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SARSIA
Short communication
Notes on ichthyofauna of the deep basin of the Southern Adriatic Sea
Nicola Ungaro*, Giovanni Marano & Giovanni Rivas
SARSIA
Ungaro N, Marano G, Rivas G. 2001. Notes on ichthyofauna of the deep basin of the Southern Adriatic
Sea. Sarsia 86:153-156.
Thirteen teleosts and four cartilaginous fishes occurred in bottom trawls from the 826-1196 m depth
zone of the Southern Adriatic Sea. Cataetyx alleni (Byrne, 1906), Caelorinchus occa (Goode & Bean,
1886) and Lepidion lepidion (Risso, 1810) were recorded for the first time in this area, and all occurred deeper than 1000 m depth. The families Macrouridae, Moridae, and Squalidae dominated the
catches below 1000 m depth, contributing 90 % in terms of weight and 91 % in terms of numbers.
Nicola Ungaro* & G. Marano, Laboratorio Provinciale di Biologia Marina, Molo Pizzoli (Porto),
70123 Bari, Italy. – G. Rivas, Centro Oceanologico Mediterraneo, Via Libertà 37, 90139 Palermo,
Italy.
E-mail: [email protected]
* Corresponding author
Keywords: Fish community; Deep-water; Demersal species; Mediterranean Sea.
INTRODUCTION
The Adriatic Sea (Central Mediterranean Sea) is an 800km long and narrow basin. While northern and middle
parts are relatively shallow, the southern parts are deep
(AlfireviD 1981) with the maximum depth of 1223 m
reached in the central basin known as the “Bari pit”
(Fig. 1).
Considerable information is available on the southern
Adriatic demersal ichthyofauna at depths shallower than
800 m (Bombace & Froglia 1973; Bello & Rizzi 1988;
Vaccarella & al. 1992; Ungaro & al. 1995; Ungaro & al.
1998). KirinFiD & LepetiD (1955) reported some data
about the bottom long-line catches at 800-1100 m depth,
but the knowledge on the deep demersal fish fauna remains limited.
In 1999 a trawl survey was carried out at 826-1196 m
depths in order to fill the gap in our knowledge on the
demersal fish fauna in the deep-water basin. In this paper
we present information on species composition, abundance, and size distribution of the most abundant species.
MATERIAL AND METHODS
The trawl survey was carried out in April 1999. Twelve
hauls, each lasting one hour, were made within the depth
range 826-1196 m (Fig. 1). An otter trawl net was used
(net length = 35 m, horizontal opening = 15-16 m, vertical opening = 0.8-1.2 m, stretched mesh size at cod-end
= 32 mm). Due to the operative depths, the sampling
gear was towed by a single warp (the warp line was attached to a V-shaped backstrop, in turn connected to
two 220 kg iron doors), and the towing speed was around
2.8 knots.
The entire fish catch was frozen and brought to the
laboratory. Species identification keys used were
Tortonese (1970), Whitehead & al. (1986), Fisher & al.
(1987), and Cohen & al. (1990). Truly pelagic species
were excluded.
All specimens were weighed (g) and measured (TL total length, mm). Pre-anal length (PAL, snout-anus
length) was measured to the nearest mm for Macrouridae.
Species abundance in number and weight were standardised to one hour of trawling. Length frequency distributions were constructed for the most abundant species, i. e. those for which the total catch exceeded 100
specimens.
RESULTS
Seventeen demersal fishes, thirteen teleosts and four
cartilaginous species, occurred in the samples (Table 1).
Cataetyx alleni, Caelorinchus occa, and Lepidion
lepidion were recorded for the first time in the Adriatic
Sea, all three at sampling sites deeper than 1000 m.
L. lepidion, C. occa, Galeus melastomus, Nezumia
sclerorhynchus, and C. alleni were the most abundant
species in terms of numbers, while the highest catch in
terms of weight was found for G. melastomus, L. lepidion,
Mora moro, Trachyrhyncus trachyrhynchus, and C. occa
154
Sarsia 86:153-156 – 2001
total length, and most of the specimens had lengths
greater than the length of maturity (Ungaro & al. 1996).
