Species Report Siganus Rivulatus (Marbled Spinefoot)

Mediterranean invasive species factsheet www.iucn-medmis.org

Species report Siganus rivulatus (Marbled spinefoot)

AFFILIATION FISHES

SCIENTIFIC NAME AND COMMON NAME REPORTS Siganus rivulatus 35

Key Identifying Features spines being venomous. The mouth is small with distinct lips. This medium-sized fish has an ellipsoidal, compressed body covered with small scales Body colour is brown to grey green, and embedded within the skin. It grows to a length of light-brown to yellow on the belly. There are up to 27 cm, commonly 5–25 cm. fine, often faint, yellow-gold stripes on the lower half of body. At night or when frightened, the The dorsal fin, with 13–14 spines and 10 soft colour is very mottled, withsix diagonal bars rays, begins above the pectoral fin base, and the across the flank. first dorsal spine points forward. Key taxonomical features for this species’ identification are pelvic fins with two stout spines connected by a membrane to the abdomen, and the forked tail fin. There are 7 spines in the anal fin with 8–10 soft rays. The anterior spines of the median fins are slender, whilst the posterior spines are stout, all of the

2013-2021 © IUCN Centre for Mediterranean Cooperation. More info: www.iucn-medmis.org Pag. 1/7 Mediterranean invasive species factsheet www.iucn-medmis.org

Other species that look similar

Identification and Habitat

The marbled spinefoot lives in shallow waters, preferring hard bottoms of compacted sand with rock, usually covered with vegetation. Adults live in small groups of 50 to several hundred individuals, feeding mainly green and red algae, such as Ulva spp. and Hypnea spp., and seagrasses (Posidonia oceanica).

Reproduction

The spawning season lasts from May to September.

Similar Species

Two non-indigenous species of Siganidae are now present in the Mediterranean: the marbled spinefoot, Siganus rivulatus, and the dusky spinefoot, Siganus luridus. The native salema, Sarpa salpa, also shares the same habitat and diet. The salema has characteristic horizontal yellow lines along its body; its eyes are ringed with yellow, and it has a black dot at the base of the pectoral fins. The tail fin shape distinguishes between the two Siganus species: Siganus rivulatus has a forked tail fin with narrow, translucent yellow stripes, whereas Siganus luridus has a straight or slightly concave tail fin and a uniform body colour.

2013-2021 © IUCN Centre for Mediterranean Cooperation. More info: www.iucn-medmis.org Pag. 2/7 Mediterranean invasive species factsheet www.iucn-medmis.org

Ecological Impacts

The two herbivorous fish species belonging to the Siganidae family, Siganus luridus and S. rivulatus, have become very common in most parts of the eastern Mediterranean and strongly interact with the native herbivorous fish Sarpa salpa through competition for food resources and habitat. The spread of these two alien herbivorous species can result in a drastic decrease in algal biomass, locally eradicating certain algae such as Cystoseira spp. forests, and reducing important nursery habitats for many species.

Economic Impacts

Due to its great abundance in the eastern Mediterranean, the dusky spinefoot is regularly caught by professional small-scale fisheries and nonprofessional fishermen. However, its commercial value is low. The venomous spines can cause painful injuries to bathers and fishers and the damage it may do to diving tourism and the local fishing industry still needs to be assessed.

Some fish farming trials have also been conducted in countries such as Cyprus, Israel History and Route of and Egypt. Introduction Management Options The marbled spinefoot is a species usually found in the western Indian Ocean and Red Sea. It was These include a) early eradication of new first recorded in the Mediterranean in 1927 populations by MPA technicians through spear along the Palestinian coast and spread fishing, and b) maintenance of healthy and progressively through the eastern abundant assemblages of top predators to Mediterranean: Syria, Cyprus, the Aegean Sea, encourage natural control through predation. Libya, Tunisia, the Ionian Sea and the southern Adriatic (Croatia). S. rivulatus has not yet been reported from the western Mediterranean; Further Reading however, its presence has been suspected in Corsica since 2010. Sala E. et al, 2011. Alien Marine Fishes Deplete Algal Biomass in the Eastern Mediterranean. PLoS ONE 6(2): e17356. doi:10.1371/journal.pone.0017356.

2013-2021 © IUCN Centre for Mediterranean Cooperation. More info: www.iucn-medmis.org Pag. 3/7 Mediterranean invasive species factsheet www.iucn-medmis.org

Bariche M., 2006. Diet of the Lessepsian fishes, Siganus rivulatus and S. luridus (Siganidae) in the eastern Mediterranean: A bibliographic analysis. Cybium 30: 41–49.

2013-2021 © IUCN Centre for Mediterranean Cooperation. More info: www.iucn-medmis.org Pag. 4/7 Mediterranean invasive species factsheet www.iucn-medmis.org

Map of sightings of the species Siganus rivulatus (Marbled spinefoot)

Legend

Algae Angiosperm Cnidarians Centre for Mediterranean Molluscs Crustaceans Ascidians Cooperation Combjellies / Fishes Ctenophores

More Information: Guide and reports platform for Marine Protected Areas (MPAs) in the Mediterranean. www.iucn-medmis.org

2013-2021 © IUCN Centre for Mediterranean Cooperation. More info: www.iucn-medmis.org Pag. 5/7 Mediterranean invasive species factsheet www.iucn-medmis.org

MPAs, Country Date Density Measure

Kas-Kekova, Turkey Before 2013 -- --

Patara, Turkey Before 2013 -- --

Foca, Turkey Before 2013 -- --

Gokova, Turkey Before 2013 -- --

Koycegiz-Dalyan, Turkey Before 2013 -- --

Fethiye-Gocek, Turkey Before 2013 -- --

Datca-Bozburun, Turkey Before 2013 -- --

Goksu Deltasi, Turkey Before 2013 -- --

Shiqmona, Israel Before 2013 -- --

-- 10/04/2014 -- --

-- 10/09/2014 -- --

-- 22/09/2014 -- --

Datca-Bozburun, Turkey 23/10/2014 -- --

Koycegiz-Dalyan, Turkey 23/10/2014 -- --

El-Kouf, Libya 21/11/2014 -- --

Karaburun-Sazani island, Himare,Albania 22/07/2015 -- --

-- 21/07/2016 -- --

-- 28/07/2016 -- --

-- 29/07/2016 -- --

-- 02/08/2016 -- --

-- 05/08/2016 -- --

-- 06/08/2016 -- --

-- 09/08/2016 -- --

-- 10/08/2016 -- --

Funded by: This collaborative effort is supported by: Mediterranean invasive species factsheet www.iucn-medmis.org

-- 12/08/2016 -- --

-- 18/08/2016 -- --

How to cite this tab: Siganus rivulatus - Invasive Alien Species Fact Sheet for Mediterranean Network of MPAs. From Online Database MedMIS (IUCN Center for Mediterranean Cooperation, Download date 01/10/2021.

More information about this species from: Otero, M., Cebrian, E., Francour, P., Galil, B., Savini, D. 2013. Monitoring Marine Invasive Species in Mediterranean Marine Protected Areas (MPAs): A strategy and practical guide for managers. Malaga, Spain: IUCN. 136 pages www.iucn.org/dbtw-wpd/edocs/2013-008-Es.pdf .

Funded by: This collaborative effort is supported by: