Papers Published in Japanese Journal of Ichthyology

Vol. 61, No. 2

November 5, 2014

CONTENTS
Full Papers
Larval morphological changes and salinity tolerance of aquarium-held freshwater
goby Rhinogobius sp. BF
Kentarou Hirashima and Kazuya Nakamura
The microhabitat use of Pseudogobius javanicus and P. masago at Sashiki tidal flat,
Okinawa-jima Island, JapanTaiga Kunishima, Hirotoshi Saimaru and Katsunori Tachihara
Population viability analysis for the endangered loach Parabotia curtus in the Lake
Biwa–Yodo River system, central Japan
Katsutoshi Watanabe, Hidetaka Ichiyanagi, Tsukasa Abe and Akihisa Iwata

Short Reports
First record of the lethrinid fish, Gymnocranius superciliosus from Japan
Ryohei Miki, You Sakurai and Yukio Iwatsuki
Origin of Tanakia limbata in Ehime Prefecture indicated by phylogeographic
analysis of mitochondrial cytochrome b gene sequences
Hideki Matsuba, Shotaro Yoshimi, Mikio Inoue and Hiroki Hata
Enlarged distribution of Nipponocypris temminckii as a domestic alien fish
Osamu Katano, Yoshihiro Baba, Hitoshi Ohara, Kouichi Kawamura, Masato Sato,Masayuki Kumagaya, Motoi Takeuchi, Shoichi Ito, Shigeharu Togashi and Nobuo
Inoue

Full Papers
Japanese Journal of Ichthyology
Vol. 61, No. 2, pp. xx–xx

Larval morphological changes and salinity tolerance of aquarium-held freshwater
goby Rhinogobius sp. BF
Kentarou Hirashima and Kazuya Nakamura
Abstract

Larval development and salinity tolerance of Rhinogobius sp. BF aredescribed from artificially-reared eggs, larvae and juveniles. Aquarium-held R. sp. BF
spawned small-type eggs (n=816, long axis 1.9 mm, short axis 0.6 mm) on May 17 2004,
which were guarded in the nest by a male. Newly-hatched larvae (3.2 mm in notochord
length) had a small yolk, and some melanophores apparent on the snout to caudal region.
Twenty-two days after hatching (6.8 mm in standard length; SL), the notochord tip
projected upwards, and dorsal and anal fin rays appeared. Between thirty (12.0 mm SL)
to forty-five days (14.2 mm SL), the larvae settled to the bottom of the aquarium. Sixty
days after hatching (15.4 mm SL), all fins and scales were completed (juvenile stage). Alllarvae subjected to marine salinity (35 psu) died within three days, indicative of the lentic
landlocked life history recorded for the species.
(Corresponding author: Kentarou Hirashima, Wakayama Prefectural Museum of NaturalHistory,

370–1,

Funo,

Kainan,Wakayama

642–0001,

Japan;

e-mail:hirashima_k0001@pref.wakayama.lg.jp)

Japanese Journal of Ichthyology
Vol. 61, No. 2, pp. xx–xx

The microhabitat use of Pseudogobius javanicus and P. masago at Sashiki tidal flat,
Okinawa-jima Island, JapanTaiga Kunishima, Hirotoshi Saimaru and Katsunori Tachihara
AbstractFishes of Pseudogobius, distributed widely in the Indian and West PacificOceans, are represented by 3 species (P. javanicus, P. masago, Pseudogobius sp.) inJapanese waters. Although P. javanicus is a common species at Okinawa-jima Island, P.
masago is scarce and listed as “Vulnerable” in the Red List of the Japan Ministry ofEnvironment. In the present study, micro–habitat use (water temperature, salinity, water
depth, flow velocity, median grain size and substratum hardness, percentage of mud, andpercentages of litter cover and stone cover) by P. javanicus and P. masago wereexamined in 72 quadrats on Sashiki tidal flat, Okinawa–jima Island, from May to
September 2013. In total, 36 P. javanicus and 97 P. masago were collected, the species
occurring in 8 and 16 quadrats, respectively. A significant difference in quadrat
occupation was apparent between the species. The relationships between number ofindividuals of each species and environmental factors were analyzed using generalized
linear models. Water depth, percentage of litter cover and median grain size (for P.
javanicus), and substratum hardness, salinity, and percentages of stone cover and mud(for P. masago) were significant factors in the ten top models. In particular, the presenceof both species was affected by substratum condition (percentages of litter and stone),which may be related to predation risk. The results demonstrated that microhabitat usesof the two species were different. However, the Sashiki tidal flat includes suitableenvironments for both P. javanicus and P. masago at present, the accumulated soft
substratum being preferred by both species. It is important, however, for continued
conservation of both species, that landfills and riverbank revetment works around
Nakagusuku Bay be kept to a minimum, in order to provide and prevent an outflow ofsoft substratum to the tidal flat.
(Corresponding author: Taiga Kunishima: Graduate School of Engineering and Science,
University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903–0213, Japan; e-mail:taigakunishima@gmail.com)

Japanese Journal of Ichthyology
Vol. 61, No. 2, pp. xx–xx

Population viability analysis for the endangered loach Parabotia curtus in the Lake
Biwa–Yodo River system, central JapanKatsutoshi Watanabe, Hidetaka Ichiyanagi, Tsukasa Abe and Akihisa Iwata
Abstract

