Papers Published in Japanese Journal of Ichthyology

Vol. 63, No. 2

November 5, 2016

CONTENTS
Full Papers
Spatiotemporal changes in fish assemblage structures in the Udara River, Amitori
Bay, Iriomote Island
Hiroyuki Inoue, Kusuto Nanjo, Akira Mizutani, Tadashi Kitano and
Hiroyoshi Kohno
Distribution of mitochondrial DNA haplotypes of invasive channel catfish in Japan
Takahiko Mukai, Abinash Padhi, Takahiro Usuki, Daisuke Yamamoto, Kouki Kanou,
Tomiji Hagiwara, Masahiro Enomoto and Shin-ichiro S. Matsuzaki
The importance of habitat continuity between Lake Biwa and inlet rivers
with respect to fish fauna
Daisuke Ishizaki, Takeshi Kikko, Yasuhiro Fujioka, Toshiaki Mizuno,
Takamaru Nagata, Taiga Yodo and Takuya Okubo
Population genetic structure of Sarcocheilichthys variegatus variegatus in the Tokai
region, Japan and invasion of a non-indigenous mitochondrial DNA lineage
Miyu Suzuki, Shigeru Kitanishi, Taiga Yodo and Takahiko Mukai
Additional records of the snake eel Ophichthus aphotistos (Anguilliformes:
Ophichthidae) from Japan and Taiwan
Yusuke Hibino, Fumihito Tashiro, Yung-Chieh Chiu and Seishi Kimura

Short Reports
Larval development and distributional pattern of the painted sweetlip Diagramma
pictum in Nakagusuku Bay, Okinawa Island, Ryukyu Archipelago
Masato Uehara, Itaru Ohta, Akihiko Ebisawa, Taiki Ishihara and
Katsunori Tachihara

First records of two snake eels, Phyllophichthus xenodontus and Muraenichthys
sibogae (Anguillifornes: Ophichthidae), from the Ryukyu Islands, Japan
Yusuke Hibino and Seishi Kimura

Full Papers
Japanese Journal of Ichthyology
Vol. 63, No. 2, pp. 63–79

Spatiotemporal changes in fish assemblage structures in the Udara River, Amitori
Bay, Iriomote Island
Hiroyuki Inoue, Kusuto Nanjo, Akira Mizutani, Tadashi Kitano and Hiroyoshi Kohno
Abstract

Fish assemblage structures in estuarine and freshwater areas in the Udara

River, Amitori Bay, Iriomote Island, were investigated by visual transect surveys from
November 2012 to October 2013. In total, 58 species (26 families) in the estuaries and 12
species (4 families) in freshwater, all comprising native taxa, were observed during thestudy period. Mean numbers of estuarine species and individuals were significantly
higher in the lower and middle estuaries than in the upper estuary, multi–dimensional
scaling analysis revealing that fish species compositions clearly differed among each
estuarine station. The distribution patterns of the dominant estuarine species(Neopomacentrus taeniurus and Fibramia amboinensis) and the catadromous species
Kuhlia rupestris largely explained such spatial variation. The former two species wereabundant in the lower and/or middle estuaries with high salinity, whereas the latter wasabundant in the low–salinity upper estuary, suggesting that the salinity gradient may be afactor determining the estuarine fish assemblage. In contrast, the freshwater fish
assemblages, largely dominated by small amphidromous gobies, such as Stiphodon
percnopterygionus, showed neither spatial nor temporal variations, possibly due to thefact that several factors, including water flow and depth, being relatively stable in the
freshwater area. The study suggested that the estuarine areas were essential habitats formarine, estuarine and amphidromous freshwater fishes in the river, and should beaccorded a level of protection in keeping with a high priority for fish diversity
conservation in the small rivers of the Ryukyu Islands.
(Corresponding author: Hiroyuki Inoue, Okinawa Regional Research Center, Tokai

