119
ANNALES · Ser. hist. nat. · 27 · 2017 · 2
short scientifi c article                DOI 10.19233/ASHN.2017.14
received: 2017-08-21
RANGE EXPANSION OF ALIEN NUDIBRANCH MELIBE VIRIDIS 
(KELAART, 1858) IN THE NORTHERN ADRIATIC SEA
Lovrenc LIPEJ & Borut MAVRIČ
Marine Biology Station, National Institute of Biology, Fornace 41, Piran, Slovenia
E-mail: lovrenc.lipej@nib.si
ABSTRACT
The alien nudibranch Melibe viridis (Kelaart, 1858) was recorded in the waters of Slovenia (Gulf of Trieste, 
northern Adriatic Sea). A specimen was photographed and fi lmed on rocky hard bottom of the Natural Monument 
Cape Madona in October 2016. This is the fi rst record of this large sized nudibranch for Slovenia and for the Gulf of 
Trieste, as well, and a new one among otherwise rare records on this species in the Adriatic Sea.
Key words: Mollusca, Gastropoda, Nudibranchia, Slovenia, non indigenous species, Adriatic Sea
ESPANSIONE DELL’AREALE DEL NUDIBRANCO ALIENO MELIBE VIRIDIS 
(KELAART, 1858) NELL’ADRIATICO SETTENTRIONALE
SINTESI
Il nudibranco alieno Melibe viridis (Kelaart, 1858) è stato trovato nel mare della Slovenia (Golfo di Trieste, 
Adriatico settentrionale). Un esemplare è stato fotografato e fi lmato sul fondale roccioso all’interno del Monumento 
naturale Punta Madonna, nell’ottobre del 2016. Si tratta del primo ritrovamento di questo nudibranco di grandi 
dimensioni per la Slovenia e per il Golfo di Trieste, e di una delle poche segnalazioni di questa specie per il mare 
Adriatico. 
Parole chiave: Mollusca, Gastropoda, Nudibranchia, Slovenia, specie non-indigena, mare Adriatico
120
ANNALES · Ser. hist. nat. · 27 · 2017 · 2
Lovrenc LIPEJ & Borut MAVRIČ: RANGE EXPANSION OF ALIEN NUDIBRANCH MELIBE VIRIDIS ..., 119–124
INTRODUCTION
Melibe viridis (Kelaart, 1858) (Tethyididae: Nudi-
branchia) is a large sized tropical nudibranch with a typi-
cal head hood and infl ated cerata. It is widespread across 
the west Indo-Pacifi c region. The fi rst Mediterranean 
record of this species (as Melibe fi mbriata) was reported 
from the island of Cephalonia in the Ionian Sea in 1970 
(Moosleitner, 1986), but it has also been recorded from 
the coastal waters off peninsular Greece (Tzouval & 
Pettas, 2005), Aegean waters off the island Milos (Kot-
soubas & Cinelli, 1997), both the Ionian (Thompson & 
Crampton, 1984; Cariglio et al., 2004; Mastrototaro et 
al., 2004) and Tyrrhenian coasts of Calabria (Crocetta et 
al., 2009), the waters off Sardegna (Doneddu & Trainito, 
2008),  the waters off Cyprus (Sanchez Villarejo, 2007; 
Tsiakkiros & Zenetos, 2011), the Strait of Messina (Mo-
jetta, 1998), north-eastern Sicily (Scuderi & Russo, 2003), 
Maltese islands (Borg et al., 2016), southern Turkey (Van 
Bragt, 2001; Yokes & Rudman, 2004), off Israeli coast 
(Mienis, 2010) and the island of Djerba in the Gulf of 
Gabes (Cattaneo-Vietti et al., 1990) (maps and references 
in Despalatović et al., 2002; Zenetos et al., 2004).
Despalatović et al. (2002) published the fi rst records 
of M. viridis for the Adriatic Sea in waters off the island 
of Hvar (Croatia) and Jančić (2004) reported it close to 
the city of Herceg Novi (Montenegro). Recently, Mandić 
et al. (2016) reported on spawning of this species in 
Boka Kotorska Bay (Montenegro) in October 2014. 
In this note we report on the fi rst record of M. viridis 
in the Slovenian part of the Adriatic Sea, which also 
represent the fi rst fi nding for the Gulf of Trieste.
