ANNALES • Ser, hist. nat. • 13 • 2003 • 1
original scientific article	UDK 597.3(262.4-18)
received: 2003-03-01
HISTORICAL AND CONTEMPORARY RECORDS OF SHARKS FROM THE SEA OF MARMARA, TURKEY
Hakan KABASAKAL
Ichthyological Research Society, Aiaturk Mahal lesi, Mente§oglu Caddesi, tdil apt., No 30, D 4, 7R-j-1764 Ümraniye, Istanbul
E-rnail: hakankabasakai@hotmail.com
ABSTRACT
Twenty species of sharks, with either confirmed or questionable presence ir i the Sea of Marmara, comprise nearly the 8 % of the total ichthyofauna of Marmaric waters. Regarding iheir species numbers, squaliform and carcharhini-form sharks, each represented by 7 species, dominated the species composition of sharks in Marmaric waters. Squaliform sharks, scyiiorhinid Gaieus melaslomus, and adult individuals of Hexanchus g rise us, have been mostly captured over the deeper parts of shelf and upper slope on the northern side, while Musteius asterias and M. muste-ius, and scyliorhinids, Scyliorhinus canicula and S. stellaris, as well as the young individuals of H. griseus. and Squatina squatina have been mostly captured in the southern part of Marmara. Alopias vulpinus is lite only pelagic species recorded in the present research. The current presence of 5 species, Carcharodon carcharias, Lamna nasus, Galeorhinus gaieus, Prionace giauca and Echinorhinus brucus, is questionable, and for the time being it is not possible to say whether their Mediterranean distribution still extends to Marmaric waters. Southern part of the Sea of Marmara appears a suitable shark nursery, in particular for scyiiorhinid and triakid species.
Key words: sharks, distribution, shark bycatches, shark nurseries. Sea of Marmara
SEGNALAZIONI STORICHE E CONTEMPORANEE DI SQUAL! NEL MAR
DÍ MARMARA, TURCHIA
SINTESI
Venti specie di squali, sia che la loro presenza sia confermata o dubbia nel Mar di Marmara, costituiscono quasi ¡'otto percento dell'ittiotauna totale di tali acque. Perquanlo riguarda squali squaliformi e carcariniformi, ognuno di essi rappresentato da setle specie, essi dominano la composizione di specie di squali in acq Lie marmanche. Squali squaliformi, il boccanera Gaieus meiastomus, e individui aduki dello squalo capopiatto Hexanchus griseus, sono stati catturati principalmente nelle parti pill profonde del piano e del pendió superiore nella parte settentrionale, mentre Musteius asterias e M. musteius, gli sciiiorinidi Scyliorhinus canícula e S. steilaris, g i ova ni individui di H. griseus, nonché Squatina squatina, sono stati catturati principalmente nella parte méridionale di Marmara. Alopias vuipinus è I'urtica specie pelagica riscontrata nella presente ricerca. La presenza di 5 specie, Carcharodon carcharías, Lamna nasus, Galeorhinus gaieus, Prionace glauca e Echinorhinus brucus, risulta dubbia, perianto non è per il momento possibile ipotizzare un ampliamenlo della loro distribuzione mediterránea anche al Mardi Marmara. La parte méridionale del Mardi Marmara appare idónea alla funzione di nursery, s oprattutto per sciiiorinidi e triachidi.
Parole chiave: squali, distribuzione, catture di squali, nursery per squali, Mar di Marmara
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Milium KABASAk'AU HISTORIC/». AND CONTEMPORARY RECORDS Of SHARKS MtOM THF SEA OF MARMARA, TURttY. »-J i
INTRODUCTION
Although the origin of the ichthyological studies in the Sea of Marmara dates back to nearly a century (see Bilecenoglu ef at., 2002, for review), very few specific studies on sharks of this unique inland sea have been produced to date. Our knowledge about sharks of the Sea of Marmara is limited to the general ichthyological works (Ninni, 1923 |in Biler.enoglu el ai, 2002]; De-vedjian, 1926; Ayaslt, 1937; Erazi, 1942; Aksiray, 1987; Bauchot, 1987: Kocatas eta!., 1993;Merig, 1995; Mater & Meric, 1996), or to a few specific studies on sharks of this sea (Benli et at., 1993; Oku? et aL 1996; Uysal el a!., 1996; Kabasakal, 1998). According to the most recent list of elasmobranch species of the seas of Turkey, 15 confirmed and one questionable species of sharks are present in the Sea of Marmara (Kabasakal, 2002), while the presence of another 4 species of sharks, Gaieorhinus galeus, Prionace glauca, I'ichtnorhinus brucu.t and Squatina oculata, from Mar mane waters have also been reported in some pioneering works and in a single recent ichthyological work dealing with
Turkish seas (Ninni, 1923 {Bilecenoglu ef ai, 2002); Devedjian, 1926; Ava$li, 1937; Meric, 1994 |in Bile-cenoglu ei ai., 2002}). With the exception of S. oculata, whose presence was described in a recent report (Meric, 1994 jBilecenogfu et ai, 2002]), the status of the remaining 3 species, G. gaieus, P. glauca and E. brucus, is uncertain and regarding their ¡presence in the Sea of Marmara (Ninni, 1923 (Bilecenoglu ef at., 2002]; Devedjian, 1926; Ayasli, 1937), it would be proper to consider them as "doubtful species".
