I; A STUDY OF THE MACKERELS, CYBIIDS, AND TUNAS ^^/^y 2 2 1950 ^VOODS HOLE, M/i,i;s. SPECIAL SCIENTIFIC REPORT: FISHERIES No. 24 ■Ifl ' UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE A STUDY OF THE MACKERELS, CYBIIDS, AND TUNAS Marine Biologic.?.! L ^^f^y 2 3 1950 WOODS HOLE, ms. SPECIAL SCIENTIFIC REPORT: FISHERIES No. 24 UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE Explanatory Note The series embodies results of investigations, usually of restricted scope. Intended to aid or direot management or utilization practices and as guides for administrative or legislative action* It is issued in limited quantities for the official use of Federal, State or cooperating agencies and in processed form for economy and to avoid delay in publication* Hashington, D* C* Hay 1950 Tftilted States Department of the Interior Oscar L* Chapman, Secretary- Fish and Wildlife Service Albert M. Day, Director Special Scientific Report - Fisheries No. 24 A STDDY OF THE MACKEKELS, CYBIIDS, AND TONA.S By Eamakichi Kishinouye l/ Translated from the Japanese language by W* 6* Campen Pacific Oceanic Fishery Investigations CONTENTS Preface P*S« Introduction •••• • ^ Scombridae •••• ....•• 2 Cybiidae •• 3 •nmnnidae. ••• • ^ 1/ Frcm Suisan Gakkai Ho, Vol, 1, No. 1, pp. 1-24, May 1915. In the present taxonony the tunas and bonitos are included with the mackerels and cybiids in the family Scombridae, This is a little astonishing in view of the tendency toward more and more detailed classification, however, there are many in- conveniences in the study of these fishes and for this reason detailed investiga- tions have been naturally delayed. The fishes at present assigned to the Scombridae are for the most part widely distributed and exist in great numbers. They grow fast, are generally large in size, and their flesh is well-flavored. Consequently they are important economi- cally. The species are particularly numerous in Japan, and about 25*000,000 jean [1 kan « 8,27 lbs.] with a value of 13,000,000 yen are taken each year, showing that these are fishes which are worthy of a great deal of attention. This study was started in 1912 and was carried on at the University and the Fisheries Bureau. For aid in obtaining materials and reports thanks are due to the various prefectural fisheries research stations and to many of ny friends, espe- cially Hagatsugu Akiyama, Seiao Adachl, Torakichi Imano, Shoshi Okada, Naotaro Oda, Koji Ota, Elao Kono, Koichi Kamei, Rainosuke KubO, Tokujiro Koshida, Hijcozo aiimura, Hidezane Seno, Misuke Takahashi, T5zo Na^^ajima, the late Kotaro Maeda, Kichitaro lamada, and T?jiro ffakiya. I also wish to express ny thanks for the kindness of Dr. Rathbum, assistant curator of the American JSuseum of Natural History, t*o sent me specimens of Atlantic mackerels and bonitos. Dr. Jordan, who sent me mimeographed copies of papers, and Mr. Goby, the assistant chief of the Netherlands East Indies Bureau of Agriculture, who sent me specimens of mackerels and cybiids ftrom the South Seas. As a result of ny studies I have found that there are two species of macKerel, five species of cybiids, two species of Oriental bonito, five species of tuna, and four species of bonito, a total of ten genera and 18 species, which occur in Japanese waters, and that these may be suitably divided into three families, the Scombridae, Cybiidae, and Thunnidae. I have also found errors and omissions in past definitions of the relationships between these genera and species. The detailed results of ny study will be published in the Journal of the College of Agriculture. The oldest mention of these fishes -in our national literature is in Ekken Kaibara's Yamato Honao (5th year of Hoei, that is, 1708). He listed the saba. (1712) Ryoan Terajima in Kuroda in his Suizokushi recorded the saba (kisaba. hirasaba) . SBSaXA (vanagi sgwara, okisawara. shirouo. uke). shibi (kuroshibi, maguro. meiika. medaishibi. binQaga* kihata. mebachi). katsuo (mochigatsuo. su.iJgatsuo. sumadara. nzuwa. phibuwa. yokpwa), and so forth. In 1829 Cuvier in his Regne Animal established uftder "Les Scombres" the genera Scomber. Thvnnus. Orcynus. Auxia. Sarda. Cybium. Thvrsites. and Gemovles. This work marked a great advance in taxonomy, and among the species ftom the Far East which it recorded were the sawara. uahisawara. and tomboshibiC?). From the time of Linnaeus until Cuvier these fishes had all been included haphazardly in the genus S99ml^y, except that Lacepede had established the genus Scomberoaorus for one species of £aaa» There were, however, errors in his description, and since he placed all the other kinds of sawara in the same