MATERIAL AND METHODS
On the 25th of October 2016 diver Kristijan Murn 
photographed and fi lmed a 10 cm long specimen of Me-
libe viridis with Go-Pro camera at the location of Natural 
Monument of Punta Madona in Piran (Slovenia) (Fig. 1) 
The specimen was sighted at 7 m depth, creeping  on 
rocks at the sea bottom (Fig. 2) in front of the Norik 
diving club Piran. Photographs and fi lm shots of the 
studied specimen are stored as a part of species record 
collection of Marine Biology Station (National Institute 
of Biology) in Piran. 
RESULTS AND DISCUSSION
The observed seaslug was easily determined due 
to the typical shape, large and dilated buccal hood 
and other diagnostic features (Thompson & Crampton, 
1984; Gosliner & Smith, 2003). This is the fi rst record 
of this nudibranch in the Slovenian part of Adriatic and 
at the same time in the Gulf of Trieste and the north-
ernmost record in the Adriatic Sea, as well. The speci-
men was photographed in rocky environment while 
crawling over the substrate and scaning the sediment 
between rocks with its oral veil. The habitat was not 
typical one for this species, since in most reports M. 
viridis was found in seagrass meadows of Cymodocea 
nodosa. However, it is also true that the rocky habitat 
host a high abundance of many small sized decapods 
and other crustaceans. 
The occurrence of M. viridis in the waters off Piran 
occurred in October, where temperatures are still rather 
high (above 20oC). At the end of summer the Gulf of 
Trieste is facing the intrusion of southern water masses 
into the area (Adriatic ingression) which could affect the 
occurrence of thermophilous faunistic elements (Dulčić 
et al., 2004). The possibility that M. viridis could be 
related with the ingression of southern Adriatic water 
masses was previously already pointed by Mandić et 
al. (2016) for Montenegrin waters. Tsiakkiros & Zene-
tos (2011) considered the ballast waters as a probable 
vector of M. viridis introduction into the Mediterranean 
Sea, since this species was not reported neither from the 
Levantine waters nor from the Red Sea. 
The new Adriatic record on this species proved again 
the importance of an effective cooperation between 
SCUBA diving organisations and scientifi c institutes. 
In Slovenian coastal sea at least nine alien mollusks 
were recorded (Tab. 1) prior the fi nding of M. viridis (De 
Min & Vio, 1997, 1998; Lipej et al., 2008., Mavrič et 
al., 2010; Crocetta, 2011; Dailanis et al., 2016; Lipej 
et al., 2017). Six of them are bivalves, while other are 
gastropods with three of them being seaslugs (Bursatella 
Fig. 1: Map of the northern Adriatic Sea with the studied 
area. The sampling locality of Melibe viridis is presented 
with a circle. 
Sl. 1: Zemljevid Jadranskega morja z obravnavanim 
območjem. Lokaliteta, kjer je bil najden primerek vrste, 
Melibe viridis je označena s krogcem.
121
ANNALES · Ser. hist. nat. · 27 · 2017 · 2
Lovrenc LIPEJ & Borut MAVRIČ: RANGE EXPANSION OF ALIEN NUDIBRANCH MELIBE VIRIDIS ..., 119–124
Fig. 2:  A specimen of Melibe viridis photographed on hard bottom in the Nature Monument Punta Madona, Piran 
in October 2016 (Photo: K. Murn).
Sl. 2: Primerek vrste Melibe viridis, fotografi ran na skalnatem dnu znotraj naravnega spomenika Rt Madona v 
Piranu oktobra 2016 (Foto: K. Murn).
Tab. 1: Alien molusks up to date recorded in the Slovenian part of the Adriatic Sea with the locality, year of fi rst 
record and literature reference. 
Tab. 1: Tujerodni mehkužci v slovenskem delu Jadranskega morja s podatki o lokaliteti, prvem zapisu in literaturnih 
virih. 
Alien mollusk
Pathway/
Probable vector
Locus year source
Arcuatula senhousia 
(Benson, 1842)
mariculture Gulf of Koper 2005
Mavrič et al. 
