OCT 27 I Qp3

ISSN 0704-3716

Canadian Translation of Fisheries and Aquatic Sciences

No. 5018

1 Fii.:'H n & 0 c ea n s 1î Y Ë ! ,• Some data on the systematic position and biology oe a , Pacific member of the genus Reinhardtius Gill 5 i OCT 27 i_qp3

M.F. Vernidub, and K.I. Panin

Original title: Nekotoryye dannyye o sistematicheskom polozhenii i biologii tikhookeanskogo predstavitelya Reinhardtius Gill

In: Uch. zap. LGU (Scientific Journal of Leningrad State University) 15: 250-272, 1937

Original language: Russian

Available from: Canada Institute for Scientific and Technical Information National Research Council Ottawa, Ontario, Canada KlA 0S2

1983

35 typescript pages 4. ISSN 0704-3716

Canadian Translation of Fisheries and Aquatic Sciences

No. 5018

Sonie data on the systematic position and biology of a Pacific member of the genus Reinhardtius Gill

M.F. Vernidub, and K.I. Panin

Original title : Nekotoryye dannyye o sistematicheskom polozhenii i biologii tikhookeanskogo predstavitelya Reinhardtius Gill

In: Uch. Zap. LGU (Scientific Journal of Leningrad State University) 15: 250-272, 1937

Original language: Russian

Available from: Canada Institute for Scientific and Technical Information National Research Council Ottawa, Ontario, Canada KlA 0S2

1983

35 typescript pages • Secretary Secrétariat of State d'État

MULTILINGUAL SERVICES DIVISION — DIVISION DES SERVICES MULTILINGUES

TRANSLATION BUREAU BUREAU DES TRADUCTIONS

LIBRARY IDENTIFICATION — FICHE SIGNALÉTIQUE

Translated from - Traduction de Into - En

Russian En g li s h Author - Auteur M.F. Vernidub and K.I. Panin

Title in English or French - Titre anglais ou français Some data on the systematic position and biology of a Pacific member of the genus Reinhardtius Gill.

Title in foreign language (Transliterate foreign characters) Titre en langue étrangère (Transcrire en caractères romains)

Nekotoryye dannyye o sistematicheskom polozhenii i biologii tikhookeanskogo predstavitelya Reinhardtius Gill.

Reference in foreign language (Name of book or publication) in full, transliterate foreign characters. Référence en langue étrangère (Nom du livre ou publication), au complet, transcrire en caractères romains.

Uchonyye zapiski LGU

Reference in English or French - Référence en anglais ou français

Scientific Journal of Leningrad State University

Publisher - Editeur Page Numbers in original DATE OF PUBLICATION Numéros des pages dans not available DATE DE PUBLICATION l'original

Year Issue No. 250-272 Volume Place of Publication Année Numéro Number of typed pages Lieu de publication Nombre de pages dactylographiées USSR 1937 15 33

Requesting Department Translation Bureau No. Ministère-Client D F 0 Notre dossier no 1253729

Branch or Division SIPB Translation (Initials) Direction ou Division Traducteur (Initiales) N. De

Person requesting P. Power Demandé par

re a UNEDITED TRANSLATION Your Number — — (3, Votre dossier no For informallon only TRADUCTION Date of Request NON REVISEE Date de la demande August 15, 1983 C.03 Information seulement

Canada SEC 5 - 111 (Rev. 82/11) Secretary Secrétariat 11 of State d' État

MULTILINGUAL SERVICES DIVISION — DIVISION DES SERVICES MULTILINGUES

TRANSLATION BUREAU BUREAU DES TRADUCTIONS

Client's No—N° du client Department — Ministère Division/Branch — Division/Direction City — Ville

D F 0 SIPB Ottawa

Bureau No.—K1 0 du bureau Language — Langue Translator (Initials) — Traducteur (Initiales) 1253729 Russian N. De. SEP 3 0 1983

Uchonyye zapiski LGU (Scientific Journal of Leningrad State University), 1937, No. 15, p.250-272 ( 5-<0 ) Some data on the systematic position and biology of

a Pacific member of the germs Reinhardtius nil' by M.F. Vernidub and K.I. Panin

The so—called "Pacific black halibut", which is similar to

the Greenland halibut Reinhardtius hippoglossoides Walb., was

detected in a comparatively large number during an expedition of

the Pacific Institute of Fisheries (Vladivostok) in the Sea of

Okhotsk and the Bering Sea in 1931-1932.

The literature contains hardly any data on the black halibut

that inhabits the waters of these two seas. There is only one

E mention of the discovery of a Reinhardtius species in Sagami Bay

t VISE n (Japan, Pacific coast) where only one 375 mm specimen was caught E o RE leme SLATION (stuffed specimen, No. 456, Tokyo Museum). In 1897, it was de- o u se

scribed by Ischikawa and Matsuura as Hippoglossus granlandicus. n TRAN io o

e After studying this specimen, Jordan and Snyder described TION NON rm DITED io u. it as a new species, Reinhardtius matsuurae, in 1901. DUC In UNE

TRA According to these authors, the new species was established

on the basis of the fact that it could be distinguished from

*The numbers in the right—hand margin are the pages of the Russian text — translator

SEC 5-25 (Rev. 82/11) Canacrâ -2--

R. hippoglossoides Walb. by a greater abundance of scales and by a number of other characters which were not indicated. Therefore, the purpose of our investigation is to clarify the systematic position of the Pacific black halibut, and on the basis of the data available to us, to characterize it from the biological and

commercial point of view.

Our research was based on our own collections and observations, as well as on the collections of other expeditions of the Pacific

Institute of Fisheries.

We analyzed 36 specimens fixed with Formalin and alcohol (13 from the Sea of Okhotsk and 26 from the Bering Sea). In order to compare these Pacific black halibut with the Greenland halibut, we used the collections (8 specimens) of the Zoological Institute of the USSR Academy of Sciences.

The genus Reinhardtius belongs to the Hippoglossinae subfamily

(Pleuronectidae family). In many of its characters, it is inter- mediate between the Atheresthes and Hippoglossus genera of this

subfamily, which is clearly seen in table 1.

The following is a brief description of the genus.

Genus Reinhardtius Gill.

Pleuronectes Fabricius, Fauna Graenlandico, p. 163, 1870; Walbaum, Artedt piscium, p. 115, 1792. --Hippoglossus Reinhardt, Kg1.-Dansk, Vidensk. Selsk., p. 116, 1838; Günther, Cat. Fish. Brit. Mus., p. 404, 1862. --Reinhardtius Gill., Cat. Fish Coast N.A., p. 50, 1861; Gill., Proc. Ac. Nat. Sci. Phila., p. 218, 1864; Jordan a. Evermann, Bull. U.S. Nat. Mus., No. 47, p. 2610, 1898; Jordan a. Starks, Proc. U.S. Nat. Mus., v. XXXI, p. 195, 1907; Normann, Brit. Mus. Nat. Hist., V-1, 1934; Jensen, Mém. l'Acad. Roy. Sci, V-VI, No. 4, 1935. Platysomatichtys Bleeker, Bompt. Rendus Ac. Sci. Amsterdam, p. 426, 1862; Goode a. Bean, (! 51) Bull. Essex. Inst., 1879; Collett Norske Nord. Havs. Exped., p. 142, 1880; Jordan a. Goss, Rev. Flounders and Soles, p. 237, 1889; Smitt, Hist. Sci. Fish., 418, 1893. -3-

Table 1. Comparative characteristics of three related genera from the subfamily Hippoglossinae

Atheresthes Jord. et Reinhardtius Gill. Hippoglossus Cuvier. Gilb. Greenland halibut True halibut Arrowtooth flounder

Teeth large, arrow- Teeth in jaws large, not arrow-shaped, two rows shaped, two rows on on upper jaw, one row on lower jaw both jaws

Upper eye in notch of Upper eye in notch of Upper eye completely upper profile of head upper profile of head on pigmented side or on pigmented side

Gill rakers long, thin, Gill rakers massive, Gill rakers short, wide with a row of denticles short, thick, with at the base, pointed, along one edge accessory denticles on with denticles the end

Scales cycloid, quite Scales cycloid, spherical Scales cycloid, spherical large, fall off easily on body, elongated and on body, elongated and small on caudal peduncle small on caudal peduncle, very small accessory scales present Lateral line without Lateral line gently Lateral line highly arch in front sloping, without arch arched in front in front

Lower pharyngeal teeth Lower pharyngeal teeth Lower pharyngeal teeth small, in two rows very large, in a single in two rows TOW

Vertebrae (11)12+(35) Vertebrae 18+45=63 Vertebrae 16+35=51 36, 37(38)

Both eyes are found on the right side of the body. In comparison with the flounders, its body is elongated and compressed from both sides. The greatest thickness of the body is equal to approximatley 1/3 of its greatest depth. The head is large, approximately k of the length of the whole body. The mouth is large, the maxillary extends to the posterior margin of the eye, or beyond the eye. The teeth on the jaws are large and sharp; they are arranged in two rows on the upper jaw, and there is a single row of very widely spaced teeth on the lower jaw. In addition, there are -4—

L fang—like teett... 2-3 pairs of large interiorly.d-iredtjC1 7-7—T'on the upper jaw in front. The teeth on the pigmented side and on the blind side are almost equally developed. The vomer and palatina have no teeth.

