Juvenile Euthynnus lineatus and Auxis tbazard from the Pacific Ocean off Central America MILNER B. SCHAEFER AND JOHN C. MARR1

IN A PREVIOUS PAPER (Schaefer and Marr, in gonads in a very advanced stage of maturity. press), juvenile stages of two commercially A female with running-ripe eggs was taken on important tunas, N eothunnus macropterus a trolled feather jig off Quepos Point; Costa (Temminck and Schlegel) and Katsuwonus Rica, on April 4. A ripe male was taken in a pelamis (Linnaeus) were described. They purse seine haul off Cape Blanco, Costa Rica, were taken, with dip nets at night, under on April 29. It is thus apparent that this species flood lights, in the oceanic waters of the . spawns in Central American waters during the Pacific off Costa Rica and northern Panama. early spring. The capture of juveniles further At some of the same stations where these confirms this. were taken, and at others, juveniles of two Juveniles were taken at the following sta­ other species of scombroid fishes which have tions on die dates indicated: 08° 20' N., 84° been identified as Euthynnus lineatus Kis­ 10' W., March 18, 1947; 8 specimens, 48 to hinouye, the black skipjack, and Auxis thaz­ 86 mm. total length. 09° 20' N., 85° 20' W., ard (Lacepede) , the frigate mackerel, were March 19, 1947; 10 specimens, 29 to 56 mm. captured by the same means. Neither of these total length. 09° 10' N., 85° 20' W., March is utilized by the American commercial fish­ 20, 1947; 1 specimen, 61 mm. total length. ery in the Pacific. The black skipjack of the (All total lengths in this paper are from tip Asiatic side of the Pacific, E. yaito Kishinouye, of snout to tip of shortest median caudal ray.) however, is of considerable commercial im­ In Figures 1 and 2 representative specimens portancero the Japanese fishery and it may be of these juveniles are depicted. They are rela­ expected that E. lineatus will eventually be tively less deep bodied than the juveniles of similarly exploited. Commercial catches of Neothunnus of the same sizes, being similar in frigate mackerel in the middle Atlantic states this regard to Katsuwonus, from which, how­ averaged slightly over 100 tons in 1942-44 ever,they may easily be distinguished by the (Fiedler, 1945; "Anderson and Power, 1946, pigmentation of the first dorsal fin. The entire 1947). first dorsal is heavily pigmented in EuthynnuJ of all sizes collected, while in Katsuwonus, up Euthynnus Iineatus Kishinouye 1920 to 44 mm. at least, there is only a light pig­ mentation of the anterior margin and of the Adults of this species are occasionally cap­ distal edge of the fin. tured in Central American waters incidentally The second dorsal fin remains completely to the tuna fishery. Four specimens were unpigmented in fish up to about 45 mm. total examined by us in the early spring of 1947. length, at which size the fin begins to show Two of these were captured in a bait-net in some pigment at the bases of the rays. In our the Gulf of Nicoya, Costa Rica, on February largest specimen, 86 mm. total length, the 22; these fish, one male and one female, had second dorsal is fairly dark about half way to

1 South Pacific Investigations, U. S. Fish and W ild· the tips of the rays, the distal half remaining life Service. Published by permission of the Director unpigmented. The pigmentation of the head of the U. S. Fish and Wildlife Service. Manuscript received March 25, 1948. and body is similar to that of Katsuwonus at (262 J Juvenile Turias--:-SCHAEFER "and "MARR " " 263

FIG. 1. Photograph of juvenile Euthynnus lineatus Kishinouye.