The population of the botiid Parabotia curtus in the Katsura River, Lake

Biwa–Yodo River system, Kameoka, Kyoto Prefecture, Japan, the only one recorded in
the Kinki region since the year 2000, was subjected to a population viability analysis(PVA) based on demographic data between 2006 and 2013 (8 years). Count-based andage-structured models with several conditions for density-dependence, carrying capacity,
migration rate, and bias in population estimation (48 settings in total) were used for
calculating the quasi-extinction probability within 50 years (extinction threshold <10individuals), using computer simulations. The estimated population for the 8 year period
fluctuated from 200 to 2,300 individuals (average ca. 935, with a coefficient of variationof 66%). PVA demonstrated a significant extinction risk for this population (23–82%extinction in 45 of 48 settings). Although further population monitoring is necessary for amore precise evaluation, we conclude that this population faces a real extinction risk.
Sensitivity analysis suggested several requirements for effectively enhancing population
viability, i.e., restraining large biotic and abiotic environmental perturbations to avoid
extreme depression of the recruitment of young, enhancing winter survival, andpromoting upstream migration into the spawning site.
(Corresponding author: Katsutoshi Watanabe: Division of Biological Sciences, Graduate
School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto 606–8502,
Japan; e-mail:watanak@terra.zool.kyoto-u.ac.jp)

Short Reports
Japanese Journal of Ichthyology
Vol. 61, No. 2, pp. xx–xx

First record of the lethrinid fish, Gymnocranius superciliosus from Japan
Ryohei Miki, You Sakurai and Yukio Iwatsuki
Abstract

Six specimens (189–306 mm in standard length) of the lethrinid fish,Gymnocranius superciliosus Brosa, Béarez, Paijo and Chen, 2013, recently describedfrom New Caledonia, were collected from the Ryukyu Islands, Japan, being the firstrecord of the species from the Northern Hemisphere. Gymnocranius superciliosus isdistinguishable from its congeners by the following combination of characters: elongatedbody (body depth at 1st dorsal-fin spine origin 2.53–3.06 in standard length); villiform toconical teeth on sides of both jaws; forked caudal fin with rounded posterior margins on
both lobes, tips slightly pointed; six rows of scales between 5th dorsal-fin spine base andlateral line; no transverse dark brown bar laterally on head or body, except between eyeand interopercular flange; blue speckles dispersed on snout and cheek; body scales eachwith a basal dark brown dot, forming longitudinal rows; reddish color on margins ofdorsal, anal, and pelvic fins.
(Corresponding author: Ryohei Miki: The Graduate School of Agriculture, University ofMiyazaki,

1–1

Gakuen-kibanadai-nishi,

Miyazaki

889–2192,

Japan;

e-mail:ad13007@student.miyazaki-u.ac.jp)

Japanese Journal of Ichthyology
Vol. 61, No. 2, pp. xx–xx

Origin of Tanakia limbata in Ehime Prefecture indicated by phylogeographic analysisof mitochondrial cytochrome b gene sequences
Hideki Matsuba, Shotaro Yoshimi, Mikio Inoue and Hiroki Hata
Abstract

Phylogeographic analysis of the bitterling Tanakia limbata in western Japan

was conducted to identify the origin of the fish population in Ehime, Shikoku Island. A
survey of rivers and spring-fed ponds on the Matsuyama Plain, Ehime, indicated that T.
limbata had become distributed on the plain over a period of 19 years to the present day.
Sequences of the mitochondrial cytochrome b gene indicated that the 42 individuals
sampled included 4 haplotypes, which were shared with a T. limbata population in theYabe River, Fukuoka, Kyushu Island. All 4 haplotypes belonged to the West Kyushu
group of T. limbata. On the other hand, T. limbata comprising the West Seto clade
inhabits western Honshu and eastern Kyushu, which regions shared the same paleoriver
system with Ehime 20,000 years BP. These results suggest that individuals of T. limbata
presently collected in Ehime originated from the Yabe River or adjacent waters, having
artificially transported over the mountain chain that may act as a natural barrier
separating the West Kyushu and West Seto groups. To conserve an endangered native
bitterling, T. lanceolata, in Ehime, management of the introduced T. limbata, so as toprevent competition and hybridization with the former, is necessary.
(Corresponding author: Hiroki Hata: Graduate School of Science and Engineering,Ehime University, 2–5 Bunkyo–cho, Matsuyama, Ehime 790–8577, Japan; e-mail:hata@sci.ehime–u.ac.jp)

Japanese Journal of Ichthyology
Vol. 61, No. 2, pp. xx–xx

Enlarged distribution of Nipponocypris temminckii as a domestic alien fish
Osamu Katano, Yoshihiro Baba, Hitoshi Ohara, Kouichi Kawamura, Masato Sato,
Masayuki Kumagaya, Motoi Takeuchi, Shoichi Ito, Shigeharu Togashi and Nobuo Inoue
Abstract

The distribution of Nipponocypris temminckii was investigated in 24 rivers inNagano, Niigata, Yamagata, Akita, Iwate, and Aomori Prefectures, the species being
collected at seven study sites. Amongst non-benthic fishes, N. temminckii was exclusively
dominant in two rivers. Supplementary records of the species in Nagano, Niigata, Akita

and Iwate Prefectures were also described. Rivers in which investigations had been
conducted over two or three years showed an increasing proportion of N. temminckii,indicating successful colonization of the species.
(Corresponding author: Osamu Katano: National Research Institute of Aquaculture,Fisheries Research Agency, 1088 Komaki, Ueda 386–0031, Japan; e-mail:katano@fra.affrc.go.jp)