Spring Marine Vegetation on Rocky Substrata of the Tremiti Islands (Adriatic Sea, Italy)
253
Circa littoral Zone
Below 20 m depth (Table 5), Dictyota
dichotoma generally shows low per cent cover
values except at Porto San Nicola (St Nicola) at
-22 m and at Cala Sorrentino (Caprara) at -30
m. From 22 to 30 m depth (Table 5) the vegetation is more varied: the dominant species is
Peyssonnelia bornetii accompanied, according to
stations, by other species with high percent
cover values: by Peyssonnelia rubra and
Osmundaria volubilis at Punta Secca II (Caprara,
-24 m); by Halimeda tuna at Porto S. Nicola
(St Nicola, -22 m) and at Punta S. Maria
(St Nicola, -30 m); by Womersleyella setacea
at two stations of 8t Domino (Punta Coccodrillo
at -22 m and Grotta del Sale at -24 m) as well as
at San Nicola I (St Nicola) at -23 m. At
Punta Romito (Caprara) at -30 m, a community
with Womersleyella setacea and Sphaerococcus
coronopifolius occurs.
Circalittoral communities (Table 6) were found
only at the following three stations: Punta Secca I
(St. Domino) at -33 m, Cala dei Turchi (Caprara) at
-36 m and Punta Romito (Caprara) at -40 m. The
number of species per sample is 56. 46 and 38
respectively with a mean value of 46.7. The communities are characterised by a dominance of soophilous species: in the first station, Peyssonnelia
squamaria. P. bornetii and unidentified encrusting
Corallinaceae; in the second one, Lithophyllum
stictaeforme, Codium effusum, Neogoniolithon
brassica-jlorida, Sebdenia rodrigueziana and
Rodriguezella strafforelloi; in the third station,
Peyssonnelia squama ria, P. crispata. Neogoniolithon brassica-jlorida, Codium effusum,
RodriguezeUa strafforelloi, R. pinnata, Codium
bursa and unidentified encrusting Corallinaceae.
Table 6. Circalittoral communities
Number of transect
2
9
10
Depthinm
33
36
40
Per cent total cover (xlO)
10
10
10
Number of species per sample
56
46
38
Peyssonnelia squamaria (Gmelin) Decaisne
2.
+
2
Peyssonnelia bornetii Boudouresque et Denizot
2
Agltlothamnion sp.
1
+
+
Brongniartella byssoides (Goodenough etWoodward) Schmitz
1
Chylocladia verticillata (Lightfoot) Bliding
1
Polysiphonia elongata (Hudson) Sprengel
1
Unidentified encrusting Corallinaceae
3
2
Lithophyllum stictaeforme (Areschoug) Hauck
3
Codium effusum (Rafinesque) Delle Chiaje
2.
2
Neogoniolithon brassica-florida (Harvey) Setchell et Mason
2.
2
Rodriguezella strafforelloi Schmitz ex Rodriguez
2
2
Sebdenia rodrigueziana (J, Feldmann) Parkinson
2
Rodriguezella pinnata (Kiitzing) Schmitz ex Falkenberg
+
+
2
Codium bursa (Linnaeus) C. Agardh
2
Peyssonnelia crispata Boudouresque et Denimt
2
Antithamnion CTuciatum (C. Agardh) Nligeli
+
+
+
Ceramium bertholdii Funk
+
+
+
Ceramium codii (Richards) G. Mawyer
+
+
+
Erythroglossum sandrianum (Kiitzing) Kylin
+
+
+
Herposiphonia secunda (C. Agardh) Ambronn
+
+
+
Lomentaria chylocladiella Funk
+
+
+
Pseudochlorodesmis furcellata (Zanardini) Borgesen
+
+
+
Sphacelaria plumula Zanardini
+
+
+
Hypoglossum hypoglossoides (Stackhouse) Collins et Hervey
+
+
Stictyosiphon adriaticus Kiitzing
+
+
Cladophora albida (Nees) Kiitzing
+
+
Hydrolithon boreale (Foslie) Chamberlain
+
+
Gulsonia nodulosa (Ercegovic) J. et G. Feldmann
+
+
Polysiphonia denudata (Dillwyn) Greville
+
+
Number of species per sample not reported in the table
36
26
17
253
Circa littoral Zone
Below 20 m depth (Table 5), Dictyota
dichotoma generally shows low per cent cover
values except at Porto San Nicola (St Nicola) at
-22 m and at Cala Sorrentino (Caprara) at -30
m. From 22 to 30 m depth (Table 5) the vegetation is more varied: the dominant species is
Peyssonnelia bornetii accompanied, according to
stations, by other species with high percent
cover values: by Peyssonnelia rubra and
Osmundaria volubilis at Punta Secca II (Caprara,
-24 m); by Halimeda tuna at Porto S. Nicola
(St Nicola, -22 m) and at Punta S. Maria
(St Nicola, -30 m); by Womersleyella setacea
at two stations of 8t Domino (Punta Coccodrillo
at -22 m and Grotta del Sale at -24 m) as well as
at San Nicola I (St Nicola) at -23 m. At
Punta Romito (Caprara) at -30 m, a community
with Womersleyella setacea and Sphaerococcus
coronopifolius occurs.