genus with the mackerel, it is believed that the adoption of this new genus was not opportune. In Tempo 2 (1331) Shusaku Take! In his Gvokan mentioned the saba. gawaira. maguro imBlSS,* ineUka. kihata. mebachl. fei,gnaaL?7 '^^ katsg^ (suHkatsuo. aodakateao, ashikagatauo. uzmragatauo, vokowa) . Later Nobutoshi Okada in his Nippon Dobutsu Sonokuroka, Tasaku Kltahara in Vol. 6 of the Suiaan Ch3aa HSkoku. Tsunenobu Pujlta in HioDon Si^-aan Dobuteugaka. and Jordan* Tanaka* and Snider in Vol. 33 of the Journal of the College of Science have given indexes of these fishes, but they do not agree on many points, and since their classifications are baaed mainly on the outtrord fora of the fish, there are maqy unsatisfactory points in their definitions both of genera and of species. Scomfaridae' (sabq-kq) The body is generally slender and flattened laterally. The dorsinl surface of the head is someidiat flattened. The caudal peduncle is thick and is round in cross- section with no keels at its center. The eye ordinarily has an adipose eyelid. The corselet is not clearly defined, and the scales on the pectoral region are cycloid Just like those on the rest of the body. There are many scales on the opercle, the posterior edge of irtilch is more or less indented. The interopercular bone is covered by the operculum so that it is almost invisible. The mouth is large and the tongue is small. The teeth are small and there is a single row in each Jaw. Teeth are also seen sometimes on the vomer and the palatines. Ibe fins are small and weak, and the rays are articulated both transversely and longitudinally. The first dorsal is slightly separated from the second dorsal. The skeleton is thin and weak. There are from 31 to 33 vertebrae. The neural spine of the first verte- bra is not separate from the centrum. The last vertebra is not fused to the hypural. There are numerous pyloric caeca; they all open directly into the intestine and do not branch. The fish of this family attain lengths of about one foot, and generally occur abundantly along the coast and in bays. The genus Scomber shows that this family is close to the Carangidae in that they have adipose eyelids, separate spines in front of the anal fin, and an indentation in the posterior edge of the operculum. On the other hand, through the genus Gramma torcynns. the family is shown to be close to the Cybiidae in lacking adipose eyelids and separate spines anterior to the anal and in having flattened teeth. There are three genera in this family, the interrelationships of which are shown below. Lateral line is single Body spindle-shaped, teeth present on vomer and palatines ... Genus Scomber Body flattened, no teeth on vomer and palatines, gill-rakers very long and numerous ... Genus Rastrelli^er Lateral line double Genus Gramma tor cynu a Sgosj^ laBSBiSliS (sabffi) D. 9 - 12, 12, 5. A. 1, 12 or 13, 5. Vert. U / 17 Gill-rakers 13 / 23 The body is slender and an air bladder is present. The back is blue-green with many crooked black lines. The species likes warm water and is very widely dis- tributed. It occurs in the Pacific and also, it is said, in the Atlantic. In Japan It is found from the west coast of HokkaidS on the north to the Izu Shichito on the south (the bones of this species have been recognised in the stomachs of fish taken -2- I In the Ogasawara Is.). It occurs as far south in the Pacific as Australia. The largest specimens are about 2 feet in length and weigh .400 aomiBO [3 pounds 5 ouncfioj, but there are said to be some in the Japan Sea which weigh 6 pounds 10 ounces. They first become sexually matiirc at a length of about lAi inches (a full three years old?), and their spawning season is in I&y and June. They grow rapidly and appear to be oyer 7.2 inches long at tlie end of their first year. They feed on ▼arlous pelagic organisms and also eat small fish. There are two varieties of this species. On^^ is called the hirasaba Qflat mackerel3 and the other is called the marusaba [round mackerel) or gomayiba [^sesame mackerel?]