The gill rakers are short and stout, with a row of accessory denticles on the end. The scales are small and cycloid, spherical on the body, elongated on the caudal peduncle. The lateral line is gently sloping, with no arch in the anterior. The dorsal fin overlaps by 1/3 of the length of the upper eye along the orbital margin. There is no spine in front of or within the anal fin.

The caudal fin is slightly notched. The blind side of the body is pigmented. (252) Some data on the internal structure of Reinhardtius

The number of vertebrae is on the average greater than in other members of the subfamily Hippoglossinae, in which it varies from 46 to 51.

Due to the fact that the eye in Reinhardtius is found in the notch of the upper profile of the head, the bones of the skull and jaws are almost symmetrical; slight asymmetry is observed only in the anterior part of the skull. All of these characteristics make it similar to Atheresthes stomias Jord. a. Gilb, and the genus

Cleisthenes Jord. a. Starks (Protopsetta Schmidt), and indicate that this genus is an old one.

The upper eye of Reinhardtius lies in a totally closed bony orbit. The orbit is oval in young specimens and spherical in large ones. There are no infraorbitalia.

All of the cranial bones are unusually porous and contain cavities, which can be attributed to the deep—sea mode of life of Reinhardtius. We should also mention that not a single one of these bones is suitable for determining age.

The suboperculum has a very thin and brittle margin. There are four pairs of gill arches, and false gills are also present.

There are 7 branchiostegal rays; the urohyale is r—shaped, flat- tened from the sides, with highly developed cavities. The intes-

tine is short and there are 4 pyloric caeca.

Species of the genus Reinhardtius have long been known in

the northern waters of the Atlantic Ocean where they can be found everywhere north of Bergen to Bear Bank, including the western part of the Barents Sea, along the southern coast of Iceland and along the western coast of Greenland, including Baffin Bay. Allof

these areas -are inhabited by one and the same species, Rein- hardtius hippoglossoides Walbaum.

Systematic position of the Pacific black halibut 1 A detailed study of approximately 30 morphological characters

of Atlantic and Pacific representatives did not reveal any great

differences between them. Table 2 gives a comparison of the data

obtained for the main group of characters. The data for repre-

sentatives of the Okhotsk and Bering seas are given separately.

From this table, we can see that the Atlantic and Pacific repre-

sentatives differ significantly only in the following two charac-

ters:

1) the depth of the caudal peduncle, which is equal on the

average to 82.6% of its length in the Atlantic representatives,

1 Determination of morphological characters based on Duncker's system for flounders (1895).

-6-

Table 2. Comparison of morphological characters of the Atlantic and Pacific representatives of the genus Reinhardtius

Atlantic Ocean Sea of Okhotsk Bering Sea Morphological characters Av. 1 Maximum Av. 1 Maximum Av. Maximum Number of fish 8 13 23 Length, au 52.9 44.0-64.5 38.0 26.2-59.0 28.8 12.3-47.8

In 7,of body length Length of head 27.9 24.7-30.1 28.5 26.8-30.5 27.7 25.9-30.1 Greatest depth of body 33.8 30.5-35.5 32.0 30.3-33.4 32.1 29.6-34.4 Depth of caudal peduncle 9.2 8.6-9.7 8.3 7.6-9.2 8.1 6.5-8.9 Length of caudal peduncle 11.2 9.9-12.6 12.3 11.1-13.4 12.5 11.1-14.2 Pectoral fin of eyed side 11.8 10.8-13.3 11.3 10.0-12.7 10.8 8.3-13.0 Pectoral fin of blind side 10.8 9.9-11.9 10.4 9.2-11.1 9.85 8.2-11.1 Pelvic fin 6.45 5.5-7.6 7.1 6.5-8.0 7.1 5.3-8.0 Depth of caudal peduncle in 70 of its length 82.6 70.2-97.6 68.5 56.5-83.1 65.5 54.0-75.0

In 7. of head length

Length of snout 29.0 27.1-30.4 27.9 26.6-31.25 26.5 24.0-31.7 Postorbital region of head 60.2 58.8-61.9 59.3 57.5-61.3 59.8 52.3-63.9 Maxillary of eyed side 37.4 35.8-39.5 33.7 31.2-35.5 33.6 31.3-34.8 Maxillary of blind side 38.5 36.5-39.9 35.9 33.7-37.1 35.2 32.5-36.5 Lower jaw 52.9 51.3-55.6 50.5 48.4-52.3 49.8 47.8-54.8 Interorbital distance 14.65 13.5-15.5 14.1 12.4-15.7 11.5 7.1-13.9 Horizonal diameter of normal eye 13.9 12.9-15.1 14.2 12.5-16.1 15.3 12.3-20.9 Horizontal diameter of upper eye 15.4 14.0-16.8 15.9 13.4-19.0 16.6 13.8-20.3 Vertical diameter of normal eye 12.0 10.0-12.7 11.3 9.7-12.9 12.4 8.8-18.2 Vertical diameter of upper eye 13.2 12.4-15.0 11.6 10.0-13.0 12.4 10.9-16.7 - 7-

and to an average 68.3% and 65.6% in the Pacific representatives from the Sea of Okhotsk and the Bering Sea respectively.;

2) the length of the upper jaw on the eyed side, which is equal to not less than 35% of head length (average 37.4%) in the

Atlantic representatives, and not more than 35% of head length

(average 33.7%) in the Pacific representatives.

Insignificant differences are observed in the length of the upper jaw of the blind side and in the length of the lower jaw, which in the Pacific representatives are also slightly smaller than in the Atlantic ones.

The meristic characters are compared in table 3.

Table 3. Comparison of the meristic characters of the Atlantic and Pacific representatives of the genus Reinhardtius Number -of rays D

Number of 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 109 n rays

Atlantic 2 - 1 1 - 2 1 - - 1 (8) Ocean Sea of 1 - - 2 - - 2 - 2 2 1 1 1 - - - -(12) Okhotsk Bering Sea 1 - 1 1 4 2 2 1 1 - 3 2 1 1 - 1 - (21)

Average for Atlantic representatives - 98 rays Average for Okhotsk representatives - 95 rays Average for Bering representatives - 95 rays

Number of rays A

Number of rays 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 n

Atlantic Ocean 1 1 1 1 2 - - 1 1 8 Sea of Okhotsk - - - 2 - 1 1 2 1 1 1 1 2 - 1 13 Bering Sea 2 1 - 1 - 1 3 2 5 2 3 3 - - - 23

Average for Atlantic representatives - 74 rays Average for Ohkhotsk representatives - 72 rays Average for Bering representatives - 71 rays As we can see from the table, there is no significant difference in heristic characters between the Atlantic and Pacific representatives.

Our data on both the Atlantic and Pacific representatives of (254) the genus Reinhardtius are compared with those of other authors

(Günther, 1862 and Smitt, 1893) in tables 4 and 5.

Table 4. Comparison of our data with Günther's data (1862) on Reinhardtius hippoglossoides Walb.

Atlantic Ocean Collécli -ons -of - Zoo- Günther's data Sea of Okhotsk Bering Sea logical-Museum of . USSR Academy of Sci.

av. av. av. D 100-102 98 95-109 95 88-100 95 89-103 A 75 74 69-78 72 67-78 71 74-75 Greatest depth of body 28.67 of body length 29.9 26.8-31.6 28.3 26.7-30.0 28.5 26.0-30.8 Length of head 25% of body length 24.7 21.9-26.4 25.3 23.7-26.8 24.6 23.2-26.3 Horizontal diameter of lower eye 50% of snout length 48.2 44.0-53.1 51.0 45.5-60.6 58.1 44.8-82.4 Horizontal diameter of lower eye 12.5% of head length 13.9 12.9-15.1 14.2 12.5-16.1 15.3 12.3-20.3 Length of P on eyed side 407 of head length 42.6 38.8-46.7 39.6 35.2-43.75 39.1 27.7-47.8

A comparison of our data with Günther's (1862) shows some

differences, but only very insignificant ones in the horizontal

diameter of the lower eye; in the Pacific representatives, it

is greater than in the Atlantic ones.

A comparison with Smitt's data (1893) shows an insignificant

difference in the length of the lower jaw (noted earlier), which

is smaller in the Pacific representatives. Table 5. Comparison of our data with Smitt's data (1893) for Reinhardtius hippoglossoides Walb.

Atlantic Ocean Collections of Smitt's data Sea of Okhotsk Bering Sea Zoological Museum of USSR Academy of Sciences

av. av. av. Greatest depth of body in specimens up to 18 cm, up to 25% of body length - 27.5 26.0-28.7 Greatest depth of body in specimens 40-75 cm in length, up to 26-28% of body length 29.9 26.8-31.6 28.3 26.7-30.0 28.7 26.6-30.8 Greatest thickness of body up to 31% of body depth 27.1 23.7-30.1 24.2 21.9-26.7 22.2 16.9-28.8 Greatest depth of body up to 297e of body length 27.2 25.2-28.8 26.0 24.5-27.8 25.3 21.9-26.8 Length of lower jaw greater than 50% of head length 52.9 51.3-55.6 50.5 48.4-52.3 49.8 47.8-54.8

Thus, our study of the morphological and meristic characters

of the Atlantic and Pacific representatives of the genus Reinhard-

tius did not reveal any great differences between them, i.e. dif-

ferences of species importance. Significant differemces were

observed only in two of the characters associated with migration

and feeding, namely, 1) the length of the lower jaw is smaller

in the Pacific representatives, and 2) the depth of the tail is

smaller in the Pacific representatives as compared with the

Atlantic ones. -1 0-

(255) On the basis of all this, we believe that the differences between the Atlantic and Pacific representatives of the genus

Reinhardtius lie within the limits of a species/ and are subspecific.

