original scientific article	UDC 597.3:591.9(262-191.2)
received: 2005-06-29
ON THE OCCURRENCE OF THE PORBEAGLE, LAMNA NASUS (BONNATERRE, 1788) (CHONDRICHTHYES: LAMNIDAE), OFF ITALIAN COASTS (NORTHERN AND CENTRAL MEDITERRANEAN SEA):
A HISTORICAL SURVEY
Tiziano STORAI
Museo Civico di Sicenze Naturali della Valdinievole, 1-51017 Pescia, P.zza Leonardo da Vinci 1, Italy
E-mail: tstora@tin.it
Antonio CELONA
Aquastudio Research Institute, I-98121 Messina, via Trapani 6, Italy Marco ZUFFA
Museo Archeologico "Luigi Donini", I-40064 Ozzano dell'Emilia, via Prunaro 1, Italy
Alessandro DE MADDALENA Banca Dati Italiana Squalo Bianco (Italian Great White Shark Data Bank), via L. Ariosto 4, I-20145, Milano, Italy
ABSTRACT
In Italian Seas, a total of 33 Lamna nasus were recorded, ranging in size between 86.7 and about 250 cm; TO were females, 5 males and 18 of unknown sex. Of the 33 observed specimens, 14 were considered as possibly mature, corresponding to 42.4%. In the Adriatic and Ligurian Seas, four new-born specimens were recorded, ranging in size between 86.7 and 91 cm. It seems that L. nasus does not reproduce in Italian seas, although its reproductive area may exist in some other part of the Mediterranean. L. nasus was most often recorded during the summer, but seems to be present in the study area throughout the year.
Key words: Chondrichthyes, Lamnidae, porbeagle, Lamna nasus, Italian seas, Mediterranean Sea
PRESENZA STORICA E CONTEMPORANEA DELLO SMERIGLIO, LAMNA NASUS (BONNATERRE, 1788) (CHONDRICHTHYES: LAMNIDAE), IN ACQUE ITALIANE (MARE MEDITERRANEO)
SINTESI
Un totale di 33 esemplari di Lamna nasus viene segnalato nei mari d'Italia. Le dimensioni degli esemplari sono comprese tra 86,7 e circa 250 cm; 10 erano femmine, 5 maschi e 18 di sesso ignoto. Abbiamo stimato 14 dei 33 esemplari come verosimilmente maturi, corrispondenti al 42,4%. Quattro neonati sono stati registrati nei Mari Adriatico e Ligure, di dimensioni comprese tra 86,7 e 91 cm. L. nasus sembrerebbe non riprodursi nelle acque italiane, ma un'area riproduttiva potrebbe esistere all'interno del bacino Mediterraneo. L. nasus e stato registrato piu frequentemente durante l'estate, ma sembra essere presente nell'area di studio durante tutto l'anno.
Parole chiave: Condritti, Lamnidae, smeriglio, Lamna nasus, mari italiani, Mare Mediterraneo
INTRODUCTION
The porbeagle Lamna nasus (Bonnaterre, 1788) is a member of the Lamnidae Müller & Henle, 1838 family. It can be easily identified by its spindle-shaped body, strongly conical snout, lunate caudal fin, strong primary caudal keels and small secondary keels, moderately large bladelike teeth with a pair of lateral cusplets, a conspicuous white rear tip of first dorsal fin (Castro, 1983; Compagno, 1984). Its speed and power can be explained by a complex blood vessel heat-exchanging arrangement: in fact, we could consider this condition as warm-bloodedness or endothermy, well known also in other mackerel sharks (Carey et a/., 1985). It feeds on bony fishes, sharks, squids and crustaceans (Joyce et a/., 2002). Its longevity estimate is 46 years (Natanson et a/., 2002).
The porbeagle is an important object of commercial fisheries all around the world for its high-quality meat, mainly caught on pelagic longlines, and also highly considered for sport-fishery. Intensive fishery greatly reduced the population of porbeagles in the North Atlantic Ocean and the Mediterranean Sea (Castro, 1983; Compagno, 1984; Moreno, 1995; Vannuccini, 1999; Watts, 2001).