N. sclerorhynchus lengths ranged between 15 and 50
mm PAL and most specimens were between 35 and 45
mm.
DISCUSSION AND CONCLUSIONS
Fig. 1. Investigated area and sampling stations.
(Table 1). The families Macrouridae (4 species), Moridae
(2 species), and Squalidae (2 species) together represented 90 % in terms of weight and 91 % in terms of
numbers in the catches from 1000 m depth and beyond.
Length frequency distributions were constructed for
L. lepidion, C. occa, G. melastomus, and N. sclerorhynchus (Fig. 2). With regard to the new findings for the
Adriatic Sea, L. lepidion lengths ranged from 150 to 340
mm TL (mostly between 150 and 250 mm) and C. occa
lengths ranged from 35 to 95 mm pre-anal length, mostly
of specimen from 60 to 90 mm. The length range of C.
alleni was 90-120 mm TL, mostly between 100 and 110
mm. Length frequency distribution of the latter species
was not reported because of the low number of specimens.
G. melastomus lengths ranged from 100 to 540 mm
The list of demersal fishes collected by bottom trawl net
at 826-1196 m in the deep Southern Adriatic Sea comprised seventeen species, some of which were reported
in previous species lists based on investigation in adjacent shallower areas of the Adriatic Sea (Bombace &
Froglia 1973; Bello & Rizzi 1988; Vaccarella & al. 1992;
Ungaro & al. 1995; Ungaro & al. 1998).
The scarcity of the deep fauna in the Mediterranean
Sea (Fredj & Maurin 1987) compared to open ocean studies at the same depths has been noted previously
(Haedrich & Merrett 1988); however, the number of species observed depends strongly on the gear design
(Gordon & Bergstad 1992), net selectivity, and the
number of hauls (Stefanescu & al. 1992), hence our limited data series may not have included all species inhabiting the area.
The dominance of the Macrouridae, Moridae, and
Squalidae families was also found elsewhere in the Mediterranean at similar depths (Stefanescu & al. 1992).
With regard to bony fishes, Lepidion lepidion,
Caelorinchus occa, and Cataetyx alleni were reported
for the first time in the Adriatic Sea but have previously
been recorded at similar depths in the Catalan Sea (northwestern Mediterranean) (Stefanescu & al. 1992). The
Fig. 2. Size frequency distributions of the most abundant species collected on the South Adriatic bathyal bottoms (826-1196 m
depths).
Ungaro & al. – Ichthyofauna of the deep Adriatic basin
findings of a large number of specimens in the samples
supplement information about their occurrence and distribution within the Mediterranean Sea (Torchio 1961;
Raimbault 1963; Bini 1969; Relini-Orsi & Relini 1972;
Relini-Orsi & Relini 1973; Allué 1983; Matallanas 1983;
Whitehead & al. 1986; Cohen & al. 1990).
L. lepidion and C. alleni of maximum reported sizes
(Whitehead & al. 1986; Cohen & al. 1990) occurred in
the area. The gear used collected L. lepidion of a wide
length range, only excluding individuals smaller than 150
mm TL.
Compared with trawl catches at 200-700 m depths
nearby (Ungaro & al. 1999), G. melastomus catches in
the deep-water basin contained higher proportions of
155
relatively large specimens. Stefanescu & al. (1994) found
the same in the Catalan Sea.
Most specimens of N. sclerorhynchus were between
35 and 45 mm PAL which is the length interval in which
maturity is attained in the Mediterranean (D’Onghia &
al. 1996; D’Onghia & al. 1999). Moreover, the fraction
of adult specimens in the samples was higher than in
upper slope catches in the same area (unpublished data)
and in adjacent seas (D’Onghia & al. 1999).
ACKNOWLEDGEMENTS
We would like to thank the Italian Petroleum Company ENIAGIP for the funding of this research.
Table 1. Collected species and abundance (kg/trawling hour, specimens/trawling hour) at each trawl station.