University, 870–277 Uehara, Taketomi, Yaeyama, Okinawa 907–1541, Japan; e-mail:calopteryx.cornelia@gmail.com)

Japanese Journal of Ichthyology
Vol. 63, No. 2, pp. 81–87

Distribution of mitochondrial DNA haplotypes of invasive channel catfish in Japan
Takahiko Mukai, Abinash Padhi, Takahiro Usuki, Daisuke Yamamoto, Kouki Kanou,
Tomiji Hagiwara, Masahiro Enomoto and Shin-ichiro S. Matsuzaki
Abstract

The North American channel catfish Ictalurus punctatus, an invasive

freshwater fish introduced to Japan for aquaculture in the 1970s, has become establishedin several rivers and lakes, with subsequent detrimental effects on local fisheries andother freshwater fauna. The origin and invasive distribution of channel catfish in Japan
was assessed from the geographical distribution of mtDNA haplotypes of channel catfish
populations, utilizing partial (412 bp) nucleotide sequences of the mtDNA control region
from 174 individuals collected from 7 localities. A total of 12 haplotypes (J01–J12) were
found in Japanese freshwater systems. Populations in eastern Japan (Fukushima and
Ibaraki Prefectures) and a fishing pond in Aichi Prefecture were characterized by many
haplotypes, shared among those localities. However, the haplotype compositions of
populations in western Japan (Yahagi River, Aichi Prefecture and Lake Biwa water
system, Shiga Prefecture) differed from the former and also from each other. A
phylogenetic analysis using Japanese (non-indigenous), Chinese (non-indigenous) andUnited States (indigenous) haplotypes indicated that all of the Asian haplotypes were
included in "Lineage VI," distributed over a wide area of the United States, confirmingthat lineage as the primary source of introduced Asian populations. However, theintroduction of channel catfish into Japan occurred on at least three occasions (in easternJapan, Yahagi River and Lake Biwa water system).
(Corresponding author: Takahiko Mukai, Faculty of Regional Studies, Gifu University,

1–1 Yanagido, Gifu, 501–1193, Japan; e-mail: tmukai@gifu-u.ac.jp)

Japanese Journal of Ichthyology
Vol. 63, No. 2, pp. 89–106

The importance of habitat continuity between Lake Biwa and inlet rivers
with respect to fish fauna
Daisuke Ishizaki, Takeshi Kikko, Yasuhiro Fujioka, Toshiaki Mizuno, Takamaru Nagata,
Taiga Yodo and Takuya Okubo
Abstract

Although ca. 67 indigenous fish species and subspecies inhabit the Lake

Biwa water system, (Shiga Prefecture, central Japan), including many endangered taxa,
studies on the continuity of fish habitat between Lake Biwa and inlet rivers are few. The
distribution pattern of fishes in 6 inlet rivers around Lake Biwa was examined during
2011–2012, with 32 and 26 fish species/ subspecies being recorded in autumn and spring,
respectively. The relationships between presence/absence of these species and 21
physical environmental factors were analyzed by generalized linear mixed model, theresults for 12 species in autumn and 4 species in spring being appropriate forpredictability. Distance from the river mouth and number of dams from the river mouth
were significant variables for Plecoglossus altivelis altivelis and Cottus reinii in autumn,
suggesting that both species were influenced by dams. However, riparian plants weresignificant for Lake Biwa trout (Oncorhynchus sp.) in autumn, suggesting an important“shelter” component. Furthermore, water quality, including electrical conductivity anddissolved organic carbon, were significant for Tribolodon hakonensis in autumn. Other
environmental conditions were more important for a number of other species. Clearly,
active conservation of the inlet river environments and their continuity with Lake Biwa isnecessary.
(Corresponding author: Daisuke Ishizaki, Agriculture and Fisheries Division, Fisheries
Management Office, Shiga Prefectural Government, 4–1–1 Kyomachi, Otsu Shiga, 520–