The Pacific form should be regarded as a subspecies of the

Atlantic species Reinhardtius hippoglossoides Walb.

We have already mentioned that only one specimen described by Jordan and Snyder (1901) as the new species Reinhardtius matsuurae was known from the northern waters of the Pacific Ocean.

According to their description, it is very similar to our specimens

from the Okhotsk and Bering seas. Proceeding from this, we believe

that the Pacific form should be referred to as Reinhardtius hippoglossoides matsuurae Jordan a. Snyder.

Characteristics of Reinhardtius hippoglossoides

matsuurae Jord. a Snyd.

Hippoglossus groenlandicus Ishikawa a. Matsuura, Prel-Cat. 1897, p. 25. Reinhardtius matsuurae Jordan a. Snyder, Journ. Coll. Sci. Imp. Univ., XV, 1901, p. 301; Jordan a. Starks, Proc. U.S. Nat. Mus., XXXI, 1907; Tanaka, Sh. Journ. Faculty Sci. Imp. Univ., Tokyo, V-III, 1931. Reinhardtius hippoglossoides Walb. Taranets A., Journal of the Far Eastern branch of the USSR Academy of Sciences, No. 2-3, 1933; Schmidt, P. Proc. 5th Pac. Sci. Con- gress, V-5, 1934; Andriyashev A. USSR Marine Research, No. 22, 1935; Andriyashev A. USSR Marine Research, No. 25, 1937.

D=88-103, A=64-78, P=14-15 11 - approximately 120, Br. I, 13-15 Number of vertebrae 18+45

Morphological characters In % of body length: Length of head 25.9-30.5, average 28.0; Length of caudal peduncle 11.1-14.2, average 12.4; Length of P on eyed side 8.3-13.0, average 10.0; Length of P on blind side 8.2-11.1, average 10.0; (256) Length of V 5.3-8.0, average 7.1; Greatest depth of body 29.6-34.4, average 32.0 Smallest depth of body 6.5-9.2, average 8.2; Depth of caudal peduncle in % of its length 54-83.1, average 67.0. In % of head length: Upper jaw of eyed side 31.2-35.5, average 33.6; Upper jaw of blind side 32.4-37.1, average 36.5; Lower jaw 47.8-54.8, average 50.0; Length of snout 24.0-31.7, average 27.0; Postorbital region of head 52.3-63.9, average 59.5; Interorbital distance 7.1-15.7, average 13.0; Horizontal diameter of lower eye 12.3-20.3, average 15.0; Horizontal diameter of upper eye 13.4-20.3, average 16.0; Vertical diameter of lower eye 8.8-18.2, average 12.0; Vertical diameter of upper eye 10.0-16.7, average 12.0.

The body is elongated and quite low. The dorsal fin overlaps by 1/3 of the upper eye along the edge of its left orbit (fig. 1 and 2). The anal fin begins under the 25-26th ray of D. There is no anal spine. The pectoral fins are of the same form and size on both sides of the body. The pelvic fins are symmetrical. The membrane connecting its rays does not extend to the end of them,

leaving the ends of the rays free. The caudal fin has a barely

perceptible notch.

Fig. 1. Reinhardtius hippoglossoides matsuurae

Fig. 2. The same from the left side -12-

(257) The entire body and head are covered with very small cycloid, tightly imbricated scales. The scales are spherical on the body, and elongated and larger on the caudal peduncle. The lateral line begins on the head behind the lower eye, slopes gently under the pectoral fins and then extends in a straight line along the median

line of the body onto the caudal fin. space The interorbital Vis flat and covered with scales. The membrane between the rays of the vertical fins is free of scales.

The upper jaw extends to or overlaps the vertical line of the posterior orbital margin of the lower eye. The upper eye is found in the notch of the upper profile of the head. There are teeth on the dentale and praemaxillare. The teeth on the lower jaw are in a single row; there are 11-15 large fang-like teeth on the eyed side and 8-11 weaker teeth on the blind side.

The number of teeth, their size and the spaces between them vary with age. The teeth on the upper jaw are in two rows. The outer row consists of large interiorly hooked teeth, about 25 on each side; the inner row consists of small closely spaced teeth set at a right angle to the teeth of the first row, about 50 on each side. In front, the praemaxillare bears 2-3 pairs of the

largest fang-like teeth which point into the mouth.

The teeth on the lower pharyngeal bones are arranged in a single row; they are slender, high and sharp, and number up to

12 on each side (fig. 3). The upper pharyngeal teeth are arranged in 3 rows (fig. 4). The gill rakers are short, widely spaced and massive, with a row of denticles on the end (Fig. 5). The gill rakers in young specimens are not as developed and are more widely -13-

spaced. The eyed side is light brown and grayish-brown. The *,eeg blind side is dark and bluish-gray.

Fig. 3. Lower pharyngeal teeth Fig. 4. Upper pharyngeal teeth of R. hippoglossoides matsuurae of R. hippoglossoides matsuurae Jord. a. Snyd. Jord. a. Snyd.

Fig. 5. First gill arch of R. hippoglossoides matsuurae Jord. a. Snyd.

Geographic distribution

One specimen was discovered in Sagami Bay (northern Japan) at the end of the 19th century, and one was found for the first time in the Okhotsk and Bering seas in 1931. According to 1931 and 1932 data, its distribution in these seas is as follows.

In theSea of Okhotsk, it is found along the entire 0 coast of Kamchatka from Cape Lopatka to Point Khariuzov (57 N) at a depth of 100-600 m. In the northern part of the sea, it is found within a 60-mile zone in the Koni Peninsula--Babushkin Bay (2(258) ■ area. In the central part, it is found at a depth of 592 m near

Tony Is. We have no data on the northwestern and western part of the sea. In the southwestern part of it, this form has been found off the eastern coast of Sakhalin Is. It is not encountered in the Shantar Sea.

In the Bering Sea, it has so far been discovered only in the northeastern part between Cape Navarin and Matveyev Is at a depth of 100 m and greater. It is not encountered south of Matveyev Is.

It is apparently not encountered in the northwestern part of the sea either. Here, we are obviously faced with the fact that this area of its habitat is completely isolated from the others, a fact which is impossible to explain because of insufficient research in this area.

Biological characteristics of R. hippoglossoides

matsuurae Jord. a. Snyd.

Conditions of existence

In the Okhotsk Sea, the black halibut is found at depths from

100 to 600 m, and possibly at greater depths. Almost all of the above—mentioned areas are characterized by a gradual lowering of the bottom relief, and only in the southernmost part of the Kam- chatka coast and on the eastern coast of Sakhalin Is. is there a drop in the continental terrace, beginning with a depth of 200m.

The near—bottom temperatures are above zero degrees in all of the indicated areas with the exception of the northern part

(Koni Peninsula--Babushkin Bay), and only in the northern part was the black halibut encountered at temperatures ranging from —0.5 °

° C. to +0.1

The areas with above—zero temperatures abound in thermophilic forms. They are especially abundant and increase in number in the bathyal region of the southern part of Kamchatka. This part

-probably St. Matthew Is. — transl. of the sea is most abundant in various Decapoda, Polychaeta, Echino-

dermata and various members of the Pleuronectidae and Gadidae.

All of the known habitats of the black halibut coincide mainly with the areas of above-zero temperatures, and are confined mainly

to stony-sandy bottoms near drops of the continental terrace, or

to silty-sandy bottoms at depths of 100-300m.

In the Bering Sea, the black halibut apparently inhabits only

the part adjacent to Anadyr Gulf. So far, it has been encountered

only at depths of 100-200m where the temperature varies from +1

to +2 ° C. Further research may show that it inhabits greater depths.

Below-zero temperatures have been established north of the

100m isobath, and the black halibut is apparently never encounter-

ed in this part. The region inhabited by the black halibut at

depths of 100-200m is confined to silty-sandy bottoms and abounds

in various Decapoda.

Because the black halibut is found at great depths with con-

stant above-zero temperatures, it should be assigned to the boreal

fauna, instead of the artic fauna.

Feeding

The literature contains no data on the feeding of the black

halibut. Only Jensen (1935) indicates that a Greenland halibut

(R. hippoglossoides) measuring 150-300 mm in length feeds on Gadus

saida and the young of Sebastes marinus and Pandalus borealis.

Our observations include only 25 specimens measuring more than (259) 50 cm in length. The predominant item_ in the diet of these

specimens is Theragra chalcogramma (Pall.); Lycodes are consumed

to a much smaller degree, and various crustaceans of the families -16-

Hippolytidae, Pandalidae and Crangonidae are preferred even less

According to the data of A.P. Andriyashev, exclusive- ly young Theragra chalcogramma were found in the stomachs of five specimens of different age. This type of feeding, which necessi- tates migrations irrespective of the type of bottom, is in step with the general appearance of the black halibut which has clearly defined predator features, namely 1) a strong muscular body with a well-developed caudal region; 2) an almost symmetrical mouth with well-developed teeth on the right and left strong and large jaw bones; 3) a branchial system with teeth on the branchial tubercles, and 4) a highly developed liver and short intestine.

We do not know whether there are intervals in their feeding during the year. The distribution of the sclerites in the scales is almost uniform, and if because of this we believe that the growth of the black halibut proceeds uniformly, then we should also expect its feeding to be more or less the same at all times. How- ever, we have seen otoliths with annuli, which may be an indication of the opposite, i.e. irregular feeding during different seasons of the year. Some of the otoliths had so-called "false annuli"

(true, weakly defined ones) beginning with the 4th year and on.

