Historical and Contemporary Records of the Angular Rough Shark Oxynotus Centrina (Chondrichthyes; Oxynotidae) in Turkish Waters
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Mediterranean Marine Science Vol. 11, 2010 Historical and contemporary records of the angular rough shark Oxynotus centrina (Chondrichthyes; Oxynotidae) in Turkish waters KABASAKAL H. Ichthyological Research Society, Tantavi mah. Mentesoglu cad., Idil apt., No. 30, D:4, Umraniye, Istanbul, TR-34764 http://dx.doi.org/10.12681/mms.84 Copyright © 2010 To cite this article: KABASAKAL, H. (2010). Historical and contemporary records of the angular rough shark Oxynotus centrina (Chondrichthyes; Oxynotidae) in Turkish waters. Mediterranean Marine Science, 11(2), 361-368. doi:http://dx.doi.org/10.12681/mms.84 http://epublishing.ekt.gr | e-Publisher: EKT | Downloaded at 05/09/2019 02:25:43 | Mediterranean Marine Science Short Communication Indexed in WoS (Web of Science, ISI Thomson) The journal is available on line at http://www.medit-mar-sc.net Historical and contemporary records of the angular rough shark Oxynotus centrina (Chondrichthyes; Oxynotidae) in Turkish waters H. KABASAKAL Ichthyological Research Society, Tantavi mahallesi, Mente o lu caddesi, No: 30, D:4, Ümraniye, TR-34764 stanbul, Turkey Corresponding author: [email protected] Received: 16 December 2009; Accepted: 20 July 2010; Published on line: 1 October 2010 Abstract During the last 58 years only 12 angular rough sharks have been recorded in Turkish waters. Rare captures of the species in the area indicate a need for immediate action to be taken for the con- servation of O. centrina. To protect the habitat of O. centrina, strict regulations should be imple- mented regarding diving in the localities where angular rough sharks occur regularly. Protecting the habitat of the angular rough shark is an urgent need before subjecting O. centrina to 100% protec- tion in the seas of Turkey. Keywords: Rough shark; Oxynotidae; Protection; Mediterranean. Introduction 2004), and the upper limit may cover shal- lower areas around 30 m, as observed in the The angular rough shark, Oxynotus cen- present study. trina (Linnaeus, 1758), is an uncommon, lit- In the Mediterranean Sea occurrence tle-known shark, reported in the entire of O. centrina, a rare bycatch in deep-sea Mediterranean Sea (SERENA, 2005) and trawling, is well-documented (SERENA, eastern Atlantic from south of the British 2005). The presence of the angular rough Isles to Senegal, and farther south off South shark in Turkish waters was reported in sev- Africa (COMPAGNO, 1984). O. centrina eral studies (BA USTA et al., 1998; is a sluggish shark found over the continental BAYHAN et al., 2006; ERAZ , 1942; shelf and upper slope at depth ranges gen- ERYILMAZ, 2003; KABASAKAL, 2003; erally between 60 and 660 m (COMPAGNO, KABASAKAL & KABASAKAL, 2004; 1984); however, a recent DESEAS survey ÖZ & YILMAZ, 2006). revealed that lower limit of the depth range Some traits of the reproductive biolo- of the angular rough shark extends to 800 gy of O. centrina were given by CAPAPÉ et m in the western Ionian Sea (SION et al., al. (1999) for specimens from both Langue- Medit. Mar. Sci., 11/2, 2010, 361-367 361 http://epublishing.ekt.gr | e-Publisher: EKT | Downloaded at 05/09/2019 02:25:43 | docian and Tunisian coasts, while a de- (COMPAGNO, 1984). Because of the in- scription of a female bearing developing convenient conditions of in water meas- embryos was reported by MEGALOFONOU urement, divers were not able to measure & DAMALAS (2004) from the Aegean Sea. the total length of specimen Nos. 11 & 12 DRAGI EVIC’ et al. (2009) made obser- accurrately. Therefore, their TOTs are giv- vations on the reproductive tract of a ma- en as approximate values. Raw data and im- ture female accidentally caught in the east- ages are kept in the archives of I.R.S. To ern Adriatic Sea. Additionally, CAPAPÉ et watch the underwater video footage of spec- al. (2001) reported biological observa- imen No. 12, please visit the following link: tions carried out on O. centrina from the http://derintakip.blogspot.com/2009/11/an- coast of Senegal. Some aspects of the diet gular-rough-shark-in-sea-of-marmara.html of O. centrina were given for specimens off Tunisia (CAPAPÉ, 1975), from Catalonia’s Results continental slope waters (BARRULL & MATE, 2001) and off the Languedocian Historical and contemporary records of coast (CAPAPÉ, 2008). O. centrina from Turkish waters and fishing The aim of this paper is to present the data are presented in Table 1. Fishing lo- historical and contemporary records of O. calities are shown on the map in Figure 1. centrina from Turkish waters. The status of the angular rough shark in Turkish waters Discussion and Conclusions with respect to the conservation of the species is discussed in the light of current data. The earliest record of