This paper not to be cited without prior reference to the author

Interntional Council for C.M. 1983/K:18 the Exploration of the Sea Shellfish Committee

Bath~letric distribution of in the Catalan Sea by

Pilar Sanchez Instituto de Investigaciones Pesqueras Paseo Nacional s/n, Barcelona (3) Spain

Abstract

A total of 104 fishing sampIes were taken between 4 and 832 m in Catalan coasts (N.E. of Spain) using commercial gears was analyzed and classified. A total of 22 identified species and others identified only like a family are studied. Results limited to depth distribution and abundance in this area are exposed.

Le material utilise provient des 104 peches effectues dans la Mer Catalane (N.E. de la Espagne), ades profondeurs allant de 4 a 832 m. Nous avons classifies 22 especes du cephalopodes et quelques identifies

seu~nent comme a familie. Des resultats sur la distribution et l'abondan- ce des cephalopodes dans cet area sünt donnees. -2-

•

Introduction

Little has been published on the vertical distribution of cephalopds in the Mediterranean Sea since they are normally caught only in small numbers by the nets most usually employed in research. One notable excep­ tion is the Mediterranean programme of biolrigical studies of the Smithso­ nian Institution (Roper,1972). In the present work material proceded from commercial trawling catches using conventional gears. At present there are some continual and seriated sampIes which are being acomplished and come from all the catalan continental shelf and slope. They will give an important information about the bathJ~etric and abundance distribution which give tao more knowledge about the area.

Material and Methods

The species collected and studied come all of them from comercial trawling catches from June 1981 to June 1982, using conventional gears surrounded by an overnet of 16 mm of mesh. Our specimens were caught from Cape of Creus in the North to the delta of Ebro in the South (Fig. 1). One hundred four fishing sampIes were taken between 4 and 832 m. There have beeil classified 22 species; 13 of the ord3n Teutoidea ~ and 8 of the orden Octopoda. In some cases they have been classified li- ke a family only. The direct data that were obtained (number of individual per fi­ shing) have been change to number of individual per hour of tra~vling. Bathymetric distribution has been represented takingthe following intervals:O to 50; 50 to 100; 100 to 200; 200 to 400; 400 to 600, more to 600. -3-

Bathymetric . distribution of species

Figure 2 is the grafie rcpresentation of thc data shown in table I. Some of the species, such as Elcdone moschata and Octopus vulgaris, are clearey'defin~das inshore spccies, while other ones, such as Alloteu­ this media, subulata, Loligo vulgaris, Sepia elegans and Sepia officinalis, .although.are also fOUnd in shallow waters, they go . down into the slope. Ancistroteuthis lichtensteini, BathyPolipus spon­ salis, Scaergus unicirrhus and Histioteuthis reversa' ~ake up agroup 'of sp<:cies living in deeper waters, and they'are never found over 200 m. .Moreover, these·specics appear ~poradically. A very wide vertieal ran­ ge is sen in Eledone cirrhosa, Octopus salutii andTodarodes sagittatus, although tl~ey live ,at a preferent depth. That' s th~ ease of Eledone ci­ rrhosa, that appears most freeuently between 100-200 m. In the Catalonia Sea the greastest number of cephalopods is found at a depth between 50-200 m.

Table 2 shows maximum ~nd minimum depth where the species of the present work have been collected in comparison with data from other seas,. mainly from the Atlantic. Inthe Mediterranean many of the species do not reaeh so deep wa­ ters as they do in other sens . In .the same way shallow waters species from cold watersin temperateand warm seas are found in deeper layers. Für instance, Bathypolipus sponsalis and Neorosia caroli,two ben­ tonic species living in deep \vaters,in theAtlantic are found in dee­ per waters'than in the HediterraneaJ;l. andAlloteuthis media a pelagic species, reaches decper waters inthe Mediterranean. Octopus .vulgaris; Sepia officinalis·.and can be considered strictly inshore species, and the Mediterranean they.do not bellow ·150 m•. Other species such as Eledone cirrhosa, Sepia orbigniana,Sepia elegans, Loligo vulgaris, and ·Illcx coindetii usually lives on the continental shelf and the slope. -4-

Correspondence analysis

Correspondence analysis (also called reciprocal average analysis) have been apply in the present work. This method is descrive and no ex­ plicative one , useful to know patterns of multivariate systems. Tbis analysis let the representation as a wholeof species and trawls.

In the plane 1-2 it is possible to detec a gradient related with depht~ is the Guttman effect. (Fig. 3)'.

Species such as Sepia officinalis, Loligo vulgaris and Octopus vulgaris placed in an extreme of the gradient are associated whit. trawls made in a inshore waters. Tbe other side of the gradient ~how up species such as Bathypolipus sponsalis, Ancistroteuthis lichtenteini and His­ tioteuthis bonelli with trawls madein-a offshore waters.

We can observe the species with a distribution's rank very great (such Octopus salutii, Eledone cirrhosa, etc) placed in central part of the gradient.

Abundance

TI~ere have been calculated abundan~e and mean weight fro.~ Dlore abur.dant species (Fig. 4). Winter and summer are season when the abundance is maximum and the mean weight are minimum. Tbis is an indication of the invasion of inmature in fishing area sustituting the adults which had emi­ grated or dead after spa\\TI.

