic
guide to the gobioid fishes of Japan. Heibonsha
Co. Ltd., Tokyo. 536 pp.
Takahara, H. and J. Matsumoto. 2002. Climatologicalstudy of precipitation distribution in Yaku-shimaIsland, southern Japan. Journal of Geography,
111(5):726–746.
Tsukamoto, K. 1988. Migratory mechanisms andbehavioral characteristics in Ayu. Pages 100–133
in T. Uyeno and M. Okiyama (eds.). Ichthyology
Currents. Asakura-shoten, Tokyo.
Yonezawa, T. 2002. Rhinogobius sp. DL. Izu Oceanic
Park Diving News, 13(8):1.
Yonezawa, T. and A. Iwata. 2001. First record of gobiid fish Stiphodon surrufus from Yakushima Island,
Japan. Izu Oceanic Park Diving News, 12(9):2–4.
Yonezawa, T. and A. Shinomiya. 2002. Record of two
gobiid fishes, Ophieleotris sp. and Schismatogobius ampluvinculus, from Osumi Islands, Japan.
Izu Oceanic Park Diving News, 13(8):2–6.
Yonezawa, T., A. Shinomiya and T. Kishino. 2003.
Brackishwater and freshwater fishes [original
title in Japanese: Kisui-tansuisan gyorui]. Pages
117–158 in Environment and Citizens Affairs Department, Kagoshima Prefectural Office (ed.). Kagoshima Red Data Book (Zoology). Kagoshima
Environmental Research and Service, Kagoshima.

261