Page 2 - Gambi_Guidetti_1998

550 M.C. G A M ~ PI.. G u i ~ ~ i - r i

base of the rhizome, while in others seeds were lacking. Phenological and
morphological measurements, and leaf biomass estimates (dry weight) were
performed on 9 specimens with seed and 11 without seed, respectively. Differences
between two groups (mean I standard deviation) were tested in pairs (t-test).

Results and discussion
Seedlings were observed between 0.5 m and 2 m depth, settled on rocky bottom

and big stones colonized by photophilic algae, mainly the Phaeophyta Padina
pavonica (L.) Lamouroux. Severa1 seedlings were dispersed as isolated shoots,
while others were grouped in 3-4 specimens.

In the shoots still bearing the seed, this latter was black coloured with clear
traces of decay; the primary root was always broken (Fig. l). Data about

Fig. 1 - Seedlings of P. oceanica

collected at Favignana, and
still bearing the seed
(arrows).
Germogli di P oceonlco
osservati o Fovignana e
portanti ancoro il seme
W (frecce).

phenology, morphology and leaf biomass are reported in Table 1. As no significant
differences (t-test) were found between the shoots with and without seed, the values
of the measured parameters have been pooled. Al1 the seedlings showed a well
developed root system. The leaf apices had often brown tissue (48%) or were
broken (34%), and showed a heavy covering of epiphytes, mainly characterized
by encrusting corallinaceous algae and egg capsules of molluscs. In some cases,
shoots were observed in division. Considering the number of leaves together with
that of scales and scars, a total mean number of 26.1 leaves per shoot were
produced after germination (Table 1). These results have been compared with
literature information on seed germination and culture in aquaria and with the
scarse "in situ" data available. Various authors observed a high number of leaves
produced during the first months after germination, both in laboratory conditions