. The differences between these t'ro are not marked and there are specimens with all degrees of variation linking them. The hirasaba has nine spines in the first dorsal and twelve in the anal besides the separate ones. The body is flattened and its breadth is about equal to the length of the head. The markings on the back are long, crossing the lateral line, and there are no spots visible below the lateral line. The caudal fin is yellow- ish. These fish occur close to shore and do not form large schools. They are said to swim at rather deep levels. They are well- flavored. The marusaba has eleven or twelve spine e in the first dorsal and thirteen in the anal besides the separate spines. The body is slender and round in cross-sec= tioD. Its breadth is less than the head length. The markings of the back disappear near the lateral line, and there is a single row of spots along the middle line of the side of the body. Many gray spots are also visible on the belly. These fish are generally found in large schools off shore and are said to swim near the sur= face. Their flavor is not as good as that of the hirasaba. In the Atlantic there is another species besides this one which has no air bladder. Its flavor is said to be better than that of this species. Rastrelliger chrysozonus (agifurakiya) D. 10, 12, 6. A. 12, 5. Vert. 13 / 18. This is a fish about one foot in length which occurs around Anaml Oshlma. It is distributed from India to the South Seas. Cybildae (sawara-ka) The body is generally slender and flattened laterally. The dorsal surface of the head is somewhat rounded and convex. The caudal peduncle has a median keel which is covered with scales. The corselet is fairly distinct, but its scales are not of any special form. The part of the corselet which extends pcsteriorly follows the upper edge of the pectoral fin and then runs ventral to the lateral line. The scales are small and round, and are sometimes hidden under the akin. They are some- times lacking except on the corselet. The lateral line is undulating and sometimes has small branches. The mouth is broad, the posterior edge of the maxillary is round, the teeth are large, compressed, and cusrved. There are villlform teeth on the vomer and palatines, however, the hakatsuo j^Sarda orientalis] and the iaomaguro [(ivmno>ard-a Pttda^ have no vomerine teeth. The tongue is broad and large. The fins are generally small, particularly the ventrals. The first dorsal is low and long and its spines are weak. The articulated spines are only divided longitudinally, only the ventrals being articulated transversely. The first dorcal -3- 1b almost oontlnuouB ulth the eaeond* and its first spine is shorter and weaker than the foUpvlng ones. Except in the genas Sarda. the median keel of the caudal pedonole is covered with fine scales, and the cross- section of the peduncle is rou£^i3jr round. The pyloric caeca are dendriform. The skeleton is rather coarse and the skull is long, niere is no cartilage in the dorsal part of the skull, and ^e opening at the posterloventral end of the skull is snail and opens horizontally. Scales az«. usually visible on the operole, the dorsal edge of wlilch is convex. The number of vertebrae is very indeterminate, but most species have from 40 to 50. The greatest number is found in the kamasuaawara [Aoanthocybiumi . which has 6Up and the fewest in the isomaeuro |]Gymno sarda] . iriilch has 38. The ratio of pectoral and caudal vertebrae has not been determined. The last vertebra is fused to the hypural. The first vertebra is not fused to the orahium and its neural spine is separate. The flesh is almost colorless, but the upper layers of tissue along the median part of the sides are slightly reddish. The flavor is generally excellent. The fishes of this family sometimes reach Teiy large sises. Most of them swim near the surface in pelagic waters or close to the shore, and they are distributed between temperate and tropical waters. They form schools of varying sizes and feed voraciously on sardines, anchovies, decaptorids, Tfachurue laponlcus. and mackerel. They sometimes leap out of the water, and they are very clever at escaping through the meshes of nets. They often damage fishing gear with their sharp teeth. The color of the back varies between green and steel-blue, with a purplish cast in some cases, and the belly Is silvery white. Although there are some fish vriiich have longitudinal or transverse lines on the sides of the body, most of them have dark spots. Rarely individuals are found iriilch have no markings at all. The first dorsal is ordinarily blackish. This family approaches the broadblH swordfish in the genus Acanthocvbium. which has reticulated gill filaments and no gill-rakers, while the su.1ikatBuo nsoQus San^lf with its short thick body and scaleless keels, is closer to the Thunnidael The flattened sharp-toothed fishes of the genus Cvbium link the family to tee Scombrldae through the genus Qrawmatorcvnus. This family has four genera, the relationdiips of iriiioh are shown below. Body slender, teeth in both Jaws compressed and sharp, teeth on vomer Gill filaments connected in reticulated form ... Genus Acapthocvbium Gill filaments not reticulated ... Genus Cvbium Body short and thick, teeth in both Jaws compressed but roiuided on both sides, no teeth on vomer No teeth on the tongue, whole body covered with scales ... Genus S^qIA Teeth on tongue, no scales except on the corselet ... Genus Ovmnosatrda There are four species of the genus Cvbium in Japan (excluding Formosa), and only a single species in each of the other genera. The following shows the H- I relatione hips of the speoies of Cybium* Many transverse stripes present .». gybium multifasciatum (yolcojimazawara) Round spots present Spots in seven or eight rows, no teeth on tongue *.. Cybium niphonivnn (sawara) Spots in four or five rows, teeth on tongue, body broad .