Papers Published in Japanese Journal of Ichthyology

Vol. 62, No. 2

November 5, 2015

CONTENTS
Full Papers
The effects of ayu Plecoglossus altivelis altivelis on the abundance and algal-grazing
habit of introduced pale chub Zacco platypus
Osamu Katano, Yoshihiro Baba, Kouichi Kawamura and Hitoshi Ohara
Habitat use by newly emerged fry of red-spotted masu salmon(Oncorhynchus masou ishikawae) in a mountain stream, northeastern Kyushu,
southern JapanKeisuke Kimoto, Masaaki Kagehira, Kazuhisa Azechi and Kazuya NagasawaIdentification of the reproductive mode for internal gamete association in
Vellitor centropomus (Cottidae): gonadal histological analysis
Yasunori Koya, Naoya Mitsuhashi, Satoshi Awata, Takeshi Ito andHiroyuki Munehara
Feeding behavior and interactions of three cyprinid species in experimental streams
Hiromu Ogawa and Osamu Katano
Intergeneric hybridization between Japanese char and red-spotted masu salmon ina tributary of the Ibigawa River, Gifu Prefecture, Japan
Takahiko Mukai, Ryo Futamura, Taiki Niwa, Akihiko Goto, Naoki Miwa,Wataru Ishizuka, Yuichi Yaoi and Masaki Takagi

Short Reports
Different timing of spawning migration of sexes in Honmoroko
Gnathopogon caerulescens from Lake Biwa to the Ibanaiko Lagoon, JapanTakeshi Kikko, Haruo Okamoto, Muneji Ujiie, Daisuke Ishizaki,
Jin Saegusa, Yoshiaki Kai and Yasuhiro Fujioka

Embryonic and larval development of the rosy seabass
Doederleinia berycoides (Acropomatidae)
Yuta Yagi, Makoto Nitta, Naoki Iida, Hiroyuki Takeuchi, Tatsuya Yamada,Sou Nagasoe, Takeo Yamamoto, Hideo Takahara, Tomoaki Iseki and Shinji UeharaLong-term effects of bluegill on the population sizes of two freshwater fishes in
artificial ponds
Osamu Katano, Hiromu Ogawa, Tomoyuki Nakamura and Shoichiro Yamamoto
The records of the chiasmdontid fish Pseudoscopelus obtusifrons from Japan
Seishi Kimura, Junji Yonezawa and Marcelo R. S. MeloFirst records of the cardinalfish Neamia notula (Perciformes: Apogonidae) from thenorthwestern Pacific Ocean
Tomohiro Yoshida and Hiroyuki Motomura

Full Papers
Japanese Journal of Ichthyology
Vol. 62, No. 2, pp. 99–106

The effects of ayu Plecoglossus altivelis altivelis on the abundance and algal-grazing
habit of introduced pale chub Zacco platypus
Osamu Katano, Yoshihiro Baba, Kouichi Kawamura and Hitoshi Ohara
Abstract

Nonbenthic fishes were investigated in 16 rivers in the Chubu and Tohoku

regions, into which pale chub Zacco platypus had been introduced. Pale chub coexisted
predominantly with Japanese dace Tribolodon hakonensis, followed by ayu Plecoglossus
altivelis altivelis, and were abundant in rivers lacking the latter. Although pale chub, ayu,Japanese dace, dark chub Nipponocypris temminckii and Amur minnow Rhynchocypris
lagowskii steindachneri all fed on both benthic algae and invertebrates, the percentage ofalgae in the diet of pale chub was less when ayu were present. However, the population
abundance and diet of pale chub were not affected by the other nonbenthic species.
Although pale chub and other cyprinids rarely fed on cyanobacteria, a main food item of
ayu, pale chub was considered to be negatively affected by ayu through interference,
exploitative competition and indirect effects via changes in algal composition.
(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)

Japanese Journal of Ichthyology
Vol. 62, No. 2, pp. 107–119

Habitat use by newly emerged fry of red-spotted masu salmon (Oncorhynchus
masou ishikawae) in a mountain stream, northeastern Kyushu, southern Japan
Keisuke Kimoto, Masaaki Kagehira, Kazuhisa Azechi and Kazuya Nagasawa
Abstract

