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«4 EIS Prv„ FISHPRIES RESEARCH BOARD OF CANADA /1/24 , 1

. Translation Series No. 726 c r CliN,104

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The distribution.of Cottus laoonicus Okada (Cottidae) and of Tukugobius flumineus 1:Azuno (Gobiidae), with - special reference to peculiarities related to both the land-locking and their Speciation • from amphidromous ancestors

By Nobuhiko,,f•izuno

- • . From: Gakugei University (Pf-e- S>, pp. l29-161,,,,.19ô5,

Translated by: Kenji Makin°,

7 7-7- - BUreau -for Translations Foreign-Languages- Division, - . Department of the Secretary of State Of Canada

Fisheries Research Board of - Canada Biological -Station, - Nanaimoi- B. - .C. -----

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fgt.; 44. sPEPARTMENT OF THE SECRETARY OF STATE r SECRÉTARIAT D'ÉTAT BUREAU FOR TRANSLATIONS BUREAU DES TRADUCTIONS

FOiZE-IGN LANGUAGES ; DIVISION DE-S LANGUES DIVISION CANADA ÉT.'2AN&.-"!`2'ES

TRANSLATED rRom TRADUCTION DE IN •ro - Japp nos ri sh

SUI3JECT - SUJET

Fish (lard-lock irg. and spooi.?,t:ion)

AUTHOR - AUTEUR Yobuhiko Mizuno

TITLE IN ENGLISH - TITRE ANGLAIS • I) The ..bl istri.buti on of Cottus Jp..nonicus 'Tuk-up,-obitims 1 71unineu s 7',.eference to thirdr /FrE- tr[1. -1,' ri-ties in both LI itand-Locking ar.d Seciatien erorn.

YITLEIN roREIGN LANGUAGE - TITRE EN LANGUE ETRANGEklE d . ,. • ``. • „ ■ “.17 \% 7 11 ( C 1 (-2 .7.2l > - / ) a./ 17.1" . ...

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RErERENCE - ReFdRENCE (NAmE OF Book: OR PUBLICATION - NOM DU LIVRE OU PuBLIcATtoN) Osakaukbge71 University Per -l.ndfical .

PUBLISHER - dDITEUR OsakaE;akuFèi University Press

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Osaka, Jan. n . 1963- 129-161

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(129) - The Distribution of Cottus Janonicus and TukuJ...-obious Flur_lineus with Specinl Reference to t:12eir Pnculinrities in both Land-Docking and Sneciation - from Arnhidromous Ancestors

Nobuhiko MIZUNO

Biological Laboratory • Osaka Gakugei University

10. Foreword

The migration of fish, es vieil as that of birds, has been known as a peculiar phenomenon and has attracted the attention frP of scientist for a long time* Various classifications of these fish have been uu ,7gested (Myers, 1949). It is well known that some migratory fish cone to inhabit fresh-water regions permanently. This -phenomenon is Called land-locking. In my reportson the Tukugobious filleineus and the large-egg type Cottus japonicus of 1960 and 1961, I suggested that they were the fish which were land-locked and speciated fron the migratory Rhinogobius brunneus + (or i!elated-species) and the small-egg type CottUs japonicus (Lama°, 1960; Mizuno Tanba, 1961). In the following chapter, i would like to study the relationship. between the migration and land-locking of such fish mainly in our country and present the peculiar aspect of the land-locking. of the above-mentioned Tukugobious flumineus and the large-egg type Cottus . japonicus._ Further- more, I would like to investigate their way of spe(eiation in reference to their geographical distribution.

RO similis Gill was formerly'used as the name of this species until ft was corrected by Tagaki (1962) and R. brunneus

(Temminàk & Schlegel) . waà cdoptd. -

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I waeJ given a great deal of help by many people with the investigaticn and arrangement of the data. Professor D. Miyagi of University and Professor H. Sugino of Osaka Gakugei University encouraged me and cornented on my study. Dr. Niwa of the prefecture and Dr. Kawanabe and i his group of Kyoto. University also gave me a great deal of 'assistance. Professor K. Dotsu of Nagasaki University, Profess- or I. Toyama of University, and Professor K. Matsubara of Kyoto University gave me many specimens with helpful comment. Professor M. Tsuda of the Nara Womens University, Dr. H. Shiraish of the Fresh-water Products Laboratory, the Saito Requital Museum of -city, Dr. S. Kimura of Urama-city, Messrs. M. Urata 9 K. lirai of Osaka Gakugei University, and many others helped me a great deal with the collection of specimens. To all of the above-mentioned I would like to extend my deep-felt thanks. *

Th,- Peculiarities of the Land-lockinz-of the'Lpree-eeg Tyne Cottus japonicus t,md Tul_rueobious flumineus - The classification which was published by Myers in 1949 (130) seerned to be Quite relevant to land-locking in reference to the typé of migration. He named the migration between .. sea-water and fresh-water Diadromous migration, and divided this category into, three sub-categories; namely, Anadromous migration, Catadromoils migration, and Amphidromous migration. The Anadromous migration and Catadromous migration-are seen, typically'in the salmon-trout family and the,eel family. The fore' goes from the sea to fresh-water regions in its •n ,.tu-re period, and the latter reversely from fresh-water .regions to the .sea. Both imigrations - have the same purpose of spawning. Amphidromous Migratory fish, however, travel :,back and forth between the sea 'and.fresh-jfiater in their infancy„This is not - a spawning migration. According to Myersp• the : Sicydium ofgoby. ' genus and its relatives are examples. He says that these gobies lny eLigsin and the hatched infants soon go down to the sea, live'there during the first half of their infancy, return to rivers, grow up there, and lay eggs.

, As for:the Japanese-grown Anadromaus migratory fish, there \!- 1 \ salmon and Salmopluvius•genera of the salmon-trout family; • are sJ <\ and Gastcrosteus aauleatus of the stickleback family. Besides, the 1 ariprsjy family migrates in the same manner, although it •••■ .\ does not belong to fish. These fish all go un rivers for spawning in their mature period and in re lation to land-locking it is interesting in what stage of their • growth they go down to the sea. They do not go down to the sea immediately after hatching. For example, the fish which. the salmon and Salno pluvius genus, and Tribolodon belong to • hakuensis have about 10 cm of body-length before going down, and the Gestarosteus aculeatus, whose full body-length is about 10 cm, start going down at about 3 cm. The lamprey family also stays in fresh-water until the completion of metamorphosis. As described above, they spend the first half of their infancy in fresh-water regions.

It is not irrelevant to the above-mentioned fact that land- locking often occurs among such fish. For example, each of the Oncorhynchus masou and Oncorhynchus nerka of the' salmon genus; Salvelinus malma and Salvelinus leucomaenis of the Salmo pluvius genus; Tribolodon haluensis and Gasterostus aculeatus of the stickleback family produces land-locked • fish such as Salmo nocrostoma, 0.n.f. adonis; and Tribolodon hakuensis, Gastercstus aculeatus (the last two have not been named yet). Furthermore those, except 0.n0f. adonis, are all land-locked in rivers (fluvial land-locked). Those which live in fresh- water regions and that in rivers for the first.half of their infancy should not have nuch difficulty renaining,there to live for their lifetime. In fat, land-locking occurs among them and there are also many examples that such land-locked fish live with migratory ones, such as Salvelinus nalma and

its land-locked fish (-U\i- x.c..7,,:.÷,te. in Saghalien, S. leucomaenis and Oncorhynchusmnsou andtheifc land-locked fich and Salmo mocrostoma in and Tohoku district, and G. aculeutus.and itsland-locked fish • (Kobayashi, 1957) in the Ishikari . .

The term "land-lockine gives an_impression that migratory fish are passively locked-infreshwater regions, but as (131) 0no v(1933) . about Oncorhynchus masou and Ricker (1938) about Oncorhynchus nerka, the 'behaviour of lan d-locking seems to be explained mainly by the relationship between growth nrd naturity. It is not an abnormal phenomenon that Anadromous migratory fish are land-locked, since they do not have to change their early life histories, and in tact they never do. It also happens very easily that the descendants of land-lockec fish become migratory fish again. This phenomenon is proved in Oncorhynchus masou (Ono, 1933) 9 and in Oncorhynchus nerka (Ricker, 1938). It is known in Tohoku district that the migra- ,

tory female -Oncorhynchus masou inter-breeds with the land- locked tale and that rot of their male descendants remain in fresh-water regions, but that most of the females go . down to the sea (Tanaka, 1956). In short, in Anadromous migratory fish, migration and land-locking are, to a great extent, reversible.

;As: for Japanese-grown Catadromous migratory fish, there are Anguilla japonica, A. marmorata, and Trachidermus fasciatus and Cottus hazika of the Cottus japonicus family. There are, however, no land-locked fish reported. The Catadromous migra- tory fish live in the sea during the first half of their infancy, cone up the rivers, and go back to the sea again in their mature period to lay eggs there. The life history is completely reversed in this case and it seems to be difficult for them to become land-locked fish.

Japanese-grown Amphidrous migratory fish are Plecoglossus artivelis, fish of the goby family such as Eleotris oxycephala, Rhinogobious brunneus, R. ziUrinus, Chaenogobius urotaenia, Ch. annularis, Tridentiger obscurus, iuciogobius guttatus, and Sicydilim- japonicum, and the small-egg type Cottus japonicus. They go doWn to . the seaa immediately after hatching, spend the first half of their infancy:there. and.then they goup . and spawn. In this:regard they are rivers where they grow . Similar to 1,iyers' (1949) examples of Sicydium and its relativ-. es. From the morphological point of view, their bodies are frail-looking and their fins are incomplete immediately after hatching, and in theÉe respects they are distinctively differ- ent from Anadromous migratory fish in the . same situation. . One of the reasons that they go down -bothe sea directly _ . after hatching seems tobe that they.have difficulty staying in the stream of.their hatching-place morphologically. Corresponding- ly, there. is no example of their fluvial land-locking• . . that has been reported. . . .

The Amphidrous migratory fish are, however, often land-locked in lakes (the- lacustrine land-locking). The examples are • Plecoglossus altivelis in Biwa Lake and Ikeda Lake and the small-egg type Cottus japonicus in Biwa Lake and Nojiri Lake. Of - the aboVe-mentioned goby family, all species except Eleotris oxycephalà and Sicydiub japonicut is reported to haveA.ts land-locking fish (Uizuho l- i960; Dotsü,'in press)0

fl.though it is mentioned that:A±phidromdüs migratory fish • stay in the se“uring the first half of their infancy, they live only near the shore, where the salt density changes to a considerable extent. Besides, they go back and forth between fresh-water and salt-water during their infancy. • ,Such a life history is possible only if the fish have a 'strong resistance to the sudden change of salt-density. This ;resistance seems to i)e one of the factors that creates the possibility of the occurrance of land-locking in lakes and Iswnmps. It does not seem to natter very much to them h32) whether it is.fresh-water or salt-water as long as it is stagnant, which allows them to live their floating life of infancy. In Such a case also there is no difference between the life history of the miratory fish - and that of the land-locked fish (Mizuno, 1960). Even if they are land-locked once, they seem to be able to go back to the state of the • - Migratory fish easily. There is no possible proof for this at present, but there is also no reason to deny the hypothesis. In short, it can be said that the relationship between Amphidromous migration and lacustrine land-locking, as well afin the case of Anadronous migration, is reversible.