Perhaps, they are an indication of intervals in feeding during the spawning periods.

Reproduction and development

There are no specific data on the time and place of spawning of the Pacific black halibut in the Okhotsk and Bering seas. For the black halibut of the Sea of Okhotsk, the reports from expeditions of the State Hydrological Institute and the Pacific Institute of Fisheries (Generozova and Polutov) indicate that in August 1932,

females and males of every size were at the lst-2nd stage of sexual maturity, and only one female (80 cm long) was at the 5th stage

of maturity, i.e. had running eggs. For the black halibut of the

Bering Sea, we ourselves observed females and males at the 3rd-4th

and 4th stage of maturity at the beginning of September 1932, and

several male specimens were even at the 4-5th stage (the testes

contained a large amount of semen). For the same area, A.P. Andri-

yashev (1936) also indicates that adult females measuring 66-83 cm

in length had fairly large, light and transparent eggs at the 4th

stage of maturity in September. Thus, we have different data on

the stages of maturity for the two seas, and on the basis of these

data, we have no choice but to conclude that the spawning in the

Okhotsk and Bering seas takes place at different times, apparently

in July-August in the Sea of Okhotsk (which may be related to the

migration of the black halibut to depths exceeding 300 m at this

time) and in October-December in the Bering Sea.

Sexual maturity apparently sets in during the 9th-10th year

in females and slightly sooner in males. The first and second

stages of maturity are already observed in 35-50 cm specimens,

which corresponds to 5th--6th-year fish.

There are no data on the spawning grounds of the Pacific

black halibut, and so it was very interesting to read Jensen's

report (1925, 1935) that the Greenland halibut (R. hippoglossoides

Walb.), which is usually encountered at relatively small depths 260) in Baffin Bay (up to 300 m), was found spawning at depths ranging

from 384 to 1200 m. Its early larval stages were found at the same depths. Our data permit us to assume that the Pacific black

halibut probably spawns at great depths as well.

There is no data on the embryonic development of the Greenland halibut (R. hippoglossoides Walb.) either, but all of its subsequent development beginning with the early larva has been studied quite thoroughly by Schmidt (1904) and especially Jensen (1925, 1935).

Their data are of great interest to us, for the stages indicated by them can be applied in our own investigations.

According to Meek (1916), a R. hippoglossoides egg measuring

3-4 mm in diameter does not have a fat drop, and after spawning

the eggs remain in the near-bottom layer of water. Jensen (1925,

1935) also indicates that the ripe eggs of this halibut have a

diameter of 4-4.5 mm and spawning takes place at great depths.

The eggs apparently remain in the near-bottom layer up to the time

the larvae hatch out, and only later do they migrate to the upper

layers.

Jensen (1925, 1935) distinguishes the following larval stages:

1st instar - bathypelagic larvae. The larvae measure from 10

to 18 mm in length. The younger larvae have a yolk sac equal to

1/4-1/6 of the total length,and have no pigment at all; embryonic

pectoral fins are present. In the more mature larvae, the yolk is

almost resorbed, and the eyes and ventral part of the trunk is

well-pigmented (fig. 6).

Meeiemq.4.:\M!. ------

ci44;e7D7 .7. Fig. 6. Bathypelagic larva of R. hippoglossoides Walb. Length 22 mm (after Jensen, 1935) -19-

2nd instar - young pelagic larvae. These larvae measure from

16 to 24 mm in length. They are quite symmetrical, but the left

eye is somewhat higher than the right one. The body is elongated

and low; its greatest depth, including the vertical embryonic fin

folds, is equal to about 1/5 of the total length. P are large.

Rays appear in C. Mainly the posterior of the body and region of

the intestine are pigmented.

3rd instar - late pelagic larvae. These measure from 25 to

57 mm in length. At this stage, rays appear in D and A; D and A

separate. The embryonic pectoral fins are reduced. The depth of

the body and fins increases. V appears by the end of this stage,

and the left eye gradually moves higher. However, the larvae always

remains quite symmetrical and both sides are equally pigmented.

Towards the end of the stage, the pigment is abundantly distributed

in groups. Teeth develop on the praemaxillare and lower jaw begin-

ning with a body length of 33 mm (Fig. 7).

Fig. 7. Pelagic larva of R. hippoglossoides Walb. Length 32 mm (after Jensen, 1935) (261) Metamorphosis takes place when the larva has reached a

length of more than 57 mm, and ends when it is about 80 mm in

length. By this time, the left eye is in the upper profile of

the head on its right side. The larva now has scales (fig. 8).

From this point, the pigmentation on the right side of the body

increases. At the stage of metamorphosis, the larvae begin to -20-

settle on the bottom. At the pelagic stages, the larvae are carried by the current to different places, and so they settle on the bottom both in shallow and very deep places.

Fig. 8. Larva of R. hippoglossoides Walb. Length 65 mm (after Jensen, 1935)

Migrations

Migrations of the Pacific black halibut were observed on the western coast of Kamchatka in the summer of 1932. It was in June that this halibut was found everywhere at depths of 100-300 m, whereas in July and August it disappeared almost completely and only single individuals were caught in an otter trawl. These migrations to greater depths are apparently spawning migrations.

Other migrations by this halibut at some other time of the year are completely unknown to us.

It is also possible that the black halibut migrates to shallow-

er waters high in biomass productivity only in early summer, in which case the migrations would be related to feeding. Its early migration to greater depths is due to the nearing of the spawning

season.

The behavior of the Pacific black halibut in the Bering Sea

differs somewhat. Both in August and at the beginning of September, quite a large number of them (up to 100) were caught in an otter

trawl at depths of 100-200m (greater depths were not studied).

It is unlikely that its pre-spawning behavior would differ from

that of the Okhotsk black halibut.

Age and growth rate

The available material on age (in the form of scales and

otoliths) came from the catches of otter trawls. Seventy-nine

specimens came from the Sea of Okhotsk, and 75 from the Bering Sea.

However, a study of the scales showed that they were completely

unsuitable for determining age. Small elongated scales do not have

clearly defined annuli, and the latter do not become any clearer

after treatment with ammonium, or after staining of the scales with iron sulfate by Trempovich's method (1932). The scales

stained uniformly, which can serve as an indication of its uniform

growth. The odd form of an otolith, which is the result of its

peculiar growth mainly in length, and the splitting in its anterior

part make it brittle and very difficult to handle.

However, without preliminary processing, otoliths cannot be

used for determining age either. The most common method, polishing,

could not be used because of the brittleness of the otolith. Clari- 262) fication in glycerin and xylene did not improve the clarity of the

annuli by much; only clarification in oil of cloves with preliminary

dehydration in absolute alcohol made them much more distinct. We

therefore used this method in our investigation. The length of

time an otolith was kept in oil of cloves varied from 0.5 hr to

5 hr (increased with age). -22-

Table 6. Average lengths according to individual years for various age groups of the Pacific black halibut of the Sea of Okhotsk (cm)

.4.e...:..:,r.4,,i

tpreelieky4e4 '• - Leneh' e 0 U P . , • • 5., • • e- t.-!•7" •,' . - .!' -1/4'.--'. ii4;:e • '.71:rii' ":"1: -. - , xx. 1 ' XXI .3(XII . ix "; XII xtvi - ,...,-::-...--.-,,,,,..I. . .: • , . . :--• . .*:-.1:; 1 ,%, - - .. -..:•.: ::. :: . . ,- , - 'ef.' ..--.', .. •.:•••'::. . :T. ; • • . . : 11,6 16,8- -9,3- 7,5 11 3 9,3 16,8- 26,4 16,0 : 21,0. ' 26,4r-17,8 8.6 20,7' 20,5' - 18,6 ' 35,0-22,5 12,5 27$ r 27,0 26,3 35,0 22,5 _ 29,0 - •_28,1 [1:•24,4. 27,5 , 35,0 241,4-27,5 13,9 . 33,5. 8. 33,8 28,6 33,6 • 41,4 39,3 47,8 32,0 - 40,6 - 47,8-32,0 15,8 38,9: 40.0 38.8 . 46,2 •153,0-36,2 16,8 43,8 - 44,4 43,4 44,0 53,0 36Z e41.0: - 48,6 57.13 • 40,0 :51,0 -57,0-40,0 17,0 48,2- 45.5 43,5 55,8 61,8-43,5 18,3 ..52,1 . 51,2 . • 50,8 ,0: 53,0 61,8 18,2 56;7. , 1.1 r 57,0 65,0 46,8. 60,4 - 54,2" 54.0 15,55,8 . 50;2. :64,4 68,2-50,2 18,0 - 60,4 '57,4 59,0 68,2 17,5 . 63,9- 63,5 71,1- , 96 68,6. - . 611,6 57,2 •71,8 74,0-57,2 16,8 67,2" 64,4 66,4 74,Œ -61,0 15,2 69,8. , 69,4 76,2- 61p 74,5 76,2, 64,6 78,0 78,4-64,6 -13,8 72,7. ' , 72,3 78,4 76.2- 75,2, 80,8 : 69.0 80,4 80,8-69.0 11,8 " : 73,0 8Z5 82,8-73,Q " 9,8 79,1 78,0 82,8 - 7,5 81,2 80,4 84,8 •«76,3, . 84,3 84,4-76,3. 86,4 79,8 86,2 86,4-79,8 6,6 83,9- 83,0 , 88,6-82,6 6,0 86,2 85,5 8a6 .82,6 '88,0 - 85,0 89,6 - 90,3-85,0 .5,3 88,35 .90,3 .91.2-87,0 4,2 89,1; . . 87,0' ;91;2 89m. • 93,0: • 93,0-89,0 de 91,0 :94,8. "` 94,8: • • , 94,8

. "

r La 62 .•

Determination of age was carried out with the help of a magnifying glass.