the smailer sizes, but the snout and anterior part gradually to a white belly. In some specimens of the head is rather more extensively pig­ of about 45 mm. to 60 mm. the pigment on the mented in the smaller Euthynnus of these col­ upper sides is concentrated to form 8 or 9 lections than in either Katsuwonus or Neo­ extremely faint vertical bars. In the 86 mm. thutlnuS of similar sizes. On the smaller of our specimen these are not visible. The peritoneum specimens of EuthyntlUS the lateral pigmentation bears numerous large dark spots dorsally which does not extend far below the mid-line, but are visible through the body wall in small there is a conspicuous series of black spots specimens. The caudal fin begins to exhibit along the bases of the anal fin and following some pigmentation in fishes of about 50 mm. finlets. As the fish increase in size the pigmen­ total length. tation extends further down the sides, par­ In addition to the examination of specimens ticularly posteriorly, until at about 45 mm. the preserved in alcohol, two specimens of 54 mm. pigmentation at the level "of the anal fin ex­ and 56 mm. were prepared for study of bony tends the entire depth of the fish, although parts by staining with alizarin and clearing, shading off ventrally. By the time the fish has after the method of Hollister (1934). The "reached 55 mm. the entire head is rather dark, pectoral fin in the two stained specimens 'has the body is almost black dorsally, shading off 29 rays and 27 rays, respectively. These rays PACIFIC 'SCIENCE, Vol. II, October, 1948

FIG. 2. Juvenile Buthynnus lineatus; photographed against a white background to illustrate pigmentation of . dorsal fin. cannot be counted accurately in unstained in­ and anal are difficult to count except in stained dividuals because of the small size of the most material because of the shortness of the first one inferior rays. The dorsal fin has 15 spines in or two rays. The finlers are connected to each six specimens examined and 14 in a seventh, other and to the fin by a thin .membrane which the first or second anterior spines, which are extends less and less far toward the tips of the of nearly equal length, being the longest and finlets as the fish grow until in the largest speci­ the remaining spines decreasing in length rapid­ men of 86 mm. it is only a vestige between the ly and successively. The first dorsal reaches bases of the finlets. almost to the insertion of the second. The sec­ The gill rakers of our smallest specimens are ond dorsal fin rays, counted in 5 specimens, are very tiny projections on the gill arches and 12 in number, and there are in each case8 dorsal are difficult to count accurately. On such a finlets, The anal fin has 11 or 12 rays, and there specimen, of 32 rom. total length, they were are 7 anal finlers, The rays of the second dorsal counted on the first gill arch as 7 + 20. As the Juvenile Tunas-SCHAEFER and MAIm 265

fish increase in size the gill rakers not only in­ extended posteriorly rhree-fourrhs ormore of crease rapidly in length, but their number ap­ the length of the body cavity. parently increases. Counts of rakers on the first That these specimens belong to either the arch on specimens of various sizes are as fol­ genus Ettthynnus or Katsuwonus is iridiCated lows: by the morphology of the vertebral column, 48mm. 8+25 The well-developed :inferior foramina on some 52mm. 9 + 25 precaudal as well as caudal vertebrae, forming 61mm. 10 + 26 86mm. 11 +27 with the very large haemal arches the so-called "trellis," ischaracrerisric of these genera (Starks, The vertebrae, counting the urostyle, are 1910; Kishinouye, 1923). 19 + 18 in one stained specimen and 20 + 17 These specimens have several characters in the other. They bear large inferior foramina agreeing with Ettthynnus but not Katsuwonus. on the last three or four precaudal vertebrae The very great elongation of the right lobe of and on the first nine or ten caudal vertebrae. the liver is definitive. In Katsuwonus, both in The haemal canal is very large, being broader adults described by Kishinouye 0923: 363, than the body of the vertebrae beneath the 450, and 453, Fig. N) and by Godsil and precaudal and anterior caudal vertebrae. The Byers (1944: 11, 30), and in juvenilesdescribed lateral processes of the posterior caudal ver­ by Schaefer and Marr (in press), die right tebrae are well developed in both specimens; lobe, although much larger than the other two, there are no lateral processes on the anterior is not nearly as large as that of these specimens, precaudal vertebrae. The first complete haemal which corresponds to Kishinouye's description arch was found to be on the 15th vertebra by of the liver of Ettthynntts. The first .closed dissection of the 56 mm. specimen. haemal