The main objective of the present work is lo provide information on the basis of a number of historical and contemporary shark records from the Sea of Marmara, and to update the species list with the addition of new data.
MATERIAL AND METHODS
The area encompassed by the present research is a subunit of the Mediterranean Sea and known as the Sea of Marmara (Fig. 1). it is connected with the Mediterranean Sea via the Dardanelles and with the Black Sea


7*


Jdr
41°?

K \
fig. I: Map of the study area; circled numbers indicate Uw sampling locations; ft indicates the stranding site of Carcharodon carcharias in the Bosphorus Strait in February 1881.
SI. 1: Zemljevid preučevanega območja; obkrožene številke označujejo posamezna vzorčišča; -k ponazarja mesto v Bosporski ožini, kjer je februarja 1881 nasedel beli morski volk Carcharodon carcharias.
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MA*»« KAUASAk'Al: HISTORICAS, AW CONTEMPORARY RECORDS OF SHARKS ("ROM THE SF.AOF MARMARA, TURKEY, 1.12
through the Bosporus Strait. While Marmara's surface waters are affected by the Black Sea, its deeper layers remain under the influence of the Mediterranean (Ko-cataf ef a/., 1993). According to Ozttirk & Ozturk (1996}, the Sea of Marmara is an ecological barrier, a transition zone or an acclimatisation area, influencing the dispersal of species between the Mediterranean and Black Seas.
An extensive field survey was carried out between 1991 and 1999 along the coast of Sea of Marmara (Fig, 1) to collect or examine sharks. Whenever possible, the author joined fishermen (mostly purse-seiners, gill-netters and bottom long-liners) lo collect shark samples. Sharks delivered to the Istanbul Pish Market were also analysed for the purpose of this research. Furthermore, the available ichthyological literature on the Sea of Marmara was critically reviewed. The following data were recorded for each species: total length (TOT} in cm, sex of the animal, date and location of the capture. Total length of the specimens was measured with the caudal fin in the depressed position. Whenever possible, teeth and skin samples were also collected, now kept in the author's personal collection. Capture locations of the examined specimens, as well as those of recent records are shown in circled numbers in figure 1. Dashed lines in figure 1 indicate northern and southern borders of the by calx h area of C. carcharias, L. nasus, A. vul-pinus and P. glauca, reported by Devedjian (1926), Aya^li (1937), Guney (1974), Oner (1984) and Ak$iray (1987) from the Sea of Marmara.
for an easier understanding, status of occurrence of sharks recorded from the Sea of Marmara was classified under the following categories: (A) species examined in the present study; and (B) species cited by other researchers but not examined in the present study. Status of occurrence of each species is denoted in parentheses after its scientific name. The absence of a species in the recent catch records or in the recent general ichthy-ological lists, concerning exclusively the fish fauna of the Sea of Marmara, at least for the last 25 years, was used as the criteria for considering the species as "questionable".
identification of the species follows Whitehead et a/. (1984) and Compagno (1984a, b). Taxonomic nomenclature follows European Register of Marine Species, Chondricthyes brief checklist (http://erms,biol.soton. ac.uk/lists/). All photographs (Fig 2-9} were taken by the author.
RESULTS AND DISCUSSION
Field surveys and review of the available literature have revealed the presence, either confirmed or questionable, of 20 shark species, representing 11 families in the Sea of Marmara. Relevant details about these species are given below.
Order Hexancliiformes
Family Hexanchidae
1.	Hexanchus griseus (Bonnaterre, 1788) (A)
Previous recordings: Ninni (1923, [Bilecenoglu et a!., 20021}, Devedjian (1926, as Notidanus griseus), Oner (1984), Merle (199S), Kabasakai (1998, 2002).