Eledone cirrhosa one of the two species studied that the greatest abundance'notcoincided wiht mean weight. The greatest abur.danca i8 in winter; in that'season the both sexes are seach bottom and they remain over there until spawd.ng (Mangold, 1963). Tbe minimum mean weight shO\v up in summer;season when adultE:: have been sustituded in fishing area for the inmatures (Mangold,op. cit.) -5-

Octopus vulgaris has the greater abundance in autum and the mi- nimum weight in winter. This is because the inmature animals begin to be caught in november. These animals had passed summer in coastal water but they are not caught for the bottom trawls.The greataniIilals in March begin to invade coastal waters searching the suitable bottoms for the reproduction.

Aknowledgements

I wish to thank Dr. Jordi LLeonart and MissPaloma. Martin for their assistence. Also many thank to all group of the program nAQUDE n •

. ..,. ..~-~. ',,:.~:.,.". , -6-

References

ADA~,W.-1962. Cephalopodes de l'Archipel de Cap-Vert, de l'Angola ey du Hozambique.Hem.Intes.Invert. ULTRAHAR (2) 33:1-64 AD~I,W.& W.J. REES.-1966.A review of thw family Sepiidae. TIle J. Hurray Expedition 1933-4, XI(1):163. LEBART ,L. & J.P.FENELON.-1971. Statistigue et informatigue appligues. Dunod,Paris.426 pp. HAt~GOLD, K.-1963. Biologie des Cephalopodes benthique et neetoniques de la mer Catalane. Supl.13 a "Vie et Milieu":1-285. ~~~GOLD, K.-1972 La migration des ·Cephalopodes·mediterranees. Rapp.P-V. Reun.Comm.Int.Explo.Sci. Her Medit. 16(2) :299-304. MANGOLD,K.-1973. La fawle teuthologique actuelle en Mediterranee et ses rapport avec les mers voisines. Rapp. Comm. int. Mer Medit.,21(lÖ): 779-782. HORALES,E.-1958. Cefalopodos.de Catalufia.I.Inves. Pesq.,XI:3-32 NAEF,A.-1921-23.Cephalopoda. Fauna and Flora of the Bay of Naples. 35(1) Fase. II(Traslated from German; Israel Program for Scientific Trans­ lations, Jerusalem 1972) ROPER,C.F.E.-1972 Ecology.and vertical distribution of Mediterranean

pelagie cephalopods.In: Mediterranean Biological Studies final report, ~ 1:282-346.

RL~Y,G. & J. Knudsen.-1972 Cephalopoda from the Eastern Mediterranean. Israel J. Zool. 21:83-97. VOSS, N A.-1969. A monograph of the Cephalopda of the north Atlantic. The family Histioteuthidae. Bu1l.of Marine Scienee, 19 (4):413-867.

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SPECIES CATALAN SEA OTHER SEAS

Sepia officinalis 10-130 0-190 Sepia orbigniana 40-460 80-450 Sepia elegans 30-235 60-430 Rossia macrosoma 125-700 55-600 Neorossia caroli 150 800 430-1230 Sepiolidae 15-700 Loligo vulgaris 15-200 15-150, Alloteuthis media 0-200 20-50 Alloteuthis subulata 15-190 JE 0-500 Onychoteuthis banksii 500-570

Ancistroteutis lichte~steini 280-)800 500-1000 JE Histioteuthis bonnelli 220-430 . 70-2000

Histioteuthis reversa 275-625 ?-1000 Illex coindetii 50-280 50-500 Todarodes sagittatus 80-625 200-1000 Octopus vulgaris 0-115 0-400

Octopus salutii 30-700 Scaergus unicirrhus 235-700 70-430 Pteroctopus tetracirrhus 110-570 70-680 Eledone moschata 25-100 • Eledone cirrhosa 10-570 10-770 Bathypolipus sponsalis 220-800 630-930

TAßLE 2.- Maximum and minimum depth where species of the present work have been collected in comparision with data from other seas.

JE very occasional -9-

-.------'---'-"-"'-~--"""'------' --_._ .• -'---.~- ..------,..... _---. : : 1 I 1

o'

Figure 1.- Distribution of cathes in bottom trawls from June 1981 to June 1982. • There are represented the isobaths of 50, 100, 200,400 and 600 m. -10-

500

- (1 c=1-10 = 10-50 - 50-100 O}100

Figure 2.- Bathyrnetric distribution and abundance (number per hour fished for haul) of Cephalopods. -11-

,•

.50

..OY .AL .HB

00 ..... •EM o • . OB .0 ~LY ·0- .NC o 0 o ·.AM .. . . o -15 .~C ·AS 0 05 • 0 -SE 0 .. . . -PT .-Ie i SR-

FIGURE 3.- Correspondence analysisoLittle points represented trawls ~5.6 -12- ,", ," SEPIA ELEGANS , , ILLEX COI~DETII ,, . , ,, ' .. 70 ' ,, I, ,, I • , \ , , , I ,, 50 ,• \, . 17.0 , , ,, , , \ ,• . '25.7 " 30 •. ' \ SEPIA ORBIGNIANA ,, ,•• • •• 10 \-,;;;18...:-.9__ . 6.1 '..12.7 . 743 .,~ ..•_-.J A 10.5

70 .. ALLOTEUTilIS MEQIA LOLIGO VULGARIS " i

50 1.5

24.1

30

10

70 'ELEDONE CIRRHOSA OCTOPUS VULGARIS 430

50

128.7

30 51>.6 ~-----4135J 128.5 135.6 10

SP s . A w· SP s A w

Fi,gure 4.- Abundance and mean.weight für seven s:.... ecies üf the Catalan"Sea.