arch of Katsuwonus occurs on the 12t4 Specimens of all sizes in our collection have vertebra according to both .Kishinouye ana about 20 to 30 conical, inwardly curved teeth Godsil and Byers, whereas Kishinouye states on each side of each jaw. The palatines each that Ettthynnus has the first complete haemal bear a row of eight to ten rather large conical arch further back, on the 16th vertebra. The teeth. The vomer bears four or five rather low. vertebral ' count of our specimens is also small teeth which may be easily overlooked. definitive, although this was a matter of 'some Our very smallest specimens, of about 30 concern at first because it does not agree with mm., have visible the remnants of three spines the literature. Kishinouye .( 1923: 338, 452) at the lower posterior angle of the preopercle. found that Ettthynntts has 39 'vertebrae count­ In larger specimens the growth of the bone ing the urostyle, probably based on E. yaito has completely obliterated these. Smaller speci­ alone. He described E. lineatus from a single mens than those in our collection may be pre­ specimen from Manzanillo, Mexico, but . prob ~ sumed, by analogy with Neothunnus, to have ably did not dissect the fish to count the verte­ more prominent and perhaps more numerous brae. (Kishinouye : in the Suisan Gakkwai Ho, preopercular spines. III, 113, 1920. We have been unable to The intestine of these specimens, as is char­ examine this reference and our information is acteristic of the Katsuwonidae, is relatively from Kishinouye, 1923.) He differentiates this straight and is not folded. It runs back along species from E. yaito on the coloration and the the right inferior portion of the stomach. The relative size of the head. In his discussions he liver is in three lobes, the right lobe being very assumes all species of Euthynnus to have 39 much longer than the other two. In seven vertebrae. This matter was cleared up through specimens examined, the right lobe of the liver the kind cooperation of C. R. Clothier of the 266 PACIFIC SCIENCE, Vol. II, October, 1948

California State Fisheries Laboratory, who has 10.1 rom. in length, which he referred to examined the skeletonsof four adults identified Euthynl1us alliteratus (Raf.). He differentiated from Kishinouye's description as E. .lineatus. these specimens from those of Auxis thazard He has sent us the following. data regarding only with great difficulty, on the basis of the these .specimens, the first three of which were first dorsal rays. The identification seems doubt­ from tuna-clipper landings from unknown ful, but, since none of our specimens 'of Eu­ points somewhere south of the Mexican border, thynnus areas small as Ehrenbaum's, we can­ and,the fourth of which was captured off Espi­ not verify it. ritu Santu Island in the Gulf of California: Auxis thazard (Lacepede) 1802 Specimen number...... 1 2 3 4 Vertebra bearing Isr haemal As is the case with many of the scombroids, arch...... - 16 15 16 there is some doubt as to whether there is a Total vertebrae (including single cosmopolitan speciesof Auxis or whether urostyle) ...... 37 39 37 37 Abdominal vertebrae.....',...... - 21 19 20 different species occur in different parts of the Caudal vertebrae...... - 18 18 17 world. The solution of this problem is be­ yond the scope of this paper and our juveniles , Three of these four specimens have 37 are referred to Auxis tbazard. No adult speci­ vertebrae, corresponding with our juveniles, mens were examined by us during this voyage, and disagreeing with Kishinouye. Mr. Clothier but the capture of juveniles indicates that this has also advised us that, in addition, H. C. species spawns in Central American Pacific Godsil of the same laboratory, has examined waters during the early spring. Juveniles were two specimens from near Magdalena Bay each taken at the following stations on the dates of, which had 37 vertebrae. It appears that E. indicated: 08° 20' N., 84° 10' W.; March 18, lineatus has 37 vertebrae as a rule. The verte­ 1947; 2 specimens, 67 and68 mrn, total length. brae counts of our juveniles agree, then, with 09° 43' N., 85° 54' W.; March 19, 1947; 52 those of adult E. lineatus identified from other specimens, 21 to 53 mm. total length. 08° 7' characters. All other characters examined 30" N., 83° 8' 30" W.; May 7, 1947; 3 speci­ agree well enough with Kishinouye's descrip­ mens, 23 to 41 mm. total length. 