(2010)
Magallana gigas 
(Thunberg, 1793)
mariculture Sečovlje Bay 1971
De Min & Vio 
(1998)
Ruditapes philippinarum 
(Adams & Reeve, 1850)
mariculture Sečovlje salina 1993 Lipej (1994)
Anadara kagoshimensis 
(Tokunaga, 1906)
Shipping/ Ballast 
waters
Gulf of Trieste (Slo) 
sandy environments
1996
De Min & Vio 
(1997)
Anadara transversa 
(Say, 1822)
Shipping/ Ballast 
waters
Piran, Debeli rtič 2011 Crocetta (2011)
Brachidontes pharaonis
(P. Fischer, 1870)
Shipping/ Ballast 
waters or fouling
Cape Strunjan 2012
Lipej et al. 
(2017)
Bursatella leachi 
Blainville, 1817
Suez Canal/ 
spreading
Marine Biology Station, 
Piran
2001
Lipej et al. 
(2008)
Rapana venosa 
(Valenciennes, 1846)
Shipping/Ballast 
waters
Many infralittoral sites 1983?
De Min & Vio 
(1997)
Polycera hedgpethi
Er. Marcus, 1964
Shipping/fouling and/
or mariculture
Škocjan Inlet 2015
Dailanis et al., 
(2016)
Melibe viridis 
(Kelaart, 1858)
Shipping/ Ballast 
waters?
Cape Madona, Piran 2016 This paper
122
ANNALES · Ser. hist. nat. · 27 · 2017 · 2
Lovrenc LIPEJ & Borut MAVRIČ: RANGE EXPANSION OF ALIEN NUDIBRANCH MELIBE VIRIDIS ..., 119–124
ŠIRJENJE AREALA TUJERODNEGA GOLOŠKRGARJA MELIBE VIRIDIS (KELAART, 1858) 
V SEVERNI JADRAN
Lovrenc LIPEJ & Borut MAVRIČ
Morska Biološka Postaja, Nacionalni Inštitut za biologijo, Fornače 41, Piran, Slovenija 
E-mail: lovrenc.lipej@nib.si
POVZETEK
Tujerodnega morskega polža gološkrgarja vrste Melibe viridis (Kelaart, 1858) so v oktobru 2016 opazili v sloven-
skih vodah (Tržaški zaliv, severni Jadran). Potapljač je primerek fotografi ral in posnel s fi lmsko kamero na skalnatem 
dnu znotraj akvatorija Naravnega spomenika Rt Madona. To je prvi zapis o pojavljanju te velike vrste gološkrgarja v 
Sloveniji in eden izmed maloštevilnih opažanj te vrste v Jadranskem morju.
Ključne besede: Mollusca, Gastropoda, Nudibranchia, Slovenija, tujerodna vrsta, Jadransko morje
leachi de Blainville, 1817, Polycera hedgpethi Marcus, 
1964, M. viridis). The introduction of the bulk of them 
is related to shipping or to mariculture (Zenetos et al., 
2004). Some of them such as B. leachi, Rapana venosa 
(Valenciennes, 1846), Arcuatula senhousia (Benson, 
1842), Magallana gigas (Turnberg, 1893), and Ruditapes 
philippinarum Adams & Reeve, 1850 could already 
be considered as established in the area. The fate of 
M. viridis in the northernmost Adriatic area remains 
questionable, since these waters are facing low winter 
temperatures (<10 °C), which have an important impact 
on the survival of newcomers and probably prevent the 
establishment of viable populations. For now the occur-
rence of this seaslug species in the Gulf of Trieste should 
be considered purely as a casual one. 
ACKNOWLEDGMENTS
We would like to express our gratitude to mr. Kristi-
jan Murn and mr. Marjan Makuc who shared with us the 
information on the presence of the seaslug studied in this 
paper and provided photographs and movie shoots of 
the investigated sea slug. The authors acknowledge the 
fi nancial support from the Slovenian Research Agency. 
123
ANNALES · Ser. hist. nat. · 27 · 2017 · 2
Lovrenc LIPEJ & Borut MAVRIČ: RANGE EXPANSION OF ALIEN NUDIBRANCH MELIBE VIRIDIS ..., 119–124
REFERENCES
Borg, A. J., J. Evans & P. J. Schembri (2016): Oc-
currence of the alien nudibranch Melibe viridis (Kelaart, 
1858) (Opisthobranchia, Tethydidae), in the Maltese 
Islands. Mediterranean Marine Science, 10/1, 131-136.