•• Cybium korsanim (hirasawara) — — — _^_^__^ Spots large and few, in two rows, pectoral fin round ••• Cybium ohinense (inusawara) — — — ———^ Acanthocybixim sara (icamasusawara) Called sawara in Miyataki, Kagoshima, and the Ogasawara Is., oktsawara in Kanagawa, tojinsawara in Chiba, and okamasu in Nagasaki. 6. 7. D. 26, 11, 9. A. 11, 9. Vert. 32 or 33 / 31 Gill-rakere 0. The body is slender and compressed. It is covered with small scales which are long and narrow. An air bladder is present. The back is indigo, and in young specimens there are about 30 dark transverse stripes. The fins are dusky. This fish lives close to the surface in warm clear waters and does not form schools. Since it is voracious and easily takes the bait, many are eaught on trolling lines* They grow to a length of 6 or 7 feet and a weight of about 83 pounds. Specimens with fairly ripe ovaries have been seen in the middle of June so the spawning season is probably around July or August. The flavor is excellent, better than that of the common Cybium niphonitmi, and in the Ogasawara Is. it is made into dried fish sticks. The species is distributed from Chiba, Kanagawa, Shimane, and Yanaguohi on the north to the Ogasawara Is,, the Ryukyus, and the Philippines. Cybium mul tif as o ia turn n.sp. ( yoko J Imas awara ) D. 17, 15, 9, A. 14, 9. Vert. 20 / 24, Gill-rakers 1 / 2, The body is slender and spindle-shaped, eoid is almost round in cross -section* The greatest depth is in the vicinity of the origin of the second dorsal. The teeth are short, trftsngolar, and compressed. There appear to be no teeth on the voner and palatines. The scales are small and -vorar tite whole body. The lateral line forms a large bend below the first dorsal* There is an air bladder and there are four bends in the intestine* The back is indigo, and there are about 60 stripes on the sides* The fins are black* A specimen of this rare species was obtained through information supplied by the head of the Tamaguchi Prefecture Fisheries gx** periment Station* The fish was taken in a yellowtail gillnet at Kawajiri in the middle of December^ 19U* The following is the report of the head of the Station, Mr* To£0 Nakajima, concerning this speoies* Some of these fish are taken from October to Jtamuary, but they are most abun- dant in Hovember* In Tamaguchi Prefecture they are taken in the ooastal waters of Abu and Otsu oounties, at lawajiri, Kiwato, Oshima, and ffl.t«u«hiiiia (the two last- named places are islands whioh lie off Hagimaohl) in yellowtail pound nets and gillnets* They appear not to form large schools and there are never more than two or three taken at a time* They are taken in depths of about 17 or 18 fathons, but we have heard of no case of their having been taken in water of lesser depths* They are taken only oeoasionally during the season mentioned above, and are never caught in very great n\xmbers. They usually weigh about 40 or 50 pounds, and very large or very small ones are never taken* The flesh is white, oily, and fimer tlian that of the connnon sawara. It ia very tasty and is prized by gourmets. This species probably occurs in other localities also, but we have had lo ports of it yet nor has there been any mention of it in the literature. It im to Acgnthocybium sarq in the shape of its teeth and the fewness of its giil-7«ter«« Cybiutn nJ^phoniua (sawara) Called sagoehl in Kjrusbu and Vlakayania. D. 19, 15, 9. A. 15-17, S. Vert. 22 / 28. Gill-rakers 3 / 9 or 10. The body is slender and compressed. The teeth are lanceolate, flat, and eurrsd inward; they are sharp on both sides. There are villiform teeth on tho voBer and palatines. The tongue is large and is without teeth. The scales are small and cover the head and the whole body. The lateral line ia undulating and slopes gradually from the posterior part of the first dorsal to a point below the second flnlet whence it runs roughly along the median line of the body. There is no air bladder. The back is dark indigo with a greenish lustre. There are numerous small spots arranged in seven or eight or more rows. The species is widely dis- tributed and occurs in Japan^ Korea, and Kwangtung. It is particularly abundant in the waters off central Japan, diminishing in numbers to the northward and southward. It lives in turbid coastal waters, stays near the bottom in the cold season, and comes to the surface in warm weather. It attains a length of about 3 feet and a weight of about 12. ^ pounds. Around May and June it comes into sounds and bays to spawn. The eggs are round and very large. The young fish are about 1.2 inches long in June, about 3.6 inches long in August, and grow to about one foot in length by the following Jatfuary. The juveniles have neither spots nor stripes. The fla- vor is good and the ovaries are salted and dried to make a product called karasumi. Cybium koreanum a. sp. (hirasawara) D. U, 18 - 21, 9. A. 1^ - 21, 8. Vert. 20 / 26. Gill-rakers 3 / 10, The body is broad with the greatest depth at a line connecting the origins of the second dorsal and the anal. The body appears to be almost aealeless. There are scales on the corselet, alon g the lateral line, and around the baaes of the fins, but they are hidden beneath the skin. The teeth resemble those of C. niohonium. but they are fewer and larger. There ar^ teeth on the tongue. The lateral line is un- dulating and follows in general the outline of the back. There is no air bladder; the intestine is long and is bent in several places. There are spots forming three or four longitudinal lines along the center of the sides of the body. The fins are blaek. The specimen was eolleotod by Mr. Tbjiro %kiya on the west coast of Korea in 1913. The fish attains a length of about 3 feet and a weight of about 15 pounds. Cvbium ohinense (innaawara) Called ha sawara in Kanagawa, hoteieawara in Akita, ttffh?.gqffWrfl or lMgM99M in Kanagawa, and j^ in Wakayama. D. 16, 15, 8. A. 16, 7. Vert. 18 / 22. Gill-rakera 2/9. The body is compressed and the head if large aiMl pointed. The teeth resemble those of G. niphoniuBft. There are teeth on the tongue. The lateral line turns sharply downward at the posterior end of the first dorsal and at a point anterior to the second dorsal it descends below the median line of the side of the body whenoe it follows an vindulating oourse to the keel. The scales are small and are found all over the body. There is an air bladder. The pectorals are large and their posterior edges are rounded. Large obscure spots are arranged in two rows along the center of the sides of the body. The back is dark blue -green and most of the fins are black. The fish attaint a length of 7 or 8 feet and a weight of 165 to 260 pounds. It is oily and the flavor is said to be inferior. It ranges north to Chiba Prefecture on the Pacific coast and to Akita Prefeotu]*e in the ,fepan Sea, while to the south it extends to the coasts of China and Formosa. It is taken only rarely. It feeds on sardines and oarangids. Sarda orientalis (snjikatsno) Called haga'^uo, ki tsunekatsuo, shimakatsuo, and sabakatsuo in Nagasaki, tggan in Kanagawa, and hSffan in Chiba. D. 19, 15, 7 or 8. A. 15, 5 or 6. Vert. 25 / 20. Gill-rakers 4/9. The body is short and thick, becoming somewhat longer proportionately in old fish. The teeth in both Jaws are compressed, rounded on both edges, and bent inward* They are uneven in siee. There is one row of teeth on the palatines, but none on the vomer, l^e scales are very small, except for those on the corselet, which are rather large. The lateral line is undulating, and runs from the neck at somewhat of a slant to the middle of the tail. There is no air bladder. The back is grayish indigo, and there are about six longitudinal stripes. Posterior to the second dor- sal there are short markings lying in between these stripes. The dorsal fins are black. The species likes warm waters and is particularly abundant around Ejnishu, however, it is widely distributed and is seen in seme nvsabers everywhere south of Hokkaido on both the Pacific and Japan Sea coasts. It swims near the surface in rather turbid coastal waters and does not form large schools. The largest specimens are around 3 feet long. In the TCkyo region fish with ripe ovaries are seen in the latter part of Jtme, but in KyushiT it appears that they spawn in the spring. They are said to gi-ow very rapidly. Juveniles about 9.6 inches long have about eleven odorless treoisverse stripes which cut across the stripes of the back leaving eleven or twelve dark-colored transverse bands. They are voracious and easily take artificial lures. The flesh is soft and of rather poor quality. They are taken mixed in with oarangids, mackerel, and skipjack. Sometimes they also come into nets which are used along the shore. Many iohthyologlsts consider this species to be identical with that found off Chile in South America, but the Chilean species has vert. 22 / 22 and gill-rakers 9/17 and is a completely different speoiee* Oymnosarda nuda (iscmagnro) D. 14, 13, 7. A, 12, 6. Vert. 19 / 19. Gill-raker« 2/10 The body is apindle-ehaped and appeara to be soaleless, however, there are scales on the corselet and lateral line and around the fins, but most of them are hidden under the skin and cannot be seen. Both Jaws have strong teeth whi oh some- what resemble those of «ie hagatsuo [S. orientalis ]# There are no teeth <» *n« vomer, but villif orm teetii can be seen developing on the paUtines and on the tongue. The lateral line roughly follows the outline of the back from !*• "**'^°f,. end to the last spine of the first dorsal whenoe it runs obliquely to a point ventrai to the first f inlet. The back is purplish-indigo and the fine are all black. howoTer, the tips of the second dorsal and the emal are white* This fish ooours along the ooaats of tropioal and subtropioal regions* It is fo\md in the Ogasavara Is*, the Isu Shiohito, and the Red Sea* It is not a numerous species* The fish ar« said to attain a length of several feet and a weight of several tens of kan [l kan ~ 8*27 pounds]* It prefers to feed on deoapterids, and the flesh is said to be soft and inferior in quality* Family Thunnidae (ehibi-ka) The body is generally short and thick and very slender at both ends* The dorsal surface of the head is flat, and the caudal peduncle is compressed dorsoven- trally with a soaleless keel on each side* The corselet is well developed and is oovei*ed by a membr«ine* The scales on this part of the body are much larger and thicker than the rest; ther« are many minute scales anterior to the base of the pectoral fin* Except in the genus Thunnus the posterior extension of the corselet follows roughly along the lateral line, and except for the same genus there are no scales aside from those on the corselet* The lateral line generally follows the dorsal outline of the body* The posterior end of the maxillary does not reach the middle of the eye, the teeth are small, conical in shape, and bend somewhat imrard* It is uncertain whether or not there are teeth on any bones other tdian those of the Jaws. The fins are well developed, especially in the genus Thunnus * The first dorsal is high and its spines are strong* The first spine is the longest* The rays of the fins aire also well developed and only those of the ventrals are articulated transversely* The caudal is stiff and forked* The pyloric caeca are remarkably well developed end consist of a mass of fine tubules at the tips of large dendriform tubes* The whole mass is covered with a membrane and is pale yellowish in color* It is very large* The skeleton is very delicate, the dorsal surface of the skull is roughly triangular, and there is oartilage between the f rentals, parietals, and oocipitals* The posterior ventral foremen of the skull opens obliquely or vertically* The operculum is scaleless and its dorsal edge is indented* The fi]*st vertebra is fused to the cranium (ex* cept in the genus Auxis)'^ and there is little variation in the number of vertebrae, which is 42 in the genus Katsuwonus and 39 in all the other genera* The haemal spines of the posterior thoracic vertebrae are long and their tips can be seen to be attached to the ribs* There aire blood vessels of a special type which run along the surface of both sides of the body from a point posterior to the pectoral fins* Groups of capilla- ries branch off from these blood vessels and enfold a laminar strip of tissue on each side of the spinal column* The muscle fascicles of the enfolded portion are small and soft, and the tissue is dark red in color because of the abundance of capillaries* This is what is commonly called the chiai* The fishes of this family sometimes attain tremendous sizes, but aside from the genus Thunnus most of them weigh about 8*27 lbs* They are plentiful in the open sea and are widely distributed in the tempertite and tropical zones* They form schools and feed on anchovies, sauries, sand lances, carangids, flying fish, squid, and planktonio crustaceans* The back is indigo in color and some of them have short oblique stripes on the sides of the body, black spots or stripes on the belly, or white spots and stripes on a gray background* 8 In th« genus Thtauma this family approaches the Cyblidae* It has four genera, the relationships of which are shoim below* First dorsal oontinuous