09° 43' N., tions, and it was therefore concluded that these 85° 54' W.; May 17, 1947; 1 specimen,42 mm. were juveniles of E. lineatus. total length. Through the courtesy of Dr. J. T. .There are few references to juvenile Euthyn­ Nichols, we were also able to examine 5 speci­ nus in the literature. Kishinouye's (1923: 388) mens, 22 to 31 mm. in total length, taken smallest specimens, 13 em. in length, from the under a light at night from the "Askoy" at Asiatic side of the Pacific, were larger than any 04°01' N., 80° 26' W. on March 24, 1941. of ours. He described' them as follows: "They Nichols and Murphy (1944 : 241) suggest that are very slender and have eight or more trans­ these may be young Euthynnus, but they are verse bands on the side. These bands are nearly undoubtedly Auxis. vertical and fade toward the ventral median line. When they grow to a total length of 19 em, Representative specimens of juvenile' A. the body becomes very broad, the thoracic spots thazard are shown in Figures 3 and 4. In the appear, the bands gradually disappear from the smaller specimens the prominent areas of pig­ ventral part and the dorsal part of the bands mentation are on the upper and lower jaws, becomes oblique:' above the snout, around the postero-ventral Ehrenbaum (1924) found among the Medi­ margin of the orbit, on the upper operculum, terranean collections of the Danish Oceano­ between the orbits, along the mid-line of the graphical Expeditions six young tunas, 5.9 to body, along the bases of the dorsal and anal fins Juvenile Tunas-5cHAEFER and MARR 267

FIG. 3. Photograph of juvenile At/xis thaza,d (Lacepede) , including the finlets, and around the posterior body is uniformly dark. This dark area extends end of the urostyle, Large chromatophores in below the mid-line on the caudal peduncle. the peritoneum show through the body . wall . The chromatophores in the peritoneum are no along the upper half of the body cavity. None longer visible through the thickened body wall, of the fins or finlets bears pigment spots, with and the ventral surface is unpigmented. Even the exception of the first dorsal. The first dor­ in our largest specimens none of the fins is sal bears a few scattered chromatophores, large­ heavily pigmented; the caudal is more pig­ ly distributed along the spines. However, the mented than the others. first dorsal in general appearance is virtually Juvenile Auxis are rounder in cross section colorless, as may be seen in Figure 4, especially than Ettthynnus, being relatively less com­ as contrasted with Euthynnus or Neothunnus. pressed laterally. The head length and length With increasing size the local areas of pigmen­ of the caudal region in Auxis are less in com­ tation expand. In our largest specimens the parison to the total length than is the case in head is well pigmented. The dorsal half of the Euthynnus. The maxillary in Auxis generally 268 PACIFIC SCIENCE, Vol. II, October, 1948

FIG. 4. Ju venile Auxis thazard photographed against a white background, illustrating lack of pigmentation of fins. extends to a point between the anterior margin mens, .that seven more spines are present in of the iris and the vertical bisector of the iris, smaller individuals. Similarly, a figure of a 17.5 whereas in Euthynntts it generally extends to a mm, specimen of A. thazard from the Medi­ point between the vertical bisector of the iris terranean (deBuen, 1932: Fig. 27) shows a and the posterior margin of the iris. In the total of nine preopercular spines. The lateral smaller specimens the lower jaw is shorter than keel along the caudal peduncle starts to develop the upper, but the jaws become equal at about at about 40 mID. total length. 50 mID. total length. The smallest specimens The large dorsal interspace characteristic of have three spines at the angle of the preopercle, Auxis actually contains small spines or rays. but these are gradually grown over and dis­ These are usually subcutaneous. Even in our appear at about 35 to 40 mm. total length. smallest specimens they are not visible unless There are indications, on alizarin-stained speci- the fish is cleared and stained or unless the Juvenile Tunas--5CHAEFER and MARR 269 specimen is shrunken from the preservative so the angle of the arch increase in length and that the spines project above the dorsal profile. new rakers are added distally on each arm. In adult Auxis from Culion, Philippine Islands, The full complement of rakers is apparently examined through courtesy of Dr. G. S. Myers attained at about 50 mm. total length, as of the Stanford University Natural History judged by the following counts on specimens Museum, the interneural supports of the sup­ of various sizes: pressed rays are well developed; the rays them­ 21 mm. 4 + 18 selves are vestigial, however, and can be found 24 mm. 5 + 21 only by staining and dissection. Fin ray counts 27 mm. 6 + 24 on our stained juvenile specimens are as fol­ 32 mm. 9 + .26 lows: 42 mm. 9 30 mm. mm. mm. + 46 mm. 10 + 31 Total length of specimen...... 25 31 46 First dorsaL ._ 11 11 11 52 mm. 12 + 36 Dorsal interspace ._.______6 7 8 54 mm. 11 + 35 Second dorsaL.. .._. 