Cariglio, D., G. Fanelli & F. Rubino (2004): First 
record of the alien gastropod Melibe fi mbriata (Opisto-
branchia: Tethyidae) in the Taranto seas (Mediterranean 
Sea). J. Mar. Biol. Ass. U.K., 84, 1067-1068.
Cattaneo-Vietti R., R. Chemello & R. Giannuzzi-
Savelli (1990): Atlas of Mediterranean nudibranchs. 
Roma: Ed. La Conchiglia, 264 pp.
Crocetta, F., W Ren Da & A. Vazzana (2009): Alien 
Mollusca along the Calabrian shores of the Messina 
Strait area and a review of their distribution in the Italian 
seas. Boll. Malacol., 45: 15-30.
Crocetta, F. (2011): Marine alien mollusca in the 
Gulf of Trieste and neighbouring areas: a critical review 
and state of knowledge (updated in 2011). Acta Adri-
atica, 52 (2), 247-260.
Dailanis, T., O. Akyol, N. Babali, M. Bariche, F. 
Crocetta, V. Gerovasileiou, R. Ghanem, M. Gökoğlu , 
T. Hasiotis, A. Izquierdo-Muñoz, D. Julian, S. Katsane-
vakis, L. Lipej, E. Mancini, Ch. Mytilineou, K. Ounifi 
Ben Amor, A. Özgül, M. Ragkousis, E. Rubio-Portillo, 
G. Servello, M. Sini, C. Stamouli, A. Sterioti, S. Teker, 
F. Tiralongo & D. Trkov (2016): New Mediterranean 
Biodiversity Records (July 2016). Mediterranean Marine 
Science, 17/2, 608-626.
De Min, R. & E. Vio (1997): Molluschi conchiferi del 
litorale sloveno. Annals for Istran and Mediterranean 
Studies, Series Historia Naturalis, 11 (4), 241-258.
De Min, R. & E. Vio (1998): Molluschi esotici 
nell’alto Adriatico. Annals for Istran and Mediterranean 
Studies, Series Historia Naturalis, 13, 43-54.
Despalatović, M., B. Antolić, B., I. Grubelić & A. 
Žuljević (2002): First record of the Indo- Pacifi c gastro-
pod Melibe fi mbriata in the Adriatic Sea. J. Mar. Biol. 
Assoc. U. K., 82 (5), 923-924. 
Doneddu, M.& E. Trainito (2008): Melibe viridis 
(Kelaart, 1858) (Opisthobranchia: Tethydidae): prima 
segnalazione per il Tirreno (Sardegna settentrionale). 
Boll. Malacol., 44(1-4): 45-47.
Dulčić, J., B. Grbec, L. Lipej, G. Beg Paklar, N. Supić, 
& A. Smirčić (2004): The effect of the hemispheric 
climatic oscillations on the Adriatic ichthyofauna. Fre-
senius Environmental Bulletin, 13, 293-298. 
Gosliner T.M. & V. G. Smith (2003): Systematic re-
view and phylogenetic analysis of the nudibranch genus 
Melibe (Opisthobranchia: Dendronotacea) with descrip-
tions of three new species. Proceedings of the California 
Academy of Sciences, 54(18), 302 - 356.
Jančić, G. (2004): Melibe from the Adriatic. Sea Slug 
Forum. Australian Museum, Sydney. Available from 
http://www.seaslugforum.net/fi nd/12280. 
Koutsoubas D. & F. Cinelli (1997): Indo-Pacifi c 
origin gastropod species in the Aegean Sea. Melibe fi m-
briata Alder & Hancock, 1864 a new invader. Bollettino 
Malacologico, 32 (1- 4), 1-6.
Lipej, L. (1994): Assessment of infl uence of salt-
making and maricultural activities on the ornitofauna 
of Sečovlje salinas. Acrocephalus, 15(62), 31-33. (In 
Slovenian)
Lipej, L., Dobrajc, Z., Mavrič, B., Šamu, S. & 
Alajbegovič (2008): Opisthobranch Mollusks (Mollusca: 
Gastropoda) from Slovenian coastal waters (Northern 
Adriatic). Annals for Istrian and Mediterranean Studies, 
Series Historia Naturalis, 18(2), 1-14.
Lipej, L., L. Acevedo ,E. H. K. Akel , A. Anastasopou-
lou , A. Angelidis , E. Azzurro , L. Castriota , M. Çelik , 
L. Cilenti , F. Crocetta, A. Deidun, A. Dogrammatzi, M. 
Falautano, F. Á. Fernández-Álvarez, R. Gennaio, G. In-
sacco, S. Katsanevakis, J. Langeneck, B. M. Lombardo,G. 