Since the material was very limited, the yearly increment was determined by the method of inverse calculation using the Einar Lea board.

The limited material and the difficulty of age determination, especially in adult specimens, definitely increased the error in the determination of age and the growth rate significantly. Regard- less of this, the given material still cannot serve as initial data

for further investigations in this area.

*literal translation - transi.

Table 6. Average lengths according to individual years for various age groups of the Pacific black halibut of the Sea of Okhotsk (cm)

. ...,..... ..,. . - • --. ••• • '.",,.,;(.1.:e •;-.•.: . ,. _. ,., .•. • : ., • . ielee-±,,...1:--,, .:-...---::-.--->. ::•-•.c. -' ,..,7'...',.- -._.. -,..-2 ,-- . -.. • • • 1 t.,C4... 1.::-> ...... -:: ,r, „g.,...e-i "-.... :g. -• .r. -..• 0 .. p . . , A •e-e-...-.. "i: «.6....A1.i'l-.11:- -. Length e - . . - :- ' .,.. . ,...., ..- ..... - varia- - • .e ,.*...,‘,.. .,Y..e.r...-?..,--,,si-ci- ,..7-.., el. XXII XXIII ., . - -.V :- •-:vi vu _VIII:. ., I),;-; XII Ç.• 1: XVI. XVi 1" XVII:17.#Villl X14 - 1.71X, X X.I •-f., ier`-' ri: • -•-•:. - , , ---.- : • 1 1.1 2;• ''. - ' ' . , . ". • \ , - - ' • '' ,„ i», 3 - -,,.' ..-2 ',-,•• .. • -. '... ,. ..12,4:.. .-13,-07 -.1'1;8" .11,2 ..1.1/. 11,2 : 11,7' 12,1. ...1.1,3 12,3 r- • .. ...<5"gi 1.0,9 • 11.5. ,,,,...._. ,"--• .1- : 36 . 216:84* - . ,-± 1: if,• ,08- : 211 ,--,.. : --- ZE-;-:- .. 21 e 20 5,- 212 20 8 • 207 ' 20,3 - - 21 ,1 20 ,6. - 21 . 1 2 3,4 , 2, ,':,817 . : 18 , 4 21 ,2 -` • - ,27.9.: -270 -. -28,7 27,2 .27,7 27,5, . 28.6' 27,5- .28,1 25,7 29,6 .,.....ff - , ,-0 28,3 ' ":'.24,4.. 2349051 11243611231127,:83r05. 1:489565 -'' 13:1;87::!...- ••••-7, 7:3!,8 -. 33,9 -- 32A. 32,8- .32,8 ..• 34,8. ;3Z7 • 33,8 34,2 ; , :,.. 28,6 .32,7,"- • 36,5 , • ,..7 . .... ;'." 2g6,3 35441.,04a ....t-2..: . 22732,50 k, .:-.--• • • ---..--. .37,4 - 86,4. 37,4 :• 37,3: 40,0 ' • 37,9 38.8 39,4 - :35,0 .... 39,1; 43,1 :.• :----,-. . • 53 0-36 2 16,8 43,8 :-..:, ...-..- --... › -• .,. 39,1 • -2 44,0 53,0 - 36,Z, 46,2 , , e. •-•'' . 41A., 12 a 44,4 ..42,6 43,4 44,4 . / ,.- , F -.- 4to ..44,8 : 48,4 .-,-,>. .• - ,44,6 .45,7 , -48,2. 46,7 . : 45.5 49,6 I, eeg04 ,'"4.6,2- • 48,9 ... 52,7; ;'. --. , _ . ' 48,6 57.8-.‘-._:. ..,-. -e, - "..'..' 48,7: 51,2 - 50,5 , 50e 54,3 1 ...". 51,0 53,1 .. 57,1: ...-7,:, ;;;-- ., 53,0 • 61,8 _ , . . -,, ...._- › - ' -..-' -• 54,2 • 53,6 0-46 ...e, : , 54e 58,3 ; 10 L4 45°337.,:. 25;O . 11 88867.,, 02. 50?8- . 485?307::277942 ... _ ,. -••••%,,,.,--,,, .,. •,-.e..., __ -..... -57,0 - 57,4 61 ,6 1 :6„,7 ,0 15 . . F.12.7 ...... -7-..-.:: 44345603:5i - :. 55261 414!. 8 - 256687:17541 ,:,8 °2 -- -i ) .,..,., - . - • •.,.,- • • - 60 6 64 6 : .,.... 2e. ,e.::555692,80°...;: 566714:3,00E' : 6°61 " --'-: • . ,...Z. '.:. __ _ , _..... , ..„. s 24 , ,,, 26261:9 69,8, e. --- . .._, ,• ' • -1 64_7. i '''• ... e a. f .,. 644 629 06 : , 7072 48 :. ..-"..-7..2 ....':. :,;...7-.., ,.,.. -. 66,1 .....u.:,.... 152 .; --- '. ..., - 8 .. ,.... .‘- ...... ,.. '.•-• , ' ::.:„..... ;25:23,•780348 . ,..- . _2...... , 664,9,g - 7,10:1 • 7880:E.1,6 1.91...u. it:7,2: -1.,.. '''''' V:68,0 22f, ...;;:l_ ,...,..,:.„ ..„ _..,..,. A A ' '' " ' .- 78,.0 8 2,8 , - ",,.-1.1,-1 ' -,... ,...._:• ::-... - , .t.,...., f :"""" . . ":. 7',.7.' .."-;77.; .... s.....; • -• ,___. ■ 86,2 86 4-79,8 6,6 83,9 ye • „1,,,.., : . - --4.. . • ' . • ' . ' 79,8 -,-, t : ... ■ 31 ...r.... ,, . 5.-.., -,?..44,4• • '''-' .,-. :L.,_' , ...... :, • ,--...:--•••, "- - e -- I 9.' • " 0 4 2 891_,23:1 '.... • '''•8583:5° • -"88861 •3' -•; ---a:: -:. 827"60 - • 88.91: • .88912-88275,11 65:1, 87 kt • • 89'O. ..:79.43,80....‘• 9934:08789,0 *"..1.:e . 9914;u8 ...... -M 7.-.--•-• ...'-‘..-.; - .- .7--- F e ... _ 1f. .. . ..-,-: -?....::,-„,• ....., ,,...,.- .',- -"ç-. -..' - ' ' - " '. ., • .._. • -. _ r' -'-' - • w .-,:- . . %Titer of " !..„.,..:. . - • - ef .specirrens .• _ r.,- , • -p t.a 162- ' ,-

Determination of age was carried out with the help of a magnifying glass.

Since the material was very limited, the yearly increment

was determined by the method of inverse calculation using the Einar Lea board.* '

*literal translation - transi. Since we noted a number of very insignificant morphological differences and some spawning differences between the black hali- but of the Okhotsk and Bering seas, we thought it would be suitable to discuss the material on age and growth rate for each sea separately. (263) Sea of Okhotsk. The linear dimensions of our specimens formed the following series:

Length, cm 20 30 40 50 60 70 80 90 100 No. of specimens 4 10 19 14 9 12 6 5 n=79

However, only 63 specimens could be used for the determination of age, as the others were represented only by scales.

Age determination showed that the catch of 1932 included 23 age groups. Table 6 gives the average lengths of each age group both at the time of landing, and according to the years. The latter data were derived by inverse calculation. A comparison of these data with the absolute ones shows that inverse calculation increased the length somewhat in all cases, and this error increased with age. For example, a 7-year-old black halibut measures approximately 45 cm; according to the data derived by inverse calculation, the length of a 7-year-old fish is overstated in all the cases ex- cept one.

The rate of growth is characterized quite well in table 7.

In this table, we are first of all struck by the nature of the growth of the black halibut. It is very similar to that of the true halibut (Hippoglossus hippoglossus stenolepis Schmidt), but it differs greatly from the growth rate of other Pleuronectidae

(e.g. Limanda, Pleuronectes, Cleistenes, etc.) which reach a length -24-

(264) of 30 cm at the age of 5-6 years. A 3-year-old black halibut is about 30 cm long. Secondly, the growth rate slows down consider- ably from the second year, which is not observed in other non- pleuronectids.

The significant variations in "growth can be attributed to two circumstances, i.e. individual characteristics and error during age determination.

Table 7. Average yearly growth of different age groups in the Pacific black halibut of the Sea of Okhotsk

•••• •••• e•;:1 2•-•- ••• • ••• ...• . •■•éV ■••.: - . •• • - CD 'i# 1 e- ill • 44

Years . QJ 0 griçieTet '; • :•;9;ia xix me. 2

ïèi , ; 4e. „1„5 6■7f.

k' 2e 3,0 2,4 . 3,Ct * -L› Y.:2 6

2tej

ei 1,5 .0 • 4 ',. ;';1,-Er 'Alew VI:eti7kr.4e ■.*;

ge.•••• ■ • • — • ••■■ •,; Number of ' specimens 1 5 Bering Sea. The linear dimensions of our specimens form the following series:

Length, cm 10 20 30 40 50 60 70 80 90 No. of specimens 7 6 9 13 5 9 22 4 n=75

( 264) of 30 cm at the age of 5-6 years. A 3-year-old black halibut is

about 30 cm long. Secondly, the growth rate slows down consider-

ably from the second year, which is not observed in other non-

pleuronectids.

