No.23 Nethi:ng

C.M
No.23
International Council for the
Exploration of the Seil.
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Rapport Administratif
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1955
Par A.M. RAMALHO
Angleterre
(A,C. Sinlpson)
Nethi:ng; to repert of work on the scombrif'orm fishes from laDoratories in
E:ng;land and Wales.
Belgique
(E. 1eloup)
'"
Biological observatiens were made on mackerel landed at the Eelglan 1'1811. !n"rkot.
Determination 01' length, weight, sex, ~tages of maturity, mesenterio tat and aga,
Ecosse
(B.B. Parrish)
No investigations on the soombriform fishes 11.ave been undertaken.
Espagne
(Jöse M.Nava;:)
Dans 1e 1aboratoire cle Vi go de l'Institut Espano1 d'Ooeanographie ont ete
faltes des experiences sur la maniere la plus convenable da saigner
bord 1es
bllnites oaptures (a1hacoras), question polemique qu'a ete pose
Vig" au cours
de 1a oampagne bonitiere anterieure et qua notre conseil a contribue
reseu~re,
Dans 1e Lab .. ratoire Ooliano~raphique da San Sebastian on a poursuivi l' etude
biometrique des "'differentes especas da thonides qu' on a oapture sur la cote basque
pendant la periode qui Va de 1a fin de mai jusqu'au milieu de novembre. On a fait
egalement des observations sur les modalites de 1a pElohe de <lette region.
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France
(J. Furnestin)
En jllin 1955 100 navire "President-Theodore~Tissie,." a detecte les premieres
appari tions de germons en sllrface cO:; signale l' emplacement de ces lieux da peche
aUX thoniers franqais. Les thons blanes oaptures ont ~te examines et des observations physiologiquesont ete faHes Bur les organes preleves (hypophyses. thyroi:des
et foies). Au total 86 poissons ont 6te lUGSures.
A Saint Jean de Luz 58 Sa:rda sarda et 134 ThuffilUS thynnus ont Eite mesures.
Ir Lmde
(Arthur E ,J, Went)
No work was done on speoies covered by this COl1l111itteo during 1955 but it
would seem appropriate to report that a specimen cf the Blain Bonito (Auxis
rochei Risse). the first to be recorded fram Irish wators. was captured off
Ballycotton, Co. Cork, on thc 23rd Septomber 1955. This speoimen was rocorded
by Arthur E.J. 'Went in a short paper "'rhe Plain Bonito, Auxis roch,li Risso, and
~
- 2
other members of the mackerel family in Irish water,,"? Irish ·l!aturalist's Journal,
vol. XI.
,
Norvege
(Arne Revheim)
Mackerel. The Norwegian investigations on mackerel have been continued
during the season 1955 as folIows,
1. Studies non aga and growth hava been carried out on the basis cf samples
from the oommercial catches.
The sampIes include all sizes of mackerel.
2. Tagging experliments have been oarried out in some fjords and in outer
skerries in Western Norway as weIl as in offshore waters, in the Skag;erak
off Arendal.
The total nllinber of mackereltagged in 1955 was 2409, of these 1368 speoimens were tagged in the Skagerak.
The investigations on maekerel will be oontinued during the winter.
'"
Tunny. (Thunnus thynnus), During the summer of 1955 investigations have been
stll.rted on the tunny which ooeurs in Norwegian waters in June-August-September.
Biological dates of the fish are obtained fram the commeroial oatches.
Thc dates comprise, Length, weigth, and Sex ef the fish.
The 1st vertabra has been cut off for aga determination.
Th€> total number of tunny examined was 700.
Portugal (Outremer)
(F. Frade)
Thonides. La "Mission scientifique de S. Tome" a continue ses observations
concernant les Thonides dans 1es eaux da S. Tome et Principe, notamment Neothunnus
albacora et Euthynnus alliteratu.s, ces dewe especes etant oapturees ä 1a ligne, en
profoDdeur par 1es pecheurs natifs pendant toute l'annee, mais 8n plus grande
quantite depuis octobre ä f~vrier. En plus on a constate vers 1a fin d'ootobre
l'apparition de nombreuxbancs diE, alliteratus dans les saux de surface (temperature
variant de 24,2 ä 24.9 'C.; salinite de 33.33~; les poissons, ayant ete entoures
par les bateaux des p~cheurs, sünt ensuite captures dans les mailies des filets
verticawe ,
Des mensurations et pesages(poids total et poids des.gonades) ont ete faites;
les po.:!.ssons de oette derni~re espece etant, pour la pluspart, au mois considere,
en maturite sexuelle, reconnus par les valeurs du rapport gonosomatiquo, ainsi
que par I 'observation microscopique des gonades.
Suode
(.s.
/Si/rensen)
MackereI. In 1955 an inv8stigation on the biology of the mackerel has been
commenced. Material for age determination was secured during the cruises of the
"Skagerak" in the Skagerak and thc North Sea (Dogger Bank and West Bank).