Canadian Translation of Fisheries and Aquatic Science1

CANADIAN TRANSLATION OF FISHERIES AND AQUATIC SCIENCE1

No. 4643

The growth and life span of Sthenotheuthis pteropus in the east-central Atlantic

by G.V.Zuyev Ch. M. Nigmatullin V.N. Nikol'sky

Original Title: Rost i prodolzhitel'nost' zhizni krylorukogo dal'mara Sthenoteuthis pteropus v vostochno-tsentral'noi Atlantike

From: Zool. Zh. 58: 1632-1641, 1979.

Translated by the Translation Bureau (NDE) Multilingual Services Division Department of the Secretary of State of Canada

Department of Fisheries and Oceans Northwest Atlantic Fisheries Center St. John's, Nfld

1980

18 pages typescript • DEPARTMENT OF THE SECRETARY OF STATE SECRÉTARIAT D'ÉTAT TRANSLATION BUREAU BUREAU DES TRADUCTIONS

MULTILINGUAL SERVICES DIVISION DES SERVICES CANADA DIVISION MULTILINGUES

TRANSLATED FROM - TRADUCTION DE INTO - EN Russian English AUTHOR - AUTEUR G.V. Zuyev, Ch.M. Nigmatullin and V.N. Nikolisky

TITLE IN ENGLISH - TITRE ANGLAIS The growth and life span of"Sthenoteuthis« pterOpus in the east-central Atlantic

TITLE IN FOREIGN LANGUAGE (TRANSLITERATE FOREIGN CHARACTERS) TITRE EN LANGUE ÉTRANGÉRE (TRANSCRIRE EN CARACTÉRES ROMAINS) Rost i prodolzhitel'nost' zhizni krylorukogo dal'mara Sthenoteuthis pteropus v vostochno-tsentral'noi Atlantike

REFERENCE IN FOREIGN LANGUAGE (NAME OF BOOK OR PUBLICATION) IN FULL. TRANSLITERATE tFOREIGN CHARACTERS. RÉFÉRENCE EN LANGUE ÉTRANGÉRE (NOM DU LIVRE OU PUBLICATION), AU COMPLET, TRANSCRIRE EN CARACTÉRES ROMAINS. Zoologicheskiy zhurnal

REFERENCE IN ENGLISH - RÉFÉRENCE EN ANGLAIS Zoologica1 Journal

PUBLISHER - ÉDITEUR PAGE NUMBERS IN ORIGINAL DATE OF PUBLICATION NUMÉROS DES PAGES DANS DATE DE PUBLICATION L'ORIGINAL "Nauka" Publishing House YEAR ISSUE NO. VOLUME 1632-1641 PLACE OF PUBLICATION ANNÉE HUME NUMBER OF TYPED PAGES LIEU DE PUBLICATION NOMBRE DE PAGES Moscow, USSR DACTYLOGRAPHIÉES 58 11 18

REQUESTING DEPARTMENT D - 0 TRANSLATION BUREAU NO. 2149984 MINISTRE-CLIENT NOTRE DOSSIER N 0

BRANCH OR DIVISION TRANSLATOR (INITIA LS) N. De. DIRECTION OU DIVISION SC. Info. & Pub. Br. TRADUCTEUR (INITIALES)

PERSON REQUESTING Mr. Earl Dawe DEMANDÉ PAR TRAN.U,ATION YOUR NUMBER -- UNEDITED VOTRE DOSSIER NC) For infzunatbn only TRADUCTION t3N RUVISEE DATE OF REQUEST March 19. 1980 DATE DE LA DEMANDE Informal-ion seulement

MAY MAI 5 1980

SOS-200-10-6 (REV. 2/68) 7 530-21-029-5333 Secretary Secrétariat • 111+• of State d'Ètat

MULTILINGUAL SERVICES DIVISION — DIVISION DES SERVICES MULTILINGUES

TRANSLATION BUREAU BUREAU DES TRADUCTIONS

Clients No.—No du client Department — Ministère Division/Branch — Division/Direction City — Ville

D F 0 Sc. Info.& Pub. Br. St.John's,Nf] d. Bureau No.—No du bureau Language — Langue Translator (Initials) — Traducteur (Initiales) 2149984 Russian N. De. 11,1 5 1980

Zoologicheskiy zhurnal, 1979, v. 58, No. 11, pp. 1632-1641 UDC 594.582.5:591.134+139(261.5/7) (1632)* The growth and life span of Sthenoteuthîs Pteropus in

Lu 7.`e! the eastcentral_Atlantic 0 ,..;u by G.V. Zuyev, Ch.M. Nigmatullin E (LI and V.N. Nikolysky {D. 0-,, (7) Institute of South-Sea Biology of the Academy of Sciences of c. the Ukrainian SSR (Sevastopol) 2 0

eT) C.: The linear growth and weight gain of Sthenoteuthis pteropus L.) k- the structure of the 0 P are studied by analyzing dynamics ofthe size catches in the east-central Atlantic, and its life span is deterr. mined on the basis of this. The relative daily increases in mass diminish from 15 to 0.5% in the course of development, and Its life span does not exceed 1-1.5 years.

Despite the significant number of papers that have been devot- ed to various aspects of the ecology of cephalopods, data on their growth and age are still extremely scarce. This is due to the fact that cephalopods, with the exception of a few- small littoral species, adapt very poorly to life in captivity. The number of cephalopod species presently reared in laboratory conditions does not exceed 15-20 (review: Boletzky, 1974 ). Observations of cephalopods in natural environments are associated with serious difficulties due of these invertehrate,qy to the high motor activity and the lack of sufficiently effective fishing techniques and equipment. Mass tagging,- a method of di- rect grohirate analysis which ensures tag returns, has been . -- * • _ • The numbers in the right-hand margin are the pages of the Russian text - translator

SEC 5-25 (Rev. 6/78) 2

carried out only for Todarodes pacificus, the object of a specializ- ed industry. No. morp171ological.structureb that would characterize growth rate, such as the scales, otoliths or bones in fish, have been detected so far in cephalopods. Clarke (1965) attempted to determine the age and growth rate of Moroteuthîs ingens by the mandibles of the bees on which he detected clearly defined structural formations resembling those on fish scales; he called these structures "growth rings". He associates the zones in which these rings come closer together with the periods of overall growth inhibition as a result of yari'a.r bility in biotic and abiotic factors. Since we still do not know- how long the squid are exposed to these factors, it is impossible to establish the duration of each cycle of mandible growth. As a, Me7 suit, the author arbitrarily gives ît as 6 to 12 months. The e..7- tempts to study the growth and age of cuttlefish by their shell (sepium) were also unsuccessful, as the rate at which new septa are formed depends to a great extent on the environment of theeftï mals (Choe Sang, 1963; Richard, 1 9-67, 1969; Boletzky, 1934aY. It has been established that, when cuttlefish are reared in laboratory conditions, the rate at which new chambers are formed diminishes drastically when there is a shortage of food, or when the tempera ture drops. The number of septa can serve as an age indicator only when the cuttlefish inhabit an unchangeable environment. (1633) The growth rates of cephalopods in natural populations are most commonly analyzed with the use of empirical data on the modal size classes and their time bias - -_- (Summers, 1968; 1971; Holme, 1974; Tinbergen, Verwey, 1945; Fields, 1965; Murata, Ishii,/ 1977; Ishii,1977); however, this method can be used successfully 3

only in the cases where the spawnirig of cephalopods is of a well- defined seasonal nature, and usually In temperate zones. The growth, age and life span of oceanic squid - are not as well- researched as in the other groups of cephalopods. They-, preSumably, grow more quickly than the neritic species. For eXample, the Month4 ly increases in the size of some Todarodes- patificus (iweth. a, mantle length of 15-25 cm) have been known to reach 2-4 cm during the grow.r ing period in summer. T. saggittatus is distinguished Byan even faster growth rate. During the summer growing period in the vicinity of Iceland ànd in Norwegian waters, the average monthly Increases in size amount to 5.2-7.6 cm with a length. of 2 0.. 30 cm Wridriksson e

According to our own data, the young of this 1943; Wiborg, 1972). species measuring 19-24 cm in length grow by 4.5 cm in a month dur 7 ing June-July in the vicinity of Cape Blanc. The life span ofNem-r mastrephes bartrami in the East Pacific is one year, and the 'maxi mum increases in size for individuals 25-30 cm in length amount to

3-4 cm in a month (Murata, Ishii, 1977; Ishii, 1977 ). .