The habitat use of newly-emerged fry of red-spotted masu salmon

(Oncorhynchus masou ishikawae) was studied on a channel-unit scale in the Ogata River,northeastern Kyushu, southern Japan from January to March in 2007–2009. Fryabundance was investigated by snorkeling along both banks and the habitat components(channel-unit type, water depth, velocity, vegetation cover, width-depth ratio and distancefrom spawning redds) assessed in 56 consecutive sections of the lower distribution areaof the species in the river. The number of fry per section was positively associated withchannel-unit type near the riffles but negatively related to water depth near the banks anddistance from spawning redds. Fry were strongly associated with channel-units near theriffles in their lower distribution area, probably because of the profitable microhabitat(low water-velocity habitats adjacent to a fast current, thereby ensuring high energy
efficiency, were common in the upper distribution area but were restricted to the marginal
area of riffles in the lower area). It is also suggested that fry moved downstream fromprofitable channel units which lacked profitable microhabitat. Therefore, for maintaining
sustainable reproduction and effective stock enhancement of the species in the lower
distribution area, it is important to create profitable microhabitats within channel-units
near the riffles, thereby balancing the abundance of fry with the carrying capacity ofsuitable habitats.
(Corresponding author: Keisuke Kimoto, Fisheries Research Division, Oita Prefectural
Agriculture, Forestry and Fisheries Research Center, 194–6 Tsuiura, Kamiura, Saiki,
Oita 879–2602, Japan; e-mail: kimoto-keisuke@pref.oita.lg.jp)

Japanese Journal of Ichthyology
Vol. 62, No. 2, pp. 121–131

Identification of the reproductive mode for internal gamete association in
Vellitor centropomus (Cottidae): gonadal histological analysis
Yasunori Koya, Naoya Mitsuhashi, Satoshi Awata, Takeshi Ito andHiroyuki Munehara

Abstract

Artificial fertilization experiments were performed and male and female

gonads observed histologically to confirm the oldest known description (published 1934)of the reproductive mode for internal gamete association (IGA) in Vellitor centropomus(Cottidae). Stripped eggs from mature females were unfertilized such commencing after
their immersion in seawater, indicating that V. centropomus is an IGA species. Many
spermatozoa were stored in the immature ovary with non-vitellogenic oocytes, evidence
that males of the species mature before females and that copulation occurs when females
are still immature. The male reproductive organ consisted of paired testes, a specialized
seminal vesicle and a functional urogenital papilla. A sperm duct in the testicular hilus
was absent. Spermatogenesis occurred sequentially, posterior most first, suggesting that it
occurs over an extended period of time. A ventral luminal ampulla, central expanded
main sperm duct and dorsal saccular ampulla were observed in the seminal vesicle, allparts being involved in sperm storage. The saccular ampulla had an exocrine function,
secreting a periodic acid–Schiff (PAS)-positive substance. Sperm heads stored in theposterior part of the testis or lumen of the seminal vesicle were also PAS-positive. Spermheads were slender, a typical morphology in IGA species.
(Corresponding author: Yasunori Koya, Department of Biology, Faculty of Education,
Gifu University, Yanagido, Gifu, Gifu 501–1193, Japan; e-mail: koya@gifu-u.ac.jp)

Japanese Journal of Ichthyology
Vol. 62, No. 2, pp. 133–147

Feeding behavior and interactions of three cyprinid species in experimental streams
Hiromu Ogawa and Osamu Katano
Abstract

Three cyprinid fishes, pale chub Zacco platypus, dark chub Nipponocypris

temminckii and Japanese dace Tribolodon hakonensis, are common in the middle reachesof Japanese rivers. To investigate their feeding behavior, and intra- and interspecificinteractions, 10 individuals each of pale chub, pale chub and dark chub, pale chub andJapanese dace, and dark chub and Japanese dace, respectively, were observed in four
experimental ponds that simulated natural rivers. All species exhibited intra- andinterspecific aggressive behavior, pale chub and dark chub establishing intraspecificdominance hierarchies. Large individuals tended to win in interactions, although darkchub, the most aggressive among the three species, occasionally won against large palechub and Japanese dace. Pale chub, dark chub and Japanese dace most frequently
exhibited algal feeding, drift feeding and bottom feeding, respectively. However, marked
individual differences existed in feeding behavior and appearance rate. Habitat use by thethree species did not differ greatly, but in the pond inhabited by dark chub and Japanesedace, the former showed the more concentrated habitat use. Feeding behavior of palechub was affected by dark chub and growth rate of pale chub was lowered in the presenceof Japanese dace. The behavior of the three cyprinid species was partly species-specific,
but was also affected by individual differences and the presence of other species.
(Corresponding author: Hiromu Ogawa; Graduate School of Marine Science andTechnology, Tokyo University of Marine Science and Technology, Minato Tokyo 108–8477, Japan; e-mail: hiromu0725@fra.affrc.go.jp)

Japanese Journal of Ichthyology
Vol. 62, No. 2, pp. 149–156

Intergeneric hybridization between Japanese char and red-spotted masu salmon ina tributary of the Ibigawa River, Gifu Prefecture, Japan
Takahiko Mukai, Ryo Futamura, Taiki Niwa, Akihiko Goto, Naoki Miwa,
Wataru Ishizuka, Yuichi Yaoi and Masaki Takagi
AbstractJapanesecharSalvelinus

leucomaenis,

red-spottedmasusalmon

Oncorhynchus masou ishikawae, hybrid individuals were collected from a tributary of theIbigawa River, Gifu Prefecture, Japan. The char and hybrids were mainly distributed in
the headwater area where eyed eggs of red-spotted masu salmon are released in each year.