There is, however, one more type of land-locking of the AmphidromouS migratory fish. It is mentioned that there is no fluvial land-looking of Amphidromous migratory fish, but this is only about ones which do not change their life history. Thei-e are, however, ones, although a few, that change their life history to a great extent and that coma to live in rivers. Japanese-grown examples are Tukugobious flumineus (Mizuno,196o) and the lai-ge-egg type Cottus japonicuo (Mizuno, Niwa, 1961). Their bodies become already close to those of the full-grown fish during hatchin,z or deuto ,plasm absorption and they immediately start their lifu at the bottom as the grown fish do. To state this in extreme terms, they practically go through, before hatching, the growth steps which are eouivalent to those of the sea-living period an .Arlphidromous fish. Amphidromous migratory fish seem to be able to live in rivers only if they change the growth process:in such a way as mentioned above. Corresponding to the changes of the life history, there are also morphological transformations. Tukugobious flumineus is distinctiVely different from Rhinogobious brunneus which seems to be similar to the ancestral form of the former in the number of vertebral columns, pectoral fin rays and sDecks. They are clearly different species. The large-egg type Cottus japonicusliS also different from.the SmallHegg -:type in the number of pectoral fi n rays , e.-cg-ize, and life history. The differences seem to be sufficient enough to say that they are different species (Uizuno, 1960; Mizuno & N1wa 9 1961)0 Thus the changes in life history and egE-siza accompanied by norpholor'.cal transformations are necessary for Amphidro-• mous migratory fish to be land-locked. This process does not seem to occur very often. In fact, we have found the. lacustrine land-locking offspring for almost all of the Amphidromous migratory fish mentioned above, but only two fluvial ones. Mogurunda obscura is also a fluvial land-locking fish and its life history is quite similar to that of the two mentioned above. We l however, are not certain that this one is- also an offspring of the AnDhidromous migratory fish. Even if we.recognize this Q. an Amphidromous fish, we,only have • three of them. The land-locking which needs such a speciation or similar differentiation is naturally thought to be non- reversible. From this point of view, it is understood that the fluvial land-locking of Âmphidromous migratory fish is. a peCuliar case which is:different from the lacustrine land-

. , locking of them, and which is also different from the fluvial and lacustrine ones of Àndromous migratory fish, Norman (1931), Svardson (1957), or Wyne- :Edwards (1952) offer many facts, mainly about the life histories and land-locking of Anadromous migratory fish, although these articles, are fragmentary. Comparing. with these foreign-grown •examples, we still consider that the land-locking of Tuku(-:obious, flumineus and the large- egg'type Cottus japonicus are peculiar occurances. Or rather we should say that such land-locking is not yet known. Do such differances also affect s .ûeciations and fornations of (133; distribution ranges.which occur in the pro;:.:es of land-locking? • First, let us take a look at the formation of distribution ranges.:The distribution range of Salmo mocrostoma which is. the land-locked offspring of Oncorhynchus nasou covers the iwhole of Hokkaido and north-eastern Ja-oan and, moreover 9 it extends to the south-western and Sea side of Japan as far as a part of Formosa. Most of the Salmo mocrostoma in these rivers have been produod indtrpendently from Oncorhynchus masou which ha:ye come up the rivers. This phenomenon seems to have occurred ubiquitously; so to speak. This iG not the result of dispersion of. Salmo mocrostoma through fresh-water from w'fiere the original speciation occurred. For exam'ele, as Ohchima (1936) explained, Salmo mocrostona which live in Daikokey in Formosa did not come from ,japan :but diffe .rentia- ted from Oncorhynchus masou which went up to Formosa during the Ice Age. Salvelinus malna und S. leucomaenis, which are the land-locked offspring of , are found in Sagl?halein and Hokkaido and they also seem to have been produced in th a same way 'as Salmo macrostoma. The case of Gasterosteus aculeatus and its land-locking sumecics, Gaterosteus aculeatus microcephalus • is also - the same (Ikeda, 1935). The sanie thing can also be said about the lacustrine land-locking of Amphidrous migratory fish. For example, Rhinogobious brunneus is land-locked in many lakes and ponds throughout the country from Hokkaido to Kyushu (Shiro, Tomito et al., 1960). Sone of them may be transported with young fresh-water trout and so on, as the ones in Towada Iake.which are from Biwa Lake, but certainly not all of them. It is certain that the lacustrine land-locking fish of Tridentiger obscurus in the reservoirs in Tsu City and the . ones in the irrigation ponds in Matsuyama City are independent- ly land-locked.

The rIubject of migration is often discussed with reference .to Anadromous micratory fish, but there seems to be no fact which definitely negates the hypothesis that the land-lockings have independently occurred.in different districts. Ikeda (1935) rather agrees with the hypothesis and Oshima's (1936) idea is also close to it. Hence the word land-locking seems to include such an idea of independent occurrence.

Now the second topic is that of speciation. There are land- locked fish which have differentiated from their migraory ancestors and have made new species or subspecies. For exanple 9 , there are 0.n.f0 adonis in Atan Lake and 0. kawanurai in . Tazawa Lake which are close relatives of Oncorhynchus .nerka,' 0 0 rhodurus and 0.r.±. macrostomus in. the. west of Chubu district , which are close relatives of Oncorhynchus masoU, Salvelinus pluvius and S. japonicus which have differehtiated from S. leucomaenis, Gasterosteus aculeatus microcephalus which is a subspecies of G. aculeatus, Chaenogobius isaza in Biwa Lake which is a close relative of Chaenogobius annularis and Ch. vrotaenia,. and so on. It is thought that such differentia- tions have taken place gradually during living in fresh water after land-locking. That is to say, the differentiation and . land-locking are not simultaneous processes, but there is a considerable period of time between thon. It is interesting 134) that Ricker's study (1939, 1940) of - fish in the Fraser River and its water system in Canada clearly proves this point. Many lakes belong to this water system and some of them have Kokanee and 0.n. kennerlyi which are the land-locki ,ig subspecies of red trout. However, Anadromous migratory red trout also annually go up to the lakes and lay eggs and part of the hatched fish do not go down to the sea but stay their fcr their life-time. That is to say, the land-locked fish and the land-locked subspecies .coexist in the same lakes. They are different not only in form and in contagious resistance to outside parasites, but also in the spawning time and place. Hence there is no interbreeding between the two groups. It • also happens that sone of the young of the land-locked'fish go down to the sea. This case, however, does not apply to Kokanee. Paying attention to this difference, Ricker thoroughly investigates both subsmecies'morphologically, sexually, and ecologically. He divides the differentiative process of Kokanee into two stages: (a) the occurrence of the land-lbcked off- . spring, for which the complex effects of sex and of rate of growth plays an important rôle. At this stage there is no morphological difference between the migratory fish and the land-locked fish and (b)the codification of such land-locked fibh into the typical Kokanee, which is said to be a long process of continuous small gene mutations and natural selee- tfon. He considers 0.n0f0 adonis in Akan Lake as Kokanee.

However, as I mentioned above, the changes in egg-size and life history are indispensable for the fluvial land-locking of Amphidromous migratory fish, and the morphological modif- ication accompanies these in the case of Tukugobious fluminaus (Mizuno, 1960). This also applies to Cottus japonicus (mizuno, Niwa, 1961). In short, the differentiation at the species or subspecies levei- in these cases occur concomitantly with the land-locking process and hence such periodical diviàions as in the case of Kokanee cannot ba applied here. It is possible to introduce different ideas about the differentiation of Amphidromous migratory fish to the fluvial land-locked fish and to the distribution of the latter than to the cases of land-locking of. Anadronuus migratory fish- andlthe lacustrine land-locking of Amphidromous migratory fish. That is to say, it is plossible to think 'that the fluvial land-locking fish which differentiated from Amphidromous migratory fish in a certain location have spread out as far as to the present distribution range. This is a rather orthodox idea because our discûssion on the origin of the present distribution range of primary fresh-water fish has been predominantly based upon the idea of the dispersion from where the original specia- , tiOn.was effected. Furthermore, such fish as Tukugobious flumineus and the large-egg type Cottus japonicus which have completed their differentiations with the fluvial land-locking process seem to be more suitably dealt with as primary fresh-water fish such as cyprinids or catfish. In short, it is rather odd to apply the idea that the differentiation at • the species level or the level worthy of the species occurred independently in each river. However, when we compare the distribution range of the large-egg type Cottus japonicus with that of other Japanese fresh-water fish, we cannot help assuming that they differentiated ubiquitously an so did Tukugobious flumineus. In the next chapter, surveying their distribution ranges and living conditions, I would like to investigate the basis for the ubiquitous differentiations and the concerning problems.

III. The Distribution Range of CottUs jaronicus

First, it is necessary to talk about the scientific term Cottus japonicus. Cottus japonicus in (the mainland of Japan) used to be identified as Cottus pollux. The name Cottus pollux.was first used by Günther in 1873 for a specimen collected in *the Ishikari'River in Hokkaido. However, the studies of Aoyanagi (1957), Watanabe (1958), and Okada - (1960) indicated thé fish in Honshu WaS different frem the Cottus pollux. Finally Okada (1960) classified it es a' different speciéS_and named it Cottus japonicus. He alSo understood that:Cottus nozawae was a synonym for Cottns pollux. Since I do not have any objection on this point, I have nsed the ter.re Cottus:japonicus. ..ccording to Watanabe (1958), besides Cottus.japonicus, C..kazika, and there is another species called C. reinii whose distribution range is Honshu, ,r and Kyushu. Howe»ver, as far as I know, there is no such fish that can be classified as C. reinii in Honshu. As I mentioned in my report of 1961, both the large-egg type fish and the small-egg type fish belong to Cottus japonictLs.

The large-egg typ&fish and the small-egg type fish in this species are different not only in egg-size and aire history but also in the nimber ?)f pectoral fin rays. We can distin- guish collected specimens by this - point toc. The distribution ranges of these two types distinguiàhed by three differences were mentioned in the previous report (Mizuno, Niwa, 1961). We, however, did not have enough space for the names of the locations of collections. Vie decided to include them in this report. For the production of the list of locations, I was helped to a great extent by Tokyo University Zoological Laboratory, Saito Requital Museum, and others. I would like to extend thanks for their kind cooperation. I found old names , of the locations in the old samples, but I changed them into new ones in this report with reference to Japan Prefectual Maps and Place-names (1961 edition), edited by the Internat- ional Geographical Society.

Locations of Collection of Large-egg Tyne Cottus Jàponidus

Iwaki River /. Hamano Town, Hiromal• City, Yonashiro River / Numadate, Odate City, / Nakatsugawa, City, lwate Prefecture Towa Town, Wagagum., Tozawa Town, Iwate Prefecture Iwabuchi, Onikubi Village, Tamazukurigun, .Miagi Prefecture Naruko Town, Tamazukurigun, Miagi Prefecture Kisen River /• Oriheki Village, Bansengun, Iwate Prefecture Prefecture Huga River / Hokaigun, Yamagata (ii) / ishida Town, Kitanuraiamagun, Yamagata Pref. gfbranches; -upper:-reaChes of -thé; ank-ako -RiVer Y: • middle reaches of the Run River / Sazawa Town, ' Akagawashin River / Asahi Town, Takawagun, Yamagata Prefecture Ara River / Funawatashi, K. kuni Town, Nishiokiigun, Yamagata P. . / Shirakawa City, Fukushina Prefeeture Koseki, Nishishirakawagun, Kaji River! Yonekura Village, Kitakanaharagun, Nigata Pref. / Kurosawa Villaze, Kujigun, Ibaragi Pref. Kadonoi, DaiShi Town, Kujigun, Ibaragi Pref. Oksa, Daishi Town, Kujigun, Ibaragi Pref. Guna River / Yutcugami Village, Nasugun, Pref. / Niko Town, Tochigi Pref. Muromachi Village, Asogun, Tochigi Pref. Sarugakio, Shinji Village, Tonegun, Guma Pref. Atsuta, Azuna Town, Azumagun, Guma Prof. Ara River / Ashigekubo Village, Chichibugun, Saitama Pref. / Ochiaihachioji City, Tokyo / Taninura Town, Tsuru City, Yananashi Pref. Yanagawa, Otsuki City, Yamanashi Pref.

I Sakanioi River / Gotemba City, Pref. / Tenjinpio, Kofu City, Yamanashi Pref. Kaminoyama, Hizaki City, Ya=nashi Prcf. Umekubo, Minamikiomagun, Yamanashi Pref. - Chikuna River / Fuse Village, Kitasakugun, Pref. Buceki Village, Kogatagun, Nagano Pref. Komaki, Ueda City, Nagano Pref. Kawatapura, Kamitakaigun, Nagano Pref. Shinano River - / Kamishirigawa, Kamiminauchigun, Nagano Pref. Ooka Village, Sarashinagun, Nagano Pref. • Noguchi, Daimachi City, Nagano Pref. - Sotochimada Village, 1.atsumoto City,Nagano,P. I. Village, Linamiandongun, Nagano Pref. Nagawa Village, Minamiandongun, Nagano Pref. Tenriu River / Tatsuno Town, ramiinagun, Nagano Pref.

ma City, Nagano Pref. • / Shimotsugu Village, Kitasetsuratugun, Aichi P. (main stream) / Tamataki Village, Nishitsukumagun, Nagano Pref. Pukushima Village, Nishitsukumagun, Nagano Pref. Natsugawa, Natougawa City, Gifu P. Fulmoka,:Tukuoka Village, Enagun, Gifu P. Kiso River - / Karo Town, Ekitagun, Gifu P. Jinbuchigawa, Shchiso Village, Kamogun, Gifu Pref. Kiso River - / Hirugano, Takawashi Village, Gunjogun, Gifu P. Yawata Town, Gunjogun,. Gifu Pref. Takasa3o, Takatamura, Gunjogun, Gifu Pref. Itadori Village, Bugigun, Gifu Pref. Gifu City, Gifu Pref. Kutoriu River / Ishitetsuhaku Village, Onogun, Pukuyi Pref. Yu-Pa River / Sasazato„ Elyama Town, Kitakuwatagun, Kyoto. U River / D, kenogur Kyoto Mia River / Nomatabachi, Miakawa Village, Takigun, Mie Pref. Biwa Lake - Amano River / Tanjo, Yonehara Town, Sakatagun e, Shiga Pref. - Kitsu River / Nogi, Otsue Village, Udagun, Nara P Nahari City, Mie Pref. Yodo River - / Ido, Kiokita Town, Kitakuwatagun, Kyoto Akuya, Kiokita Town, Kitakuwatagun, Kyoto Kameoka City, Kyoto Uenobashi, Ukio-ku, Umetsu, Kyoto Sakio-ku, Yase, Kyoto Yodo River - Angi River / Tobetsuin, Kameoka City, Kyoto ma River / Nose Town, Toyonogun, Osaka' Ichi River / Kanzaki Town, Kanzakigun, Hiogo Pref. Seho River / Tobisawa Village, Shishikurigun, Hiogo Pref. / Yuhara Village, Babagun, Okayama Pref. "Cori() River / Tetsta Town, Atetsugun, Okayama Pref. Eno River / Mirazaka Town, Ftutamigun, Hiroshima Pref. Doki River / Nakatoshi, Miai Village, Ayautagun, Kagawa Pref. Hiji River / TOnohijikawa Town, Kitagun, Ehime Pref. Muromi River / Hitotcuya, Sagara Town, Sagaragun, Fukuoka P. / Sakae Village, Hitagun, Oita Pref.

• ••• ' Loctions. of Collection of Sm!:-.11-eg Type Cottus Japonicus

Towada Lake / Kamitizagun, Aomori Pref. / near Aoba Castle, Sendai City . Abukuma River / Ejiri, Tsunoda City, Miagi Pref. Shirakawa City, Fukushima Pref'.

Kuji River / Tatsunokuchi, Ibarai Pref. «; 3 Fuji River / Minoshiro Town, Minamikiomagun, Yamanashi P. Nojiri Lake / Shinano Town, Kamiminaochigun, Nagano Pref. Toyo River / Shiragi, Minamisetsurakugun, Aichi Pref. Ishimaki, Toyohasi City, Aichi Pref. Kiso River (Main Stream) / inuyama City, Gifu Pref. Kiso River Nagara River / Takasago, Takata Village, Gum_jogun, Gifu Pref. Hodojima, Seki City, Gifu Pref. Shirogane, Seki &ity„ Gifu Pref. . Kose, Seki City, Gifu Pref. Chiusetsubachi, Gifu City, '3-ifu Pref. Kiso River - Kai River / Gifu Pref. Sai River / Kanazawa City, Ishikawa Pref. U River / Tango Town, Takenogun, Kyoto Biwa Lake / Iba Village, Kanzakigun, Shiga Pref. Asai Village, Ihoreun, Shiga Pref. Nagahama City, Shiga Pref. Sakatagun, Shiga Pref. 7atada Town, Shigagun, Shiga Town, Shigagun, Shiga Pref. Kino River / Hashimoto City, Wakayama Pref. Wakayatia City, Wakayama Pref. Kako River / Kako City, Hiogo Pr. Yada River / Totsuka Village, Mikatagun, Hiogo Prefw Ohio River / Kahara Town, Yatogun, Katuri Pref l Saba River / Bofu City, Yamaguchi Prof. Nyodo River / Ino Town, Awagun, Kochi Pref. Muromi River / Nishishin Town, Fukuoka City, Fukuoka Pref. Unknown river - Muramatsu Village, Sonogigun, Nagasakie Pref. •

Illustration 1 shows the above7mentioned places of (138) collection. As you can cee in the illustration, Cottus japonicus, either large-egg type or small-egg type, is distributed in Honshu, Shikoku, and Kushu. Hokkaido used to •be includedln this distribution range because Cottus pollux was identified as Cottus japonicus. Cottus pollux, as 'mentioned before, is a different species. Okada and Nakamura (1958) already mentioned that the distribution range of Cottus

- Saponicus covered almost all of Japan except Hokkaido. Although .,_oyanagi (1957) mentioned that none of this species lived in Kochi prefecture and the Pacific coast of Kyushu, recently, •Ito collected the small-egg type. in the Niyodo River in the • Kochi prefecture and Kamahara (1961) also reported that this species had lived for a long time already in the rivers east of Ahi City in this prefecture.

'As you can see in Illustration 1, -Cottus japonicus has a wide .range of distribution and moreover, it is distributed (139) in the rivers in each district. In'Okada's repôrt (1960), the Ohata River in Aomori prefecture, the Haguro River in Yamagata prefecture, the - Nureishi River, Sarugaishi River, Sekii River e •Koshi River in Iwate prefecture, Kitakata -district of the Fukushima Prefecture, the in Tokyo -, and the in and Shimane prefedture are also men- tioned for this species. (The types. they belong to are not mentioned). As these fish are apt to hdde themselves among the stones at the bottom of rivers, they are rather difficult to be collected and observed. Hence we are apt to miss them - in rivers during a short period of collection and observation. If we consider this point, we can hardly be wrong to judge that this species, especially the large-egg type fish, inhabits almost all of the rivers in Honshu, Shikoku, and Kyushu except those with strong acid content or polluted ones. • In my report of 1961, I pointed out that while the_laree-egg type Cottus janonicus which spends its whole life in rivers was collected mostly in the upper streams, the sma11-ei2g type which were Amphidroous migratory fish, as well as Cottus Kagika which were Catadromous migratory fish, were mostly found in the middle or lower rivers. This tendency is clearly seen in Illustration 1. The large-egg type Cottus japonicus definitely belongs to stream fish.

jOkra

cà 1. à E; irjU311(0) • iigi%M(0)0)5111: -1M Fig. 1. Distributions of the large-egg type (0) and the small-egg type (0) of Coitus japonicus •

■.■

The Distribution Pane Cf Tukugobious flumineus

It is known that the distribution range of Rhinogobious brunneus in our country covers all of Jaman including Hokkaido and Ryuku (Tomiyama, 1936; Okada, 1960). My invest- igation also confirms it and furthermore it Droves that Tukugobious flumineus lives only in the south-west of Japan (Mizuno, 1960). As the locations of tha collection also are no -t; shown in the report as in the case of CottUs janonicus, I would like to present them here with additional ores which • . have been recorded since the last report. As in the case of Cottus janonicus, I was helped very nuch by Tokyo University Zoological Laboratory, Saito Requital Museum, and others. (140 1 also changed the old names into the new ones. Locations of Coljectir‘n of Tulcurobius flumineus

Fuji River / Uizaki City, Yananl.shi Prefecture • Tenriu Rive / Tatsuno Tom, Inn Citlr, Eg ,fano Prefecture

Inazato Villaue, In City, .:*.ag -lo P.

Ina City, Magano P. •

Toyo River / Cit ,•Ichi. P.

Jintsu River / Takayama City, Gifu P.

Sho River / Tode Town, Toyama P.,

Kiso River / (main strear;.) ..Enegun,Gifu P.

Natsnp-awa C4 ty, Gifu P.

Kiso River --Hida River / resudagyn, Gifu P.

Og-unra Masudagun, Gifu P.

Shirakawn Toyn, Kamogun, Gifu P.

,Kiso Aver--Nagara River! Gu -,, jor.un. Gifu P.

- Seki City, Gif*,:' P.

Gifu City, Gifm P.

Kiso River / Yorc«un, Gifu P.

. . Makite Village, Gifn P.

Biwa Lake-- .rA)su .Y.-ernre Field, Toynni Tor.Kovegn ,-, Shigsa P.

Ocra Field; Toyema Tonn, Kogagun, Shiga

*The iroper reaches Posu Rive— Dan, Toyana To•n,

Kog;, 1711r Shiga P.

Yod° River--Kitsu River,/ Kagagun, Mie p"

teno City, Mie P.,' •

*Nahari City. Mie P.. •

• :Udarrun; Nara P. •

• SaFercgur, Koto

Uatsnka Town. Sagarawun, Kyoto

Yodo River--Ugi River / Otsu City, Shign P.

Yodo River--K-tsura River/Kitakuwatn7un,

. . . . ' Kameoke City, Kyoto . .

• • Salçyffl•cn. Yyoto. ,

Yodo River ( rain. st,ream ) / Debai , T itsu1i CYr, Oka (2,"' Oen Kemooka Cit.. , Osaka

Y-rato River Katakand '1,32 Tra n Tc -14 n 1.' r ikoc.c n r. Osaka h:i no, ro City, ,iÇreh 1 ro Cuir 057i; ka

Kin() River Yorl-'1.ro . 'Pe rp (1).1e1-1 shilroFhi ro Vi.-1 Yo phinot7-un 'Ara P.

Kaman° River--Totsu River • An ,111 AmP YoshiroFur 1g^ -.5•;:, P. Takio, Ara P.?ra. Vi11re, Yoshirorun„ Nar? P.

z Inc. River nomEr3 , rond. Osaka • crt Os.:9 1/e

Y.., mrhe Os.-.1.1ca Karanihi Cjtir, Hioczo P.

Ura River / rrn ta. , TOT-Tr ,K.i•talcuwe.tp.pun, K7,reto • rrs Kitak.-..)ratar;un, Kyoto Tye be City, Kioto

Soho irer Shishikuri Ffun. 7.-lio‘:."0 P. , • Asana. .L1-71.ver \Ur e- e. Okavara. P. • • Uhs.ra rr,..rfwa Villa-e, Okayama P.

Korio River / Yorio City, P.

Eno River itsut..'a City, rosbina P. • ° Ota ?liver I Koh-i.re Ton. 11".1 rtarfl.)n, irohirr P. 7.1rci reem-n, P. (->ki pun, I•ii roshi ra P. C.-31116,cm Eiroshi ,-a P. Town ,Yari.bp-.n.tapur., Hi.roshi ma P.

Yoshino River P.,:er.9 a Torr , shi shiya P. ipu n , Tc-.)1<-us1.-ti P.

yoci o P. 0 P nd V i:e , CUM. _

Shi rsh à River Su2.3.k-_i_ City, Kochi. P. . _ . .

Soshi a River TP rai VfLl ple, Eciu r, -ire P. - . Jushi n RiVer--Tobe River / Tobe Ivorrun, hire P. ..

River - -1:(.alf.7.,-Prr.e. River/ Tom, -Iv° , Eh.ireP.

Oitp iiiver--Seri River Tour, Ncor1.7r -n, Oit. a .

Eki c'a.te . v er -Po ••= River/ • ..;•..ns.hini.n Torn., Us a n, 01.ta. P.

P--uver Yanakuri Town, Shl.roteg...un , 05 ta., P. . :

Sc.leda 911, !U1 1 P. -

Tsukugo River •• / Kj.takoo.ini Vilie, Asogun, P. er,\ The above-mentioned places of collection are shown in (-14.1-) Illustration 2. But the places which are in the carne river • and are close to each other are abridged. Although they are . not shown in this illustration, Xitatane•Village, Tanigawa- , guchi in Tanegashina,. Hisha River in Okinawa, and Amami- oshima have this species.

)

• 2- /3 3 .1*, 05-)le Fig. 2. Distribution of Tukugobius flurnineus

There is no collection in the south of Kushu. I, however, •(142) Would not negate the possibility of their living because our investigation was rather rough. Since they inhabit Tanegashima or the Ryuku Islands, they quite likely do in the south of Kyushu. In short, this species inhabits.the south-west of Honshu, Kyushu, Shikoku, and Ryuku Islands.

I would like to discuss the east boundary of this distribu- tion. From Sept. 6, 1961 to Sept. 10, we surveyed thè - - Touryu River, the Sai River which is a branch of the Sinano River, the Puji River, the Sagami River, '3hs. Sakenioi•River, and the Oce River, a branch of the , laying stress on the upper middle basins. Of these rivers, the Tenryu River and the Fuji River had this species. They are Ine 'act • lisited above. However, despite/that, we collected quite a few fish.ineluding the fish that lives at the botton of the water, we neither - collected nor observed Tukugobious flumineus in the Sagami ' River passing through Otsuki City. and Yamura Town in Tsuru City in the Sakenoi River in Gotemba City , and in the Ose River at Iwanami in Gotemba City. And Norio Pukushima of Gunma University, who undertook a wide range of collection of Cottus japonicus along t1-1 Tone River, did not see this species J. Considering the above results, I am quite certain that the distribution range of this specied on the Pzicific Coast side is limited to the west of Fuji River. As for the Japan Sea side, we surveyed th Sai River in i:atsumoto City and in Meika,Town. We collected Rhinogobious brunneus with rainbow trout and Tribolodon hakuensis, but it seemed that . the lacustrine type land-locked fish had fled from a breeding pond. And Tukugobious flumineus was not found in both places. Although these two places are not enough to decide, if the Sinano River water syStem (Sinnno Basin) also is not inhabited . the species, the boundary is drnwn between the Gintsu River by and the.Sinano River, as you can see in Illustration 2. The line from the Itoi River on the Japan Sea side to the Fuji River on the Pacific coast side almost accord with the central trough belt which is the border line of the west according to the geological structure (from the Itoi River to the . Shizuoka line). It is an interesting fact that the distribution of Tukugobious flumineus is limited to the west of this line. (143) I discussed the distribution range of Tukugobious flumineus in the previous chapter, but I would like to mention its living condition in this chapter0 I already reported that Tukugobious flumineus which were the fluvial land-locked fish were collected mostly in the upper-middle and upper reaches of rivers, while Amphidromous migratory Rhinogobious brunneus were found in the middle-lower reaches of rivers (Mizuno, 1960) Mizuoka (1962) also confirmed this in the Ota River water system and Illustration 2 clearly proves it. Many fish of this species were collected in the rivers in the south-west of Japan. In Illustration 2 we can find almost all of the main rivers in the area, which amount to 82. It is confirmed that in 29, that is, more than 1/3 of 82 rivers, the fish of this species live. If we undertake a survey over the rest of the rivers to know whether or not they live there, we are quite sure to find that they do. Because we find them almost always whenever We examine the upper-middle reaches of rivers in the area. 'o' we investigated last year for the first time such rivers in the listas Sinraku River, Ani River, Akuta River, Makio River, Inona Riverand the branch, Dairoji River, Yono River, Yamate River, Yamat6 River and the branch, Ishi River, and Tojo River, and we collected them without fnil. As far as I know, the only exceptions are the U River in Kyoto-fu and the Muromi River in the . They are, however, little rivers whose lengths are about 20 km0 end the very fact that the fish do not live there is rather interesting, as I explain later. • • ,

As' Mizuoka (1962) mentioned with -srecial reference to the Ota River water system, the fish of this species live everywhere in the middle and upper reaches of the branch or main stre-ee, of a river. This tendency is shown to a certain extent in the Kiso River water system in Illustration 2 It was also confirmed in the Kitsu River and the Inona River in 1962. I plan to report this in detail later. mus they inhabit quite widely in the main stream and branches Of a water system. And the population density is quite high as compared with that of other fish. 3-5 per 1 m2 is a «rather 2 low figure for them. The density often reaches 20-60 per 1 m in sone places. However, the situation is a little changed near the border of.the distribution range. Sone branches do not have then. For example, in the Tenryu River water system, they inhabit in great quantities the lower reaches of Sulea Lake, but none of them do in the Kami River and Kokotu River, which flow into the lake, except the lacustrine land-locked type Rhinogobious brunneus that have come up from the lake. In the Fuji River water system also, they inhabit the En River but not the upper middle reach of the Puefuki River°

Tuitugobius flumineus does not seem to inhabit lakes and • - ponds. They were all Rhinogobieee .brunneus, but not this species that we collected from more than 20 lakes and ponds (I will report later). Herre (1927) 2 who made a record of the sub- sp ec i es of IthiS species, also :Lentione.d that the fish lived in the streams. In short, it is understood that the fish of. the Tukug obius flunineus genus are no t only mountain fish (144) but also river fish.

Study

I would like to examine Cottus japonicus first. As nentionod above, Cottus japonicus, both the large-egg type and the small-egg type inhabit Honshu; Shikoku, and Kyushu. Especially the large-egg type.inhabit almost . all of the upper reaches of rivers within the distribution ranee. One of the problems here is whether the distribution range has been gradually fo.ened from a long time ago or whether it has been forred recently. If it is rather recent, the differentiation of • the l e-e - '- e" type has ouite likely taken place independently in eech river. But if it is old, the differentiation seems to have occurred in a certain location. But the recency end oldness cannot be decided by such a standard as a million • e yea,s ago . They have to be discussed in a comparative sense with other fish. To prepare for this, we should discuss the formation period of fresh-water fish.

concerning the distribution ranges of Japanese frash-water j. • • fish, Jordan (1901), Kawamura (1918), Tanaka (1931), Berg (1933) . and Mori (1936) have done research. Recently, Aoyanagi (1957) • and Okada (1961) have published the results of their research. . All of the research 9 however, belongs to divisional biogeog- raphy and mainly concerns dividing Japan into some geoeraphical divisions. As far as the topography is concerned, they discuss • only to the extent whether there is any bridge. There are apparently two groups of fresh-water fish which differ,from each other to a great extent in the spread of distribution , . that is, the migratory group whose members spread their \ distribution by going through the sea, and the primary fresh- water group whose members do by fresh-water only. The above- mentioned research does not seem to concern this difference. Aoyanagi (1957) - seems to be interested in this point but also ignores the difference when he arranges the biological divisions.

Geherally speaking, fresh-water fish in Honshu, Shikoku, and • Kyushu consist of primary fresh-water fish which came from thesouth and migratory fish which came from the north. They ./mee-- together in these islands so to speak. When we study , the distribution condition in -,:hese areas 2 we cannot ignore the difference in migration and dispersion of the two groups. Referring to Aoyanagi's data (1957), he chose fresh-water fish which were distributed almost all over the country and

divided into th'e; two groups 9 that is 2 primary fresh-water • fish and migratory ones which included their land-locked fish. The result is shown in Table

A point which attracts our attention in this table is that almost all of the primary freshwater fish tend to inhabit the lower reaches of rivers,,that is to say, they are ground fish. The only exception to this in the table is Moroco steindachneri which ie a mountain fish and-is seldom found7.. 14-5) in the lower waters. Although there are SOM.': 'other Mountain

fish such as Pungtungia herzi, Zacco temmincki, Hemibarbus 1st,. longiroseris, Cobitis delicata, and Liobagrus Reini, they= only inhabit south-western Janan. Tukugobius flumineus which can be treated as a primary fresh-water fish after being land-locked is . also a mountain fish, and, as mentioned in Chapter 5, inhabits south-western Japan. The difference between the ground fish and mountain fish can be found in comparison with their eubspecies. Of the above-mentioned mountain fish, Zacco temmincki, Hemibarbus longirostris, and Cobitis delicata

have subspecies of the same genera such as Z. platypus, • H. barbus, and C. biwae. The eubspeci.es inhabit the ground,.

as well as the mountains, but their distributions spread more towards north-eastern Japan than the distributions of the former three.

When temperature plays an important rôle as.a limiting cause of the distribution, one with a higher position in the vertical distribution will generally inhabit north in the horizontal distribution. This is well-known as Hunbolt's Law. It is well-known that the distribution of salmon and Salmo pluvius genera which are migratory follow Hunbolt i s Law. . However, the fact that these mountain primary fresh-watèr fish only inhabit south-western Japan directly opposes th'e law. The difference in the speed of their migration and in their topographical relationships seem to be very relevant. to the conflict.

e 1. *en • nEl • 12J:e.-.o.3

Yi --e Y 11 • .. Pseudogobio esOcinus -::. Z '',, N -. Luciogobius guttatus ... • F e 3 , , Misgurnus anguillicaudatus jj collusiaponicus v--e, y e 3 Cobitis bineae il 7 9 C. haz-ika 1- '1X - Parasilunis asolus ." i" Y ...e .Lampctra planeri ,. ..e.y .4: • Pseudobagrus nudiceps .

* • ietizt5.7ilit- -olv-c, ••Z) *In * Since,this fi sh occurs also both in Hokkaido and in Saghalien, it is regarded to have invaded into Honshu from north through these regions as well as from south through korea or Ryukyu Archipelago. 0;her truly freshwater fishes in this column, seem to have invaded through the latter course only.

Concerning the north-east of Japan, which •ià east of the Ï146) central trough belt, we know most of the area except both . Kitakami and Abukuma mountain areas were attacked by the violent geological alteration from the Miocene Epoch of the Tertiary period to the Diluvial Epoch of the Quaternary period.

That is to say, the violent folding and volcanism were • repeated and'sometimes most of the area sank into the sea. In the Diluvial Epoch the movement became less violent, but in the middle and the last part. of the Epoch it was still fier- ce. In contrast > most of south-western Japan was stable through the Cenozoic - era. The great geological difference between north-eastern Japan and south-western. Japan'is due to this fact (Hata, 1954; Hata, Ijiri, 1958). The Jepanese Islands were part of the continent until the last half of the Diluyial Epoch. Hence the primary fresh-water fish would have come to Japan through present Korea or Loochoo (Ryukyu) but they could come only to south-western Japan. They could not enter north-eastern Japan because of the violent geological change0 kence their entry into this area seems to have begun in the Diluvial Epoch0

The speed of migration and dispersion of the primary fresh- water fish wieeech migrate only •through fresh-water is very slow as compared with land animais (Darlington, 1957). It is, however, Quite possible that swamps and ponds which covered the ground abundantly then helped the migration of the groUnd fish towards the north. But the mountain fish did not utilize them and have remained in south-western Japan. The difference of the present distributions seems to show it. The distributions o±'. the primary fresh-water fish in-2able 1 show various degrees of - their entry. Some have reached Aomori prefecture which is " in the northern end of north-eastern Japan, some have stopped at iwata or Yamaguta prefecture, and some hava not even reached the prefectures. In short, theyeeen still in the process of migrating north and hence it is suggested that their distri- butions in north-eastern Japan is not very old.

I would like to mention the Lioroco steindachneri. I already mertioned that despite the fact that it is a mountain fish, it is an exception in that it inhabits Honshu, Shikoku, and all of Kyushu. In short, above-mentioned generalization about distribution does flot seem to be applicable to fris fish. However, it is possible that this fish, although it is a mountain fish, was rather a ground fish and changed into a mountain fish under the warm conditions of the eras between the Ice âges and of the Alluvial Epoch.

The following findinrzs Seem to support m7 bynotllesiq: M. percnurus, the relating species of Lioroco steindachneri inhabits widely Siberia, North China, the Maritime Provinces of Siberia, Korea, and Hokkaido and it is also considered to be the ancestral species of this fish. -; despite the fact that M. percnurus in Korea inhabits the streams between mount- ains as M. steindachneri does and further both species often live mixed (Uchi-da l 1935); it does not inhabit the uPper reaches of rivers in Ebkkaido and rather inhabits the sAmps and ponds (Aoyanagi, 1957; Kobayashi, Hirose, 1957). Miyagi (1935) believes also that M. steindachneri migrated not only from the south but also from the north through Hokkaido. With these considerations, the present distriution range of M. steindachneri does not seem to conflict with the above-mentioned generalization.

What about the Diadromous migratory fish? Since'they can (147) spread their distribution ranges through the sea, the speed of dispersion is faster. As you notice in Table 1, many of them have spread over all Honshu, Shikoku and Kyushu. In the rivers'between mountains in north-eastern Japan, most of the fi sh consist of them. Y. Mizuno's investigation fresh-water (unpublished)/in the upper reaches of Ara River in Yamagata prefecture. My work in the Yamizo River, the branch of the Kuji River in the Ibaragi River and Aoyanagi's record (1957) tell me that the fresh-water fish which live in the mountain streams consist of Salmo mocrostoma, 9 Salvelinus pluvius, Plecoglossus altivelis, Tribolodem hakuen- Anguilla:japonica, Rhinogobius brunneus,,.and the large- egg type Cottus japonicus.. Especially the fish that.belong to Salmo mocrostoma and the Salmo pluviUs genera, Tribolodon hakuensis, the large-egg type Cottus japonicus are predoMinant. Concerning the primary' fresh-water with the exception of Moroco steindachneri, only a few fish which inhabit the - ground level have entered such as Peudogobio esocinus„ Bacco platypus, and Cobitus biwae. • • - e 2. emElelbfli*Oe.;MODIZelà

• _ER1r-'1UtliCbM, TalcitEZ.M OR1-4 S.tub;i;:à. . Table 2. Endemic freshwater fishes in the southwestern ,region and the northeastern region of Japan. Truly freshwater fishes shown. in the upper •column, and both migratory fishes and their landelocked forms in the lower column. •

e m E3 ez . 1.1i t Ei * , • . The southwestern region The northeastern region

4 ...".e. 'ie e'.« Acheilognathus cyanostigma Z -3t, e 1- / Tanaitia tanago • 43,. .ty , , A.r.epi.iù - zee'e T..tsiobuta . .. Acheilognathus moriohae . e-n• . Biwa zezera p e* pseudorasbora parvapumila JI 4 Sarcocheilichthys e. variegatus . . tt; y -1:3 Gnathopogon caerulescens• 9 e e G. suwae . . ' "f 1- zet:r G. gracilis ' • 5"'. >r -t:t = G. japonicus Ji 9 .,■ yri 7 licnn;granunocypris rasborella J.>. Opsarichthys uncirostris 9 3' 33 Ishiliania steenaciari • . 7 i71 F « a e Cobitis dclicata 7.e-... F k Hymenophysa curia • ee9 =.._. ex Parasilurus biwaensis . 49 1- =1•-•-t X P. lit'ophilus "*' • Pseudobagrus nudiccps • • ihe LItiobagmseli Oncorhynchus rhodurus • e.:.-,_-e.x • Oncorh)'nchus kawanzurae (i -e ) • :Iv 9 4 9 9 • Salvelinus pluvins 4 V) . O. iwame - •Y "et- 4 9j- SalYelinuijaponicus . 4 .9-9 Chaelogobiusisai.a * s . This is a endemic subspecies. p. The fact that fresh-water fish in north-eastern Japan (148) consist of the Diadromous mirate-fy f;c•11 end the primary fresh-water fish indicates that the establishment is rather • new. If vie compare the species which have differentiated in this area, that is, the endemic species of north-eastern Japan, withihose of south-western Japan, we can see this point more clearly (Table 2).

There are many problems aboUt the relationships between the above-mentioned endemic species and the relating species in Japan and the continent, especially with regard to degrees of speciation. Concerning fish in north-eastern Japan, for

- example, it is only . .the Pseudorasbora parva pumila that does not bring any opposition to its being an endemic eubspeciès but about other fish such as Tanakia tanago, T. miobuta, Acheilognathus moriokae, OncOrhynchus kawamurae, and Salvelinus

« pluvius, and their relating species 9 Acheilognathus lanceolatus, 00n0f. adonis and Salvelinus japonicus, there is-atheory whiCh claims.that the latter are aly.subspecies• of thé former rather than relating species, or that the speciation of the latter have advanced.only so far as to the Forma degree (Okada and Matsubara, 1938; Aoyanagi, 157). There is a same type of theory about:the . fish in south-western Japan. It is also known, though . 'fragmentarily, that the speed of speciation.in fresh-water fish differs according to the specics-and the licing eircum- stances . (many examPles in Myers, 1960).

However, even if we consider these points, we have to admit

that there is a great • difference in the numbers of the endemic species between north-eastern and south-western Japan and that there afre fish such as Biwa zezera that hae- 3 achieved the differentiation of the genus in south-western Japan, but there ara none in north-eastern Japan. These facts clearly indicate that the establishment of the.composition of fresh-

water-in north-eastern Japan is rather new. •

Now, the fact that in opite of these differences between both areas the large-egg type Cottus japonicus inhabits all of Honshu, Shikoku, and Kyushu su.egests that the distribu- tion of this species itself is rather new , (but the problem is how it spreads and'I will discuss this later). The followini findings support the above-mentioned pointe Watanabe (1958) says that the form of Côt.tus janonicus in this essay is similar to that of C. pollux in Hokkaido when they tare infants and that the confusion in the academic tes occurred •because of the sir- 11‹, Y.ity; he also says that the Cous japonicus genus in Japan came from Korea and one which -

, reached Hokkaido achieved the speciation into Cottus pollux. Although there is some doubt about its going north up to Hokkaido, it seems to be certain that the differentlation of 1Cottus junonicus and C. pollux occurred earlier,than the • into ( differentiation of Cottuj japonicus the large-egg type and the small-egg type. The separation of Honshu and Hokkaido is said to have played an important rôle for the differentia- tion of Cottus janonicus and C. pollux. Tokuda (1941) assumes that the seDaration started in the middle of the Diluvial

7epoch owing to the distribution of the rat genus. Hata and Ijiri (1958) however assume that it started in the third non Ice Âge which was later than the Diluvial Epoch. Anyway it appears that the differentiation of Cottus japonicus and •C. pollux occurred about j,n,the middle of the Diluvial the large-egg tvne Enoch and the differentiation/occurred in thelater pe -:'iod of the Diluvial'Zpoch. I already mentioned that the large-egg type Cottus japonicus also inhabits the U River Kyoto and the Muromi River in the Fukuoka prefecture. But it is known tbat the coast near these two rivers was under the sea in the first period of the Diluvial Epoch. Then these rivers must have been under the sea. This fact also implies that the differentiation of the large-egg type occurred in the latter period of the Diluvial Epoch.

The following findings are reported: the large-egg type Cottus janonicus and the small-egg type are very similar in extero - and inrior for:_- --_. e and hence only th number of the pectoral fin rays can tell the difference; there seems' to ba a case that the small-egg typ'e 'r.nle fertilized both types of females; the egg-sizes of both types mutate to a grat extent (Mizuno a Niwa, 1961). These findings also indicate from a different angle than the distributive conditions that both types are very closely related and that their differentiation is new.

It was mentioned in Chapter II that the large-egg type Cottus japonicus was land-locked by changing its egg-size and life history and hence its change back into the small- egg type would not occur very easily and hence its dispersion had to be undertaken only-through fresh-water. On the other hand, this fish inhabits mountain rdvers and hence the speed of the dispersion is slow. And this point together with the hypothesis that its differentiation is new lee.ds to a conclu- sion that its differentiation occurred independently in different rivers. The theory of the dispersion from where the original speciation is effected cannot be applied to this case.

Cottus nozawae like the large-egg type Cottus japonicus is 'a fluvial land-locked fish and C. hangiongenSis which Watanabe (1958) claims to be the only migratory species from the north, is Amphidrous miratory (Mizuno Niwa, 1961). As there is a great difference between Cottus nozawae and C. Hangiongensis from a morphological point of view, the former is said to have differentiated from Cottus japonicus as ment- ioned before (Watanabe, 1958). On the other hand, since the small-egg type Cottus jw.poricue does not inhabit Hokkaido, it. is not possible that Cottus nozawae, which is a fluvial land-locked fish,- differentiated from the small-egg type Cottus japonicus. The following findings rather imply that e some of the characteristics of Cottus nozawao are equivalent to that of the small-egg type Cottus japonicus; the nurlber of pectoral fin rays of Cottus nczawae mutates to a large extent (Watanabe, 1958); the territo•y inhabited in a river covers from the upper reaches to near -the mouth of a river (Sato â Kobayashi, 1951). Although there have to be more investigations on the point, it is interesting that the fluvial land-locked Cottus nozawae has been differentiating.. Cottus gobio which inhabits widely in Europe also seems to be a fluvial land-locked fish because of its egg-s ±2 e and the inh-bitil-lfr territory.. Thus it can be sic: that the fluvial land-locked fish in three areas such as Europe, Hokkaido, and Honshu, Shikoku and Kyushu independently differentiated in each area. This also supports the hypothesis that the large- egg type Cottus japonicus differentiated independently and at the same time this suggests that the differentiation of Cottus nozawae and C. gobio, liken±mu the largo-egg type Cottus jamonicus, ware undertaken ubieuitously.

What about Tu1zugobious flumineus? The fact that its distribu- tion is limited within couth-western Japan and that it is different from Rhinogobi:es brunneus to a considerable extent \ from the morphological poin% of view makes this fish different( - from Co - tus japonicus. Hence, for the ubiquitous differentiation of this fish, we have to have a different explanation than that.for the Cottus japonicus. As ore of the explanetionz we could consider the distributive condition for areas outside Japan. Tomiyama (1936) compiled a list of synonymo in use for Rhinogobius brunneus and found nine of these to be in use outside of Japan. Herre (1927), in consideration of morphology and peculiarly large egg-size, recorded the.following names for three new species found in the Luzon Island in the Philippines: Tukugobious carpenteri, T. bucculenatus, T. philippinuc; but when he compared them• with Japan-produced Rhinogobius brunneus, he rejected these three names. Tomiyama (1936) decided that they belonged to the species Rhinogobius brunneus; however, when we consider their morphology (especially the number of the first pectoral fin rays), their egg-size, and that they live only in the upper reaches of rivers, it is clear that these three are only comparable to Tukugobious flUmineus (Mizuno; 1960) and that is one of the reasons that I decided that Japan-produced Tukugobious flu:...ineus belong to the genus Tukugobious. Besides, when we consider the origiAal description of the following it'seems that the China-produce.: - àeStivarega MORI Le. and R. fukushimae MORI belong to Rhinogobious brUnneus, and tbat the Formosa-produced R. formosanus OSHIMA and R. taiwanus OSHIMA belong.to Tukugobious flumineus (Uizuno; .1960).

When we also consider the fish of the Tulcugobious flumineus species found in Honshu, Shikoku, Kyushu and the Loochoo Islands, we come to realize that Tukugobious flumineus and its closely related species are widely distributed over the Philippines, Chine, Formosa and all of Japan except Hokkaido. Since all these fish are morphologically similar encugh to be co,lsidered members of the:same,species,, it - is ouitepoible that they share a common.ancester. I already:mentioned-that:the dispersion of Tukugobious fluMineUs ispossible onlythrough:fresh-water channels and that those in Japan . and , the Philïpinesiive in mountain areas and are fluvial fish Which do'not Iive .1 in lakes and ponds. Quite possibly those that live in Formosa and' China are of the same type. It is impossible to think›that . the present distribution range of Tukw;obiou.s flumineUs is -ethe result of disprsion from where the original spcciation was effected, esp-cially since there is no primary fresh-water fish in the Tuzon Islands in the Philippines yilich originally came frem China (Darlington, 1957).