Circalittoral communities (Table 6) were found
only at the following three stations: Punta Secca I
(St. Domino) at -33 m, Cala dei Turchi (Caprara) at
-36 m and Punta Romito (Caprara) at -40 m. The
number of species per sample is 56. 46 and 38
respectively with a mean value of 46.7. The communities are characterised by a dominance of soophilous species: in the first station, Peyssonnelia
squamaria. P. bornetii and unidentified encrusting
Corallinaceae; in the second one, Lithophyllum
stictaeforme, Codium effusum, Neogoniolithon
brassica-jlorida, Sebdenia rodrigueziana and
Rodriguezella strafforelloi; in the third station,
Peyssonnelia squama ria, P. crispata. Neogoniolithon brassica-jlorida, Codium effusum,
RodriguezeUa strafforelloi, R. pinnata, Codium
bursa and unidentified encrusting Corallinaceae.
Table 6. Circalittoral communities
Number of transect
2
9
10
Depthinm
33
36
40
Per cent total cover (xlO)
10
10
10
Number of species per sample
56
46
38
Peyssonnelia squamaria (Gmelin) Decaisne
2.
+
2
Peyssonnelia bornetii Boudouresque et Denizot
2
Agltlothamnion sp.
1
+
+
Brongniartella byssoides (Goodenough etWoodward) Schmitz
1
Chylocladia verticillata (Lightfoot) Bliding
1
Polysiphonia elongata (Hudson) Sprengel
1
Unidentified encrusting Corallinaceae
3
2
Lithophyllum stictaeforme (Areschoug) Hauck
3
Codium effusum (Rafinesque) Delle Chiaje
2.
2
Neogoniolithon brassica-florida (Harvey) Setchell et Mason
2.
2
Rodriguezella strafforelloi Schmitz ex Rodriguez
2
2
Sebdenia rodrigueziana (J, Feldmann) Parkinson
2
Rodriguezella pinnata (Kiitzing) Schmitz ex Falkenberg
+
+
2
Codium bursa (Linnaeus) C. Agardh
2
Peyssonnelia crispata Boudouresque et Denimt
2
Antithamnion CTuciatum (C. Agardh) Nligeli
+
+
+
Ceramium bertholdii Funk
+
+
+
Ceramium codii (Richards) G. Mawyer
+
+
+
Erythroglossum sandrianum (Kiitzing) Kylin
+
+
+
Herposiphonia secunda (C. Agardh) Ambronn
+
+
+
Lomentaria chylocladiella Funk
+
+
+
Pseudochlorodesmis furcellata (Zanardini) Borgesen
+
+
+
Sphacelaria plumula Zanardini
+
+
+
Hypoglossum hypoglossoides (Stackhouse) Collins et Hervey
+
+
Stictyosiphon adriaticus Kiitzing
+
+
Cladophora albida (Nees) Kiitzing
+
+
Hydrolithon boreale (Foslie) Chamberlain
+
+
Gulsonia nodulosa (Ercegovic) J. et G. Feldmann
+
+
Polysiphonia denudata (Dillwyn) Greville
+
+
Number of species per sample not reported in the table
36
26
17