Invasive Callinectes sapidus and Portunus segnis in Libyan waters
Corsini-Foka et al. (2021), BioInvasions Records 10(4): 885–893, https://doi.org/10.3391/bir.2021.10.4.13
890
Table 1. Data on the findings of Portunus segnis in Libyan waters. (ID: Sample identification number; N: Number of specimens).
ID
Date
Place
Longitude
Latitude
Depth (m)
N
Gear
A
13/10/2018
Sabratha
32.81139°N
12.47194°E
10
1
Diver, hand collecting
B
5/11/2018
Zuwara
32.95750°N
12.05139°E
8
2
Trammel net
C
15/9/2020
Abukammash
33.08611°N
11.70056°E
1
2
Trammel net
D
11/11/2020
Tajurah
32.85306°N
13.45139°E
10
7
Trammel net
E
20/1/2021
Sorman
32.79556°N
12.57417°E
2
3
Diver, hand collecting
F
25/11/2020
Sabratha
32.81139°N
12.47194°E
1
7
Diver, hand collecting
constitute a natural range expansion of the species from the already invaded
Egyptian waters. They may indicate furthermore that the species is
establishing viable populations within the Umm-Hufayn Lagoon, an area
evidently suitable to invasive alien species, as testified by the recent record
of yet another NIS decapod of Atlantic origin, Penaeus aztecus Ives, 1891
(Abdulrraziq et al. 2021).
Callinectes sapidus has been reported from estuaries and other oligothalassic environments (e.g. embayments contiguous to the mouth of
rivers), including bays within the Ebro Delta in Spain (Prado et al. 2020),
which it invades for feeding purposes (oysters, clams, gastropods). This
could explain its occurrence along the eastern Libyan coast, specifically in
the Jabal al Akhdar region, which is characterized by seasonal coastal
runoff from non-perennial watercourses fed by precipitation levels which
are higher than those for the rest of Libya.
The lessepsian blue swimming crab Portunus segnis has long established
a presence in Mediterranean Egyptian waters (Galil 2011; Abdel Razek et
al. 2006, 2016) as well as in shallow waters along extensive swathes of the
Tunisian coastline (Annabi et al. 2018; Ben Abdallah-Ben Hadj Hamida et
al. 2019a; Shaiek et al. 2021). Currently, blue swimming crabs, being
particularly abundant in these areas, are exploited commercially, becoming
an important part of the local fisheries with an increasing economic value.
Indeed, the species has also become commercially important in some local
markets as well as a value-added product for export to foreign markets
(Ben Abdallah-Ben Hadj Hamida et al. 2019b; Ennouri et al. 2021).
The species has been recently recorded along eastern and western swathes
of the Libyan coast (Shakman et al. 2017, 2019). The rapid establishment
and proliferation of P. segnis along the western coast of Libya was expected,
given the invasive nature of the species and a further imminent expansion
of the species along the entire coastline of Libya is anticipated.
Sympatry is not uncommon within decapods, with sympatric species
reducing the intense competitive pressure arising from their affiliated
niches through adaptations (Baumart et al. 2015). Through fishing operations
in the shallow coastal waters of Tunisia, the concomitant occurrence of the
two invasive portunids C. sapidus and P. segnis has been recently
documented (Ben Suissi et al. 2017; Mili et al. 2020). To date, along the
Libyan coastline, it appears that the two allochthonous decapods occupy
areas which are spatially distinct and non-overlapping, but the fact that the
Corsini-Foka et al. (2021), BioInvasions Records 10(4): 885–893, https://doi.org/10.3391/bir.2021.10.4.13
890
Table 1. Data on the findings of Portunus segnis in Libyan waters. (ID: Sample identification number; N: Number of specimens).
ID
Date
Place
Longitude
Latitude
Depth (m)
N
Gear
A
13/10/2018
Sabratha
32.81139°N
12.47194°E
10
1
Diver, hand collecting
B
5/11/2018
Zuwara
32.95750°N
12.05139°E
8
2
Trammel net
C
15/9/2020
Abukammash
33.08611°N
11.70056°E
1
2
Trammel net
D
11/11/2020
Tajurah
32.85306°N
13.45139°E
10
7
Trammel net
E
20/1/2021
Sorman
32.79556°N
12.57417°E
2
3
Diver, hand collecting
F
25/11/2020
Sabratha
32.81139°N
12.47194°E
1
7
Diver, hand collecting
constitute a natural range expansion of the species from the already invaded
Egyptian waters. They may indicate furthermore that the species is
establishing viable populations within the Umm-Hufayn Lagoon, an area
evidently suitable to invasive alien species, as testified by the recent record
of yet another NIS decapod of Atlantic origin, Penaeus aztecus Ives, 1891
(Abdulrraziq et al. 2021).
Callinectes sapidus has been reported from estuaries and other oligothalassic environments (e.g. embayments contiguous to the mouth of
rivers), including bays within the Ebro Delta in Spain (Prado et al. 2020),
which it invades for feeding purposes (oysters, clams, gastropods). This
could explain its occurrence along the eastern Libyan coast, specifically in
the Jabal al Akhdar region, which is characterized by seasonal coastal
runoff from non-perennial watercourses fed by precipitation levels which
are higher than those for the rest of Libya.
The lessepsian blue swimming crab Portunus segnis has long established
a presence in Mediterranean Egyptian waters (Galil 2011; Abdel Razek et
al. 2006, 2016) as well as in shallow waters along extensive swathes of the
Tunisian coastline (Annabi et al. 2018; Ben Abdallah-Ben Hadj Hamida et
al. 2019a; Shaiek et al. 2021). Currently, blue swimming crabs, being
particularly abundant in these areas, are exploited commercially, becoming
an important part of the local fisheries with an increasing economic value.
Indeed, the species has also become commercially important in some local
markets as well as a value-added product for export to foreign markets
(Ben Abdallah-Ben Hadj Hamida et al. 2019b; Ennouri et al. 2021).
The species has been recently recorded along eastern and western swathes
of the Libyan coast (Shakman et al. 2017, 2019). The rapid establishment
and proliferation of P. segnis along the western coast of Libya was expected,
given the invasive nature of the species and a further imminent expansion
of the species along the entire coastline of Libya is anticipated.
Sympatry is not uncommon within decapods, with sympatric species
reducing the intense competitive pressure arising from their affiliated
niches through adaptations (Baumart et al. 2015). Through fishing operations
in the shallow coastal waters of Tunisia, the concomitant occurrence of the
two invasive portunids C. sapidus and P. segnis has been recently
documented (Ben Suissi et al. 2017; Mili et al. 2020). To date, along the
Libyan coastline, it appears that the two allochthonous decapods occupy
areas which are spatially distinct and non-overlapping, but the fact that the