Material examined: 1 S (TOT 250 cm) captured on February 20, 1997, off the coast of $arkóy Í40°09'50" N, 27°18'40" E) at a depth of SO m (Kabasakai, 1998) (Fig. 1, stat. 1); 1 ? (TOT 125 cm), captured in March 1997 off the coast of íjarkóy (same location as the previous specimen. Fig. 1, sí. 1); 2 ? (TOT 380 and 450 cm, respectively) captured off the coast of Tuzla, at a depth of 200 m (Fig. 1, st. 2), second specimen is shown in figure 2; 1 9 (TOT 420 cm) captured in December 1999 off the coast of Yassiada at a depth of 220 m (Fig. 1, st. 3).
According to Uner (1984), bluriloose sixgili shark is one of the common and largest sharks of the Sea of Marmara. Merig (1995) recorded this species from the catches at depths between 120 to 350 m by gill-netting over the northern continental slope, describing it as a rare bycatch by demersal fishing gear.
Order Lamniformes
Family Lamnidae
2.	Carcharodon carcharias (Linnaeus, 1758} (B!
Previous recordings: Devedjian (1926, as Carcharo-don Rondeletii), Cüney (1974), Oner (1984), Akjiray (1987), Fergusson (1996), Bilecenoglu etal. (2002).
Devedjian (1926) reported on a great white shark (TOT 400 cm) captured in the Sea of Marmara, and added that, its stomach content included a number of bonitos. According to Guney (1974) and Oner (1984), C. carcharias is present in the Sea of Marmara in all seasons and it approaches Marmaric entrance of the Bosporus Strait especially in winter. One of the common points stated by these three authors was that the great white shark was usually a common bycatch by tuna handliners in the Sea of Marmara, and this one was captured incidentally as a result of chasing schools of tunas and bonitos. Uner (1984) also reported that most of the great white shark captures were made between December and late March, and that most of the individuals were captured around the Prince Islands (Fig. 1) and near the Bosporus Strait. According to Akjiray (1987), C carcharias inhabits the Sea of Marmara and rarely occurs near the Pontic entrance of the Bosporus Strait. Fergusson (1996) reported the capture of three individuals of C. carcharias in the Sea of Marmara. These are: one stranded individual (TOT 391 cm) near Beyler-
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Hakan KABASAKaL: HISTORICAl. AND CONTEMPORARY RECORDS Of SHARKS FROM THE SfAOf MARMARA, TuRKfV.M 2
beyi coast (Bosporus Strait) in February 1881 (* in Fig. 1); 1 3 (TOT 470 cm, W 1500 kg), captured on November 17, 1881; and 1 ? (TOT 500+ cm, W 3750 kg), captured in February 1962. Fergusson (1996) stated that the weight of the last individual was no doubt an error. No contemporary record oí C carcharías is available, and no individual of this species was captured or even sighted during the field surveys. Although the presence of C. carcharías in the Sea of Marmara has been reported by Bilecenoglu ef ai. (2002) in the Checklist of the marine fishes of Turkey, the information given herewith is probably based on previous recordings. Therefore, its current presence in Marinarte waters is "questionable" and requires confirmation.
recording of L. nasus by Kabasakal (2002) from the Sea of Marmara is based on previous recordings of this species by other researchers. Although the presence of L. nasus in the Sea of Marmara has been reported by Bile-cenogiu et ai (2002), the information given herewith is probably based on previous recordings. No individual of this species was captured or even sighted during the field surveys. Therefore, its current presence in Mar-maric waters is "questionable" and requires confirmation.
Family Aloptidae
4. Alopias vuipinus (Bonnaterre, 1788) (A)
3. l.arnna nasus (Bonnaterre, 1786) (B)
Previous recordings: Ninni (192.3, [Bilecenoglu el ai, 2002|), Devedjian (1926, as Lamna cornubic.a), GLiney (1974), Uner (1984), Akjiray (1937), Bauchol (1987), Mater & Merit;. (1996), Bilecenoglu et a!. (2002), Kabasakal (2002).
Although no capture information on I. nasus individuals is available, porbeagle is, according to Devedjian (1926), Cuney (1974), Uner (1984) and Aksiray (1987), yet another common lamrioid shark of the 5ea of Marmara, with most of its raptures made around the Prince islands and near the Marmaric entrance to the Bosporus Strait (Fig. 1). Cuney (1974) and Oner (1984) also reported that, as for C. carcharias, bycatches of L. nasus by tuna fishing gear occurred mostly in the winter, as a result of chasing schools of tunas and bonitos. The
Previous recordings: Ninni (1923, [Bilecenoglu et ai., 2002]), Devedjian (1926, as Alopias vulpes), f-ra/i {1942, as Alopias vulpes), Uner (1984), Kocataj ef ai (1993), Kabasakal (2002).