with second dorsal, dorsal surface of skull dosed with cartilage with one pair of foramina Hhole body covered with scales, two subeutemeous lateral vessels on each side of the body olose'/ together, teetli on both Jaws and on the vomer, palatines, and mesopterygoidf vert* 18/21 »o» Genus Thuzinus (shibi-golcu) No scales except on corselet ^o subcutaneous vessels on each side of the body, teeth only on the iame, stripes on the belly, vert. 20 / 21 ••• Geniis Katsuwonus n»g« C^fttsuo-joku) One subcutaneous vessel on each side, teeth in both Jaws and on the Tomer and palatines, oblique or longitudinal markings on HtB back with ■pots generally on Hm anterior pectoral region, vert* 20 / 19 •*• Genus Enthynntts (yaito-toku) First dorsal not oontinuous with second dorsal, no~f oramen in the dorsal surface of the skull, no scales except on the corselet, one subcutaneous vessel on each side of the body, teeth in both Jaws only, oblique markings on the back, vert* 20 / 19 *** Genus Auxis (nejlka-y.oku) Genus Thunnus (shibl-goku) The first vertebra is very thin eoid is fused to the skull* Its neural spine is separate* Siere are lateral projections on several of the thoracic vertebrae. The fins are well developed, particularly in mature fish. The lateral line makes a peculiar curve above the peotoz*al fin* The back is dark Indigo with a greenish lustre posteriorly* The belly is gray with white spots and stripes* Bie fins are sometimes yellowish* Most of these fishes are large-sised and form big schools* They are timid* Five species are found in Japanese waters* Their relationships are as shown below* The suboutaneoiis lateral vessels pass between the fifth and sixth vertebrae PBctor«.l fin short not reaching second dorsal, no air bladder **• Th* orlentalis (kuroshlFl) Pectoral fin very long reaching to second or third dorsal finlet, an air bladder is present •** _^« alalunga? (tomboshibi) The subcutaneous lateral vessels pass between the seventh and eighth vertebrae Caudal vein does not connect directly with the Cuvierian duct, head and eye are large •** Th* mebachl n*sp* (mebaohi) Caudal vein connect* directly with the right Cuvierian duct, there are groups of oapillarles below the spinal column Pectorals long reaching to second dorsal *** Th, macropterus (kihata) Iteotoral does not reach second dors&l *** Th* rarus n*Bp. (koshinaga) ThunnitB orlentalis (kuroshibi) Called gotoshlbl in Mlyacakl. D* 12 - 16, 14, 8 or 9 A* 13 - 15, 7 or 8. Gill rakers 12 / 24. This spedes is distinguished by the shortness of the pectoral and caudal fins, the marked bend in the lateral line, the absenoo of an air bladder, and the dark red color of the flosh. the anterior edge of the operole is indented, and the haemal arches of the thoracic vertebrae are very narrow and are bent markedly up- ward and forward. There is a dense plexus of blood vessels on the surface of the liver. On the back the color ranges from black to grayish-indigo with an indigo or greenish lustre posteriorly. The belly is grayish with white stripes and lines of white spots alternating transversely. !Ihe first dorsal is gray and the second dorsal is gray with a yellowish tip. The dorsal finlets are yellow while the anal finlets and the anal fin are silvery white. The pectorals are black and the ventrals are gray. This species prefers comparatively cold waters. In the winter it appears in the coastal waters of Wakayama, Eobhi, and Uiyasaki prefectures, but in the sxamner it is abundant off Iwate, Aomori, Akita, and Hokkaido. It comes into depths of about 10 fathoms. It spawns in the sunmer and in the auttmin juvenile fish from 6 inches to one foot long are seen. These small fish are called kakinotane in Sana- gawa Prefecture, yokowa in western Honshu, and imoshibi in Miyazaki Prefecture. Young fish over one year old are called me.ji . The species is widely distributed and occurs in both the Japan Sea and the Pacific. These fish grow to weights of over 579 pounds, and once in a while one is taken which weif.hs 827 pounds. Bie flesh is firm and the flavor is excellent. It is the most important of the Japanese species of the genus Thunnus . Thunnua alalunga (tanboshibi) Called binnaga and bine ho in eastern Honshu and kantaro in Mie Prefecture. D. 14, 14, 8. A. 14, 8. Gill-rakers 9 / 18 or 19. This species can be easily distinguished by its extraordinarily long pectorals. The body is small and comparatively slender, but the tail is short. There is an air bladder which is very thin-walled, and which has a round simple anterior tip. The haemal spines of the thoracic vertebrae are bent markedly forward and upward. There is a dense plexus of