CHAPTER 28
Notes on the Biology and Ecology of Opeatogenys gracilis (Canestrini
1864) (Pisces: Gobiesocidae) from Coastal Environments in Sicily
(Mediterranean)
s. Vizzini, A. Mazzola, and D. Scllipoti
ABSTRACT
A particularly large number of specimens of the Mediterranean coastal fish Opeatogenys gracilis
(Canestrini 1864) (Pisces: Gobiesocidae) were collected from Posidonia oceanica mats of the
"Stag none di Marsala u sound (western Sicily) and in the Gulf of Carini (northern Sicily). A study
was made of biometric and meristic characters andt for the first time for this species, diet composition. The biometric and meristic data did not distinguish between specimens from the two
study sites. In accordance with its benthic habitt O. gracilis feeds on small phytal prey living on
Posidonia oceanica leaves. The preferential food items throughout the year were Copepoda
Harpacticoida.
Introduction
Gobiesocidae is a cosmopolitan family of small
marine fish, typical of shallow and warm temperate waters. Specimens are characterised by an
adhesive structure located on the ventral body
surface formed by two contiguous disks and
flanked by pelvic fins. This adhesive structure
determines the benthic habit of this species. The
family includes 8 subfamilies, 43 genera and 150
species. Only 5 genera, all belonging to the subfamily Lepadogastrinae, are present in the
Mediterranean Sea. Opeatogenys gracilis
(Canestrini 1864) (Pisces: Gobiesocidae) is an
endemic species of this area. It distinguishes
itself from other Mediterranean Gobiesocidae by
an acute and strong spine from the subopercolum. The literature data concerning O. gracilis
are very poor, lacking information on both its
distribution and ecology. This species is indicated as uncommon in that it has been recorded
only at Nizza. Messina and in the Adriatic Sea
(Bini 1968; Tortonese 1975). It has also been
found recently along the southern coast of Spain
(Reina-Hervas and Nunez-Vergara 1985;
Cardona and Guerao 1992). Furthermore, the
existing information regarding O. gracilis is
derived from an exiguous number of specimens
captured (two reported in Reina-Hervas and
Nunez-Vergara 1985 and five in Cardona and
Guerao 1992).
This paper reports the finding, distribution
and feeding ecology of O. gracilis from the
"Stagnone di Marsala". The first occurrence of
this species in the Gulf of Carini (northern
Sicily) is reported, verifying its distribution in
Posidonia oceanica beds.
Materials and Methods
The "Stagnone di Marsala" is a semi-enclosed
coastal sound on the western coast of Sicily. It is
characterised by a wide range of salinity and temperature values. Its bottoms are covered by
phanerogames (Cymodocea nodosa and Posidonia
oceanica) associated with macroalgae (Caulerpa
prolifera and Cystoseira spp.) (Calvo et al. 1980.
1982). The Gulf of Carini is located on the northern coast of Sicily. In this area the physical parameters are those typical of western Mediterranean
shallow environments with little variation during
the year (Giaccone and Sortino 1964).
Samples from the "Stagnone di Marsala"
were collected monthly during one year by
means of a trawling net (3.5 metres long and 3
millimetres mesh diameter). In the Gulf of
Carini, samples were collected exclusively over
Dipartimento di Biologia Animale, Universita di Palermo, Via Archirafi 18,90123 Palermo, Italy
F.M. Faranda, 1. Guglielmo, G. Spezie (eds)
Mediterranean Ecosystems: Structures and Processes
© Springer-Verlag Italla 200 1
Notes on the Biology and Ecology of Opeatogenys gracilis (Canestrini
1864) (Pisces: Gobiesocidae) from Coastal Environments in Sicily
(Mediterranean)
s. Vizzini, A. Mazzola, and D. Scllipoti
ABSTRACT
A particularly large number of specimens of the Mediterranean coastal fish Opeatogenys gracilis
(Canestrini 1864) (Pisces: Gobiesocidae) were collected from Posidonia oceanica mats of the
"Stag none di Marsala u sound (western Sicily) and in the Gulf of Carini (northern Sicily). A study
was made of biometric and meristic characters andt for the first time for this species, diet composition. The biometric and meristic data did not distinguish between specimens from the two
study sites. In accordance with its benthic habitt O. gracilis feeds on small phytal prey living on
Posidonia oceanica leaves. The preferential food items throughout the year were Copepoda
Harpacticoida.
Introduction
Gobiesocidae is a cosmopolitan family of small
marine fish, typical of shallow and warm temperate waters. Specimens are characterised by an
adhesive structure located on the ventral body
surface formed by two contiguous disks and
flanked by pelvic fins. This adhesive structure
determines the benthic habit of this species. The
family includes 8 subfamilies, 43 genera and 150
species. Only 5 genera, all belonging to the subfamily Lepadogastrinae, are present in the
Mediterranean Sea. Opeatogenys gracilis
(Canestrini 1864) (Pisces: Gobiesocidae) is an
endemic species of this area. It distinguishes
itself from other Mediterranean Gobiesocidae by
an acute and strong spine from the subopercolum. The literature data concerning O. gracilis
are very poor, lacking information on both its
distribution and ecology. This species is indicated as uncommon in that it has been recorded
only at Nizza. Messina and in the Adriatic Sea
(Bini 1968; Tortonese 1975). It has also been
found recently along the southern coast of Spain
(Reina-Hervas and Nunez-Vergara 1985;
Cardona and Guerao 1992). Furthermore, the
existing information regarding O. gracilis is
derived from an exiguous number of specimens
captured (two reported in Reina-Hervas and
Nunez-Vergara 1985 and five in Cardona and
Guerao 1992).
This paper reports the finding, distribution
and feeding ecology of O. gracilis from the
"Stagnone di Marsala". The first occurrence of
this species in the Gulf of Carini (northern
Sicily) is reported, verifying its distribution in
Posidonia oceanica beds.
Materials and Methods
The "Stagnone di Marsala" is a semi-enclosed
coastal sound on the western coast of Sicily. It is
characterised by a wide range of salinity and temperature values. Its bottoms are covered by
phanerogames (Cymodocea nodosa and Posidonia
oceanica) associated with macroalgae (Caulerpa
prolifera and Cystoseira spp.) (Calvo et al. 1980.
1982). The Gulf of Carini is located on the northern coast of Sicily. In this area the physical parameters are those typical of western Mediterranean
shallow environments with little variation during
the year (Giaccone and Sortino 1964).
Samples from the "Stagnone di Marsala"
were collected monthly during one year by
means of a trawling net (3.5 metres long and 3
millimetres mesh diameter). In the Gulf of
Carini, samples were collected exclusively over
Dipartimento di Biologia Animale, Universita di Palermo, Via Archirafi 18,90123 Palermo, Italy
F.M. Faranda, 1. Guglielmo, G. Spezie (eds)
Mediterranean Ecosystems: Structures and Processes
© Springer-Verlag Italla 200 1