The significant variations in "growth can be attributed to

two circumstances, i.e. individual characteristics and error during

age determination.

Table 7. Average yearly growth of different age groups in the Pacific black halibut of the Sea of Okhotsk

' Variâtiotr-'; ..1) . .■ b.0 '....: i :-..., -,., ,.,. ._ g e, g r .o,..u,.p, s H ' • ."'..in " gi, ô" -xyl- :94Si-ii - zy [it , x•fx ),;ic : kg:1'; , xid ïiiii.e ro w t h: :: • › 1.... "::. :. : •.-•..,:,: : . : :-....' ":'•••• • " ' - -, ,"-"..:-..';'". -....-.;. t.i"-.7.- .';;;,...... ,,, e-, ‹ 66

..._ .. • r , : , ,, ;-;;; ; . ',-.«..,,:, '',«,,i'';,.;„1. i.-",.:.:;... ,:::., 1,:f.:e..,- . ,9,3f. .., 16,8 i, , -.- .,,.. •: -.9,8 ":->11,& • .•16,-9,•i *.-.e:. g12,12 111,3 ....9,9, 7;;.fj-li•-:,"• ,.I.2,•-• '.... •9,3. ' '9,6: ' +. • .....6,2.. 9:11. ',•,.10,5-7-62.:',' ....4;5. d;,.9,Ce; , 7:2 " 8,6. :7''' '.. ..'...-.6i5::- • '. 8,0: ,..,8,6" -6.5..;::1 •Zr, k"8,0` Z6 . ..•8.2: -'- • ...: ,i,i'62, • 5 0 : . 6,0- •,ï;:7,5-1-5,0,-.., -.:1,5 'se 7.5 - --..- - .7,3_ -6.4 .,"•--., '17, i sy. "6,4. -":" '...:i . . 50 I6 .^:. ,1' 67 - 7 :::,... Y...3,0 ' :3';54 5,2 .•:?6,7'. -....;:;.> > • , . :..2,9- ":".U,`,874 .: 5,4, ,•-:!_.-:„,- : &T,.. :: '5,2: . • 4.: J. . 2 • 6,03 ,1'...... ".".. 4,2 - f.:..... " .:"416:: ,:. -.4,8-. .'4. 38« 48 .:::5,2-:-,--12:::: "'up -..,,,4 3- :. -4,4-. -:-.?:::;•.-; • • ...4,e. ',.:A,o--,.:4- -.-' ..,, ''f. ■8,7 ■ t.:.• ,17 ....4,1;• 4,0:; ;,•.--;f,) • 46 ..h.4,te-t-3,0:., ..ie :.. se 34 t '32 :.."•"4,1:. -.724».... '• •'. -..1,2- 34 .',";:-.1 -. 'i,;3,e. ',...:32- .•••-•;'• >„--"• , & •,,:•:4, •••,••:.4.,0=.75,0! :.1,0, ,:.: 3,3! 3a :::: . 1 ' '?•: 3,1:; •, 12,9- 1,-4,7;:94 e i; 34 ._ 4,2,7+2,Eri.::. :1:4' :,. 13,2 ':. 2,8, •,.:3,0' -SO •;',.3,0 “..,..-- .., •29, 29.:• ''.---:, '.i. 3, 1 .-:, ' ex ...*,«.,..3,3 -ze:.....,T,2. :, • 1,6;••1;7 2,6, ..‘,2,4 ... -4= ,■ ,...... • 3.0• 2.2• - ' 4-:- , 3,8": A 2,7 •''. •: 3.82,2 . * 22' ...;.z...,e, .3,6.• :3,5, ••'...*:. 3,6L-2,9-*-.• -i.,1,6,,I.:,, 2,7: .. 2,-e• ,..' - ‘,.›....›.,. 2.5 3Ct :, -4. -gi2.9g. -..- 2,4- ---...."'. '44'. .."*. 26: "2.• 44-24'. 20 . 1 - - .- -20 7,4' - 4 0 -.- 2 "t,.. '-... 0 -2,e_-. ; ç-3s3:-"--1,8e: ""-:'1,5". 5'?.2,4-: :-:: -::. -. 2,4: '.,." . 2,0.: •.;',-,:,',: '..3,30 "-.... 1,8- . ;:,.-..49, :ï,•44. ';.2,6.... --:.1.6 - .,-,..,', ..3,5‘ ••-• 1,9: -;,.;'3,5+-1,e -...2,5:.; . 22 .•.;::•• ;.• 2,8 .': le ...,..,!,,,,,e+4,,Eki. ,..•:ixt: :::,..za: -, - ,...:, ,,'De ,...11.9t. . 17 , " "•-• -":. Z. - ::- 16 «:w...2,41,6 . . 1.• 1 .4- - 20 - 1,6, -74: 2 o---1,6.i._ :,0,4;.... e 20« : 18. :;:72 0 1.3,,:: ,--0F, 7q1,95 ,- tai.--..j• "• --,1>e ..,,, t ,

. • -.;‘, Total. .... , fe:..:-Ç,.'1,,:. '

Bering Sea. The linear dimensions of our specimens

form the following series:

Length, cm 10 20 30 40 50 60 70 80 90 No. of specimens 7 6 9 13 5 9 22 4 n=75

-25--

Only 18 specimens could be used for age determination; as a

result, only 16 age groups were established. It is still too early

to tell whether 18 years is the maximum age for the black halibut.

Determination of yearly growth did not reveal any difference in

growth rate between the black halibut of the Sea of Okhotsk and

that of the Bering Sea (table 8). The growth rate of both proved

to be very similar.

Table 8. Average yearly growth of different age groups in the Pacific black halibut of the Bering Sea

1i:rétààe rowth for 'Sea of .."t 015119t,fil.4-e-

6.24È . ,

4 )_i;"44'41517,i

; .

tj • : ft.:. 4. T,e • e/8 1 t›. e Torgi

The relationship between length and weight proved to be the

same as in HiEEoglossus hiEEoelossus stenoleEis Schmidt (table 9). (265) The correlation table shows that there is a definite regular de-

pendence between the incease in length and the weight increment,

which is similar to that in non-pleuronectids. The most rapid

increase in weight begins when a fish reaches a length of more

than 55 cm, i.e. during the 9-10th year. Only 18 specimens could be used for age determination; as a result, only 16 age groups were established. It is still too early to tell whether 18 years is the maximum age for the black halibut.

Determination of yearly growth did not reveal any difference in growth rate between the black halibut of the Sea of Okhotsk and that of the Bering Sea (table 8). The growth rate of both proved to be very similar.

Table 8. Average yearly growth of different age groups in the Pacific black halibut of the Bering Sea

The relationship between length and weight proved to be the same as in Hippog. lossus hippolossus stenolepis Schmidt (table 9). (265) The correlation table shows that there is a definite regular de- pendence between the incease in length and the weight increment, which is similar to that in non—pleuronectids. The most rapid increase in weight begins when a fish reaches a length of more than 55 cm, i.e. during the 9-10th year. •

—26—

These data are of great interest from the practical aspect,

for they serve as an indication of which age groups are the major

ones for the fishing industry. Since the given age groups are

characterized by a very small increase in length (3 cm), and the

old fish by an even smaller increase, we thought it would be in-

teresting to determine the cause of the increase in weight.

There is the opinion that the decrease in linear growth is

compensated by growth in the dorsoventral direction. However, a

study of the relationship between the increment in body depth and

the increment in length did not establish this fact for the black

halibut (table 10). The individual variations in body depth proved

to be so great that it made it impossible to speak of any relation-

ship between it and body length.

A study of the relationship between the increment in body

length and the increment in thickness showed that the latter

depended completely on body length.

Table 9. Correlation between length and weight in the black halibut of the Bering Sea

, •

. (cm) ,--,-; ..1 - . g: . _ 43,5 .- - . 49,5-:. 5, .61,5. _.. - . . - . . - .-'67,5.:'• ..! .73,5,-. .. ,5 , • . • • • •• -•' : - , .1' ...' . s . '... .,...... e • -) ,--. .,.... .,. 21 1 .....„.. • ,„..,. ,.. ••: --„, .i--,- -- ›1, ,,-..- ----•,;.. , . . ,.- ,.. , .. , ,. • • ..,, .--.-,, ..... ,•••••.• ..,_,,, , ...,, .. ..! ,....,---m :,,!•:-. 4: • . X -. . - la-. ' ' : .. • - ..

- 2 7 -

Table 10. Correlation between body length and depth

t . :4',-. 4..s.. ,T ..‹..,. "•:. •.›. ..e •'',.., ... s.... ■ ' 7. •r, • .,7 "•-•e,..A,-",.." , .•;13-'"2.• • •4i!: .. :14,-.: A - . 4 ' . 294. ,.- 1' . ., .. ' -..„•.7-'_-..,,:.,

.. ..--. ,.- '2 , '..... . f- »...... _:...... • .... --,,, e.,..----P Mr- .. ;?-:" 27 5, . , , . . _ • -:•0..•%-.28, ---"•= '..«... 28,5 ...- . . fl ›...... , 12 . ,:.....,29 0:-.` , —.4 7,- • -„--.:.29,5 .___.,...... ...... t. ,. ...-...! ... 30,0 • ... --- .. .,... :',...30,5... '...-- ,,,,,, - -.,,. ., ■-;. .-'.;, 31,0.2,7 ..... ..,,,,..., - -. - , .-+-É--. . a . ...',. ..,.,-.■ -•../.• _ *...,• sy --..o,.... [...". .