The present paper looks at the growth of one of the prolific Atlantic species, Sthenoteuthis pteropus, which inhabits the upper pelagic zone of the open waters in the tropical region of the ocean from the coast of Africa to America. The main difficulty in determining the age and growths rate og this species lies in the year-round nature of its spawningi with a weakly-defined seasonal fluctuation in the greater part of the reproductive region of the range. As a result of this, the population is constantly replenished by individuals of younger age groups, and so it is extremely difficult to establish the modal size classes. 4

The northern peripheral population of large squid (the distant neritic population of the Canary Current). from the East-Central Atlantic (EC Atlantic) was used as the modal one for analyzing the growth rate. Its range occupies the southeastern part of the nor thern subtropical anticyclone system which consists of the water masses of the Canary and Northern Equatoriallcurrents and the adja- cent regions of the northern tropical cyclone system with "divergence in its centre (Zuyev, Nigmatullin, 19771.. Some individuals of this population grow to a size of 50 cm. The chbice Of this population for calculating the growth rate was prompted by the fact that the area inhabited by it occupies the part of the species- range with the highest degree of seasonal variability in climatic and hydrological conditions.

The calculation of growth rate was based on an analysis of the size composition of the catches and the dynamics of this composim tion during the different months in the productive areas oe thé populational range with seasonal migrations taken into account. Analysiâyofthé samples from productive areas gives us the most objective picture of the size structure of the whole population. The modal size groups were established on the basts of the èamples câught with hooks and lines Cspoon,jgs for catching squie, Wè analyzed a total of 2364 specimens 12-50 cm In length, grouped into size classes differing by 3 cm. The main disadvantage of the data obtained with the help of hooks and lines is that not enough individuals of the smallest and largest classeè•(smaller than 18 cm and larger than 40 cm)were caught. 5

Throughout the year, the northern boundary of the populational Cand speciesY range in the East-rCentral Atlantic undergoes notice-. able spatial changes, shifting by 5-7 ° lat. off the coast of Africa. (1634) Squid of this species are abundant near the Madeira Islands in summ. mer (32-34 0 N lat.), and are usually encountered south of the tropics (23-25° N lat.) in winter (Zuyev et al., 19761, Simultaneously with the seasonal changes in the boundary of the range, we observe the spatial shifting of the productive zones (the areas of concentration of squid) in theoceah. During the cold winter-spring period (February-June), accumulations of squid in the East-Central Atlantic are observed mainly south and southeast of the Green Cape Islands; squid are scarce north of these islands. During the summer-autumn period (July-January), this productive zone shifts northward, to the area between the Green Cape Islands and Cape Blanc. Besides that, another productive zone in the form of a continuous strip between the Madeira and Canary islands is formed in summer. Groups of squid gather at the ,-Madeira Islands eachlrear in August-September, and disappear from the area shortly àfterwards (Clarke, 1966). A comparative analysis of the size structure and biological condition of individuals from different regions of the populational range permits us to conclude that the population of large squid is represented by at least two biological forms, apparently of .a populational class, which alté .Edistenguished by the pereods and places of spawning (the summer-spawning and autumn-,spawning fonmsE, The summer-spawning squid reproduce mainly in July-September south of the Green Cape Islands. The autumn-spawning squid reproduce in 6

October-December north of the Green Cape Islands, and forage in the productive waters between the Madeira and Canary islands in summer, Taking into consideration the above-mentioned intrapopulational differences in the periods and places of spawning, we shall study- the annual dynamics of the size structure of the population of large

squid in order to determine their growth rate. In December, the dimenal

---y series of the squid in the productkve zone between the Green Cape Islands and Cape Blanc is represented by- a bimodal curve with the modes 18-21 cm (27.5% ) and 39,42 cm (2.5 96Y (fïg! 1, al, The first modal size group consists mainly of males and immature females at the 1st and 2nd stages of maturity. The second modal group cludes only pre-spawning females (3rd, 4th and 5th_ stages of,Imatu, rity). It can be assumed that the small immature females-were-born during the summer_iand-represent the summer-spawning form; the large

mature females are autumn-spawning ones which reproduce at this particular time. In January, the productive zone is located at the latitude of Aimensionalj the Green Cape Islands and south of them. T1TTY, series of squid is characterized by the presence of a single modal size group,