The porbeagle is a pelagic, epipelagic, or littoral shark that is usually more common on continental shelves, but is also found far from land in ocean basins (Scott & Scott, 1988; Compagno 2001). It ranges in depth from the surface to at least 700 m (Compagno, 2001). It prefers waters colder than 18" C (Aasen, 1963). It is widely distributed in the cold temperate waters of the North Atlantic, South Atlantic, South Indian and South Pacific Oceans. In the Mediterranean, it is indicated as rare or very rare in all waters (Tortonese, 1938; Capape, 1989; Buencuerpo et a/., 1998; Barrull et a/., 1999; Kabasakal, 2003; Kabasakal & Kabasakal, 2004; Lipej et a/., 2004). Therefore, we consider it particularly interesting to provide a survey on the occurrence of porbeagles off Italian coasts based on both historical and recent data.
MATERIAL AND METHODS
The search for data on porbeagles from the Italian seas was effectuated by examination of the captured sharks, location and study of specimens preserved in natural history museums, collaboration with commercial fishermen, sport fishermen, scuba divers and bibliographical research. This program is an initiative lead by the Italian Ichthyological Society (Societa Ittiologica Italiana).
For every case, whenever possible, the following data were collected: date and location of the record, total length (TOT) or fork length (FOR) in cm (following Compagno, 1984), weight in kg, sex of the specimen,
type of record (capture or sighting), distance from the coast, information about specimens preserved in museums and catalogue number (cat. no.) in the collections, as well as any additional details. Detailed morphometric measurements were made by A. De Maddalena of a 163 cm male porbeagle caught off Cesenatico (Italy), Adriatic Sea, on 4 July 2001, following the procedure of Compagno (1984). The fork length - total length relationship presented by Kohler et al. (1996), FL = (0.8971) TL + 1.7939, was used to calculate the total length of a porbeagle caught off Stromboli.
Fig. 1: Area of the Mediterranean Sea showing the locations of porbeagle captures and sightings presented in this work. (Drawing: A. De Maddalena) Sl. 1: Območje Sredozemskega morja z lokalitetami, v katerih so bili ujeti in opaženi atlantski skušolovci, predstavljeni v tem članku. (Risba: A. De Maddalena)
RESULTS
To date, 33 L. nasus have been recorded off Italian coasts (Fig. 1). Of these, 7 are referred to the Ligurian Sea, 10 to the Southern Tyrrhenian Sea and the Messina Strait, 2 to the Sicilian Channel, 1 to the Ionian Sea and 13 to the Western Adriatic Sea.
In addition to the records described above, for the sake of completeness, it is of some interest to report that in other museums there are three additional specimens
Tab 1: Records of the porbeagle Lamna nasus (Bonnaterre, 1788) from Italian seas.
Tab. 1: Podatki o atlantskem skušolovcu Lamna nasus (Bonnaterre, 1788) iz italijanskih morij.
Date	Location	Sex	TOT (cm)	Weight (Ng)	Notes	Source
1871	Palermo	-	-		Captu re	Doderlein (1881)
Nov 1880	Alassio	-	-	-	Captu re	Tortonese & Trotti (1949)
6 May 1913	Genova Boccadasse	F	200		Capture. Preserved taxidermied in the Museum of Natural History "G. Doria" of Genoa (cat. no. MSNG 1662).	Ariola (1913), Tortonese (1956), G. Doria (pers. comm.)
1958	Camogli	-	236	120	Caught in tuna-trap	Boero & Carli (1979)
7 Jul 1959	Pizzo Calabro	-	138	25	Captu re	Genovese (1960)
summer 1987	Torre Faro	-	ca. 180	-	Caught with harpoon	A. Arena (pers. comm.)