Material examined: 1 <$ (TOT 190 cm) captured on April 12, 1997, off the coast of Silivri (Fig. 1, st. 4).
Devedjian (1926) reported on some enormous A. vuipinus individuals ending at the Istanbul Fish Market, without giving information on their size or biology. Its presence in the Sea of Marmara was possibly the result of chasing the pelagic fish schools. As A, vuipinus is a highly migratory shark (Compagno, 1984a), it is necessary to investigate its movements in detail to figure out whether its presence in the Sea of Marmara is regular or just incidental. Dc-spite this uncertainty, A. vuipinus is the only confirmed pelagic shark species recorded in Marmaric waters during the present research.
Fig. 2; Hexanchus griseus (Bonnaterre, 1788) TOT 450 cm) displayed at a fish market in Istanbul. SI. 2: Hexanchus griseus (Bonnaterre> 1788) {"$, TOT 450 cm), postavljen na ogled na istanbulski ribji tržnici.
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Milan KABASAKAL: HIStOftlCAl AND CON IIMPOKXRY RECORDS Or- SHARKS FROM THE SEA Of MARMARA, TURKEY, 1-12
Fig. 3/SI. .3; Galeus inel.istomus Rafinesque, til 10 (c, TOT22 cm).
Fig. 4/SI. 4: Scyiiorhinus canicula (Linnaeus, 1758) ($, TOT 20.5 cm).
Order Carcharhtniformes
Family Scyliorhinidae
5.	Galeus meiastomus Rafinesque, 1810 (A)
Previous recordings: Aksirav (1987), Bauchot (1987), Kocatas et al. (1993), Meric (1995), Mater & Meric (1996), Uysai elal. (1996), Kabasakal (2002).
Material examined: 2 $ (TOT 22 and 30 cm, respectively; first specimen shown in fig. 3), captured on October 20, 1996, off the coast of Silivri (40°57W N, 28°16'1511 E) (Fig, 1, st 5) at a depth of 350 in.
Merig (1995) reported a bycatch of G. mefastomus in bottom set giil-nets over the northern continental slope between depths of 120 to 350 m. According to Uysai ef al. (1996), G. melastomus is a rare shark in the Sea of Marmara, captured at depths greater titan 200 m.
6.	Scyiiorhinus canicula (Linnaeus, 1758) (A)
Previous recordings: Devedjian (1926, as Scylliuiv canicula), Ayasli (1937), Erazi (1942, as Scyilium canicula), Astray (1987), Bauchot (1987), Kocataj et al. (1993), Merit, (1995), Mater & Meric (1996), Okus ef al, (1996), Kabasakal (2002).
Materia) examined: 2 3 (TOT 20.5 and 40.7 cm, respectively); first specimen shown in Fig. 4) and 12 $ (TOT 20 to 38 cm) captured in June 1991 off the western coast of Ekinlik Island at a depth of 47 m (Fig. 1, st. 6); 6 (TOT 20 to 36 cm) and 2 9 (TOT 30 and 30.2
cm, respectively) captured in October 1994 off the northern coast of Yassiada at depth of 87 m (Fig. 1, st. 7). Many egg capsules, attached to the gorgonians and black corals, were observed at fc'kirilik station (Fig. 1, st. 6).
Smallspotted catshark is the most common scyiio-rliinid species in the Sea of Marmara and most of its by-catches were made in the south-western part of this sea (Oku$ etai., 1996). It has also been caught in bottom set giil-nets over the northern continental slope, although in insignificant numbers (Meric, 1995).
7.	Scyiiorhinus steilaris (Unnaeus, 1758) (A)
Previous recordings: Ninni (1923, (Bilecenoglu ef al., 2002]), Akjiray (1987), Bauchot (1987), Kocataj et al. (1993), Mater & Meric (1996), Kabasakal (2002).
Material examined: 1 5 (TOT 83 cm, Fig. 5) captured in March 1997 off the southern coast of Ekinlik island at a depth of 47 m (Fig. 1, st. 6); one egg capsule was observed in each uteri; jaws preserved.
S. steilaris is a rare scyljorhinid shark in the Sea of Marmara and its records are generally confined to the south-western part of this sea.
Family Triakidae
8.	Galeorhinus galeus (Linnaeus, 1758) (B)
Previous recordings: Ninni (1923, tBilecenoglu et al., 2002!), Devedjian (1926, as Galeus cariis).