12 11 11 68 mm. 11 + 31 Dorsal finlers__...__..__. 8 8 8 AnaL..._.... ._... 14 13 13 Gill raker counts on the adult specimens re­ Anal finlers . .__.. . 7 7 7 ferred to above are 12 + 34 and 11 + 32. Ventral ..__._.. 7 7 7 Kishinouye (1923: 462-3) gives 9 30 as the Peceoral..., .. .__.. . 22 23 25 + gill raker count for A. hira and 10 + 36 as the Other, unstained, specimens also have eight count for A. maru Kishinouye. Possible varia­ dorsal finlers and seven anal finlers, In the tion in these counts is not mentioned. He does smaller specimens the finlets are joined by a not list A. thazard, but A. maru is probably membrane that extends completely or nearly a synonym of A. thazard, as he tentatively sug­ to their distal ends. With increasing size this gests in his synonymy. membrane becomes less prominent until in our The nasal rosette is visible only in cleared longest specimens it is wanting or exists only specimens. between the bases of the finlets. The vertebrae were counted as 20 + 19 (in­ _ In all our specimens, each side of the upper cluding the urostyle) in three cleared and jaw bears about 20 small, conical teeth; each stained specimens. This agrees with Kishinouye side of the lower jaw about 25 small, conical (1923: 452 ) and Frade and deBuen (1932: teeth; each palatine 6 or 7 teeth; and the 70), but disagrees with Starks (1910: 97), vomer none. The vomer and palatines are ex­ who counted 22 15 vertebrae. On a speci­ posed. Starks (1910: 97), with reference to + men 46 mm. total length, small ventral fora­ Auxis thazard, and Kishinouye (1923: 460), with reference to the genus Auxis, state that mina are present on the 9th to 15th caudal there are no palatine teeth, and this is apparent­ vertebrae. On smaller specimens of 25 and 31 ly true in the adults. In the two adults from mm. total length, these foramina are not dis­ Culion, Philippine Islands, the vomer and pala­ cernible, if present. In our specimens, the tines are toothless and are not exposed. These pedicles (of Starks = epihaemal process of specimens are probably Auxis hira Kishinouye. Kishinouye) of the caudal vertebrae, bearing The gill rakers on the most anterior gill arch the closed haemal arches, are extremely short of our smallest specimens are very tiny pro­ or non-existent. In a specimen of 25 mm. total jections and are difficult to count. They are first length, the haemal arches of the caudal ver­ apparent near the angle of the arch. With an tebrae are long, wide, and elliptical. In a speci­ increase in the size of the fish, the rakers near men of 46 mm. total length, the haemal arch 270 PACIFIC ,SCIENCE, Vol. II, October, 1948 is still long, but less wide. In a specimen of The vertebral count, the great length of the 72 mm. total length, the :haemal arch is still right lobe of the liver, the presence of a caudal long, but even less wide. In fact, the pedicle keel, and the absence of an air bladder indicate is divided and contains a large part of the that these' juvenile scombroids belong to the haemal arch. In the two smaller specimens, family Katsuwonidae. The large interspace the haemal arch is certainly closed on the 18th between the dorsal fins and the low ray count abdominal vertebra and is probably closed on of the first dorsal, as well as the absence of the the 17th vertebia; it is definitely open on the elaborate "trellis" of the vertebrae, indicate 16th vertebra. In the 72 mm. specimen, the that they are Auxis, rather than Euthynnus or haemal arch is open on the 17th vertebra and KatJUwonus. In the larger specimens, gill raker closed on the 18th. Kishinouye (1923 : 339) and fin ray counts will also serve to separate states that the first closed haemal arch of Auxis from the other genera. Positive specific Auxis occurs on the 1st caudal vertebrae allocation must await examination of adult (= 21st). In an adult specimen examined specimens from the area. through the courtesy of Dr. G. S. Myers, the A specimen of A. thazard, 17.5 mm. long, first ,closed haemal arch is on the first caudal from the Mediterranean, was described and fig­ vertebra. This specimen is from Wakanoura, ured by deBuen (1932 : 36-38). This is some­ Japan, and is referred to AuxiJ hira. We have what smaller than our smallest specimen and the been unable to examine any adult Auxis from differences between them, such as differences the eastern Pacific in order to attempt to re­ in numbers of preopercular spines, etc., are solve this apparent discrepancy. C. R. Clothier probably due to the differences in size; Sparta has informed us that one specimen from the (1933 : 16) mentions that specimens of Auxis vicinity of Sebastian Viscaino Bay and two bisus Bonaparte (= A. thazard Lacepede) about from the vicinity of Espiritu Santu Island, all 1 