21-24 cm (27.0%), in which immature females predominate (fig. 1, b). Apparently, these are juvenile summer-spawning squid. The decrease in the relative abundance of large individuals and the disappearance of the second modal group, which is observed in December, should Be the fact that the overwhelming majority of the autumn attributed to

generation has by this time spawned and died.

1 _

0\0 10

. ow 3° 0 5 P o o o z ttl0 to

l ( t . 1 1------.------a p1 10

. e . 10

I 1 1 , i r-, r - 1 I JO i I ofc 1 q 10 , , . H11 1 5 M M 24 JO 36 112 48 Leneb, og_mant-la f •gt

Fig. 1. Changes in the size structure of squid according to the months: a - December (n=282); b - January (n=293); c - February (n=573); d - March (n=404); e - April (n=194); f, g - August (h=356 and 262)

The curve of the size composition of the squid from this area

in February is similar in form to the January curve (fig. 1, c),

its only difference beihg the ablUttagg. , , nu of the modal size to the 24-27 cm interval, which is due to the further growth of the 8

summer generation of squid. In March, squid 27-30 cm In length:predominate (20%f in the productive zone south of the Green Cape Islands, i.e. the mode con- tinues to shift toward the larger sizes (lifig. 1, d ) . At the eame time, we observe an increase in the relative abundance of squid with a length approximating the maximum one. The squid of the modal size group are represented exclusively by Immature femalee; the largest squid consist of mature females. It can be assumed that the latter are also representatives of the summer-spawning (More abundant) (1635) subpopulation, which were born the year before last, and are a year older than the squid of the modal size group. A large number of 12-15 cm squid belonging to this species, which cannot be caught with hooks and lines, is also observed in this area in March (near the surface at night). According to our assumptions, these are representatives of the autumn generation, which were born in October- December. The fact that these young squid belong to the autumn generation is indirectly confirmed by their relativelyôld-loving nature (the water temperature in the area inhabited by them does not exceed 22-24 °C). In April, the curve representing the size composition of the catches is fairly flat with two weakly-defined modes of 21-24 cm and 30-33 cm (fig 1, e). There is no doubt that the individuals of the second modal size group belong to the summer generation. As to the individuals of the first group, it can be assumed that these are squid of the autumn generation some of the males are (1636) mature, the females are all immature). According to the data of visual observations, 18-21 cm squid are the most abundant in April 9

(near the surface at night). Apparently, the first size group is flot completery represented in the catches due to the use of hooks and lines.

As we have already mentioned, another productive zone,apart from the year-round productive zone in the vicinity of the Green Cape Islands (the area of northern tropical divergence)- , develops in August between the Madeira and Canary islands, and some of the large squid migrate to this zone. Analysis of the size composI tion of the catches and the biological condition of individuals

from different productive zones has revealed significant differences. The curve representing the size cdmposition of the squid catches south of the Green Cape Islands is bimodal, with abundance peaks in the 24-27 and 39-42 cm intervals (fig. 1, f ) . Of special in-r terest is the second modal group (including_mature females) which should be identified with the summer generation. The first modal group apparently consists mainly of growing squid oe the autumn generation, which should reach maturity in December-January. The ,dimensional) series of the squid catches in the vicinity of the Canary and Madeira islands at this time is altogether different. It is limited to a fairly narrow interval (24-42 cm) with a marked predominance of the 30-33 cm size group (40% of the total numbers) (fig. 1, gl. All the individuals in this area are immature, actively feeding females. They should be regarded as the autumn generation whic h.

will be reproducing between the Green Cape Islands and Cape Blanc. The growth of the large squid of different subpopulations in the East-Central Atlantic and their conjectural age can be depicted 10

in the following way. As we can see from the table and fig. 1, the growth ratepf squid belonging to different-subpopulations are similar, and so a single curve can Be used to depict their growth. We chose to use the Bertalanffy equation which is used to

depict the growth of animals belonging to different systematic groups, including the mollusks (Zaika, 1972):

Lt = 1,03 (1— e -k(1-10),

where Lt denotes the linear size of an animaliof age t; and Loo, k and to are constants. The values of L,ce, k and to based on empirical growth data

are usually determined by the graphic method (Shcherbich, Slepo- kurov, 1976), or the method of computation (Hohendorf, 196-61, When using either of these methods, we must know the size of the animal during equal time intervals. Such data are not available to us.