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H*kan KABASAKAL: HISTORICA) AMD CONTEMPORARY RfCOROS OF SHARKS FROM THE SEA OF MARMARA, TURKEY, 1 -I,;
Although tine presence of C. galeus in the Sea of Marmara has been reported by Bilecenoglu et al. (2002), the information given herewith is probably based on previous recordings. In his monumental work, Aksiray (1987) placed C. galeus and other triakids in Car-charhinidae, but while reporting on the presence of tope shark in I urkish seas, the author gave no specific information whether it was slill present in the Sea of Marmara. Furthermore, no contemporary records of G- galeus from this sea are available. No individual of this species was captured or even sighted during the field surveys. Therefore, the current presence of C. galeus in Marnwic waters seems "questionable" and requires confirmation.
9. Mustelus asterias Cioquet, 1821 (A!
Previous recordings: Meri<, (1995), Mater & Meric (1996), kabasakal (2002).
Material examined: 1 $ (TOT 125 cm: Fig, 6) captured in November 1997 off the northern coast of Marmara Island at a depth of 100 m (f ig. 1, si. 8); embryo? carrying yolk sacs were observed in uteri.
Meric (1995) reported M. asterias from slope waters of the northern Marmara. Compared with the following congeneric species, it is quite rare in the Sea of Marmara.
10. Musfe/us mustelus (Linnaeus, 1758) (A)
Previous recordings: Devedjian (1926, as Mustelus vulgaris!, Erazi (1942, as Mustelus vulgaris), Kocata$ ei al. (1993), Men«; (1995), Mater & Merig (1996), Oku? ei al. (1996), Kabasakal (2002).
Material examined: 1 ? (TOT 120 cm) captured in the winter of 1995 off the northern coast of Marmara Island at a depth of 90 m (fig. 1, st. 9), jaws of this specimen preserved; 1 9 (TOT 36 cm) captured in lune 1999 off the northern coast of Yassiada at a depth of 80 m (Fig. 1, st. 10); unhealed umbilical scar observed on this specimen.
Meric. (1995) reported on M. mustelus from slope waters of Ihe northern Marmara. According to Okus ei al. (1996), distribution of this shark is prevalent in the south-western part of the Sea of Marmara.
Fig. 5/SI. 5: Scyliorhinus stellaris (Linnaeus, 1758) (c{, TOT 83 cm).
Fig. 6/Si. 6: Mustelus asterias Cioquet, 1821 ('■!, TOT 125 cm).
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Fig. 7/Sl. 7: Oxynolvs centrina (Linnaeus, 1758) ('$, TOT 40 cm). Family Carcharhinidae	Order S qua! ¡formes
11. Pnonace glauca (Linnaeus, 17 5 8 ) 03)
Previous recordings: Ninni (1923, [Biiecenogtu ef at., 2002)). Devedjian E1926, as Carcharías glaucus), Ayasli (1937, as Carcharías glaucus), Gi'iney (1974), Clner (1984), Biiecenoglu eta/. (2002).
Record of an enormous blue shark (TOT 800 cm) delivered to the Istanbul Fish Market (Aya$ii, 1937). The author stated that the stomach content of this individual included remains of tuna fish and dolphin. However, regarding the maximum confirmed size (383 cm} of the blue shark and the unconfirmed reports on larger 480 to 65Ü cm long individuals (Compagno, 1984b).. the size of this individual reported by Ayasft (1937) seems "unreasonable". Furthermore, we could hypothesize that by considering the size (TOT 800 cm) and stomach contents (tuna fish and dolphin), Pnonace glauca reported by Aya§li (1937} was actually a Carcharodon carcharías. No photographs or parts of this individual have been preserved. Guney (1974) and Oner 11984) reported that, as far as iamnoid sharks are concerned, bycatches of P. glauca in tuna fishing gear mostly occurred around the Prince Islands and near the Marmaric entrance to the Bosporus Strait. No individual of P. glauca was captured or even sighted during the field surveys, and no contemporary record of this shark from this sea is available. Although the presence of P. glauca in the Sea of Marmara has been reported by Biiecenoglu ef a!. (2002), the information given herewith is probably based on previous recordings, its current presence in the Sea of Marmara seems "questionable" and requires confirmation.
Family Dalatiidae
12.	Oxynotun cenlrina (Linnaeus, 1758) (A)
Previous recordings: Erazi (1942, as Squalus cenlrina), Mater & Meric (19%), Kabasakal (2002).
Material examined: 1 $ (TOT 40 cm, Fig. 7) captured in November 1994 off the northern coast of Yassiada at a depth of 90 m (Fig. 1, st. 11); 2 <$ (TOT 35 to 41 cm, respectively) captured in February 1996 off the western coast of Ekinlik Island at a depth of 60 m (Fig. 1, st. 12).