Aug 1992	Otranto		ca. 250		Capture. Possibly the same specimen was encountered by scuba diver Andrea Del Coco a week earlier between Otranto and Porto Badisco.	A. Del Coco (pers. comm.)
1994	Albarella	-	-	240	Caught by sport-fishermen	R. Basanisi (pers. comm.)
summer 1995	Ganzirri	-	ca. 200	-	Caught with harpoon, 300 m offshore	M. Mancuso (pers. comm.)
31 Jul 1995	Pieve Ligure				Caught 6 NM offshore. Preserved in liquid in the Museum of Natural History "G. Doria" of Genoa (cat. no. MSNG 48692).	G. Doria (pers. comm.)
summer 1998	Lampedusa	-	ca. 200	-	Caught with surrounding net	P. Billeci (pers. comm.)
18 Aug 1998	Sanremo	F	87.1		Capture. Preserved in liquid in the Museum of Natural History "G. Doria" of Genoa (cat. no. MSNG 50789).	Orsi Relini & Garibaldi (2002), G. Doria (pers. comm.)
18 May 1999	Salina, Eolie Islands	F	175 (FOR)	-	Caught with tuna longline	Examined by A. C.
10 Sep 1999	Sanremo	F	86.7		Capture. Preserved in liquid in the Museum of Natural History "G. Doria" of Genoa (cat. no. MSNG 50785).	Orsi Relini & Garibaldi, (2002), G. Doria (pers. comm.)
Feb 2000	Eastern Ionian Sea	-	ca. 200	-	Caught with tuna longline	V. Testa (pers. comm.)
9 Feb 2000	Giulianova	-	163	-	Caught with tuna longline	A. Celona (pers. comm.)
summer 2000	Ancona	M	152	-	Caught with longline. Preserved in liquid in the Marine Biology Laboratory of Fano.	G. Mattioli (pers. comm.)
summer 2000	Pescara	-	ca. 200	-	Caught by sport-fishermen	Cugini & De Maddalena (2003)
21 Jul 2000	Capo San Raineri	F	185 (FOR)	-	Caught with harpoon	Examined by A. C.
31 Jul 2000	Sanremo	F	89.3		Capture. Preserved in liquid in the Museum of Natural History "G. Doria" of Genoa (cat. no. MSNG 50784).	Orsi Relini & Garibaldi (2002), G. Doria (pers. comm.)
May 2001	Southern Tyrrhenian Sea	-	ca. 180	-	Caught with tuna floating gillnet	A. Sanfilippo (pers. comm.)
8 May 2001	Pescara	M	ca. 150	35	Captu re	Cugini & De Maddalena (2003)
12 Jun 2001	Panarea, Eolie Islands	-	ca. 200	-	Caught with surrounding net, 25 NM off Panarea	G. Galano (pers. comm.)
4 Jul 2001	Cesenatico	M	163	-	Brought to the fish market in Milan	Examined by A. D.
4 Jul 2001	Cesenatico	F	ca. 160	-	Brought to the fish market in Milan	L. Piscitelli (pers. comm.)
4 Jul 2001	Cesenatico	F	ca. 160	-	Brought to the fish market in Milan	L. Piscitelli (pers. comm.)
15 Jul 2001	S. Benedetto del Tronto	F	91	6.5	Caught by sport-fisherman. Stomach contained sardines, Sardina pilchardus. Preserved in the Museo Ittico Augusto Capriotti in San Benedetto del Tronto (cat. no. 1850).	Marconi & De Maddalena (2001)
Dec 2001	Pescara	F	ca. 250	-	Capture. Filmed.	Cugini & De Maddalena (2003)
Feb-Mar 2002	Giulianova	-	180	-	Caught by professional fisherman	Cugini & De Maddalena (2003)
10 Jun 2002	Filicudi, Eolie Islands	M	187 (FOR)	-	Caught with floating gillnet	Examined by A. C.
15 Apr 2003	Stromboli, Eolie Islands	M	206 (FOR)	-	Caught with tuna longline	Examined by A. C.
Feb 2004	Venezia	-	ca. 150	-	Captu re	G. Cugini (pers. comm.)