8577, Japan; e-mail: ishizaki-daisuke@pref.shiga.lg.jp)

Japanese Journal of Ichthyology
Vol. 63, No. 2, pp. 107–118

Population genetic structure of Sarcocheilichthys variegatus variegatus in the Tokai
region, Japan and invasion of a non-indigenous mitochondrial DNA lineage
Miyu Suzuki, Shigeru Kitanishi, Taiga Yodo and Takahiko Mukai
Abstract

Sarcocheilichthys variegatus variegatus, an endemic Japanese cyprinid fish

distributed from western Honshu (Tokai region) to Kyushu, has recently declined due toenvironmental damage and reduction of host mussels, and has been designated as a nearthreatened species in the Red List of the Japan Ministry of Environment. In addition, a
recent study has noted the artificial introduction of S. v. microoculus from Lake Biwa into
the Chubu, Kinki and Kyushu regions, suggesting a threat of genetic introgression. The
present study, to investigate the population genetic structure of S. v. variegatus andidentify invasions of a non-indigenous mtDNA lineage in the Tokai region, involved
phylogeographic and population genetic analyses using cytochrome b gene sequences of
253 individuals of S. variegatus from Gifu, Mie and Shiga Prefectures. In addition,
morphological characteristics of S. v. variegatus in the Tokai region, and S. v.
microoculus in and around Lake Biwa, were used to identify instances of hybridization
between the two subspecies. Phylogeographic analyses revealed greatest genetic
divergence between populations of S. v. variegatus in the eastern and western regions of
the Suzuka mountain range, and the presence of a non-indigenous mtDNA lineage in S. v.
variegatus in the Tokai region. Clearly, the latter is characterized by important endemic
genetic features, although already suffering from a loss of genetic identity due to theinvasion of non-indigenous individuals. Steps are needed for future conservation ofnative S. v. variegatus populations in the Tokai region, including risk assessment andprotection from invasive non-indigenous forms.

(Corresponding author: Shigeru Kitanishi; Faculty of Regional Studies, Gifu University,
1–1 Yanagido, Gifu, 501–1193, Japan; e-mail: kitanisi@gifu-u.ac.jp)

Japanese Journal of Ichthyology
Vol. 63, No. 2, pp. 119–125

Additional records

of

the

snake

eel Ophichthus aphotistos (Anguilliformes:

Ophichthidae) from Japan and Taiwan
Yusuke Hibino, Fumihito Tashiro, Yung-Chieh Chiu and Seishi Kimura
Abstract

A single Japanese (469 mm total length) and two Taiwanese (469 and 657

mm total length) specimens of the snake eel Ophichthus aphotistos McCosker and Chen,
2000, collected from off Yaku-shima island (East China Sea) and northeastern Taiwan,
were newly identified in museum collections. Because known morphologicalcharacteristics of the species were based solely on three type specimens, descriptions of
the present three additional specimens are provided. The present three specimens differ
from the holotype and one of two paratypes of O. aphotistos in the arrangement of jaw
teeth (biserial anteriorly and uniserial posteriorly vs. biserial), although such can be
regarded as an intraspecific variation, remaining paratype having the same tooth-pattern
as the newly-found specimens. Ophichthus aphotistos is characterized by the following
combination of characters: head 7.6–8.5% TL; tail 59–62% TL; body depth at gill
opening 2.0–2.9% TL; dorsal fin originating well behind posterior margin of pectoral fin,distance from the origin to the margin almost equal to one pectoral-fin length; pectoral fin
rounded, not enlarged distinctly; preoperculomandibular pores 6+2; teeth on maxilla andvomer biserial anteriorly; body uniformly brown, without markings; total vertebrae 157–
162 and mean vertebral formula (MVF) 18-59-160. The new Japanese standard name,“Yoiyami-umihebi”, is proposed for the species.
(Corresponding author: Yusuke Hibino, Fisheries Research Laboratory, Mie University,
4190–172,