Principal component analysis (PCA) of the morphological features of parental and hybrid
individuals indicated that hybrid body shape was similar to that of char. Partial nucleotide
sequences of mitochondrial DNA indicated the female parental species to be red-spottedmasu salmon, without exception. Genotyping of three loci of short interspersed repetitiveelements (SINE) of inserted alleles showed all hybrid individuals to be F1, with noevidence of backcrossing. These results indicated that the introduced red-spotted masu
salmon hybridized with male char, with a high survival rate of sterile F1 offspring.
(Corresponding author: Takahiko Mukai, Faculty of Regional Studies, Gifu University, 1–1 Yanagido, Gifu, 501–1193, Japan; e-mail: tmukai@gifu-u.ac.jp)

Short Reports
Japanese Journal of Ichthyology
Vol. 62, No. 2, pp. 157–162

Different timing of spawning migration of sexes in Honmoroko Gnathopogon
caerulescens from Lake Biwa to the Ibanaiko Lagoon
Takeshi Kikko, Haruo Okamoto, Muneji Ujiie, Daisuke Ishizaki, Jin Saegusa,
Yoshiaki Kai and Yasuhiro Fujioka
Abstract

The commercial gill net fishery and leisure fishing for the endangered

cyprinid fish Honmoroko Gnathopogon caerulescens endemic to Lake Biwa, Japan,
mainly target spawning aggregations around lagoon outlets and in the lagoons during
early spring. Accordingly, spawning migration information for the species is essential for
future conservation and management. Sex ratios and gonadsomatic indices (GSI) ofHonmoroko in the Ibanaiko Lagoon and its outlet, the Daido River, from mid-February tolate March 2012 showed a male bias the Daido River mouth, in mid-February, thereafter
decreasing significantly. In the Ibanaiko Lagoon, sex ratios were significantly malebiased in both February and March, except on 30 March. Mean GSI of females and males
ranged from 14.5 to 18.4, and from 8.0 to 9.1, respectively, during the study period.

Apparently, males with advanced reproductive status migrate to the lagoon from Lake
Biwa prior to females, the latter migrating to the lagoon when ready to spawn. Intensive
commercial gill net and leisure fishing around the outlet of the lagoon during early spring
may result in overfishing of recruitment cohorts.
(Corresponding author: Takeshi Kikko, Fisheries Management Division, Department ofAgriculture and Fisheries, Shiga Prefectural Government, 4–1–1 Kyomachi, Otsu, Shiga,
520–8557, Japan; e-mail: kikkou-takeshi@pref.shiga.lg.jp)

Japanese Journal of Ichthyology
Vol. 62, No. 2, pp. 163–168

Embryonic and larval development of the rosy seabass Doederleinia berycoides(Acropomatidae)
Yuta Yagi, Makoto Nitta, Naoki Iida, Hiroyuki Takeuchi, Tatsuya Yamada, Sou Nagasoe,
Takeo Yamamoto, Hideo Takahara, Tomoaki Iseki and Shinji Uehara
Abstract

The eggs and larvae of rosy seabass Doederleinia berycoides(Acropomatidae) are described based on specimens reared from eggs artificially fertilized
in September 2013. Fertilized eggs, measuring 0.80–0.83 mm in diameter, were buoyant,spherical and transparent with a single oil globule measuring 0.21–0.23 mm in diameter.
Melanophores were present on the yolk, and embryo and oil globule after closure of theblastopore and appearance of myomeres, respectively. Hatching occurred 29‒35 hrs afterfertilization when incubation temperatures ranged from 22.1–23.8°C. Newly-hatchedlarvae (1.76–1.83 mm notochord length, NL) had melanophores on the head, dorsolateraland anterior parts of the trunk, and dorsolateral abdomen. Eggs after detachment of thecaudal end of the embryo and yolk-sac larvae also had xanthophores on the embryo andtrunk, respectively. The mouth opened at 2.51‒2.74 mm NL, the yolk being absorbed
thereafter. Notochord flexion started at 4.19 mm NL, after which body depth increased
rapidly, being completed at 5.53 mm standard length (SL). The dorsal and anal finanlagen appeared at 4.19 mm NL, each fin, except pelvic fin, nearing the full adultcomplement at 5.53 mm SL. Head spination, including a supraoccipital crest, began todevelop during the preflexion stage. Although the body proportions and head spination
were closely similar to previous descriptions of larval D. berycoides after the preflexion
stage, melanophores had appeared earlier and were more dense than in the latter.
(Corresponding author: Yuta Yagi, Japan Sea National Fisheries Research Institute,Fisheries Research Agency, 5939‒22 Suido-cho, Chuo-ku, Niigata, Niigata 951‒8121,
Japan; e-mail: yagiy@fra.affrc.go.jp)