blood vessels on the surface of the liver which resembles that of the kuroahibi [Th. orientalis]. The vertebral column is slender. The coloration of the back ranges from black to grayish indigo with a greenish lustre posteriorly. The belly is silvery. In juvenile specimens there are ir- regular stripes ruiming longitudinally on the posterior part of the belly. The edge of the first dorsal is black, the pectorals are blaok, the second dorsal and the ventrals are gray, and the anal is almost oolorless. The dorsal finlets are gray with a yellowish tinge, and the edges of the ventral finlets are gray* During the winter these fish are taken in the vicinity of Wakayama Prefecture. They gradually move northeastward and reach the waters off Iwate and Aomori around July. They follow the kuroshibi and precede the skipjack. They swim in schools and do not come Into shallow waters. The northera and southern limits of their dis- tribution are not clearly known, and they have never been taken in the Japan Sea and probably do not occur there. Host of those which are taken weigh from 26 to 34 pounds and individuals over 50 pounds in weight are rarely taken. The flesh is pale and soft and of inferior flavor for which reason there has been no particular fishery for this species in the past* 10 Thunnus mebaohi n.sp. (mebaohl) Called mebaohl or baohl in eastern Honshu^ meppaohi and dairumashibi in Mie, and hirashibi or mebuto in Miyageiki • D. 14 or 15, 13, 9. A. 13, 9; Gill-rakers 8 - 10 / 18 or 19. The body is broad and the head and eye are large while the tail is oompara- tively short and slender* The air bladder is large and its anterior tip is bifur- cated. The haemal spines of the thoracic vertebrae are not markedly bent forward* The foramen of the haemal aroh is broad* The interopercular bone is triangular and long posteriorly* The pectorals are long, sometimes extending past the anus in Juvenile specimens* The coloration of the back ranges from black to grayish indigo, and the belly is gray or silvery* The dorsal fins are gray with a yellow tinge, euid the finlets are yellowish with gray edges* The pectorals are black, sometimes with yellowish tips* The ventrals are also gray with a yellowish oast* The anal is white with a yellowish tip, and the eoial f inlets are similar to the dorsal ones* Sometimes one sees on Juvenile specimens colorless stripes and rows of spots on a gray background in the region of the anus, but these markings cannot be seen on mature fish* This species oocurs south of about 36^, preferring rather warn waters* It is found in the Ryukyus and Formosa* It is also said to occur in the Japan Sea, but this is very doubtful* It •wins at deeper levels than the other thtmnlds and does not come in to shallow waters* The flesh is pale and soft and the flavor is inferior, particularly in young fish* Thunnus maoropterus (kihata) Called kinhire in Mlyatakl, hashibi In Kyushu, itoshibi in Mie and Hiyasakl, hatsu and hOmpatsu in Ehime, ajid hirenagia or gesunaga in ShTsuoka* D* 13, 14, 9. A. 14 or 15, 8 or 9. Gill-rakers 9 / 21. Head and eye small, tail long* It is easily distinguished by the exti*«mely long second dorsal and anal, which are bright yellow* fhe air bladdar is large €md its anterior edge is bifurcated* The foramen of the haemal arch is broad and is enveloped by bundles of oapillairLes originating from the caudal vein* The coloration resembles that of the mebaohl [Th* mebaohi], but is brighter. The tips of the second dorsal and the anal are irtiits, and the belly resembles that of fk, orientalis in having alternate white stripes and rows of white spots. There are two varieties, one having the second dorsal and the anal developed to a great length so that they reaoh to the oaudal, and the other lacking this de- velopment* The former is oommonly called gesunaga in eastern Honshu and oitoshibi in western Honshu. — ^— — This speoies prefers warm waters and is widely distributed. It ooours in the Ryulcyus and at Formosa, and is said to appear in the South Pacifio and the Indian Ooean* In Japan it is most abundant in the sunaer and ocoun also in the Japan Sea. It remges north to Akita IVefeotur« and oomes in close to the shore in the suanar* In the KyuslnT region Juveniles about 6 inohes long are seen in the suomer. These are called pinkirl in Miyasaki Prefecture. Fish about one foot long are taken 11 Mixed with skipjack, and in eastern Honshu they are called kitne.11. The flesh is pink and firm, and the flavor is very fine. Thunnus raras'n.cp. (koshinaeMi) D. 13, U, 9. A. U, 8. Gill-rakers 6/17. Head and eye small, snout short, tail long, body broad. There is no air blad