Table 11. Correlation between body length and thickness _ ...... ,.-- ,.. .'-• ..-1 , .. : . . - ,...... ) ce. _, .. it, ' :!..'.. '‘. .. , 41 . . -- ;-5' 53 iT.' ..., ., _. . ' . ' . ..., ' ..'it,:i.,".t.l.fr4••',- ■••••0,;:;. . , . ,fe . .‘ . - , -.-... . ,, ce .... ----.. . . . '.- ';`,•. , .i... ., , _ .„ -...., - 5 ' ---.... s,-rs...., • ...,...1--e 4: ...... -,. i-..., 7-r-' . •,' . . , •-., •' . . • . , ....."..,-. ..r... i.= ... -- '....‘ • • •:—.--4 , , .,, . . . %It.' . ,...';) B.; ,3- ,-, .....:.: 4; ,s,z, ',1.J.,•',5,,,i,:. -,.s.' 7.:',9'.--? -, -. ‘. ;.;',7-4. 1 - ,..,• ..•. ,--,.:..,4 ,:. -,..--.: , -.- -. :.<:,-- 1.2 -e.7.--.;:-:-.;

It follows from table 11 that fish measuring over 40 cm in

length grow rapidly in thickness. Consequently, the Pacific black

halibut, like all non-pleuronectids, grows heavier as it increases

in thickness.

Due to the fact that comparatively large variations in body

length were obtained for each year, we began to wonder what actually

can serve as a criterion of accurate age determination. Having -28-- • .•

(267) studied the age composition of Pleuronectes flesus and the relation-

ship between body length and the length and width of an otolith,

Ye.K. Suvorov (1927) came to the conclusion that each age group is

characterized by its own average length and width of an otolith.

We attempted to verify this on our own material. The results of

this are given in table 12. (268) As we can see from this table, this tendency is also observed

in the Pacific black halibut. Each age group has its own otolith

length and width. Using these data, we can now ascertain where

the most serious errors in age determination were made. For exam-

ple, the Okhotsk specimens assigned to the XII, XIII and XIV age

groups should apparently have been placed in age group XIV. All

of these specimens have the same otolith length and width, as well

as the same body length. The specimens assigned to age group XVI

most likely belong to age group XVII.

Fishery characteristics

In the commercial respect, the Pacific black halibut is a

valuable fish because of its large size and its tastiness. It has

long been recognized as a valuable commercial fish in the USA and

Canada, and a special halibut fishery has been set up in Baffin

Bay. It is marketed only as a smoked fish.

In our opinion, the black halibut is not of prime commercial

importance in the Bering and Okhotsk seas, but it is a very impor-

tant bonus catch in addition to cod (Gadus callarias macrocephalus)

in trawl fishing. In both seas, it is caught with otter trawls to-

gether with cod, Hippoglossus hippoglossus stenolepis Schmidt and

Atheresthes evermanni Jord. a. Starks, which are of great commercial value. So far, there have never been any large concentrations of

any of these species on the western coast of Kamchatka; they are

dispersed and this makes trawl fishing unproductive in this area.

It would probably be more efficient to develop longline fishing

from kavasaki vessels* here.

No large concentrations of these species have been detected

in the Cape Navarin--Matveyev Is. area in the Bering Sea, but the

catches of true halibut and Kamchatka flounder there ve,ry often 270) number tens of fish, and the catches of Pacific black halibut and

cod hundreds. However, it would be more efficient to organize

longline fishing at depths of 100-300 m in this area as well.

Summary

The authors had 36 fixed specimens of the Pacific black hali-

but from the Okhotsk and Bering seas at their disposal, and 108

specimens were used for age determination. Detailed investigation

of this material helped to establish the following.

1) The Pacific black halibut is distinguished from the Green-

land halibut (Reinhardtius hippoglossoides Walb.) by only two

characteristics, i.e. a smaller length of the maxillary, which in

the black halibut varies from 31.2% to 35.5 7o of head length and

is equal to 33.6% on the average, while in the Greenland halibut

it varies from 35.8% to 39.5% (average 37.4%); and by a much

smaller depth of the caudal peduncle, which is equal to 67% of its

length in the black halibut, and 82.6% in the Greenland halibut.

These differences are within species limits, so the Pacific

black halibut should be regarded as a subspecies of the Greenland

halibut, Reinhardtius hippoglossoides matsuurae Jordan a. Snyder,

* a 13-14 m long motor fishing boat indigenous to the Far East and used there in inshore fishing - transi.

Table 12. Relationship between body length and otolith length and width

i ,... ■ ■ ze. -.-.z..7 ., -s. % •••• 't• '''' ;'41:". .-.', - , ..r t . ' "-r." ;-,, , .,--- ? .--. : 14,77.,,,,, r,-...,T. -;„ ,.',.. «1«.7.11MIrgrrr,eel.nti",ileree • '.,...A'• '4.› , '')‘"e-11.^3.- - ; -1e71:1/4<;1.:: '41- - /"4 , 4 ','. 4 - '- .,,..

,.• - - -'s.,,4'..t?• -..*; -e.,. Pf Okhot.s,k._ --4 .,....,-. - e' :e:-...,...bgei..n..Sq. .,.... , 1:-... ..r; :tev . :-...,.: .,---.;"••••':- - -,...:. . ,.. :-,,,..7.,...... •(3.«, ...:.,,-:....7.;1* re.": , 4r..4'. ''r''' , ..-•'• • ". • , ' • , ' ".= ■ , ' Ul ' . ''"'" 1-, '' . ..,;,;,.....-...,.-x- v... -..e. c. ..... „..,,>.:. 4-1. --- 'e,: . ' "'' .i.-..,. --Ir „, ..,„‘...i.,,... ,,,, ,,.. 44, t.„.... . ...„..,..- ....,-.._., 0 : 0 ?ee bel: . 7; . ,... e,,,. . 0 ..4:: ,a) o 4; P • • ...`.4-4 .-1 " '''' ° 5 1. x2 '5 "--' -7 G.) 4..p....- ,tto 4.1 ,.0 , _. ,.., 0 - "61 .: Î--..rc,.0 4 •,-Ià1 u:1 ,e .,.-1 :': +5 el 4-1 .,•4 , CO Q.) 4-1 ' 7-i 4-1 .--1 ' ' RI •c1 4-1 :1.4 • .., 0 _ , " ê o ,-, -,-f ,-, ,;::, '17 0 • ,-4 W M "IJ ""4., i- 'I-I "4 Q.) ■ C1.4 0 -14 ci.) e , 0 c...) o 1-1 e o; . CI) ''e 0 CI) 0 , P › • 4./ / 14 Q.) .0 CU. 11) .1-1 - ..› •cl 4-) . 0 •,;,• 7., ,to -- .--1 -_, > •-1 0 • > •,-I 0 CJI : ‹ ..--I • , ."--""'" - r • .. :- , • ''. ,- , , ::' , :.1pi .•' • "-'''' .,..› fee>, ■ J. 4 't ,'■ 4-, ' : '';''''.. , • '..;.i•Ite4,4.e.p .ICS, 1 1 _ - , j. ,r, ' , ,-,-. -1,..çlreie y ,• , . ' l...1'.. , ■g: •■ :. ,8 1 ' '-...... ',..,,,-:7: . Ili 21 26,3" ., "0,52 • 0,/..- '«e'• ' ' 27,2 ':•-• ' ';':. 0,50 '; , iv -,.: 1 a4;2.1/4-",";.,4 " - .-' 0,62 - ' .0 50 -=- 1 ' 34,3'' '''',- 0,60 .'''''.: 0.380,507%'...-e•. 'V e;s•t.' ea • • 37,3e i'd,i.- - - , ; ,, 0,74 - , - • -- . ;13,65 . , . r-,-- • 1 38,3 " 0,68 . 0,58'7:.":. ' VI '.:;' . 41;4. ::'''''. 44,C--10,0 -.. 0,79 '. 0,82_,.- 0,73 - 70,61 ' ,_ 0,74-0,58 1 42,3, -..---, 0,78 • -;"' 0,61 .! , VII ' "‘ 6 46;0 ,-; 48,2-,L43,0 • : -0,84 -- 0,97.-0,75: '0,67 ;:. ' 0,74-0,58 46,5 ' : 0;70 -. ..?•;•: 0,60'..... V i I ! , SQt9'e : '. 52,0-49,0' .,'. 0,93 - • 1,04:-;0,80, . , 0,65 ...";• 0,70+0,60 „ - 1 47,' -.-- • 0,8e:',:.- . -• "..e.• -41. • 1:4", 7 • 56,1-Ç.e, ,.. 59, 0-53. ,0 . • 1 n3 •• • 1 15-0 87' - 0 74 ' 0 80-066, : , X .y-.•• 3 39,3: .63,0- - - 57,0 : 9,98 :_.1,05 7 0,90 .:, 0,73 .,. - 0,77 -r0,70 - - ‘• x . ,, ti 62,0*?-•.':-, 64,0-59,0, 1,00 :- . r-- f,23-0,80 • 0,76 ' 0,84-4,66 r ._ 67,0 0,90 ,80 ! 'XII 5-_, -71,0 '.- 75,0-66,0 . 1,06.:; , . - 1,20.:::-Q,90 • .: 0,80 :,:- 1,00-.--0,70 1 72,0, ' 0,80 XIIU.!- -,i.'!„,: 6 70,5 - 71,0--61,0' 1,06 .' - -1,18-0,9Q. .- 0,76 " 0,83-P 70 -• 75,0-, -', --- Q,64 69,0 ,,--.:4:' - 1,00 •, • ',- " "-' •*.•••'-'-' -,' 0,80 .; .,.,-.e. e "...» . ' :'•-:" X ' te'' _ 75,6 _2i. 78,0-74,0 .- 1,14 .:-. 1, 34-4..., ,00 • • 0 , 89 ., 0 , 94-LO . 83 - 83,5 ',..... 84,0-,-83,0 1,31 ' : I 35--1 27 : 0 , 95 0 95----0 95 • , • -- '-.. - • _ - :. , >..' xrx 1 87;0 ,6 '•• 1,03 ...... -,,e.--. r;":"•-4-.1; • - XX 1 , ',: 92,0 - --. -, 1., 10 .,_. .:- et.r...1...._ 1Z..:=11: , --''' 1• 90 0 - . 1,40 0,96' s 2 i ....., • ' '..-.XXIII' .7' .,- -:.7- • r. , •I'' i+.f eie 5..i.:.e. ,-ey.... ‘.. "-' 960- '1,27 ''': 0,95 . - r e!" ...e ,, .. - - . .;_-„.:-..:.;,.. --;.-..' ,'-iiii-- 1.- s , , ' . V4 i -?- • • ..; ' it 4e e 4 ' ``.4,:e: ' r " 1.., • !". ..,...d--:#4, e ',-...... ,,... .,...-,..-..„*..4.--1. -31-