26 Sep 2004	Lampione	-	ca. 200	-	Sighting	Sighted by A. C.
Fig. 2: A 163 cm male porbeagle Lamna nasus (Bon-naterre, 1788) caught off Cesenatico (Italy), Adriatic Sea, on 4 July 2001. (Photo: A. De Maddalena) Sl. 2: 163 cm dolgi samec atlantskega skusolovca Lamna nasus (Bonnaterre, 1788), ujet 4. julija 2001 nedalec od Cesenatica v Jadranskem morju. (Foto: A. De Maddalena)
whose capture location is unknown, but for which it can be hypothesized that they may be from Italian waters. In the Museum of Natural History and the Territory of Calci there is a young taxidermied preserved specimen, possibly referable to the 19th century, in the Museum of Natural History "Fontego dei Turchi" of Venice there is a 112 cm taxidermied female (cat. no. 7841) (Mizzan, 1994), and in the Museum of Natural History of Trieste there is a set of jaws belonging to a specimen caught in the Adriatic Sea.
For each specimen, the following data are reported in Table 1: capture date, capture location, sex (M or F), total length (TOT or, where indicated, FOR) in cm, weight in kg, notes and data source. Morphometric measurements of a 163 cm male porbeagle caught off Cesenatico on 4 July 2001 (Fig. 2) are presented in Table 2.
DISCUSSION
The paucity of data collected from Italian seas confirms the rarity of L. nasus in the Mediterranean area. L. nasus was recorded most often during the summer (e.g. Fig. 3), but seems to be present in the study area throughout the year.
The porbeagle is a large species that can reach 360 cm in total length (Castro, 1983; Compagno, 1984). The lengths of the specimens fell within the ranges previously described for this species. The recorded lengths of the specimens ranged from 86.7 to about 250 cm (e.g. Fig. 4). In December 2001, a large female was landed in the Pescara harbour, where it had been transported following its capture in adjacent waters. The total length of the specimen was not accurately measured, but it was subsequently estimated at about 250 cm (Cugini & De
Maddalena, 2003). In late August 1992, an approx. 250 cm porbeagle was caught off Otranto; possibly the same specimen was encountered a week earlier by scuba diver Andrea Del Coco at 28 m depth, between Otranto and Porto Badisco (A. Del Coco, pers. comm.). Other large porbeagles recorded are a 236 cm specimen caught off Camogli in 1958 (Boero & Carli, 1979) and a 206 cm FOR male caught off Stromboli on 15 April 2003. From the fork length - total length relationship presented by Kohler et al. (1996), we calculated the total length of the Stromboli specimen to be 227.63 cm.
Of the 33 specimens, 10 were females, 5 males and 18 of unknown sex. Porbeagle's mode of reproduction is aplacental viviparity and embryos are nourished by oophagy; L. nasus may take 5 or more years to reach maturity: in the Northern Hemisphere, males mature at about 150-200 cm total length, females at about 200229 cm (Francis & Stevens, 2000; Barrull & Mate, 2002). In our study, gonads were not examined, and we estimated the reproductive state on the basis of the specimens' size. In total we estimated 14 of the 33 specimens as possibly mature, corresponding to 42.4%. The gestation period is 8-9 months (Francis & Stevens, 2000), and in the North Atlantic birth occurs in spring and summer (Castro, 1983; Francis & Stevens, 2000); litter sizes are 2-6, and size at birth is 68-89 cm total length (Francis & Stevens, 2000; Mollet, 2001; Jensen et al., 2002). In our study, four new-born specimens, ranging from 86.7 to 91 cm, were recorded - one from the Adriatic Sea and three from the Ligurian Sea (Marconi & De Maddalena, 2001; Orsi Relini & Garibaldi, 2002; G. Doria, pers. comm.). No pregnant females were recorded. We
Fig. 3: A 152 cm male porbeagle L. nasus caught off Ancona (Italy), Adriatic Sea, in the summer of 2000, and preserved in the Marine Biology Laboratory of Fano. (Photo: M. Zuffa)
Sl. 3: 152 cm dolgi samec atlantskega skusolovca L. nasus, ujet poleti 2000 nedaleč od Ancone v Jadranskem morju in shranjen v Morskem biološkem laboratoriju v Fanu. (Foto: M. Zuffa)
Tab. 2: Measurements of a 163 cm male porbeagle Lamna nasus (Bonnaterre, 1788) caught off Cesenatico (Italy), Adriatic Sea, on 4 July 2001 (following terminology and parameters of Compagno, 1984). All measurements are given in centimetres.