Growth and age of Sthenoteuthis.pteropus- ,

Summer - spaWning AUtuMri-S pawning Month mantle - conjectural mantle conjectural length, age, months length, age, months cm cm

August 1 0 December 18-21 4 39-42 12 January 21-24 5 February 24-27 6 ■■■ March 27-30 7 (12-15) 3 48-51 19 April 30-33 8 18-21 4 August 39-42 12 30-33 8

In this case, the unlmowir ,parameters,can - - be computed with the help

of the numerical methods used for finding _ the extremum, which minimize some functional of quality (Yefimov, Igoshin, 1976). The search . procedure can be simplified considerably by reducing 11

3-parameter computation to the numerical search for one parameter, (1637) L,o0, which enables us to use a low-capacity compùter and to greatly reduce CpuA. time. 4 Having converted equation (1) to L o (2) - and having taken the logarithms of both parts, we get 1n(1---) -F Loe kt (3L

After inserting 37/ ln ; a Lco — k; b = kt o , (4) we get a straight-line equation relative to t l in its general form:

(5) Let us assume that we have a seties of empirical values of the mean dimensions of animal l i , which correspond to the series of values of age ti where i=1, 2....n. The straight line (5)_ for any 1.1>max{r1i can be plotted as a line of regression by the least squares method, having determined the values a and b. The values k and to are derived from (4). Lis determined by one of the methods of onel-dimensional searchal, including the simple methodof trying out the possible values of L„with'a prescribedstep. •Sej-v-P-s--J The minimumistandard deviation-07-as the criterion of maximum conformity of the plotted curve to the empirical values l -I t ( 1 i - y i (_6) 1 / . _i-21 Yi SD= n — 2 e values calculated then by equation (1). The coefficients k and t 0' and the standard deviation)

---y SD, are computed ,d for each assigned value of L. The Loo value corresponding to the minimum SD is chosen. * central processing unit - transl. • 12

e tr+

w . F-1 w zo

5000

te000 rn rn ni 2000

6 8 10 12 111 15 18 20 AgQr YI)Q1

Fig. 2. Growth curves of squid: a - linear growth (circless- summer-spawning, triangles - autumn-spawning); b - weight gain (1 - increase in mass, 2 - absolute daily gains, 3 - daily gains in % of body mass); c - growth of Omma- strephidae: I - Sthenoteuthis pteropus, II-- Todarodes sagittatus tafter Wiborg, 1972; L - large Ommastrephes bartrami, S - small ones (after Ishii, 1977)] 13

The numerical values of the equation parameters for S. pteropus, computed on the MIR-2 computer, are LOg =60.0 cm, k=0.091 1 and t o--- 0.18 with SD=1.3%. The middle values of the modal size intervais from the table for summen,spawning squid were used as the basic data. The computed growth curve is given in fig. 2 which also contains data on the growth of autumn-spawning squid for the purpose of comparison.

In order to pass from the linear growth of S. pteropus• to weight gain, we useC.the empirical equation for squid 1 to 4.5 cm in length, W=0.099 L 2 ' 13 , and the one for individuals exceeding the length of 4.5 cm, W=0.019 L 3 r 2 , where L denotes the length-)6fthe mantle (cm), and W the weigh±ofbthe-D:atei:d4g). The curve representing weight gain is Sn-shaped. The utaxaum increments in mass occur at the age of 11-14 months and amount to more than 12 g/day. The relative growth rate diminishes rapidly, i;e. the increment in mass amounts to 5.8% of the body mass per day at the age of one month, 1.3% at 6 months, and approximately 0.5% at the age of one year. (1638) The table contains data on the growth of squid larger than 18-21 cm, and so the plotted curve cannot be expected to depict the growth of the early young very well. Instead of attempting to describe the growth of the young, we shall limit ourselves to analyzing the possibility of such rapid growth at the age of one month, when the specific growth rate is at the highest level. According to equation (1), young squid measuring approximately 1 cm (0.1 g) grow to 6 cm (4.7 g) in a month. Such growth is possibleiïftthe mass of the squid increases by 14-15% daily, though the law of 14