Mancinelli , Ch. Mytilineou , L. Papa, V. Pitacco, M. 
Pontes, D. Poursanidis, E. Prato, S. I. Rizkalla, P. C. 
Rodríguez-Flores, C. Stamouli, J. Tempesti, F. Tiralongo, 
S. Tirnetta, K. Tsirintanis, C. Turan, D. Yaglioglu, G. 
Zaminos & B. Zava (2017): New Mediterranean Biodi-
versity Records (March 2017). Mediterranean Marine 
Science, 18/1, 179-201.
Mandić, M., V. Mačić & O. Marković (2016): Spawn-
ing of alien nudibranch Melibe Viridis (Kelaart, 1858) 
in South Adriatic Sea (Montenegro). Fresenius Environ-
mental Bullettin, 25(11), 4566-4568.  
Mavrič, B., M. Orlando-Bonaca, N. Bettoso & L. Lipej 
(2010): Soft-bottom macrozoobenthos of the southern 
part of the Gulf of Trieste: faunistic, biocoenotic and 
ecological survey. Acta Adriatica, 51(2), 203-216.  
Mastrototaro, F., P. Panetta & G. D’Onghia (2004): 
Further records of Melibe viridis (Mollusca, Nudi-
branchia) in the Mediterranean Sea, with observations 
on the spawning. Vie et Milieu, 54 (4), 251-253.
Mienis, H.K. (2010): Monitoring the invasion of the 
eastern Mediterranean by Lessepsian and other Indo-
Pacifi c Species. Haasiana, 5, 66-68.
Mojetta, A. (1998): Arriva dal Mar Rosso un nuovo 
nudibranco. AQUA, 133, 18-20.
Moosleitner H. (1986): Nota sulla presenza in Medi-
terraneo di Melibe sp. (Opistobranchia: Fimbriidae). La 
Conchiglia, Anno XVIII, 202-203, 20.
Sanchez Villarejo, F. (2007):  Melibe ‘fi mbriata’ from 
Cyprus. Sea Slug Forum. Australian Museum, Sydney. 
Available from http://www.seaslugforum.net/fi nd.
cfm?id=20207, (visited on 20 July 2017)
Scuderi, D. & G. F. Russo (2003): Due nuovi gas-
teropodi per le acque italiane: Melibe fi mbriata Alder 
e Hancock, 1864 e Tricolia tingitata Gofas, 1982 (Mol-
lusca: Gastropoda). Biol. Mar. Medit., 10(2), 618-621. 
Thompson, T.E. & D.M. Crampton (1984): Biology 
of Melibe fi mbriata, a conspicuous opistobranch mol-
124
ANNALES · Ser. hist. nat. · 27 · 2017 · 2
Lovrenc LIPEJ & Borut MAVRIČ: RANGE EXPANSION OF ALIEN NUDIBRANCH MELIBE VIRIDIS ..., 119–124
lusc of the Indian Ocean, which has now invaded the 
Mediterranean Sea. J. Molluscan Stud., 50, 113-121. 
Tsiakkiros, L. & A. Zenetos (2011): Further additions 
to the alien mollusc fauna along the Cypriot coast: new 
opisthobranchia species. Acta Adriatica, 52(1), 115 – 124.
Tzouval, K. & D. Pettas (2005): Melibe from the 
Mediterranean. Sea Slug Forum. Australian Museum, 
Sydney. Available from ttp://www.seaslugforum.net/
fi nd/13244
Van Bragt P.H. (2001):  Melibe from Turkey (March 
7). Sea Slug Forum. Australian Museum, Sydney (URL: 
www.seaslugforum.net/fi nd.cfm?id=3927).
Yokes, B. & W. B. Rudman (2004): Lessepsian 
opisthobranchs from southwestern coast of Turkey; fi ve 
new records for Mediterranean. Rapp. Comm. Int. Mer 
Médit, 37, p. 557.
Zenetos, A., S. Gofas, G. Russo G. & J. Templado 
(2004): CIESM Atlas of exotic species in the Mediter-
ranean. 3. Molluscs (F. Briand, ed.) CIESM Publishers, 
Monaco, 376 pp.