O. centrina is a rare bycatch by bottom set gill-nets and long-lines in the Sea of Marmara.
13.	Dalatias iicha (Bonnaterre, 1788) (B)
Previous recordings: Merit; (1995), Kabasakal (2002).
Meric; (1995) reported on a single male (TOT 34.5 cm) captured on July 5, 1991, off the coast of Buyuk^ekmece (Fig. 1, st. 13) at a depth of 270 m. No D, Iicha individual was captured during the field surveys. it is very rare in the Sea of Marmara, and no information is available on its distribution in the Sea of Marmara.
Family Centrophoi idae
14.	Centrophcrus granulosus (Sloch & Schneider, 1801) (B)
Previous recordings: Benii ef al. (1993), Meric; (1995), Mater & Merit; (1996), Kabasakal (2002),
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C granulosus lias been recorded for the first time in the Sea of Marmara by Benli et al. (1993); the record is based on 5 specimens captured in the autumn of 1992 at a depth of 400 m (40°36'05" N, 28[>36'Q3" D (Fig. 1, st. 14). Merit; (1995) reported that gulper sharks were rarely captured by bottom set gill-nets between depths of 120 to 350 m over the northern continental siope of the Sea of Marmara. No individual of C. granulosus was captured during the field surveys. It is very rare in the Sea of Marmara, and no Information is available on its distribution in the Sea of Marmara,
15. Centrophorus uyato (Rafinesque, 1810) (B)
Previous recordings: Meriç (1995), Kabasnkaf (2002).
Meriç (1995) reported on a female (TOT 44.2 cm) captured on May 19, 1989, off the coast of Yesilkôy (Fig. 1, st, 15) at a depth of 150 m and on a male (TOT 45-3 cm) captured on August 11, 1991, off the coast of Buyijkçekmece (Fig. 1, st. 13) at a depth of 270 m. No individual of C. uyato was captured during the field surveys. It is very rare in the Sea of Marmara, and no information is available on its' Marmaric distribution.
Fig. 8/SI. 8: Squalus acanthias Linnaeus, 1758 ($, TOT 45 cm).
Fig. 9/Si. 9: Sijuatina squatina (Linnaeus, 1758) if, TOT 87 cm).
Family Squalidae
16. Squalus acanthias Linnaeus, 1758 (A)
Previous recordings: Ninni (1923, ¡Bilecenogiu et al., 2002J), Devedjian (1926, as Acanthias vulgaris), Erazi (1942), Bauchot (1987), Meriç (1995), Mater & Meriç (1996), Kabasaka! (2002).
Materia! examined: 1 <$ (TOT 45 cm) captured in September 1994 in the Bay of Beykoz at a depth of 50 m (Fig. 1, st. 16), specimen shown in Fig. 8; 1 $ (TOT 105 cm) captured in October 1995 off the eastern coast of BQyukada at a depth of 65 m (Fig. 1, st. 17); 1 8 (TOT 85 cm) captured in June 1999 off the northern coast of Yassiada at a depth of 80 rn (Fig. 1, st. 10).
Spiny dogfish is one of the well-known sharks of the
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Sea of Marmara arid a common bycatch by bottom set gill-nets and long-lines. In terms of sea fishery in the Sea of Marmara, Kocataj et a!. (1993/ considered this species a commercially important demersal fish. Merit;
(1995)	reported it as common over the northern continental slope.
17.	Squalus biainvillei (Risso, 1826) (A)
Previous recordings: Devedjian (1926, as Acanthias blainvillii), Erazi (1942), Bauchot (1987), Kocatas ei al. (1993), Merir (1995), Mater & Meric (1996), Okus et a!.
(1996),	Kabasakal (2002).
Material examined: 2 $ (TOT 65 and 73 cm, respectively) captured in June 1999 off tine northern coast of Yassiada at a depth of 80 m (Fig. t, st. 10).
Merits (1995) reported S. biainvillei from slope waters of the northern Marmara. (2002), According to Okus ef a!. (1996), it is distributed mostly in the south-western part of litis sea. in comparison with the preceding congeneric species, Kocatas ef al. (2002) consider it an economically important species, but its occurrence in Marmaric waters is quite rare.
Family Echinorhiriidae
18.	Echinorhinus brucus (Bonnaterre, 1788) (13)
Previous recordings: Ninni (1923, jBilecenoglu eta/., 2002)), Devedjian (1926, as Echinorhinus spinosus).