For the above-mentioned reasons,• it is appropriate to consider Tukugobious flumineus and its closely related species to have speciated independently in differentaregions. If eeis true,

:Jr • then Tukugobious flumineus in Japan, even if they are limited to south-western Japan, possibly speciated independently in different rivers.

The reason that the distribution of Tukugobious flumineus is different from that of the large-e type Cottus japonicus is that the speciation of the former started in an earlier era. If the speciation of Tukugobious flumineus took place before the Diluvial Epoch, then they nust have had difficulty speciat- ing in north-eastern Japan, where violent geological changes occurred. If the speciation took place during the first period of the Diluvial Epoch, even if it occurred over the whole of Japan, repeated Ice âges would not allow them to survive in north-eastern Japan. Once driven out of north-eastern Japan, they could not go north during the later warmer period as easily as other primary fresh-lwater mountain fish This is the reason why Tukugobious fIumineus are not found in north-eastern(Pli) Japan. This fact is very interesting when you compare this with,the-fact thatRhince;obious brunneus, which ean,ni cerate - . through the sea, could go up north as far as Hokkaido. 1 Men- tioned that the large-egg type Cottus japonicus was found in the U River and the Muromi River, but not Tukugobious flumineus. This is quite natural because those two 'rivers were covered by the sea during the first period of the Diluvial Epoch.

The morphological difference between Rhinogobious brunneus and Tukugobious flumineus is greater than that between the large-egg type and the smalI-egg type Cottus,japonicus, and there is no interbreeding between the former two as there is between the latter two. The mutation of egg-size is also smaller in the case of the former two. ne fish of the species Tukugobious flumineus in China, Japan, thePhilippines_ and _ Formosa are very 'closely related l , but still there -exist certain distinctions aMong them. The abeVe-mentioned. __ • faCts• indicate • that the fluvial-land-locking of Tukugobious flumineus and its concomitant speciation took place in an earlier era - than" . that of the large-egg type Cottus japonicus. Although it ' reuires more precise examination, it seems that the speciation of the large-egg type Cottus japonicus took place during the las s1 period of the Diluvial Epoch and that the spaciation of Tukugobious flumineus occurred:before the middle perioà of the Diluvial EpochoeThe.speciation,.of•-e . ethe large-egg type Cottus •japdmicus and Tukugobious flumineus, even.though their land- ' locking is of a peculiar nature,ebbviously happened ubiquitousln As far as this point is concerned, this is inaccordanee .e„

■ Als" ) 2 ; the speciation of any land-lockin g spec i es and subspecies of fish which have Androreous mizratory fish as • their ancestor. Only in the case of the large-egg type Cottus japonicus land-locking and speciation occur D._reultaneouely, whereas in the case of Tukugobious flumineuo there is a time gap between landLlocking and speciation. Anyway, the relationship between speciation and distribution range is apparently different from what has been generally thought; that is to say, the formation of the distribution range by dispersion from where the original speciation is effected. If we call the latter case the basic type, then the former case? in which land-locking ana speciation occur simultaneously,should be considered as a separate type. However, this type has no t been studied extensively,except the Oncorhynchus nerka. Furthermore, there is no report about the 71Clat1onship between speciation and distribution range for fish which are not land-locking. In the future we may discover the

-ubiquitous speciation for some other animals; however, in the preSent stage this type of speciation is a peculiar Phenomenon which can only be found in land-locked fish. And furthermore, the Tec_kugobious flumineus and the large-egg type Cottus japon-

eibus belong to different phases of this process. The model of , the relationshiP between steciation and distribution range is shown in Illustrâtion 3.1n .',;ti ense, the speciation of the adapted dispersion type and that of the ubiquitous type are variations of the basic typeo' e't7 , )4>

Here immediately_two questions arise about the speciation of land-locked fish'. First, about the primary conditionewhich - change migratory.fish into land-locked-fish. Secondly, speciation in different rivers and lakes led to the same resulting specieb. Concerning the first peint, in the case of Anadromous migratory fish, I already considered. the - develophen- tal 'procesS. 4o -Specia1 consideratiôn is necssary'regarding the conditirs which change Amphidromous migratory fie into e _ .• • • .. _„. land-locked fish.,-If you put Tridentiger obscurus, which are . collected . in rivers, into ponds they stay and live there to breed (experiment' of Kubota of - University). I - think that the case of fresh-watar Gobi is the same. rohough Plecoi;lossus- altiVelis were put into many lakes bût failed to become land-lockede consider the failueee to be'the result of the lcw winter teMPerature of the water. Hence, in::. the cas e . oe fresh-water Gobi the causes which prevent their land-locking are rather important. How about the large-egg type Cottus japonicus and Tukugobious numinous, which change their egg- size and life histories to be land-locked in rivers? According

to Lack (1954), under the conditions of less food and fewer enemien, c'_nimals in general tond to .E-,-volve in the direction of laying fewer and larger eggs. Rivers, especially those in the mountains, are in accordance with the above conditions.

sp. L New Specia5 Group Sp. L Sp. M sp. N 1('

Sp. A Sp Sp.0 Sp. A SP.A Ancestral Spcclos Group (1) . (2) (3)

$P. L Sp. 1,A

Sp. L

lo 'A- ock.419

Wsr otiort

SP.A sP.A (1) (2) ...euoice125)-(baor,e ,eftee,-em T. -,untame ' (1) 11*.M. (2) e • (3) •Ut15). ft • • 1.1 • P11111?-. --;',. C2D fe • m mnRaweirm-am-oamt,edmge(f.tomm ,ockutme„c .7),11. à..5)1514)5e51.(topmei;;.- • (2) ileeriliss((eampus-_,).-1,-(.7).1.5%• Fig. 3. _The schematic diagrams shown the relationships between the form- ation of distribution rangea and the speciation.

O I. The general relationships • (1) Basic type. (2) Adaptive radiation. (3) Polyphyletic divergence. II. The relationships shown in thu process of land-1,cking. (1) The relationihips both in the fluvial as well as the lacustrine land-locking from anacIromous ancestors and in the lacustrine land-locking from amphidromous ones. (2) Thc relationships in the fluvial land-li)elting from amphidromous ancestors. The process of speciation from the ancestral species, spp. A, B and C, to the new species, spp. L, M and N, respectively. The distribution ranges of ancestoral species. <=a; The same of new species. ‘.

This, hor..-ever, do o ç rot serr, to be a:c.plicablo to our ca.ses. It be(P ir3)

difficult to explain the cases unless the internal. and extern2.1. conditdons

of fish thLyt make es larFer are thorouhly studied.

What about the second question ? This is more relevant to the theme. of

this report. At lerst three re;.-.).srns are considered for the cases of the

larFe-esg. type Cottus japonicus and Tukugobius flumine.us. First, it was

im.possible for .Amrhidromous airrtory fish to be land-1 coked ur.1 e.ss

-their eP1,-,- size and life. 'history. -1.Yere changed.. In Short, the ecolop;ical.

condit,ions.of rivers did nt allow t.heir land-lockiro- ,nrl.ess the chancres

occurred.. Thour,:h the larce-erp; tvr.•:e Cottus jonicus prél T,13 1,-urobAus

m in ous are not cl osely related , their eq7—size a rd life hi story have ..,‘, changed in the sr.re-direction since the fluvial lanc3-1oo 1'inr., OrctIrrr:3.

Hence' it is even more: likelv for . f.i sh of the same srecies to cha.n.p- e their

erg size and life history in the sao ddrection. •

Secondl.v, it seems that il7r-.ortant the a.bo,.., e

mentionned ti..=o species and t.heir migrratory ar.eestens 7..7ere made 'oy the

changes of ele- se and 1.ife bi story. In ral.t.i,c1117, r, the la r-e-b,me Cottr.s

ianoni cus and Trkugobius fl 11-nine:us a.re c1.e nl st.i . from the

srlall.-eyr-=t7,7pe Prd RhinoFobil‘f. *.,41 -3.e.h are

anrsid e red to" be the fCV:ST`r.sr. 1)7' t sr1t.: ?"r.r--..npr of

rectorn.1 fin rnvs. : The nnr-ber oe fo --mer, wh oh . have lar7pr er- c5, :is -

1 2-14 and 15-18 res -..ectively„-- whereas the number of the -latter - is l.L18

and 18-23 respective -1:7. Both ocurrd obscUra=ard E. eatris o-r -vrcenhnla=

belonc, to El.e..-.triF fn.milv. The eo7F 5 17. 0 and the life histor7.,- of the

eerrr- t,o thor..c cy's (.1'1:1k -ot-ob:Ins ar.d t.11rtr's of th ,,, • t.

tr V(?nse.nf Rh1nrohius brunneus. In this cso also the r1.1mber oe , •ecto) - p.1

fin rays of the former is less thn.n that oe the latter. It cnr rot be

conCluded at this stase th2.t the differences in the nrmh-er of rectoral .

fin *3-17.rs P.1-101'.7 relPtcr": were always cnused•ly,Y the clifferencee

in tharer.g sir,es and life hst.or1es. Flit the. al-..'ove menti onned frets

indic'-te that t'ur,re is some cause- .'ect- relationship 1-,-.1- 7'enn the nunber

• - 32 -

of rectoral fin rays and the e- ,r7 ar.d the 1. -1 4'n bistorv. RhiroP'ohius

hrunneus also has U-o more sPinal orlumns thPn Trobius flunineus. Hubbs

(2924) already mentiond.f.that there uns a !:ereral tendency anons closelY

related sPecies that :those with larc..er es had more sninal columns. The

case of Tukugobius flumineus agres with this tendency, Furthermore, if

you divide the seinal crlumninto two parts such as the abdoll,en Part

column and the tail part column, you find that in the ce of Tukuobius

numinous the andomen -,:art column rlus, the tail pPrt Column eouals 11 _ . plus 17, and in the case ._of Rhiro-Obins brunneus, - 10 plus 16. On the

other hand, the Éiùmbnr of ths mrs of the latter As nlways

6, but in the case of th zen -oer cent of the fish have 7 rays -

(M1.7,uno, 1961). TukuFobius ly3cculenPtus, wh.Arh i!ere examined by Herre.

P;' 1 , 1-1f —i: (1927), a:I:ways 9t, rpys._ A hveothesis thst the incre,se of a dorsal fin:rav occul‘red toç-ethrr with the incrense Of an - abdon part column, .

as well as Tkodass-hyoothesi_s (1 9--'b-) that the drcrease of c drrsal '- one 1:Tas caused bV th:e decrOPSp. e'f' an e.bdonen part column in Oasterosteus

acleatus,.dees no t seem to be imossihle. After '1.1 te erg size and

the life history change simu1taneously wi th the oceurreree

iockinr/ rd. the chams,es influence the . number of rectoralf rays,SPiral

columns, and the first dorsal fin rias, and berce 1*.. ore is no mystery- • . . .• about the:end-produCts being- -similar enough to be c1assAfied as the same _ erecies.. • ' .

Thirdly, the ecological conditions such as current speed, bottom crnditions

and water quality do not differ tr creat r7r.tet wIth rivers, es:-)eciany 1 with those in mountains, except in wPter temperature •hich differs with'

.districts..Hubbs (1940) , roired that Feorahical nuiations - of fish were • ••••

caused by differences in ecolo;71.cal conditions. In tbis sense, ;.roi -.raphicl

mutations do not occur easilY An rivers.This sers to be ore of the

answers to the euestien_why, desnite the 10117 tine nas>sed since their land-locItine:, there is no sinificant reo7raohica1 mrt!:tionemeng the •

1ar7e-egg tree Cottus japonicus and Tu1 ,7ugobius flimincu :hich sPread throush Honshu, Shikoku, and N-Jushu. Of course, T nm rot.

en: the existence of Eeo=phical mutatf.ors fin rfrvers. For example, Mizuoken

(19 )2) collected a E.reat cf islumi.*-Lns from the mnin -

stream ard the branches ef thr, Ota niver and a'''nmird the'.rumber of their

fin rays, and as a result rcconized ruttions a1thou7h they

were sliFht. He men-Uoned that Tul(rroblus Ch in; For-oea, the Pb.li-r.nincs

and Jaran also seem to be distinuished by on n of three mu .e.ntions , such

as the number of -file Fcales, the nunber of the first dorsal fin rays,

and the sensory canal -:ores. Such t'if.ferences must have been brought about

over many years by the diferences in ecoloi,ical conditions.

What about the 1-Ind-1ocked fish from Anadromous mirratr'ry fish? Ricker

(1940) mentioned that althourh the land-locked fish from Oncorhynchus nerka

subspeciated independently in different lakes, they all resulted in

Kokaree. He compared Kokance ith its ancestral land-locked Oncorhynchus

,nerka and cencluded that the f•rrner was mere adante:' to Dacustrine life

than the lptter. He also notice,2 t'.-.at the ,renetftions cf small gene

mutations ard natural selectfon made the end nrcducts in dirferent rivers

similar. He seems to ho suç-Testin.7 that,thc F 4 milar1tv. in ecolorical

conditi:ons led the ubiquitous sneciati-,ns in thn same direction. This

rcint of his is similar to the abnve mentioned t'nird -oint of mire for the'

cases of the . larEe-egg type Cottus jaonicus and Tukur:.obius flumineus. In

Janar, Salvelinus pluvius and Salvclinus jaPonicus,,uhichspeciated from

Salvelinrs leueonaenis, are beth land-locked in north-enFtern andin anuth-

western Japan . resrectively, and Gasterofiteus.aculeatuicrecenhâius, - • •

which suhSpeciated from Gasterosteus aoul.r:›-Itus, are landLlocked in the - - • - • Kuril., Tslards and in SeVerP.l n-1:::ces in south:-,..yestern Ja. - an. Thou2h theY•

are not fish, •Lamnetra planeri (Ilubbs, 1924), uhich were'lard-locked and

sn-lci -J.ed from Lampetra fluviatilrs, inhabit -widely thercian continent,

includin7 Jaran'ard Fnrth'merica. Those srocies nre considered to

have Frecia.-ted'ubicuitously as Kokancn,ard here also the - similarity in n ... - . • . . , . - r.: • the ecolorical . conditions Fr?MS to be .i1171 imnortant factor ,in haVing . led

the sneciatiOns in the same direction over such a inrcr.e.area..

Of anadromous mirratory fish there are some sr,ecins ,-7hich Pre lerd-lockcd •

•

to the ebevc nentioned hyhesis, in loth r'mrs ard lakes. Accordirr

shonid te sore differences betveen the fluvial • 'ne 1nCUStrY10

land-locked fish. Furth.7:r-ore, Rs differerces ecolc-, icl conditions

., r.lon 7. different lakes are 2-ecter th ,, n the di(Toronces arerç . :r_iv'ers;

lacustrine land-lockcd scluld be considercd ho hnme boon -.1 'SP StrOru1:(7 1 di rec t ed in the s:?ve dirention t'4-11, snociation. I pr unnble to examine

the first part because of irFuffinient d-;tP. Data for the secOni'nart is

not elA_Indant either. Hol:-ove-, I wo-.1?d. Mice tMiscuss it brief1;7. .RAcker

( 19f0) nentioned not offly Canda, ÏnUuding Vancouver TsTland, but also

the Kamchatka =-- enninsula and Hokkaido (0.n.f. adonis) as the distribution

area of Kokanee. Ricker, however, uessed.the • latter two from documents .

which, he mentioned, did rot heve enou7b. d”ta.excet concoi- -71IF the body

sizes and speckles. The terdencv to7:Tard s7 7. body size.:shen-in the

data should be explined as a co r -on 'ohenomene ,1 wich corcomit'antly

occurs with "Ind-locking, rthc-r tl7an s n characteristle of the subsrecies.

ConerninFe seckles, he re ,.7...)rti in 7.959 that there some diffeent

types i n Clv,Idian lakes. !„s, c--oared with 0.n.f. adonis in iokknido,

0. kawamrae, which hes the se ancestor. Oncorh ,., nchus nerka, hPs a few

morrholoFic'l difTerences (rshir,n,l(?). Thus. --omr Kc*., -ne there are

fish w''.ich :):Je differentiated in diforent dirF:ctiors in ir-kes..Nor:rnr

(1931) sers the;:saillesort of thin Corego'nreerà..

He sPvs that these fish, hich hr,d mirated into scui*ern lakes durirF.

the Ice' Ap- c, . F• 0 01 -

were land-locked in southern lr.kes :;nd continued charrdn2 . ther, selves , according. to the Fiven circumstances. Yprv_ made no • F•ocies (The lu.,cerilne 1 T ) .n thc rcoort of SvIrdson (-10 .g9)-too, inters-;v,lv

studi.ed the Coreonus r ,,,rus, there is an article that in '-, Urote the

"I n nd_lred srecies•srst.r tn be a diferent s---,poles r cife' e , e. ,,t

lakes. lilrernces 5n the :1 -1f- -, tipse 1..,srd-1oc?..-ir7, or ln

the researcr l r. vicw.or f,h e c 1 a . b'or't .1bou' tr ! - pb,ve di sti re ti,ns. Etifr.Frences in ecolouirorditiers -hnuld -:\

considered. As en—eared with the ' , rt that Sn7ve1irus '-ricus.Law.net-p.

pinneri, the 1Pr-re-er tyre Cottus • anonicus prd r:. •

e

flot 1-1 -,.re sireant ocolO-loal ,ir ,7 -,rences in 'ive, the a • ove rentiored

case of the lacustrine land-locked -rish rntheriffeent.

Sumrarv 1: VI.

1) As myers (1549) did, I divided the fish 1- 1..!rratien regul.arly undertaken

se a ara fresh vater into three parts such Ps between the AnadromoUs ( p),V(.) •_ migration. Catidrorous migration, and Amrhidromous migration, and discussed

the relatlonshin botwoen the ni', retion form and the land-lockin, aPvinu

stress on Janan-prodrcr,r.'. fresh ater f-çsh. There is no land-locked rish

from Catadroirous migrtory fish. Understanding their life history / .e! .

seem to understand the difficulty of their becoming land-locked fish.On

the other hand, the fluvial and lacustrine land-locking of Anadromou

rigratorv fish and the lacustrine land-lockinu of AMphidromous miuratorv

fish' are not difficult. I•any s-ecie5 are independently lard-locked in

' * different olaces.There are also r:any cases in 1•-Mch the ].2d -locked fish (1 ) about oilcorhynchus . turn back into riuratory fish, As Ri cker 9!!.0

nerka, the speciation takes :qace after the land-lockirg. There is a time

gap between the tuo phenorenon.

Understandine their life history- , wo can sen the dirficultios of -Pluvial

3 and_l ocki r • of Amphidronous migratory fish. The land-locking becomes

possible onlr vben their life history clusnt.f.cs. They cotre to have lar - er

curs 5 0 thf:t they srerd the first half of Anfancv in e!-es-- the neriod

thov are sunposFd to live in the sea. This is. the reason that ter

sneciatiop processes take niece sirultaneopsly with the land-locking

processes. Hence, once they are land-locked, the- . can hardly turn 1- ck •

into ricratory fish. In this sense this land-locking has'reculiarity.

SuCh land-lock(d fish found.in Jan are only tin srecies, such as the

lare-egg typo Cottus japonicus nrj Tukur. obius flumineus. Understandinu the

above mentioned peculiarity, it seems to be an orthodox hypothor!.s that

the formations. of distrf.,.bution ra.n - es of both sr.ecies are achieved by

. 4> diso.orsions from where the orirdnal sreciations are effected (sec' I and

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41P.

' 2 ) Fcwe'eer, rost. -orol-nblv the lere-on-,-- Cotfus • nnonieus inhabit !a1r.r)st all of the rivens over Honshu, nrd Kvrrhu, rd e:.:eiusiveh.r

!1.11 uprer rer,•.clies ( mountain fish, Fe to FrePk ). On the other hnrd'if

volt divide fresh in both ner-on ,,-- --nrr oh-•.-egiern

into thr.'e cate-ro-les ns frne=tnr fi-h. p—r1 /V

I lIrd—le)Ckerl fish ,7.-1-).-3coire ther: wilh the fixnA Sfocier in hsth ro-iors,

vou e 'e tr have nr id- th ,st the frosh wnter fish --ttern in north-

7Tne rrthel- reoentiv. Hoce the sn ,,‘cintion of thn

1”-rges,-17 tirno Coitus nrrth-eao;-. nrrq . sorth-

*:'tqrn Jr1- "" nTner,, Ti iF e.7nsistent with the

conclusion derived f2---H corr:,,-iso-, s of to te Cottue

iar. onicus with the srla:11-e!.-F t7ire Cot -Fus :1,, nonicus. The -F.solloi..,5rq three

findinr, s .3ead us to n er'v'e71V5lir that +.11 ,, 7 ,- -d-lork1nr and. the s ,- eciatior

e the larrre-e77 tyro Cottre .-1 -, nrnious'ocourred.

nrirlrv f1-2s.1- fish in mountain ! -1(7.7 the

enI?rement of the dirf --i-but rrn7-ei t»ey inhabit orl ,r..sth-w-este-n

Jannn, evce7t Mor000 steindnchneri; th e. s-eci.r;tion of the 1.,-n-•- e-tinle

Cottus • anoricus is râthç,r rv (Sne III ri part of V.)

5) Tukurroblus flunincus inhalst Jar....n which is borm'kd

the Itoi RAver-Shizuok Line. The;N!- seoir. .to exit ,)1-, ost evervhere in

the rivers of this area. Since they offly inabit rivrs in murtp.in nre., s

frnd are reuer found in :1., kes nors, their 0 --InrF. r-ont of the disl- ril-.:t'on

ranze nust he very slow. On the other heni, aecordinr, to Herre (1 927, Tlq13)

and Toriyama (1956) thc.-re nre fish 5n China, Forrosa, ard the Philinnine I • • ..

(Luzon Island) which wer- lend-loo!eed i and snecinted in the • ...t, . . direction fron RhinoP-obius brunneus, which is considorod ',c) be the D 4

form of Tk-rr.,-bius Corsir'. , rinc- the slow sneed of th' encestral

of the distrii-•tion r., 11F. e, I beieve that srnh a larl:e onU.r-c-ent

distribution rPnge nc1tdi.n onshu. Shikoku. endt7e-m-Ini ws estblished

by their independent land-look:n- and snerietien ceerent rivers.

f:-)11owincr, re.csons nre given for the fact thnt fiuminevs

inhnbit only south-western tho's.oeciation look nl-ce egrlier than

.44 • • 4. •

that of lart,e-egg tyre Cottus ipporlcus Ênci the clir:qte of the Ice Ace

drove them ("rt. of north-eastern ja.- , n: they cou:ld net ro\', rnrth rr.n7

the warmer reriod. efter the Ice Are hecAuse of tir slow snoed of

C enlerrement of distribution ranFr. This is interestir ,7 to note in com-eerison

with the fact that the migratory Rhincobius brunnous which is the anceFtrel

species of Tukegobius flumineus wet north PS far as Hokkido. The hvcothesis

that Tukugobius flumineus epeciated earlier than the ]are -egfe type Cottus

japonicus can be proved by comparison of their egF size nnd form with those

of Rhinofeohlus brunneus. (See IV and part cf V.)