Japanese Journal of Ichthyology
Vol. 62, No. 2, pp. 169–175

Long-term effects of bluegill on the population sizes of two freshwater fishes in
artificial ponds
Osamu Katano, Hiromu Ogawa, Tomoyuki Nakamura and Shoichiro Yamamoto
Abstract

The long-term effects of bluegill Lepomis macrochirus on two Japanesefishes were investigated in two artificial 28 × 22 m concrete ponds. After recording thepopulation size of Japanese minnow Pseudorasbora parva and Amur goby Rhinogobius
kurodai in the ponds from 2002 to 2004, 25 mature bluegill were introduced into each.
Bluegill successfully reproduced, increasing to 350 fish in pond A and 229 fish in pond B
by October, 2004. The population size of the two Japanese species had not varied greatly
prior to bluegill introduction, the population size of minnows reaching maximum levelsof 7411 in pond A and 1598 in pond B. However, both species decreased after bluegill
introduction. By 2015, Japanese minnow numbered 0 and 1 in the respective ponds,indicating functional extinction. Amur goby also decreased after bluegill introduction, but
had not been exterminated by 2015.
(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)

Japanese Journal of Ichthyology
Vol. 62, No. 2, pp. 177–182

The records of the chiasmdontid fish Pseudoscopelus obtusifrons from Japan
Seishi Kimura, Junji Yonezawa and Marcelo R. S. Melo
Abstract

A live chiasmodontid fish, regurgitated from Thunnus albacares individual

immediately after its capture by angling off Hachijo Island, Izu Islands, Japan, had thefollowing diagnostic characters: snout convex; a row of maxillary photophores extending
almost to the anterior margin of preopercle; a single row of transverse pelvic-fin
photophores; suprapectoral-fin photophores present; 36 vertebrae; mesial series ofpremaxillary teeth arranged in a single row; hooked teeth in lateral series on bothpremaxilla and dentary. Accordingly, the specimen was identified as Pseudoscopelus
obtusifrons (Fowler, 1934). The species listed by Nakabo and Doiuchi (2013) asPseudoscopelus sp. (Japanese name Tomaru-kurobozugisu) from off OkinotorishimaIsland is also confirmed as P. obtusifrons, having hooked teeth on the upper jaw and asingle row of transverse pelvic-fin photophores. Although P. obtusifrons has already beenrecorded from well east of Hokkaido Island (Prokofiev and Kukuev, 2006) and off Iwate
Prefecture (Prokofiev, 2011), it has received little recognition as a Japanese species. The
present report firmly supports the inclusion of P. obtusifrons in the checklist of Japanesemarine fishes.
(Corresponding author: Seishi Kimura, Fisheries Research Laboratory, Mie University,4190–172 Wagu, Shima-cho, Shima, Mie 517-0703, Japan; e-mail:kimura-s@bio.mie-u.ac.jp)

Japanese Journal of Ichthyology
Vol. 62, No. 2, pp. 183–188

First records of the cardinalfish Neamia notula (Perciformes: Apogonidae) from thenorthwestern Pacific Ocean
Tomohiro Yoshida and Hiroyuki Motomura
Abstract

Neamia notula Fraser and Allen, 2001, previously known only fromMauritius and Indonesia, is recorded from Japan (Kochi, Kagoshima and Okinawaprefectures) for the first time on the basis of 3 specimens (24.4–38.3 mm standard length),representing the first records from the northwestern Pacific Ocean. The specimen from
Kochi represents the northernmost record of the species. The new Japanese name“Shikinami-yatsutogetenjikudai” is proposed for the species. Comparisons of N. notulawith a closely related species, N. articycla, based on 6 and 11 specimens, respectively,from the Indo-West Pacific showed that N. notula differed from the latter in having fewer
predorsal scales (4 vs. 5 in the latter), shorter pectoral-fin length [20.9–25.4% of SL(mean 23.9%) vs. 26.0–30.4% (28.4%)] and a milky-white body coloration in preserved
specimens (vs. dark brown).
(Corresponding author: Tomohiro Yoshida, United Graduate School of AgriculturalSciences, Kagoshima University, 1–21–24 Korimoto, Kagoshima 890–0065, Japan;
e-mail: k5299534@kadai.jp)