According to Devedjian (1926),, E. brucus is a common shark in Marmaric waters. Although the bramble shark's presence in the Sea of Marmara has been reported by Bilecenoglu ef al. (2002), the information given herewith is probably based on previous recordings. Although Ak§iray (1987) claims that E. brucus is present in Turkish seas, the author has not given any specific information whether it is still present in the Sea of Marmara. Furthermore, no contemporary recording indicating the bramble shark's presence in tills sea is available, and neither was any individual of this species captured or even sighted during the field surveys. Therefore, lhe current presence of E. brucus in the Sea of Marmara seems "questionable" and requires confirmation.
Order Squatiniformes
Family Squatinidae
19.	Squatina oculata Bonaparte, 1840 (B)
Previous recordings: Slastenenko (1955-1956, ¡Bile-cenoglu et a/., 2002j), Merig (1994, [cited in Biiece-nogluetai, 20021).
While no 5. ocuiata individual was captured or
sighted during the field surveys, its presence in the Sea of Marmara is based on a recent report by Merit; (1994). No current information, however, is available on its distribution in the Sea of Marmara.
20. Squatina squatina (Linnaeus, 1758) (A)
Previous recordings: Ninni (1923, [Bilecertoglu ei a/., 2002]), Devedjian (1926, as Rhina squatina), Erazi (1942), Roux (1984), Kocatas et al. (1993), Mater & Meriq (1996), Kabasaka! (2002).
Material examined: 1 $ (TOT 87 cm; Fig. 9) captured in November 1995 off the coast of Karabiga al a depth of 50 m (Fig. 1, st. 18).
I! is a quite common and economically important demersal shark in the Sea of Marmara.
CONCLUSIONS
Twenty species of sharks, with either confirmed or questionable presence in the Sea of Marmara, comprise nearly 8% of the total ichthyofauna (a total of 249 species, reported by Bilecenoglu ef a!., 2002) of Marmaric. waters. Regarding their species numbers, squaliform and carcharhiniform sharks, each represented by 7 species, dominated the shark species composition in Marmaric waters.
In the Sea of Marmara, the continental shelf on the southern side is wide and extends nearly to the centre of the sea, while on the northern side the shelf is narrow, with the slope's depth exceeding 1000 m (1 335 m at lis deepest point) with a steep inclination (Kocatas et a!., 1993). The topographic structure of the Sea of Marmara has no doubt influenced the distribution of demersal sharks in this sea. With the exception of E. brucus, a species not recorded in this research, the remaining squaliform sharks, scyliorhinid C. melastomus, and the adult individuals of H. griseus, have been mostly captured over the deeper parts of the shelf and upper slope on the northern side. Squaliform sharks, recorded in tins research, mostly prefer to live over the continental shelf and the upper slope. Maximum range of the depth distribution of C. granulosus, C. uvato and D. licha exceeds 1000 m (Compagno, 1984a). Furthermore, it is known that,, while H. griseus lives at depths from the surface down to 1800 m, adults prefer waters deeper than 100 m (Compagno, 1984a), and C. melastomus lives at depths between 55 and 1000 m, with preference to deeper parts of the shelf and the upper slope (Compagno, 1984b). Regarding depth dislribution of the above mentioned species, the northern slope of the Sea of Marmara thus offers a suitable habitat for them. On the other hand, triakids, M. asterias and M. mustelus, and scyliorhinids, S. canicula and 5. stellaris, as well as : the young individuals of H. griseus and S. squatina have been mostly captured in the southern part of Marmara.
9
ANNALES • Ser. hist. nat. - 13 • 2003 • 1
l«w KABASAKAl: HISTORICAL AKO CONTCMPORARV RECORDS Of SHARKS FROM THCSlA Of MARMARA. TURKEY.! -IJ
Although maximum range of depth distribution of 5. canicula and M. mustelus can exceed 200 in, both scyiiochinids and triakids as well as squatinids piefer moderate depths over the continental slope (Compagno, 1984a,b>. Moreover, young individuals of H. griseus mostly occur in shallow waters (Compagno, 1984a). Therefore, the extended continental shelf on the southern part offers a suitable habitat for the mentioned species. Oku« el al. (1996) also reported that the distribution of scyliorhinids and triakids prevailed along the southern coast of the Sea of Marmara.
One of the special characteristics of the southern Marmara is the presence of areas occupied by rich growth of gorgonians and black corals (Oztiirk & Bour-guet, 1990). These sedentary organisms offer suitable spawning grounds for oviparous sharks, such as scyliorhinids. Many egg cases attached to gorgonians or black corals, as well as juveniles of 5. canicula, and a gravid female of 5. stellaris, were observed in the southern Marmara, mostly along the coasts of the southern Marmara islands (Fig. 1) during the field surveys, and these findings indicate a nursery ground of scyliorhinid sharks in the southern part of this sea. This area may also be a nursery ground for H. griseus and M. asterias, as some young sixgill sharks and a gravid female of M. asteiias were also captured here. The capture of a newborn individual of M. mustelus, bearing an unhealed umbilical scar, off the northern coast of Yassiada (Fig. 1, st. 10) indicate the presence of another nursery ground for the triakids in the northern Marmara. The current fisheries act prohibits any fishery action for the black corals, which is no doubt a beneficial limitation regarding the conservation of shark nurseries in the Sea of Marmara. However, extensive investigations are needed for the exact mapping of shark nurseries in this sea.