Wagu,

Shima-cho,

Shima,

Mie

517–0703,

Japan;

e-mail:yusukeelology@gmail.com)

Short Reports
Japanese Journal of Ichthyology
Vol. 63, No. 2, pp. 127–133

Larval development and distributional pattern of the painted sweetlip Diagramma
pictum in Nakagusuku Bay, Okinawa Island, Ryukyu Archipelago
Masato Uehara, Itaru Ohta, Akihiko Ebisawa, Taiki Ishihara and Katsunori Tachihara
Abstract

Larval development and distributional pattern of Diagramma pictum aredescribed on the basis of specimens collected from Nakagusuku Bay, Okinawa Island,
southwestern Japan. Pre-flexion to post-flexion larvae were readily distinguished fromother haemulid larvae by head spination, the number of dorsal spines and pigmentation
pattern. The former (3.61 notochord length – 6.36 mm SL) occurred at offshore stations
in Nakagusuku Bay from August to October, coinciding with high gonadosomatic index
values of adult individuals collected from coastal waters around Okinawa Island.
However, no larval D. pictum were collected from Nakagusuku Bay tidal flats.
Morphological differences were found in supraocular serration and melanophore patterncompared to larvae collected from Tosa Bay (Japan) and the Great Barrier Reef
(Australia). Such apparently support a recent division of D. pictum into five subspecies,
the two larval morphotypes in Japanese waters being suggestive of local populations orsubspecies.
(Corresponding author: Masato Uehara, Motobu Resident Office, Okinawa Prefectural
Fisheries and Extension Center, 853–1 Ohama, Motobu, Okinawa 905–0212, Japan;
e-mail: ueharmst@pref.okinawa.lg.jp)

Japanese Journal of Ichthyology
Vol. 63, No. 2, pp. 135–142

First records of two snake eels, Phyllophichthus xenodontus and Muraenichthys
sibogae (Anguillifornes: Ophichthidae), from the Ryukyu Islands, Japan
Yusuke Hibino and Seishi Kimura
Abstract

A taxonomic study of the speciose tropical/temperate water family

Ophichthidae, revealed a single specimen of the snake eel, Phyllophichthus xenodontus
Gosline, 1951 and three specimens of Muraenichthys sibogae Weber and de Beaufort,
1916 from the Ryukyu Islands, Japan.

Descriptions of the two species based on theJapanese specimens are herein provided.

The former, a monotypic species of the genus

Phyllophichthus, is characterized by a prolonged and pointed snout, well developed eyes
and broad anterior nostrils.

The present species has been recorded from the Ryukyu

Islands in the literature, but with no voucher specimens.

The Ryukyu Islands voucher

specimen therefore represents the first reliable record of the species from Japan based on
the voucher specimen.

Muraenichthys sibogae, is poorly known species elsewhere in

the western-central Pacific Ocean, is recorded from Japan for the first time, bringing thenumber of Japanese representatives of the Indo-Pacific Ocean genus to three (alsoMuraenichthys hattae Jordan and Snyder, 1901 and Muraenichthys schultzei Bleeker,
1857).

Although M. sibogae is similar to M. hattae in small head size [9.7–11% of total

length (TL)], position of the dorsal-fin origin (slightly anterior to a vertical through midanus), and high total vertebrae number (141–150), the former can be easily distinguishedfrom the latter by its longer tail (63–67% TL vs. 56–62%) and a single row of teeth on theupper jaw (vs. 2 rows or more).

The new Japanese standard names, “Gettoh-umihebi”

and “Shirasu-mimizu-anago”, are proposed for P. xenodontus and M. sibogae,
respectively.
(Corresponding author: Yusuke Hibino, Fisheries Research Laboratory, Mie University,
4190–172, Wagu, Shima-cho, Shima, Mie 517–0703, Japan; e-mail:yusukeelology@gmail.com)