Tab. 2: Dimenzije 163 cm dolgega samca atlantskega skušolovca Lamna nasus (Bonnaterre, 1788), ujetega 4. julija 2001 v bližini Cesenatica (Italija), Jadransko morje (po terminologiji in parametrih Compagna, 1984). Vse dimenzije so v cm.
Abbreviation	Measurement	cm	% TOT
TOT	total length (caudal fin in depressed position)	163	100.0
FOR	fork length	139	85.3
PRC	precaudal length	124.5	76.4
PD2	pre-second dorsal length	110	67.5
PD1	pre-first dorsal length	53	32.5
PG1	prebranchial length	33.5	20.6
POB	preorbital length	11.4	7.0
PP1	prepectoral length	41.5	25.5
PP2	prepelvic length	85	52.2
PAL	preanal length	111.5	68.4
PRN	prenarial length	8	4.9
POR	preoral length	10	6.1
EYL	eye length	3.1	1.8
EYH	eye height	2.6	1.6
GS1	first gill slit height	12	7.4
P1A	pectoral anterior margin	28.8	17.7
P1B	pectoral base	12	7.4
P1P	pectoral posterior margin	25	15.3
CDM	dorsal caudal margin	38	23.3
CPV	preventral caudal margin	25	15.3
CPL	lower post ventral caudal margin	18.5	11.4
D1A	first dorsal anterior margin	21	12.9
D1B	first dorsal base	14	8.6
D1H	first dorsal height	18.5	11.4
D11	first dorsal inner margin	6.5	4.0
D2A	second dorsal anterior margin	5	3.1
D2B	second dorsal base	2.5	1.5
D2H	second dorsal height	3	1.8
D2I	second dorsal inner margin	5	3.1
D2P	second dorsal posterior margin	5	3.1
ANA	anal anterior margin	5	3.1
ANB	anal base	3	1.8
ANH	anal height	3.5	2.2
ANI	anal inner margin	5	3.1
ANP	anal posterior margin	4.5	2.8
MOL	mouth length	7.5	4.6
MOW	mouth width	11.5	7.1
NOW	nostril width	1.5	0.9
therefore presume that L. nasus does not reproduce in Italian seas, but given the presence of new-born specimens we cannot exclude that a reproductive area may exist in some other part of the Mediterranean Sea.
Porbeagles appear to be inoffensive animals. These sharks very rarely approach divers closely. We are un-
aware of any aggressive, provoked or unprovoked incidents involving humans in these waters.
Apparently, porbeagles are rarely caught by professional fishermen operating in the study area. The fishing gear used is pelagic longlines, floating gillnets, surrounding nets, tuna-traps and harpoon. Most porbeagles
were taken as bycatch, primarily with the same pelagic longlines used to fish tuna and swordfish. These sharks were retained and sold for human consumption. Due to its large size and high quality flesh, porbeagle is considered an important source of shark meat in Italy. In domestic markets, porbeagle meat is marketed fresh or frozen for human consumption. It can often be found in the markets, but mainly imported from North-eastern Atlantic Countries and Japan (De Maddalena & Piscitelli, 2001). In Italy, the meat of many sharks is marketed under incorrect names and L. nasus is usually sold as "palombo" (smooth-hound Musteius sp.).
