Mediterranean) in September 2021, a loggerhead sea turtle Caretta caretta were
accidentally captured a live by a trawler in Mahdia tunisian waters (35° 32’ 19.909’’;
11° 12’ 37.79’’) at a depth of 140 to 200 m.
The turtle was disentangled, measured and photographed. All barnacles were carefully
and quickly scraped with a knife from the carapace and then fixed and preserved in 70%
ethanol. Then the animal released alive to the sea water. All Cirripedia were later counted
and identified according to the Relini (1980).
Results
On the female of loggerhead sea turtle Caretta caretta (Weight = 70 kg; Curved carapace
length= 58cm; curved carapace width= 53cm), accidentally captured a live by a trawler
in Mahdia, fifty specimens of barnacles are mainly associated on the carapace. These
barnacles belong to two different species, the native species Chelonibia testudinaria
(Linnaeus, 1758) and the non-indigenous species Amphibalanus eburneus with 20
specimens of which 15 individuals are adults. The species is characterized by a shell with
a conic/cylindrical aspect, variable in shape according to the amount of crowding, with a
toothed and almost pentagonal orifice. The diameter, taken from the base of the rostrum
to the base of the hull, varies from 10 to 20 mm. The heights vary between 7.5 and 20
mm.
Conclusion
The presence of A. eburneus juveniles suggests the successful establishment of the
species in the area. Several hypotheses concerning the possible vector transporting A.
eburneus to Tunisian waters will be discussed. Indeed, the invasive potential of the family
Balanidae is well known, with a substantial number of alien species found globally,
several of which have adverse effects on native ecosystems by competing for space and
food and contributing to biofouling on ships and anthropogenic structures. Therefore,
future studies may focus on the possible impacts of this invader on native biota.
Bibliography
CARLTON J.T., NEWMAN W.A., PITOMBO F.B. (2011) - Barnacle invasions: introduced,
cryptogenic, and range expanding Cirripedia of North and South America. In: Galil B.S., Clark
P.F., Carlton J.T. (eds), In the Wrong Place-Alien Marine Crustaceans: Distribution, Biology
and Impacts. Springer, pp 159–213.
DINEEN J.F., HINES A.H. (1994) - Larval settlement of the polyhaline barnacle Balanus
eburneus (Gould): cue interactions and comparisons with two estuarine congeners. Journal of
Experimental Marine Biology and Ecology 179: 223–234
EL LAKHRACH, H., HATTOUR, A., JARBOUI, O., ELHASNI, K., RAMOSESPLA, A.A., (2012) -
Spatial distribution and abundance of the megabenthic fauna community in Gabes Gulf
(Tunisia, eastern Mediterranean Sea). Mediterranean Marine Science, 13 (1), 12-29
FOFONOFF P.W., RUIZ G.M., STEVES B., SIMKANIN C., CARLTON J.T. (2018) National
Exotic Marine and Estuarine Species Information System.
RELINI G. (1980) Guide per il riconoscimento delle specie animali delle acque lagunari e costiere
italiane. CNR AQ/1/91. 2. Cirripedi Toracici. Monotipia Erredi, Genova, 116 pp.
ZENETOS A., ÇINAR M.E., CROCETTA F., GOLANI D., ROSSO A., SERVELLO G.,
SHENKAR N., TURON X., VERLAQUE M. (2017) Uncertainties and validation of alien
species catalogues: the Mediterranean as an example. Estuarine, Coastal and Shelf Science
191: 171–187
2nd Mediterranean Symposium on the Non-Indigenous Species (Genoa, Italy, 22-23 September 2022)
114
accidentally captured a live by a trawler in Mahdia tunisian waters (35° 32’ 19.909’’;
11° 12’ 37.79’’) at a depth of 140 to 200 m.
The turtle was disentangled, measured and photographed. All barnacles were carefully
and quickly scraped with a knife from the carapace and then fixed and preserved in 70%
ethanol. Then the animal released alive to the sea water. All Cirripedia were later counted
and identified according to the Relini (1980).
Results
On the female of loggerhead sea turtle Caretta caretta (Weight = 70 kg; Curved carapace
length= 58cm; curved carapace width= 53cm), accidentally captured a live by a trawler
in Mahdia, fifty specimens of barnacles are mainly associated on the carapace. These
barnacles belong to two different species, the native species Chelonibia testudinaria
(Linnaeus, 1758) and the non-indigenous species Amphibalanus eburneus with 20
specimens of which 15 individuals are adults. The species is characterized by a shell with
a conic/cylindrical aspect, variable in shape according to the amount of crowding, with a
toothed and almost pentagonal orifice. The diameter, taken from the base of the rostrum
to the base of the hull, varies from 10 to 20 mm. The heights vary between 7.5 and 20
mm.
Conclusion
The presence of A. eburneus juveniles suggests the successful establishment of the
species in the area. Several hypotheses concerning the possible vector transporting A.
eburneus to Tunisian waters will be discussed. Indeed, the invasive potential of the family
Balanidae is well known, with a substantial number of alien species found globally,
several of which have adverse effects on native ecosystems by competing for space and
food and contributing to biofouling on ships and anthropogenic structures. Therefore,
future studies may focus on the possible impacts of this invader on native biota.
Bibliography
CARLTON J.T., NEWMAN W.A., PITOMBO F.B. (2011) - Barnacle invasions: introduced,
cryptogenic, and range expanding Cirripedia of North and South America. In: Galil B.S., Clark
P.F., Carlton J.T. (eds), In the Wrong Place-Alien Marine Crustaceans: Distribution, Biology
and Impacts. Springer, pp 159–213.
DINEEN J.F., HINES A.H. (1994) - Larval settlement of the polyhaline barnacle Balanus
eburneus (Gould): cue interactions and comparisons with two estuarine congeners. Journal of
Experimental Marine Biology and Ecology 179: 223–234
EL LAKHRACH, H., HATTOUR, A., JARBOUI, O., ELHASNI, K., RAMOSESPLA, A.A., (2012) -
Spatial distribution and abundance of the megabenthic fauna community in Gabes Gulf
(Tunisia, eastern Mediterranean Sea). Mediterranean Marine Science, 13 (1), 12-29
FOFONOFF P.W., RUIZ G.M., STEVES B., SIMKANIN C., CARLTON J.T. (2018) National
Exotic Marine and Estuarine Species Information System.
RELINI G. (1980) Guide per il riconoscimento delle specie animali delle acque lagunari e costiere
italiane. CNR AQ/1/91. 2. Cirripedi Toracici. Monotipia Erredi, Genova, 116 pp.
ZENETOS A., ÇINAR M.E., CROCETTA F., GOLANI D., ROSSO A., SERVELLO G.,
SHENKAR N., TURON X., VERLAQUE M. (2017) Uncertainties and validation of alien
species catalogues: the Mediterranean as an example. Estuarine, Coastal and Shelf Science
191: 171–187
2nd Mediterranean Symposium on the Non-Indigenous Species (Genoa, Italy, 22-23 September 2022)
114