Page 4 - Scuderi_Balistreri_Germanà_2019

418 DANILO SCUDERI ET ALII

Cosenza, Italy; sh.: empty shell/s; sp.: living col- The left valve shows a very marked rounded
lected specimen/s. byssal ridge and bears a straight and clearly dupli-
cated anterior tooth; posterior tooth not marked.
Straight hinge line, which become almost
RESULTS deeply curved near the umbo. Seen from inner side,
the umbo is prominent in the left valve, almost in-
Systematics visible in the right one.
Anatomy of soft parts: digestive gland, kidney,
Classis BIVALVIA Linnaeus, 1758 gonad and ctenidium deep orange (Fig. 35); foot
Subclassis PTERIOMORPHIA Beurlen, 1944 whitish with numerous black spots; ctenidium and
Ordo OSTREIDA Férussac, 1822 margin of mantle orange with white stains and
Superfamilia PTERIOIDEA Gray, 1847 (1820) black radial bands corresponding to the marginal
Familia PTERIIDAE Gray, 1847 (1820) tips; anal funnel (Fig. 36) speare-shaped and
graysh. Byssus green with almost thick filaments
Pinctada Röding, 1798 (Fig. 40).

DISTRIBuTION AND BIOLOGY. Quite common in
TYPE SPECIES: Pinctada margaritifera (Linnaeus, Eastern basin, from Israel, Crete, Grece to Tunisia,
1758). Here follows the description of the main di- Eastern and Western Sicily and S-Apulia. Tyrrhen-
agnostic characters observed for each of the two ian records should be confirmed with live-collected
taxa treated in the present paper. specimens.
Calcareous to lava hard substrata, with dense
Pinctada radiata (Leach, 1814) algal turf, at low depths (-0.5/8 m).
(Figs. 2–7, 17–19, 23, 35, 36, 39, 40)

EXAMINED MATERIAL. A total of 84 sh and 48 sp Pinctada fucata (Gould, 1850)
from different localities from Italy and Tunis (see (Figs. 8–26, 20–22, 24, 37, 38, 41–50)
Table 2 for details).
DESCRIPTION. Shell almost rounded in outline, EXAMINED MATERIAL. A total of 761 sh and 392
variable in thickness and inequilateral (Fig. 27), sp from different localities from Italy, Greece and
high up to 75 mm, constituted by almost flat valves, Malta (see Table 2 for details). Maldives: Ari
the left more convex than the right one. Atoll, Kuda Rah, 96 Km S of Male, beached, 5 sh
Outer face reddish with darker radial rows, (DSC).
sculptured by numerous concentric growth lamellae DESCRIPTION. Shell almost transverse-oval in
which bear, on the lower 1/2 or 1/3 of the valve, a outline, fragile and highly inequilateral (Fig. 26),
copious number of pointed and narrow processes high up to 45 mm, with a flat right valve and a left
arranged in two orders: one larger alternated to one quite convex one. Colour very variable, from al-
or two smaller (Fig. 27). most white specimens with darker stains to yellow,
In the posterior margin of both the valves the red, but the most common is green, within its wide
rows are closer. The smooth inner surface is divided range of variations, from paler to very dark, with
in a marginal less wide non-nacreous layer, which whitish radial rows.
recalls the outer surface in colour, separated by a It is sculptured by concentric almost smooth
darker more or less wide band from the nacre one, growth lamellae, which bear, on the lower 1/3 or 1/4
which bears a wide adductor muscle scar and a se- of the valve, a low number of blunt and large
ries of small pallial muscle scars. processes arranged in two orders of 10–12 alternated
The right valve shows a not very marked rows of bigger and smaller processes (Fig. 26).
rounded byssal ridge. The hinge bears a well-de- In the posterior margin of both the valves the
fined and duplicated posterior tooth and a not very rows bear bigger processes: those of the 2nd or 3rd
well defined but thick anterior tooth with two not row could form very long and large scales which
deep sockets. stand up over all the others (Figs. 12, 13).