growth will differ from that of the given equation (1). ( 1 6 3 9 )

a 100

eo 60

ai O 40

ni rd ZO

18 20 22 2e 25 28 JO T° e, 100 F 6 x'sx /J -rd . ■ / x / ■ / • 80 1- x.,x / / - '-x--. x,„ 1 - 114 x,,.x O 60 - / , \ ' • -// / \k•, .\.\,.. / /2/ .,-10 40 - 4 e' / cri - 4 i / \ M 20 - >Lx-----x-- 5 W ...... ._,,, 44 _ // t.-.. i - i 1 I 111 I 1 :55 10 20 JO 40 50 Length_of mantle cm - -- f , Fig. 3. Abundance relationship of large .(shaded) and small sguid dépending on temperature (a) and infestation of the squid with parasites of different sizes (b): 1 - Anisakis sp., 2 - Phyllobothrium sp., 3 - Tentacularia coryphaena, 4 - Nybelinia sp., 5 - Didymozoidae

Considering that the daily food rations of the young amount to 40-180 9 of their body mass when they are reared (LaRoe, 1971; Boletzky, 1974) and the value of the coefficient of food consump-

tion for growth (K1 ) in cephalopods is equal to 0.4-0.6 (Mangold- Wirz, Boucher-Rodoni, 1973), such rapid growth is quite possible. It should be noted that the counting off of age in the given case begins when the squid is 1 cm in length. The duration of development from the moment the larva leaves the egg to the time it 15

reaches this size is unknown, but it apparently does not exceed one month.

We found that the weakly-defined seasonal fluctuation of reproduction made it impossible to study the growth rate of squid belonging to the small equatoriarpopulation, which begin to mature at a length of 18-20 cm and grow to a maximum size of 35 cm, by analyzing the dynamics of the Size structure. Nevertheless, it can be assumed that the small squid are similar to the large ones in their growth rates, but are distinguished by a higher rate of deve , reproductive system at the higher temperatues in the lopment of the equatorial zone. In connection with this, we analyzed the temperature selectivity of the large and small squid. Temperature selectivity was based on the frequency of occur- rence correlation between small and large mature females at differ , (1640) ent temperaturesof the surface layer of water. Only large mature females were observed at low temperatures (18-22 °C). As the temperature rose above 22 °C, we began to observe small mature females which became predominant at temperatures of 26-30 °C (fig. 3). There- fore, small squid are more thermophilic than large ones. At the same rate of growth, the mass maturation of small squid begins4at the age of 6 months, and the life span of a generation is less than one year. Additional data on the infestation of squid with the larval forms of cestodes, nematodes and trematodes were used in the com, parative study of the relative age and life span of small and large squid. Cestodes and nematodes accumulate in the organism oe squid throughout life, while the numbers of Didymczoidae larvae- 16

gradually diminish (Gayevskaya, Nigmatullin, 1976). Because of this, the intensity and extensiveness of invasion can serve as the, biological indicators of age in a comparative study of squid from different size groups. However, the rations of the squid must be the same when using the degree of infestation as an indicator of age. Due to the absence of food ration data, the indexes of fullness were used. They proved to be similar in squid of the same size in both the small and large forms.