The actual status of pelagic sharks in the Sea of Marmara has always been a point of discussion. Although some previous records of pelagic sharks are at
hand, their contemporary records from Marmaric waters are scarce. A. vulpinus is the only pelagic species recorded during the present research. According to the available data, bycaich of pelagic sharks In the Sea of Marmara has been paralleled with tuna fishery in the past. However, due to the drastic decline in the bluetin tuna populations and other pelagic bony fishes, the fishery of this commercially important species in Marmaric waters has almost ended since the I980's (Karakulak & Oray, 1994), atid the latest records of pelagic shark captures from Marmara correspond with these years iUner, 1984). This drastic decline in pelagic teieosts has certainly resulted in the loss of important food source of these apex predators in Marmaric waters, the same as the end of the mentioned tuna fishery resulted in the loss of bycatch possibility as far as pelagic sharks are concerned. The capture of a young A. vulpinus individual on April 12, 1997, off the coast of Silivri (Fig. 1, st. 4) is probably the only confirmed pelagic shark record from the Sea of Marmara in the last 20 years.
Consequently, among the 20 shark species recorded in the Sea of Marmara, the current presence of 5 species, i.e. C. carcharias, L. nasus, C. gaieus, P. giauca and E. brucus, is questionable, and for the time being it is not possible to say whether their Mediterranean distribution stili extends to Marmaric waters. Although the occurrence of O. centrina, D. licha, C. granulosus, C. uyi\to and $. oculata was not considered questionable in the present study, they should be considered rare sharks, since each of the species has been recorded either by the author of this contribution or by other researchers only once or twice in the Sea of Marmara during the last decade.
ACKNOWLEDGEMENTS
The author wishes to thank ail the fishermen for their help during the carried out field surveys.
10
ANNALES • Ser. hist. nat. ■ 13 • 2003 • 1
Hale«« KAPASAKAL: HISTORICAL ANO CONTCM«)RA*V M-COKOSOF 5HARK5 fftOM IHi- SfA Of MARMARA, TU*K£V. 1-12
STAREJŠI iN NOVEJŠI PODATKI O POJAVLJANJU MORSKIH PSOV V MARMARSKEM MORJU, TURČIJA
Nakan KABASAKAL
lcfitliyologica( Research Soriety. Atatiirk Mahatlesi, Mentejoglir Citcidesi, Idil iipt., No 30, D 4. TR-34764 (jmraniye, tstanbul
E-irail: hakankabavikul@hotmail.com
POVZETEK
Dvajset vrst morskih psov, katerih pojavljanje v Marmarskem morju je bodisi potrjeno bodisi vprašljivo, obsega skoraj 8% celotne marmarske ihtiofavne. Kar zadeva število vrst teh psov, so v teh vodah prevladovali tmeži in vrste iz družine Carcharhinidae, oboji s po 7 vrstami. Tmeži, morska mačka Gafeus melastomus in odrasli osebki šesteroškrgarja Hexanchus griseus so bili večinoma ujeti nad globljimi deli morske police in gornjim pobočjem na severni strani Marmarskega morja, pegasti morski pes Mustelus asterias, navadni morski pes M. iriuslelus, morski mački 5cyliorhinus can i cula in S. stellaris kot tudi mladiči šesteroškrgarja H. griseus in navadni sklat Squatina squatina pa večinoma v južnem delu Marmarskega morja. Morska lisica Alopias vulpinus je edina pelagična vrsta, ki je bila zabeležena med pričujočimi raziskavami. Trenutno pojavljanje 5 vrst, Carcharodon carcharias, Lamna nasus, Caleorhinus galeus, Prionace glauca in Echinorhinus brucus, je vprašljivo, tako da trenutno ne vemo, ali se njihova razširjenost v Sredozemskem morju nadaljuje tudi v manmrskih vodah. Južni del Marmarskega morja se zdi ustrezno razmnoževalno okolje, predvsem za Scyliorhinidae in Triakidae.
Ključne besede: morski psi, razširjenost, naključno ujetje, razmnoževalno okolje, Marmarsko morje
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