which has erroneously been described as an independent species,

Reinhardtius matsuurae Jordan a. Snyder.

2) Up to 1931, we knew of only one specimen from Sagami Bay.

In 1931-1932, the black halibut was discovered in the Sea of Okhotsk,

along the entire coast of Kamchatka up to Point Khariuzov, in the

Koni Peninsula--Babushkin Bay area in the northern part of the sea,

and south of this area up to a depth of 700 m and along the north-

eastern coast of Sakhalin Is. In the Bering Sea, it is encountered

only in the area adjacent to Anadyr Gulf, between Cape Navarin and

Matveyev Is. at depths of more than 100 m (up to 200 m). Judging by

its habitat, the black halibut should be assinged to the boreal

fauna, instead of the arctic fauna.

3) Sexual maturity apparently sets in during the 9-10th year

in females and slightly sooner in males. Spawning apparently takes

, place at great depths (more than 300m) during July-August in the

Sea of Okhotsk and during October-December in the Bering Sea.

4) Age determination is possible only from otoliths during

their preliminary dehydration and clarification in oil of cloves.

According to our data, the age composition of this subspecies is

up to 23 years in the Sea of Okhotsk, and up to 19 years in the

Bering Sea.

Growth is rapid during the first year (up to 10-11 cm); from

the second year, the growth rate gradually decreases, and after

10 years amounts to 2-3 cm.

As to the nature of its growth, the Pacific black halibut is

very similar to the true halibut (Hippoglossus hippoglossus steno-

lepis Schmidt) and differs greatly from all the other Pleuronectidae -32-

coming closer to the non-pleuronectids.

The weight of the black halibut varies from 1.5 kg at a length of up to 40 cm to 5-6 kg at a length of 70-80 cm.

Rapid increases in weight are observed from the 9-10th year, and are related not to dorsoventral growth, but to an increase in thickness, which also makes the black halibut similar to non- pleuronectids.

5) The Pacific black halibut is a valuable bonus catch in addition to cod (Gadus callarias macrocephalus), and is caught quite well with an otter trawl. There is a commercially important area fishing— in the Bering Sea, where tens and up to a hundred black (271) halibut are caught with an otter trawl during an hour of trawling.

On the western coast of Kamchatka, the Pacific black halibut, like the cod and true halibut, is more scattered, and therefore, it would be more efficient to conduct longline fishing in this area.

Our data on the biology of this halibut should be regarded as tentative ones which require further research.

References

1. Andriyashev A.P. Geographic distribution of sea fisheries in the Bering Sea. Issledov. morei SSSR, 1935, No. 22.

2. Andriyashev A.P. Some data on the ichthyofauna of the Bering Sea. Ibid, 1936, No. 25.

3. Vernidub M.F. Data on the Pacific true halibut. Trudy Leningr. ob-va yestestv., 1936, v. XV, No. 2.

4. Vernidub M.F. Kamchatka flounders of the Far Eastern seas. Trudy Petergofsk. biol. in-ta, 1937, No. 17.

5. Knipovich N.M. Key to the fishes of the Barents, White and Kara seas. Trudy in-ta po izuch. Severa, 1926, No. 27.

6. Soldatov V.K., Lindberg G.M. Review of fishes of the Far Eastern seas. Izv. Tikhookean. nauchn. in-ta ryb. khoz., 1930, vol. 5. • • >

7. Suvorov Ye.K. On the biology of the Murmansk Pleuronectes flesus. Tr. in—ta po uzuch. Severa, 1927, No. 38.

8. Taranets A. New data on the ichthyofauna of the Bering Sea. Vest. Dal'nevost. filiala AN SSSR, 1933, No. 1-2-3.

9. Trempovich P.V. Differentiated staining of scales from commercial fishes for age determination. Byull. Vsekasp. nauchn. rybokhoz. eksped., 1932, No. 3-4.

10. Schmidt P.Yu. On the zoogeographic distribution of major commercial fishes in the western part of the North Pacific. Byull. Tikhook. kom AN SSSR, 1933, No. 3.

11. Duncker G. Variation and affinity of Pleuronectes flesus L. and Pl. platessa L. Scientific Marine Research, 1896.

ti:-;•.A-;=:fie-rè-6- pacpettiecito6:.•pacitpocipatietnte.: mopcHax. rippubica.. ..-P :fosa-. Mope-, IfIccae,adià2 itOpeer CCCP;‘. Bun; 21« tut: p H Ittee•.s: friettoro1Ii4e. • eplinrosa btopst.'.. kfccae,tton

• z •' • • z 6-p,-H II jLyf M t M rpiiiw ic. rioSH1erinie,-=',:THOOKeen4eozetiY, 6e.rfoitiSpor6,-rif,T3.çà 2.L."3-936; Ztteie 6 per fe-,7x.y, mOperl t p rreT. Bnonoratiecaôrd'Hir-ia Bun ,171931-.7-, , z,-oà; ii wre o H.U p:'.1-1-":-./yr:,‘OnpeÀe ..rirrieni-iiii62«:`, BàpgittrianaePg.likee:F1,;21rapén\ro'im6Èee-- ,; 11H-r. no 1•,tayrenefFe.Cesepe-.. ; gc,?nut itÀ.e. h10Penit:fera phi6 :" • K' • 6 Honoy,ent..• e:typ eaHcaoH." euronecle.s- HH-Ta•• Ho, H31,5eiyikeer, CLoe1r uwi 3$ 1927 pe1)Hflëé.13 a1 CCCP, • , B...'i.,:ftncPiPérieeneeponaHnase:;:bi.cpaciia:.. ri.poidblènonbtx pet-r:a •on pefea6iffirr.-lioapac-ra,:. Etoaa: ,, Bceitacrr.'...naj7nr.£.-Tb160X03'. 9}cç1(em., 1932. Tri iI.l :.f12..101.0oorernacimecaor.e.1 ,pa-cnoodTbaHealin ivianuerunni.,- noombicaonbui.,'P.É4 oiteatia.- CC CP; ». 3. 1933.:Fi:4:.;:;!,:‘4..i rt»..'4V,arfation und.",-Ver;cia/tedSçhaf• ‘'Ion'..Pre• zirottecieàfiesu.S: L. und Pl. platessie,'''' e CatatoeFise--:Eist- coast. Nortfeez'Arnerieài: -.1.eàli.":1873 stékrcl S Byer in faire-W=,-.11,';,,W.:;PislieS:'71`.1,Ort.ti Bull; Nit Pi1tià.'73■.k..-477.nW ash: • e,i1:1;4,..;1.0-.r`d à ald;-,. G as kr:Re,;rieve.F1.6.1incieWe.:;SoieS:., î'1Jor d a &Si àr k s E CliReview4 Plotunders a. Soles Japan's: Proc.' IS. V7, .-- X?(X1-:,1906 1,(1907).L'f, / , Àe 192&..:., ap.' North \Vcst r. u ulmlntttLe 192471925.; .- • •. •'• Yé.ir s ere 'A its devekitinten triigratioris..,Mém:,!rAcad.-Roy.• Sci. I■e- • 4, erk., A.. Migration ftshes-.191'6,!- ' '• • "' - Systeiriatic: m on égràplifratits.i. ch ;B .i I tz; Mùs. Nat' Hist;- 19; It in I distri butto it :,.Chie frr Marine ,: food fishes in north'. Ph.1flc P roc:: flith. P actfic.Sci: Con gress:::Canada; 193 3 X.:L-Y... 1934' ç oes.-c Um I t T o h On p.elagid-Tpost-larve : • a k•a"; Set_