The extensiveness and intensity of invasion of squid belonging to the large formsproved to be considerably higher than in the small forms (fig. 3, b), which indicates that large 'forms of squid have a longer life span. Our data on the growth rates of Sthenoteuthis pteropus accord well with the data available on the growth of other species of Om- mastrephidae (fig. 2, c). Apparently, all of the oceanic species of this family are characterized by high growth rates and a short life span (1-2 years), which, together with monocycly, results in a very rapid succession of generations. References 1. Gayevskaya A.V., Nigmatullin Ch.M., 1976. The parasite-host relations of Sthenoteuthis pteropus in the tropical zone of the Atlantic. Materials of the 2nd All-Union Symposium on Parasitism and Diseases of Marine Animals, pp. 16-17, Kaliningrad. 2. Yefimov Yu.N., Igoshin N.M., 1976. Analysis of the parameters of the Bertalanffy growth equation with the help of a computer. Rybnoye khozaistvo (Fisheries), 11, pp. 33-34. 3. Zaika V.Ye., 1972. Specific Production of Aquatic Inverte- brates, pp. 1-182, "Nauka" Publishing House, Kiev. 4. Zuyev G.V., Nesis K.N., Nigmatullin Ch.M., 1976. Distribu- tion of the genera Ommastrephes d'Orbigny, 1835; Sthenoteuthis 17

Verrill, 1880; and Todarodes Steenstrup, 1880 (Cephalopoda, Oegop- sida) in the Atlantic Ocean. Byull. Mosk. o-va ispyt. prirody, otd. biol., 81, 4, pp. 53-63. 5. Zuyev G.V., Nigmatullin Ch.M., 1977. Main elements of the intraspecific structure of Sthehotenthis pteropus ( 1st. 31 in .the northern tropical zone of the Atlantic. Tezisr dokl. Vses. nauchn. konf. po ispolizov. promysl. bespozv., pp. 38-39, Moscow. 6. Shcherbich L.V., Slepokurov V.A., 1976. The natural mortalety of Notothenia rossi marmorata. Biological investigations in the Atlantic Ocean and the Baltic Sea. Trudy AtlantNIIRO, 60, pp. 76-84. 7, Boletzky S. V., 1974. Elevage de Cephalopodes en aquarium. Vie et Milieu, 24A, 2: 309- 341-1974a. Effets de la sousnutrition prolongèe sur développement de la coquille de Sepia officinalis L. (Mollusca, Cephalopoda). Bull. Soc. zool. France, 99, 4: 667- 673. Choe Sang, 1963. Daily age marking on the shell of cuttlefishes. Nattur-e,_19_Z, 4864: 306- 307. 9, Clarke M. R., 1965. «Growth ring» in the beaks of the squid Moroteuthis ingens (0egop- sida: Onychoteuthidae). Malacologia, 3, 2: 287-307.-1966. A review of the syste- matics and ecology of oceanic squids. Adv. marine Biol., 4: 91-300. IQ, Fields W. G., 1965. The structure, development, food relations, reproduction and life histo- ry of the seid Loligo opalescens Berry. California Fish Bull., 13: 1-108. /. Fridriksson A., 1943. Remarks on the age and growth of the squid (Otnmatostrephes to-' tiaras) in Icelandic waters. Greinar, 2, 2: 170-174. 12. Hohendorf K., 1966. A discussion of the Bertalanffy functions and their application in characterizing the growth of fish. Keeler Meerforsch, pp. 70-97. I. Holme N. À., 1974. The* biology of Loligo- forbesi Steenstrup (Mollusca: Ceplialopoda) in. the Plymouth area. J. Marine Biol. Assoc. U. K., 54, 2: 481-503. /4/, Ishii M., 1977.. Studies on the growth and age of the squid, Onunastrephes bartraini (Le- sueur) in the Pacific Ocean off Japan. Bull. Hokkaido Reg. Fish. Res. Labor., 42: 95-36. /5, l_aRoe E. T., 1971. The culture and maintenance of the loliginid squids Sepioteuthis se- • pioiclea and Doryteuthis pie!. Marine Biology, 9, 1: 9-25. /6. Murata M., Ishii M., 1977. Some information on the ecology of the oceanic squid, Otn- , taastrephes bartratni (Lesueur) and Onychoteuthis boreali japonicas Okada, in the Pacific Ocean off North-eastern Japan. Bull. Hokkaido Reg..Fish. Res. Labor., 42: 1-23. . „. . /7. Mangold-Wirz K., Boucher-Rodoni R., 1973. Nutrition et croissance de trois Octopodiés- Mediterranéens. Etude préliminaire. Rapp. Comm. int..Mer. Mediterr., 21, 10: 789- 791. he Richard A., 1967. Influence de la température et de la nutrition sur la forme et la stria-- tion de la coquille de Sepia officta -alis L. • (Mbllusque, Céphalopode)..Compt. rend. Soc. biol., 161, 3: 62,0-624.- 1969. The part played by.temperature in the rhythm of formation of markirip,§- On - the'Éhell of 'cuttlefish (Sépia officinalis L.). Experientia,, 25, 10: 1051-1052. /9 Summers W. C., 1968. The growth- and size distribution of current yearclass Loligo pealei. Biol. Bull., 135, 21 366-377,-- 1971. Age and growth of .Lotigo pealei, a .pop.tilation- stucly. of the common Atlantic coast squid. Ibid., 141, 1: 189-201. ‘: 20. Tinbergen L., Verwey J., 1945. On thebiology of Loligo

- vulgaris Lam. Arch. neerland. zool., 7, pp. 213-286. 21. Wiborg K.F., 1972. Octopus studies. - Toderbdesettatus- (Lamark), Norwegian and North Atlantic waters in 197.0,,I5717------Gang, 58, 24, pp. 492-501. Fiskets 18

I FaeBcitan A. B., HarmaTy.rinim 4. M., 1976. Ilapil311T0X035111HIlbIe CB11311 apbumpyxoro KaJlb- mapa Sthenoteuthis pteropus B Tp01111YOCK011 AT.111111TIIKe. MaTeplIKJIbI II Bcec. crimrio- snyma no napasiiTnamy n 60JIC311111,1 mopcarix XIIIBOTHI,IX: 16-17, KaamllimpaR. Z. Dimmou IO. I-I., 111'01.1111H H. M., 1976. Orlenaa napameTpoB ypaimeima pocTa BepTanaqm C nomombio DBM. PbI6H. X-BO, 11: 33-34. 3anKa B. E., 1972. YRenbitaa npoRyagnst BOK.HbIX 6eCTIO3BOHOgnIX: 1-182, 1'I3-Bo «Hay- Rosa RymKa», Krim 3yeB F. B., Hecnc K. H., HarmaTy.naint LI. M., 1976. PacnpocTpanemie poitos Oinmastrep 1835, Sthenoteuthis Verrill, 1880 11 Todarodes Steenstrup, 1880 (Ce--lies phalopoda, Oegopsida) B AnnairrimecKom meatte. Biooa. MOCK. 0-Ba ucimiT. npapo- A1,1, OTR. 6110K., 81, 4: 53-63. 5. 3yes r. B., HurmaTymnm LI. M., 1977. Ocuomtme 9.11eMelITM mirpriBriRoBori Œpyrrypbu aphiaopyBoro aa.nbmapa Sthenoteuthis ptero pus (St) B ceseptioil tiacTn TponimecKoil ATJKIHT111111. Te311CH Rom. Bcec. naytm. Komi). RO 11C110.111,30B. ripombic.a. 6ecno3B.: 38— 39, M. b. 11.Iep6nti J1. B., CaenoxypoB B. A., 1976. EcTecrBennan cmepTuocTb impamopnoil BROJI. 11CCJIeROBKH1111 B AT.rianTtelecKom oxeaue n EurrailcKom mope. Tp. ATJIKHT. mi-Ta obt6n._ x-Ba Il (meat-tarp., 60: 76-84.

GROWTH AND LIFE SPAN OF• ST ENOTEUT HIS PT'ERUP US« IN THE EAST-CENTRAL ATLANTIC

. G. V. ZUEV, Ch. M. NIGMATULLIN and V. N. NIKOLSKY

Institute of Biology of South Seas, Academy of Sciences of the Ukrainian SSR (Sevastopol)

Summary

The linear and weight growth of StIzenoteuthis pteropus was studied and its life. span was determined on the basis of studying the dynamics of size structure 'of the catches in the East-Central Atlantic. The growth of squids is satisfactorily described by- the equation Lt --- 60 (1 e-0,091(t-F 0.18)), where Lt is mantle length in cm and t is age in months. The values of relative daily increments of mass are reduced in ontogenesis from 15 down to 0.5%, the life span cloes not exceed 1-1.5 years.