Linkowski, Tomasz B.

Lipinski, Marek

OceanRep

����R�E�P�O�R�T�S�O_F�T_H_E�SE_·A�_F_1s_H_E_:R_I_E_s_1_N_S_T_1_T_u_r_l�O-V_O�L_._2_1-+-�-''8(; Marek R. Lipinski and Tomasz B. Linkowski SOME ASPECTS OF THE BIOLOGY OF SQUID MOROTEUTHIS INGENS (ONYCHOTEUTHIDAE) FROM NEW ZEALAND WATERS NIEKTORE CECHY BIOLOGICZNE. KALMARA MOROTEUTHIS INGENS (ONYCHOTEurHIDAE) Z WOD NOWEJ ZELANDil (Received January 1983) Abstract. The paper presents length analysis, sexual maturity, and degree of stomach fullneu in 201 squid Moroteuthls lngens caught in New Zeiand waters between May and August, 1981. The length-weight relationship was calculated; it equalled W • 0.41 DMt2 ,23 for males and W c 0.1 DML2.7 for females. Relationship between total length and length of statolith core and DML was also calculated, but the correlation values obtained were low (below 0.75). This may indicate that the age of squid Moroteuthlr lngens cannot be determined on the basis of growth rings on statoliths, (D'(\��1<) a conclusion arrived at in earlier paper�. INTRODUCTION The squid Moroteuthls ingenJ (Smith, 1881) has not been so far a subject of a sepa· rate biological study (besides a very specific paper by Clarke, 1975). The biology of this species was usually discussed in studies dealing with zoogeographical and systematic analyses (review: Clarke, 1966). The scarce knowiedge of the whole genus Moroteuthis is revealed by Clarke's (1980) speculations; he suspects that squid of this genus, caught on New Zealand fishing grounds and found in the stomachs of sperm whales there, may belong to a separate, hitherto undcscribed genus. Claike (1980) believes that M. ingens (s. str.) occurs in a very limited area (in the notal part of the Patagonian province). The goal of this paper is to describe selected biological parameters of squid provisionally determined as Moroteuthis ingens. These parameters include length CephLit 251519'98' MAREK R. LIPINSKI AND TOMASZ B. LINKOWSKI composition, sexual maturity, degree of stomach fullness, length-weight relation­sj,jp, and relationship between total statolith length and statolith core length DML. Howe,·er. the material collected is not sufficient to arrive at taxonomic con­clusions. MATERIAL AND METHOD The material consisted of 201 squid Moroteuthis ingens of both sexes. They were taken from the Profesor Bogucki catches made with a connnercial bottom trawl with a mesh size in the codend of 110 mm. Samples from 15 tows were taken for analyses. Location of sampling sites is presented in Figure 1. Most of the materials collected came from the northern slopes of the Chatham Rise, where squid are caught incidentally during fishing operations for Hoplmtet­hus atlanticus, carried out from May to July, 1981, at depths of 850-1100 m. The remaining squid were caught in single tows in August on the Campbell Plateau, Pukaki Rise and the southern slope of the 0Chatham Rise, at depths of 450-500 m. Biological analyses included length and weight measurements, determination of sexual maturity and degree of stomach fullness, and statolith preparation and measurements. Squid mantle length (DML) was measured to 1 cm below. The accuracy of weight measurements was 10 g. Sexual maturity was determined on the basis of Llpinski's (1979) scale, and stomach fullness - with the help of a 5-grade scale used in ichythyological investigations. Statoliths (total length and length of their core) were measured with a measuring microscope with an accuracy of0.01 mm. The tenninology and definitions of Clarice (1978) were used. RESULTS LENGTH COMPOSITION AND SEXUAL MATURITY The length composition of squid Moroteuthis ingens from the Chatham Rise. area is presented in Figure 2. Throughout the whole study period, sexually mature speci­mens predominated, with sexual dimorphism well pronounced. Minimum DML for mature males was 26 cm (a maximum of 39 cm), for females - 46 cm (a maxi­mum of 56 cm). In July, one juvenile �ale was caught on the Chatham Rise with the DML equalling 15 cm; in August, scarce immature males and maturing females (stage IV) were also caught. On the Campbell Plateau and Pukaki Rise 12 specimens of squid were caught; no sexually mature squid were observed. Table 1 presents the maturity stage of squid gonads in all study areas together. It was observed that, when ,,,tting the female's mantle, the pigmentation of the mantle chan�ed in the following way, depending on the gonads' maturity: BIOLOGY OF SQUID MOROTEUTHIS INGENS Campbell Platoa11 o�Campbell Island Rise 0 Bounty Platform SS0 L-�������--l��������-+-�������__J I 7o 0 E 17S0W 99 Fig. 1. Sites of squid Moroteuthis ingens biological samplings In the New Zealand waters between May and July 1981. Rys. 1. Miejsce poboru pr6b b')logicznych kalmar6w Morotcuthis ingcns z w6d Nowcj Zclat,dii w okresie od maja do lipca 1981 r. 100 MAREK R. LIPINSKI AND TOMASZ B. LINKOWSKI -; t � lj -; :; l ; I( i J, E z Mai .. N=IOO 25 / 45 Fig.�- Length composition or aqua! Moroteuthls lngem on the Oiatham Rbe. Rys. 2. Skhd dl:ugosciowy kahnar6w Moroteuthls lngens w rtjonie Chatham Rise. Table 1. Stage of gonads' maturity In aqukl Moroteuthls tngens. Tabela 1. Stan dojrzatosci gonad Morotwthls tnge,u Males Females II III IV v VI I 11 III May 56 2 . 1 June 8 July 10 August 7 13 4 10 Total 2 9 87 4 4 11 4 Grand total 104 stages I-II white stage !II light-pink stage IV pink-violet stage V dark-brown with a violet tint stage VI dark-violet, almost black. IV 14 3 4 22 97 v VI 35 I 8 3 8 SI In the literature on the subject written so far, no oceanic squid females at stage VI were obseIYed; it was a hypothetical stage (Lipinski, 1979). That is why we include below the description of stage VI females of Moroteuthis ingens: flaccid and thin mantle with very dark: pigmentation, ovary degenerated (i ts boundaries blurred), single, transp,arent eggs seen in the formless yellow mass, nida.mental glands shrinked. = BIOLOGY OF SQUID MOROTEUTHIS INGENS 10� DEGREE OF STOMACH FULLNESS AND FOOD OF SQJJID It was found that all mature males had empty stomachs while only a few females were feeding; the degree of �omachs fullness may be seen belo')V: Degree of stomach fu�ess Number of specimens O I 2 3 4 4 1. 6 4 3 The above list covers only. mature females (stage V) caught between May and July on the Chath� Rise. Their food consisted of squid, an example of the can­nibalism common among Teuthoidae.LENGTH-WEIGHT RELATIONSHIP Length-weight relationship for squid is presented in Figure 3. It is expressed by the equation W = a DML b and defined by the following parameters:males: · n = 96; R2 = 0.9800 females: a = 0.4107; b = 2.2307 n =85; a =0.1006; R2 =0.9644 b =2.6978 where: W = .weight (in g),. DML - mantle length (in cm), R - correlation coefficient, a, b = equation coefficients, n = number of specimens weighed. The length-weight relationship.is an excellent illustration of the sexual dimor­phism of the species visible in the differences in the weight of males and females in the same· length classes. These differences may be observed in a small length interval between 22 and 39 cm DML. Males with these lengths begin development ' and reach full sexual maturity_. Females with the same lengths are immature sexually and begin to develop only to a slight degree. They reach sexual maturity at lengths substantially exceeding the maximum observed length of males, i.e., over 40 cm DML. It may be seen from Figure 3 that the quick increase in the weight of females O"¥Cr 40 cm DML is · related to the development of ovaries and eggs; for enmple, the weight of eggs alone in i mature female (stage V) with a length of SS cm wu 1450 g, approximately the same as the maximum observed weight of males. STATOLITH LENGTH.:.MANTLE LENGTH RELATIONSHIP1 A d.iairarn of the statolith of squid Moroteuthis ingens and the method of its measure­mmt lff prc,mite<i in Figure 4. 101 MAREK R. LIPINSKI AND TOMASZ B. LINKOWSKI Weight (g) 5000 4000 3000 2000 1000 • --- males • -- females L.�...,.======:;::=-��-�������.--�-..�����.--Le�n���h�(10 IS 20 25 30 35 40 Fig. 3. Weight-lerigth relationship in squid Moroteuthis ingens. Rys. 3. Wykres zaleinosci ci�iaru od drugosci kalmar6w Moroteuthis ingens 45 SO SS The calculated relationships between total length or statolith core length and total length of squid have the form y = axb with the following parameters: for the statolith length-DML relationship N :' 86 R '2 = 0.2836 (R = 0.5325) a = 0.6195; b = 0.1063 for the statolith core lcn2th-DML relationship N=86; R =0.5601 (R = 0.7484) a = 0.2573; b = 0.1984. These relationships are presen tcd in Figure 5. . • I •• . . • • BIOLOGY OF SQUID J,fOROTEUTHIS /NGENS 103 'b a Fig. 4. Drawing of iqun Moroteuthis ingem statolit.h. abd method of measurements: a - length of statotlith, b - length of statolith core. Rys. 4. Schemat budowy statolit6w Moroteuthis ingens :i z:aznaczcniem sposobu porniar6w: a - dl:ugosc statolitu, b - dl:ugosc trzonu statolitu. The analysis of the relationship between statolith lengths and DML showed that the statolith increase only slightly with an increase in the length of the mantle. · DISCUSSIONThe results presented here indicate that squid Moroteuthis ingens caught cin the Chatham Rise and Campbell Plateau, and the Pukaki Rise may belong to two sepa· rate stocks, which spawn at different times. The sexual maturity of squid is, according to Kawakami (1976), the commonly accepted criterion of stock separation. The relationship between statolith length ( or statolith core length) and DML, and the low values of the coefficient R point to the allometric increase of the investigated values. It is a different type of growth to the one observed in squid 1/lex illecebrosus (Lipinski, 1981), where the correlation between TLS and DML was R = 0.95. Our results contradict t1:_e hypothesis according to which growth rings which might be observed inside statoliths are formed in the equivalent units of time (Lipinski, 1978). The hypothesis may be true with respect to other species of squid but it seems inapplicable to Moroteuthis inge1.1s. I, 104 Le�h of statolith � (mm· 10-1) 1 S J I 141 131 12 i i 11 i 7 4 2 so 100 150 MAREK R. J.:IPiNSKI AND TOMASZ B. LINKOWSKI 200 250 .. : lei • : � 0 • i • • • t I.• • •:1 . . : . .•.,. males o.-r females 300 35 40 Lcnph (ML mm) 450 SOO 550 Fig. S. Relation.ship between the length or statolith and its core and 1he length of tire !CJuil Morotcuthis ingens mantle. Rys. 5. Zalcinosc dhlgosci statolitu i jego trzonu od dhlgosci ptaszcia lcalmarow J,foroteuihis in­gen,. REFERENCES CLARKE, M.R. 1965. "Growth rings" in the b eaks of the S<juid Moroteuthis ingens (Oegopsida: Onychoteuthidae). M alacologia 3/2:287 -307. CLARKE, M.R. 1966. A review of the systematics and ecology of oceanic squids. Adv;Mar.Biol. 4:91-300. CLARKE, M.R. 1978. The cephalopod statolith - an introduction to its form. J. Mar. Biol. Assoc. UK, 58: 701-712. CLARKE, M.R, 1980. Cephalopoda in•the diet of sperm whales of the Southern Hemisphere and .their be aring on sperm whale biology. Discovuy RepU 37: 1-324. s. 3. l · 0 0 " " " "•" . 0 0 .• • • o o a· . . . 00 • o; o • BIOLOGY OF SQUID MOROTEUTHIS INGENS 105 KAWAKAMI, T. 1976. The fishery biological study on a squid, Nototod arus s/oani s loani (Gray) in the New Zealand waters.Bull. Tokai Reg. Fish. Res. Lab . SS: 31-104. LIPINSKI, M .  1978. The age of squids, Illex fl/ecebrosus (Lesueur, 1821), from their statoli ths. ICNAF Res. Doc. 7 8/II/15: 1-4, MS. LIPINSKI, M. 1979. Universal maturity scale for the commercially important squids (Cephalopoda: Teuthoidea). The result of maturity classification of the II/ex il/ecebrosus (Lesueur, 1821) populations for the years 1973-1977.�CNAF Res. Doc. 79/Il/38: 1-42, MS. . . LIPINS KI, M. 19.81.: Statoliths as a possible tool for squid aie determination. • Bull.L'Acad.Pol.Sci .. Cl.II. 28 (10-11): 569-582.S'IRESZCZENIE Praca obejmµje dane dotyczqce wfel/c{/lci, dofrzalolci plciowej, �pnia wype/ni� iolqdk6w i.pokannu ka1marow zgrztunku Moroteuthis iruren& Ponadto 11TZedstawiono zaldnolc d�lt­-ci�iar oraz prdbowano zna/e:tc po wiqzanie dwoch dlugolci rtlltolit6w :. grzbietawq dlugo!dq plasz= Zakres DML badanych lllmic wynosil 16-56 cm. a :urmc6w 15-39 cm. II' rejonie Chatham Rise kalmary wyk:azywaly wysoki stopieri dojrzalolci plciowef (razwyczaj stadium VJ, natomiast kalrnary z rejon6w Campbell P/qtt!lf1U i Pukaki Rise byly niedo/nale plciowo. ll'shl1· ruje to na istnienie co 1111/mniei itwoch roinych stad kal1711ZT6w Moroteuthis ingens w wodach nowozelandzk:ich. Stwierdzono, ie w o� badari sam ce nie ierowaly, natomilzst 3t11Tlice ierowaly tylko w nieZ1111Cznym stopniu. Obliczono raldnolt pomi�dzy dlugolcil/ (DMLJ i ci�iarem ciala samcow {II' = 0,41 DML2,23} oraz samic (II'= 0,1 DM£2,7). Uzyskar,e nislcie (poniie/ 0,75) wartolci k:orelaqi mi�dzy dlugolciq calkowltq i dlugolcil/ tnonu :statolitu a DML wskazujq, ie u kalmarow Moroteuhh ingens nie moina oladlac wieku na podsta wie pierlcieni przyrostow widocznych Wf!!"ll:lln statolitow. \\ ~. \ \ \ 

Some aspects of the biology of squid Moroteuthis ingens (Onychoteuthidae) from New Zealand waters

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Some aspects of the biology of squid Moroteuthis ingens (Onychoteuthidae) from New Zealand waters

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