Page 5 - Sella_M_1929

Migrations and Habitat of the Tuna ( Thunnus thynnus L, ), Studied
by the Method of the Hooks j with Observations on Growth, on the
Operation of the Fisheries, etOo

The direct evidences of the arrival of tuna from distant regions,
borne by the fish itself in its own body in the form of hooks or tackle
torn from the lines of fishermen, have been notably increased as a con-
sequence of numerous investigations which I have made, to such a degree
as to permit reliable deductions on some fundamental pointSo

There are in all (excepting some minor reports)? 15 hooks and
leads from the Mediterranean , which testify to the migrations of the tuna
between the various basins of the Mediterranean; 25 hooks from the Atlantic
(Tarifa, Northern Spain, the Azores), which demonstrate the passage of
tuna from the Atlantic to the Mediterranean; and one Atlantic hook, which
shows the movement of tuna from the Gulf of Gascony to Norway^

In the last two years, indeed, in addition to those which I have
alrSady made known (Rend. R. Ace. Lincei, 1926; Bullo Stat, Acquico et
P§che de Castiglione, 1927), I have been able to recover in tuna of the
Mediterranean and elsewhere, in spite of the fact that the catch of the
tuna fisheries has been extraordinarily small, the following tackles

Tackle Ori m Place of Recovery

1927 4 leadsi/ Constantinople Cyrenaica (El Mongar, Bengazi)
3 hooks 2/ Gulf of Gascony Sicily (Favignana) and
Tripolitania (Sliten)
1 hook?/ Azores Sardinia (Isola Plana)
1 hook . Gulf of Gascony Norway (Oslofjord)
1928 1 hookZ/ South -. v^^^^v. Sardinia (Peloso)
ww-w. Ireland
1 hookl/ Gascony (probably)Sardinia (Porto Paglia)
1 hook Algeria (Arzeu) Sardinia (Porto Scuso)

" "
1/ Three lead jigs of the zoka" type and one lead of the skandil"
type given me by Dr. A, Benedettio

~J Spanish hooks for tuna and "bonito" ( Th. alalonga )o That from Favignana
was given me by Comm. Caruso j the two from Sliten were found during
my stay at that fishery.
3/ This and the other Sardinian hooks were given to me by the proprietors
of the respective tuna traps; Marquis of Villamarina (l. Plana),
Dr. de Plaisant (Peloso), Cav, Carpaneto (P„ Paglia), Awo Casaretto
(p. Scuso)o
i/ French double hook for "germon" (Th, alalonga) o
5/ Spanish hook for tuna and tonito," The origin is given as probable
because at one place in Sicily (Porticello) they have now commenced
making use, although on a very small scale, bf hooks of this typep
brought from Spain, in the fishery for albacoreo This fishery lasts,
however, only a few days out of the year, in the spring, and only a
few boats participate in it, which removes the certainty but not the
probability of the North Spanish origin of the hook in question.