Sampling depth (m)
826 m
kg/h
n/h
1015 m
kg/h
n/h
1074 m
kg/h
n/h
1119 m
kg/h
n/h
1165 m
kg/h
n/h
1166 m
kg/h
n/h
Teleosts
Cataetyx alleni (Byrne, 1906)*
Caelorinchus occa (Goode & Bean, 1886)*
Conger conger (Linnaeus, 1758)
Epigonus telescopus (Risso, 1810)
Helicolenus dactylopterus (Delaroche, 1809)
Hymenocephalus italicus Giglioli, 1884
Lepidion lepidion (Risso, 1810)*
Mora moro (Risso, 1810)
Nettastoma melanurum (Rafinesque, 1810)
Nezumia sclerorhynchus (Valenciennes, 1838)
Notacanthus bonapartei Risso, 1840
Phycis blennoides (Brunnich, 1768)
Trachyrhynchus trachyrhynchus (Risso, 1810)
0.1
0.21
0.01
1.19
0.25
8.86
1
1
1
7
2
43
0.08
0.41
0.1
0.02
0.88
3
7
1
2
5
0
0.05
0.36
0.96
0.08
0.1
0.65
-
1
3
6
3
1
3
1
-
0.03
0.66
2.25
1.06
0.36
0.24
0.01
0.38
0.42
3
36
33
4
6
10
1
1
2
0.13
0.35
0.69
0.41
-
5
6
2
17
-
0.33
2.5
4.2
3.6
0.42
0.02
-
39
133
70
10
19
1
-
Elasmobranchs
Chimaera monstrosa Linnaeus, 1758
Dalatias licha (Bonnaterre, 1788)
Etmopterus spinax (Linnaeus, 1758)
Galeus melastomus Rafinesque, 1809
0.5
3.2
1.35
3.5
3
1
7
14
0.12
0.3
1
1
0.13
0.9
1
4
2.1
10
0.29
1
1
4
0.91
3.8
4
17
Sampling depth (m)
1174 m
kg/h
n/h
1175 m
kg/h
n/h
1175 m
kg/h
n/h
1178 m
kg/h
n/h
1186 m
kg/h
n/h
1196 m
kg/h
n/h
Teleosts
Cataetyx alleni (Byrne, 1906)*
Caelorinchus occa (Goode & Bean, 1886)*
Conger conger (Linnaeus, 1758)
Epigonus telescopus (Risso, 1810)
Helicolenus dactylopterus (Delaroche, 1809)
Hymenocephalus italicus Giglioli, 1884
Lepidion lepidion (Risso, 1810)*
Mora moro (Risso, 1810)
Nettastoma melanurum (Rafinesque, 1810)
Nezumia sclerorhynchus (Valenciennes, 1838)
Notacanthus bonapartei Risso, 1840
Phycis blennoides (Brunnich, 1768)
Trachyrhynchus trachyrhynchus (Risso, 1810)
0.04
0.18
0.22
0.03
-
4
10
5
1
-
0.05
3.35
5.7
3.53
0.35
1.38
0.38
6
42
104
8
5
49
2
0.01
0.4
0.3
0.2
-
1
21
7
9
-
0.02
0.06
0.06
0.12
-
2
2
1
4
-
0.01
0.11
0.09
1.06
0.05
-
2
7
2
3
2
-
0.01
0.38
0.35
2.27
2.49
0.03
0.25
0.05
2
18
1
43
8
1
10
1
Elasmobranchs
Chimaera monstrosa Linnaeus, 1758
Dalatias licha (Bonnaterre, 1788)
Etmopterus spinax (Linnaeus, 1758)
Galeus melastomus Rafinesque, 1809
0.16
4
3.9
0.49
9.5
1
2
55
0.27
-
1
-
0.25
1
0.16
0.4
1
1
0.95
0.6
6
1
3
25
* new records for the Adriatic Sea
156
Sarsia 86:153-156 – 2001
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Accepted 4 July 2000 – Printed 28 May 2001
Editorial responsibility: Tore Høisæter

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