4) As mentioned above, tho lend-locking and the specietion of the lnre-

égg , type Cottus ja -eonicus and TukuFobius flumineus occurred indenendentJy

in 'rivers in diUerent erens as well as those of other landlockinr

and eubseecies. The folleldn:- reasons ere considered for the fact , .- ,that, despite their independent 71leed-lockin7. ard seeciation -1 the end

products belong to the sr.e seeeies: (1) the eco]ofdcal conditions in

a rivers:, esPecially thoee inmeuntain areas, induced the chanecs of the

9 egg size and JiFe histrry of feeehit - re:nous mi.F:rat(;ry fish'in the same

directions vhen their land-leeMnz recurred: (2) n].1 the in-eortnrt marks

di etirereiFIljno. t'lose two lArd-locked srecies Ard their ancestrà1 srecies.

are made by the chAnFes of ee:-=, size a rd life hietrrv (3) the ecolor,icni

conditions in mountain rivnrs eo not differ very -lieh • ith districts

except i. •en -ter temperature. r.ieer (19hC) alFo leid s tes iee on the

similarity of the ecolog.ical conditions when he discussed the reasons why

the inderendent speciation from Andr(mous mivatory Oncorhrnchus nerka in

different districts ended with the creat 4 on of the s.1, me suhsnocies.•mhis

is in accord with the abcve mentioned idea in (5). This also can arial Y

to the sPecintions of any other r7E'cies or suhsncries iehoFe arcestnre .nre

Anc:'rerouF miereltor'y fe:sh. Concerning :his, the ec:1or:icp 1 cenditicns of

lakes differ with the district more than thorn of rivers. Reflectirre this

fct,tr 1;, euetrine Jen:-3-]ocked fiFh here strom - er tendency to steciete in c:iff:erent directions with leker, ce; with districts, than the fluvial z. • land-locked fish. Ree,.erding tho relationhip 14-tv- -cn n-oci,ilon r-r:- n of

prima3s and veritnbles, nrin-ry froshw , ter fish, • e used to

think that dispersions from iere the c: . :: n2]. srecintirns occurred were

ociP..tjon effected. This st-i . 1] holds true for the rdanted dispersion tyo s-,

and the ubiouitous soeciations. liourver the ,.?- are diffcrrnt :rrrm th is b-sic

relationship in th,qt the sneciltion -with -Indz.looMng occurs independently

. in diUerent rivers end the distribution r ,An-re formed by fish speciatinc in

the sac direction is the venr ne-a ristribrtion rare. Err'eciPlly in the

cases of the lare-e ty-e Cottus jc --:rnicus rd Tukuqobius flumineus,

simultaneous occurrences of snocl.qtinn ard -;.r.d-lockinc add different

peculiarlties which are not seer in other -ish whose lard-lockiru end

speciation are not simu]taneous. r'ho :1Dove rentioned rl.nt,ionhips are

illustrAted in IlluArstion '3. (See V.) - 39 -

Bibliographies

1 Aoyanagi,H., (General emarks on Japanese Islands-Produced Freshwater Fish), Tokyo,1957. 2 Dotsu,k., (The Ecology and Life History of Japan-produced Gobies), in the process of printing. 3 Ikeda,k.,(Morphological Changes of Gasterosteus in the ' process of Land-locking With Special Consideration of Back- . bone,Fin Rays,and Spines) Dozatsu-46:55h572,Uopurn.E.u. 1934. 4 Ikeda,K.,(The Sticleback iA the Kuril Islands), Nissei GeOgraphical Bulletin, 5:213-232, 1934. 5 Kamahara;n.,(Freshwater Fish in Kochi Prefecture),Kochi Univ. Academic Report,10:7-18, 1961. 6 Kawamura,T.,(Japanese• Freshwater Biology),Vol.1, Tokyo. 83Kobayashi,H.,(A Few FactS Found in Sticleback in Hokkaido) Hokkaido Gakugei Univ. BuMetin,2;8:43-52, 1957. - . 7 Nissei Geological Bulletin,22:69-74 9 Kobayashi,H.and Hirose,M.,(The Ecology of Moroco steindachneri in Hokkaido), Hokkaido Gakugei Univ. Bulletin,2;8:126-132, 1957. 10 Hata,M.i(The World After The Ice Age), Tokyo, 1954. - 11. Hat?.,M.and Ijiri,M.,(The Japanese Islands), Tokyo, 1958. 12 Miyaji,D.,(Moroco steindachneri in Saghalien), Vegetabl and • Anima1,3:1188-1199, 1955. •3 Mizuoka,S.,(Fish and Their Distribution in Ota River and Its Water System),Hiroshma Univ.Educational Bulletin,2;8:95-113, 1960. 14 Mizuno,N.,(A Study of Tukugobius'flumineus-1-1,Comparison of the MorphoIogies),Nissui Association Bulletin,27:307-312, 1961. 16 Norman,J.R.,(A History of Fish), Translated by Kurosawa,K., Tokyo, 15 Mizuno,N. and Niwa-,Y.,(Two Ecological Types in Cottus Japonicus and Cottus pollux Gunther),Dozatsu,70:267-275, 1961. • / Animal Journal) 17 Okada,Y.,(Studies on the Frb.shwater fish of Japan,11. SPecial Part), Mie Prefecture Univ. Fishery Bulletin,4:589-366, 1960. 18 Okada,Y.and MatsubaraiK ..,(Studies of Japan-produced Fish) Tokyo, 1938. . . . 19.0kada,Y.and Nakamura,J.,(Japanese Freeihwater Pish), Tokyo, 1958. 20 Ono,I., (The Life History of Oncorhynchus masou in Hokkaido) Salmon and Trout Report,5(2):15-26; 5(3):13-25, 1933. 21 Oshima,M.,(The Ecological Studies Of Trout in Oboke), Vegetable and Anima1,4:337-349, 1936. 22 Oshima,M.,(Studies on Japan-produced Salmo pluvius), Bird and Animal.Report,18:3-70, 1961'. 23. 0shima,M.,(The Studies of Vertebrata, •eish), Tokyo and Osaka. 24Sato,S.9.nd Kobayashi,Y.,(Freshwater Cottus japonicus in the .

' Southern Part of Hokkaido) e Hokkaido Univ. Fishery Report, 1:129-133, 1951. - 40 - 25 Jyo,G., Tomita,T., Ono,K., Miyaji,D., Mori,S., Kawanabe,K:, Mizuno,N., Kodama,K., and Tezuka,Y.,(Life of Fish in Rivers-11 The Group Structure and Life History of the Five Differet Kinds of Fish) 1-18, 1960. 26 Takagi,K.,(The Species-name Applied to Tukur.;obius numinous, a Subspecies of Japan-produced Goby), ( Dozatsu,71(9):295-300 1962. 'Animal Journal) 27 Tanaka,S., (The Distribution of Fish in Japanese Water), J. Fac. Sci. Imp. Univ. Tokyo,Sect.4,3:1-90, 1931; 28 Tanaka,S.,(The Present'Situation in the Syudies of Salmon and Trout),Salmon and Trout Report,8:1-3, 1936. 29 Tokuda,O.,( The Geography of the Jcpnese Animals)., Tokyo, 1941. 30 Tomoda,Y.,(Studies of FiSh in Biwa Lake-1. The Morphologies• of the Three Species Of Catfish and the Relation of the Morphologies, t6 Their Life Histories), Gyozatsu(Fish Journal),8:126-146, 1962. 31 Uchida,K.,(Korean Fish Report,Vol.1),Korean Fishery Bulletin , 6:1éi458, 1935. • 32 Watanabe,M.,(Studies of Fish of Cottus japonicus), Tokyo.

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158

- V11 31 3t it/ ifjp !z id, 1957. n*YiJnPV 1,eÉ • -4. BERG, L. S., 1934. Zoogeographical division s for freshwater fishes of the Pacific slope of Northern Asia. Proc. 5th Pac. Sci. Congr. Canada, 5: 3791-3793. -, 1948. Classification of fishes, both recent and fossils. Translated by K. F. LAGLER. Michigan. DARLINGTON, P. J., 1957. Zoogeography: The geographical distribution of animals. Wiley & Sons, New York. .1. i1tï (jet). • Fl ?ÉiTi512.. GüNntER, 1873. Ann. Mag. Nat. 1-list., 240. (OKADA, 1960 _t 1) ;JIM). * JonD.AN, D., 1907. The fish fauna of Japan, with observations on the geographical distribution of fishes. Science, (2): 545-567. HERRE, A., 1927. Gobies of the Phillippines and . the China Sea. NIonogr. Bur. Sci. Manila, 23: 1-232. . • -, 1933. On the genera Ctenogobius and Rhinogobius GILL, Tuhugobius 1-IenitE, and Drornbus JonDAN and SEAL. Science, (78): 265. • Ilunns, C. L., 1926. The structural consequences of modifications of the developmental rate . in fishes, considered in reference to certain'problems of evolution. Amer. Nat., 60: 57- 81. --, 1940. Speciation of fishes. Amer. Nat., 74: 198--211. • -, 1937. The Life-cycle and growth of lampreys. Pap. Michigan Acad. Sci., Arts et letters, (4): .3 1834 . itt..(1, go)PP.P4 fÉrc- e.c 5 eigte.; eft,

• . •••.

• • et, • . •

•

17 7 e I ez 9 05)t < ickte; 159

wee, 4 : 589-860. pu we,- 9.3 . erge f-te, 1938. J. . • eri.}-44, 1958 . FI:.0)«*5AL .41• i. lei • - 7Urial.fi, 1933. Jteiiireee • 5 (2): 15-26, 5(3): 13-25. 7z. £4, 1936. 71-0;3-.'.0)-z, *.:IgW.1Ctiffit':• ta • 0), 4 : 337-a49. 72. -, 1961. EL-4 j4 9 -Ir -r7.)0. fekletV, 18 3-70. -- ■ 1940 . 1.feieelik774., PA. 31'.:* • M,I5i . RICKER, W. E., 1938. “Residual" and kokanee salmon in Cultus Lake. J. Fish. Rel. Bd. Canada, 14(3): 193-218. -, 1940. On the origin of kokanee, a freshwater type of sockeye salmon. Trans. R. S. C. Sect. 5, (1940); 121-135. -, 1959. Additional observations concerning residual sockeye and kokanee (Oneorhynchus nerka). J. Fish. Res. Bd. Canada, 16: 897-902• • 4‘wele.1951. ec-Dt- -c • At21(&ittii, 1: 129 -133. r EDT, • lxilitam • ibrif-1.141-2. • • 11- • pueeea • *gfeife • .1).i.me. • 1960. jilopXoe.rillœ If• • 1-18, .enef*mn.- SVXRDSON, G., 1957. The coregonoid problem. VI. The palearctic species and their inte- ' grades. Inst. Freshw. Res. Drottningholrn, Rep., 38: 267-356. 2t . A*ffl ie, 1962. }3.-4-t'millip...14 0 ;It fie . wet 71(9) , 295 -300. 29. Fatpam, 1931. On the distribution of fishes in Japanese water. J..Fac. Sci. Imp. Univ. Tokyo, Sect. 4, 3: 1-90. -,1936. e*- • -e ferAO)Ne• e*- • -7efe, 8:1-3. era ere, 1941. El pritegeg . "ige. TOMIYAMA, I., 1936, Gobiidae of Japan. Jar). J. Zool., 7:37-112. 3b. ZjH , 1962. aziDees.eicorLifX - I. ubme 3mope-exopme,..7c-0).m- ()) A. Ata, 8 126-146. 1935 . MUi.tt/r1U.:, :TS 1 le. 011n*Mte, : 1-458. MC/WOW-A- 3t ete£2, 1958 . FI:4:-Cid/ eji rA• wyNE-EDwARDs, V. C., 1952. Freshwater vertebr ae of the arctic and sub-arctic. Bull. Fish. Res. Bd. Canada, (94):1-28.

è;

Distributions of Coitus japonicas OKADA (Cottidae) and Tukugobius flumineua MIZUNO (Gobiidae), with special references to their peculiarities in both the land-locking and the speciation from amphidromous ancestors.

Nobuhiko MIZUNO

(Biological Laboratory, Osaka Gakugei University)

if In the process of the evolution of the kokanee or land locked" subspecies of sockeye, Oncorhynchus nerka, RICKER (1940) considered the two stages: (a) the occurrence of 2 the lacustrine type offspring among the progeny of the anadromous stock, and (b) the modification of the progeny of such lacustrine type into the typical kokanee. He con- sidered the complex effects of sex and of rate of growth as a condition which had conduced to the former process, and that, for the latter stage, the occurrence.o. f small gene muta- dons and natural selection had played the important role. Furtherrriore, in spite of the independent origin of kokanee in many lakes in North America, Siberia and Japan, f.

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