There are no regulations or control over the porbeagle fishery in Italy. The absence of any other details on the porbeagle fishery in the area does not allow an assessment of the status of their stocks in these waters, however, according to local fishermen and traders, these sharks have greatly declined. Effective management of fisheries is needed in order to avoid a rapid decline in the near future. These management decisions are based on research on the biology, ecology, distribution, abundance and exploitation of the species. As the sharks constitute a significant by-catch of commercial fishing vessels, it is also necessary to improve management of fisheries for the effective conservation of shark populations (Vannuccini, 1999; Watts, 2001).
Fig. 4: A 200 cm female porbeagle L. nasus caught off Genova Boccadasse (Italy), Ligurian Sea, on 6 May 1913, and preserved in the Museum of Natural History "G. Doria" of Genoa with cat. no. MSNG 1662. (Photo: A. De Maddalena)
Sl. 4: 200 cm dolga samica atlantskega skušolovca L. nasus, ujeta 6. maja 1913 v Ligurskem morju (Italija) blizu Genove Boccadasse in shranjena v Prirodoslov-nem muzeju "G. Doria" v Genovi pod kataloško številko MSNG 1662. (Foto. A. De Maddalena)
ACKNOWLEDGMENTS
Very special thanks to all the people who offered their help in collecting data and general information for this work: Luigi Piscitelli, Renato Malandra, Ruggero Ba-sanisi, Gianluca Cugini, Andrea Del Coco, David Bernvi, Riccardo Giacomelli, Dario Bagnoli, Fabrizio Serena, Stefano Vanni, Giuliano Doria, Massimo Capula, Lino Di Nuzzo, Giovanni Mattioli, Manuccio di Giovanni and all the fishermen and dealers that gave their contribution in the data collection. Special thanks are due to Alex Buttigieg, who very kindly edited the English text of this work. We also thank the referees for their helpful comments. A particular thank from Ales-sandro De Maddalena goes to his wife Alessandra and to his son Antonio.
O POJAVLJANJU ATLANTSKEGA SKUŠOLOVCA LAMNA NASUS (BONNATERRE, 1 788) (CHONDRICHTHYES: LAMNIDAE) V ITALIJANSKIH OBALNIH VODAH (SEVERNO IN SREDNJE SREDOZEMSKO MORJE): ZGODOVINSKI PREGLED
Tiziano STORAI
Museo Civico di Sicenze Naturali della Valdinievole, I-51017 Pescia, P.zza Leonardo da Vinci 1, Italy
E-mail: tstora@tin.it
Antonio CELONA
Aquastudio Research Institute, I-98121 Messina, via Trapani 6, Italy Marco ZUFFA
Museo Archeologico "Luigi Donini", I-40064 Ozzano dell'Emilia, via Prunaro 1, Italy
Alessandro DE MADDALENA Banca Dati Italiana Squalo Bianco (Italian Great White Shark Data Bank), via L. Ariosto 4, I-20145, Milano, Italy
POVZETEK
V italijanskih morjih je bilo doslej zabeleženih 33 atlantskih skušolovcev Lamna nasus, dolgih med 86,7 in približno 250 cm; 10 je bilo samic, 5 samcev, 18 neznanega spola. Od 33 preučevanih osebkov jih je bilo 14 (42,4 %) najverjetneje spolno zrelih. V Jadranskem in Ligurskem morju so bili zabeleženi 4 novorojeni osebki, dolgi med 86,7 in 91 cm. Čeprav vse kaže, da se L. nasus ne razmnožuje v italijanskih morjih, pa utegne biti njegov razmnoževalni okoliš v kakem drugem delu Sredozemskega morja. L. nasus je bil najpogosteje ujet ali opažen v poletnih mesecih, vendar se v preučevanem območju najverjetneje pojavlja čez vse leto.
Ključne besede: Chondrichthyes, Lamnidae, atlantski skušolovec, Lamna nasus, italijanska morja,
Sredozemsko morje
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