em. in length have been collected under a identified as A. thazard, have a total of 39 verte­ light at night in the Straits of Messina. Ehren­ brae with the first haemal arch on the 21st baum (1924: 33-38) reported on 132 juvenile vertebra. It seems unlikely that haemal arches A. thazard from the Mediterranean collections that are closed would, with growth, become of the Danish Oceanographical Expeditions. open. Our specimens may, therefore, be juve­ His largest specimen was 12 mm. in length, or niles of an undescribed species. It is not about 9 mm. shorter than our smallest specimen. unlikely that the sides of the pedicle fuse with Again, differenc~s between his descriptions and an increase in size of thefish so that the haemal our specimens may probably be attributed to arch becomesgreatly reduced in size. The possi­ differences in size. These specimens were ap­ bility exists, however, that it may remain parently taken in May, July, August, and Sep­ divided in this form. tember. He states that Sanzo found ripe ovar­ The liver is divided into three lobes. The ies in June and July. Sella (1924) describes right lobe is almost as long as the visceral Mediterranean specimens of A. bisus Bonaparte cavity and bears a prominent hepatic vein on (= A . thazard Lacepede) ranging from 3 to 10 its outer surface; the other two lobes are small. mm. These are much smaller than our speci­ The stomach is long and lies above the rest of mens. He states that juveniles up to 10 to 15 the viscera. The caecal mass is considerably mm. in length are found from the second half shorter than the stomach. The intestine is rela­ of June to September 20. He also mentions tively short, straight, and not folded. It runs that before a length of 12 to 15 mm. is at­ posteriorly along the right inferior side of the tained, about six rays are formed in the mem­ stomach. There is no air bladder. brane connecting the first and second dorsal Juvenile Tunas-5CHABPBR and MARR 271

fins and that these rays subsequently become GoDSIL, H. C, and R. D. BYERS. 1944. A sys­ contained in the median furrow so that they tematic study of the Pacific tunas. Calif. Dio. are no longer visible. This is in accord with Fish and Game, Fish Bul. 60, 131 p., 76 fig. our findings. The dates of our collections indi­ HOLLISTER, GLORIA. 1934. Cleaning and dye­ cate the possibility of a somewhat e~rlier spawn­ ing fish for bone study. Zoologies 12 (10): 89-101. ing season for Auxis off the Pacific Coast of Central America. KISHINOUYE, KAMAKICHI. 1923. Contribu­ tions to the comparative study of the so-called We have been unable to examine papers by scombroid fishes. Tokyo Imp. Univ., Col. Agr. Sanzo (1909, 1910) which apparently contain Jour. 8 (3): 293-475, 22 pl, information on larval and juvenile Auxis. NICHOLS, ]. T., and R. C. MURPHY. 1944. A collection of fishes from the Panama Bight, Pacific Ocean. Amer. Mus. Nat. Hist., Bul. REFERENCES 83: (art. 4): 217-260,4 pl, ANDERSON, A. W., and E. A. POWER. 1946. SANZO, 1. 1909. Uova e larve di Auxis bisus. Fishery statistics of the United States:1942, Monitore Zool. Ital. 20: 79-80. U. S. Fish and Wildlife Seru., Stat. Dig. 11: --- 1910. Uova e larve di Scomberoidi. 1-248. Rev. mensile di pesca 1910: 201-205. --- 1947. Fishery statistics of the United -- . . States :1943:- U. ~S.- Fi:rhtind .Wildlife Seru., SCHAEFER, _M. B., and j, C. MARR. In press. Stat. Dig. 14: 1-241. Spawning of the yellowfin tuna (Neothun­ nus macropterus) and skipjack (Katsuwonus DEBuEN, FERNANDO. 1932. Formas ontogeni­ pelamis) in the Pacific Ocean off Central cas de peces (nota primera). Inst, Espanol America, with descriptions of juveniles. U. S. de oceanogr., Notas y Resemenes. II, 57: Fish and Wildlife Sero., Fish Bul. 51: in press. 1-38. SELLA, M. 1924. Caratteri differenziali dei EHRENBAUM, E. 1924. Scombriformes. Rept. giovana sradi di Orcynu-s thynnus Ltkn., O. Danish Oceanogr. Exp. 1908-1910. No.8. aIaIonga Risso, Auxis bisus Bp. R. Accad. 2 [Biology] (A.ll): 1-42. Naz. dei Lincei, CI. di Sci. Fis., Mat. e Nat., Rend. V, 33: 300-305. FIEDLER, R. H. 1945. Fishery statistics of the United States:1941. U. S. Fish and Wildlife SPARTA, A. 1933. Osservazioni compiute nello Seru., Stat. Dig. 7: 1-174. Stretto di Messina sui comportemento dei pesci e cefalopodi all'azione di sorgenti lumi­ FRADE, FERNANDO, and FERNANDO DEBuEN. nose. R. Comitat. Tallasogr. Ital., Mem. 206: 1932. Poissons scombriformes (excepte la 1-22. famille Scombridae). Clef de classifications princalement d'apres la morphologie interne. STARKS, E. C. 1910. The osteology and mutual Comm. Int. pour l'Bxpl. Sci; de Ia Mer Medi­ relationships of the fishes belonging to the terronee, Rapp. et Proc: Verb., 7 (annexe A): family Scombridae. Jour. Morph. 21 (1): 69-70. 77-99, 3 pl,