O. centrina (Fig. 2) from Turkish waters was made by ERAZ Material and Methods (1942). In one of the pioneering studies on the fish fauna of the Sea of Marmara and The present study is part of the KANIT the Bosphorus Strait, the author mentioned project, which was initiated in 2000 by the the angular rough shark as a Mediterranean- Ichthyological Research Society (I.R.S.), in originated fish occurring in the investigat- order to update the status of sharks in Turk- ed area. Although ERAZ (1942) added ish waters. Historical and contemporary O. centrina to the fish fauna of the Bospho- records of O. centrina in Turkish waters were rus Strait, currently the angular rough shark obtained from the following data: (a) ichthy- does not occur in the waters of the Bospho- ological literature; (b) popular media such rus (KABASAKAL, 2003). Following the as daily newspapers or fishing and/or div- earliest record of O. centrina in Turkish wa- ing magazines; (c) fishmonger surveys; (d) ters by ERAZ (1942), the angular rough specimens stored in museums; and (e) un- shark has been accounted in several ichthy- derwater photographs with information on ological studies of the seas of Turkey (BA locality of sight, date, etc. Total length (TOT) USTA, et al., 1998; ERYILMAZ, 2003; of specimens was extracted from the liter- KABASAKAL, 2003; KABASAKAL & ature, measured on board (specimen Nos. KABASAKAL, 2004; BAYHAN et al., 2006; 2, 3 & 4; Tab.1) or in water (specimen Nos. ÖZ & YILMAZ, 2006). The rarity of 11 & 12; Tab. 1). TOT is the distance from O. centrina in the Turkish waters has be- the tip of the snout to a perpendicular in- come obvious after the most recent thor- tersecting the upper caudal lobe ough investigations. 362 Medit. Mar. Sci., 11/2, 2010, 361-367 http://epublishing.ekt.gr | e-Publisher: EKT | Downloaded at 05/09/2019 02:25:43 | Table 1 Present specimen and the recent records of O. centrina from Turkish waters. The numbers seen under the "No" column are the same as the numbers seen on the map in Figure 1. No Date Locality TOT Sex Depth Gear Reference (cm) (m) 1 1942 Sea of Marmara ? ? ? ? ERAZ (1942) 2 November 1994 Yass ada 40 90 Bottom trawl KABASAKAL (2003) 3 February 1996 Ekinlik island 35 60 Gill net KABASAKAL (2003) 4 February 1996 Ekinlik island 41 60 Gill net KABASAKAL (2003) 5 November 1998 NE Aegean Sea 65 ? Bottom trawl KABASAKAL & KABASAKAL (2004) 6 ? skenderun Bay 53.2 ? 70-80 Bottom trawl BAS USTA et al. (2000) 7 September 2001 Bozcaada 22.5 ? 60 Bottom trawl ERYILMAZ (2003) 8 ? Gökova Bay ? ? 80 Bottom trawl ÖZC & YILMAZ (2006) 9 December 2000 Marmara Adas 36 ? 42 Beam trawl BAYHAN et al. (2006) 10 June 2001 Band rma Bay 52 ? 86 Beam trawl BAYHAN et al. (2006) 11 2000 Yass ada ca. 50 ca. 35 Visual sampling KABASAKAL (Fig. 2) (unpublished data) 12 September 2009 Bal kç Island ca. 60 35 Visual sampling Present specimen Fig. 1: Fishing localities of the angular rough sharks, Oxynotus centrina, along the Turkish coast. Num- bers on the map are the same as the numbers seen in ‘No’ column in Table 1. Medit. Mar. Sci., 11/2, 2010, 361-367 363 http://epublishing.ekt.gr | e-Publisher: EKT | Downloaded at 05/09/2019 02:25:43 | Fig. 2: Angular rough shark, Oxynotus centrina, observed in coastal waters off Yass ada in 2000 (speci- men No. 11; Tab. 1). (Photo: Tahsin Ceylan). O. centrina is considered to be a deep- cm total length was recorded from the Adri- water shark (COMPAGNO, 1984; SION et atic Sea, and is considered to be the largest al., 2004); however, the present study has angular rough shark recorded to date in the shown that it can ascend to shallower depths Mediterranean (DRAGI EVIC’ et al., of around 30 m. Nocturnal excursions to 2009). Total length of the largest specimen shallow water by the angular rough shark recorded during the present study was 65 increase the chance of incidental captures cm (Table 1; specimen no 5). According to by coastal fishing gear, coastal gill-netting TSIKLIRAS et al. (2005), O. centrina is one in particular. Furthermore, the shallower of the slowest growing species in reaching the angular rough shark occurs, the high- the first maturity. Ratio of size at first ma- er the chance of encountering divers. Per- turity to maximum reported size of O. cen- sonal communication with local scuba divers, trina is 0.94, which means the angular rough who regularly visit the Prince Islands (see shark is a slow growing and late maturing the locality of specimen Nos. 1, 2, 11 & shark (TSIKLIRAS et al., 2005). Deep-sea 12; Fig. 1), a favourable location for angu- fish resources are generally considered to lar rough shark watching, revealed that in have high longevity, slow growth, late ma- several instances, divers retained the shark turity and low fecundity. Thus, they have and brought it to shallower depths to dis- been considered significantly vulnerable to play it to other divers.