ANNAl.ES • Ser. hist. nat. • 12 • 2002 • 1 original scientific paper UDC 597(262) received: 25. 3. 2002 PRESENCE OF ATYPÍCAL CHARACTERISTICS IN A SPECIMEN OF SMALL-SPOTTED CATSHARK SCYLIORHINUS CANICULA (LINNAEUS, 1 758) CAUGHT IN THE MEDITERRANEAN Joan BARRULL, Isabel MATE & Manel BUENO Lab. Vertebrate, Secció Ictiología, Museu Zoología (Museu Ctencies Naturals) Ap. Cotreus 593, £-08030 Barcelona E-mail: jbarnilMpiexietes i sa be Irn ate@hotm a i I . com inanelbueno@coEreu.vtlaweb.com ABSTRACT Authors describe some morphological deformities of first dorsal and caudal fins in an specimen of a small-spotted catshark, Scyliorhinus canícula, caught on December V 2000 in Catalan waters (NW Mediterranean), and discuss its biological efficiency. Key words: Scyliorhinus canícula, atypical characteristics, dorsal tin, caudal fin, Mediterranean Sea PRESF.NZA DI CARATTERI ATIPiCI IN UN ESEMPLARE DI GATTUCCIO MINORE SCYUORHINUS CANICULA (LINNAEUS, 1 758) IN ACQUE MEDITERRANEE SINTESI Cli autori descrivono alcune de form ità morfologiche della prima pinna dorsale e della pinna caudale di un esempfare di gattuccio minore, Scyliorhinus canícula, peicato II Dicembre 2000 in acque Catalane (Mediterráneo Nord-Occidentale), e discutono circa l'efficieriza biologica de//'individuo. Parole chiave: Scyliorhinus canícula, caratteri atipicí, pinna dorsale, pinna caudale, Mare Mediterráneo 23 ANNALES • Ser. Iiist. nat. ■ 12 • 2002 • 1 BARKULl el nI,: PKCSCNCE Of ATYPICAL CHAfiACfLRIStlCS IN A SfTOMEN Of SMAU-SPOTrCO CATSHARK .... 2J-2C INTRODUCTION Small-spotted calshark Scyliorhinus canicula (Linnaeus, 1758) is an abundant temperate bottom-dwelling catshark of the Eastern North Atlantic, from Norway and British Isles to the Mediterranean and Senegal (Com-pagno, 1984b). In the Mediterranean Sea, these sharks are found on soft grounds of sand or mud from shore to depths of about 560 m (Capape, 1974; Bini, 1967; Uoris, 1977; Allui, 1985; D'Onghia et al., 1995; Barruil et at, 1999). They are usually caught by trawlers (Barrull & Mate, 1996). The current study of the ecology of the small-spotted catshark has allowed us to observe more than 1500 specimens, males and females, young and adults. In one of them several morphological abnormalities were discovered. Morphological, anatomical, and colouring abnormalities 3ro relatively rare in sharks. The ichthyological literature refers to some cases from different marine regions and cited by various authors, such as Punnet ¡1901, 1902), Lozano Cabo (1945), Arthur (1950), Me-non (1957), Cadenat (1960), Fuller (1961), Clark (1964), Bensam (1965), Barkhshi & Saxena (1966), King (1966), McKenzie (1970), Abe (1972), Nakaya (1973), Capape & Zahnd (1974), Capape & Pantoustier (1975), Quero (1978), Capape et al. (1979), Taniuchi & Yanagisawa (1987), and Heupel et al. (1999). In this report we discuss the capture of a small-spotted catshark Scyliorhinus canicula in the waters of the Catalan Sea. Some abnormalities in the first dorsal fin and in caudal fin were noted in fhis particular specimen. MATERIAL AND METHODS A female small-spotted catshark Scyliorhinus canicula (Linnaeus, 1758) (Fig. 1) was caught in Catalonia's continental slope waters on December 1" 2000 by "Maireta If", a fishing vessel based in the port of Barcelona (Spain). The specimen was caught with a trawler net, at a depth of 200 m, on the fishing ground know as "La Serola", at a geographical position of 41° 15' N - 2° Fig. 1: Smail-spotted catshark Scyliorhinus canicula, caughi on December T51 2000 in coastal ivafers off Barcelona. (Photo: /. Barrull & I. Mate) SI. 1: Mata morska mačka Scyliorhinus canicula, ujeta 1. decembra 2000 v obrežnih vodah nedaleč od Barcelone. (Foto:). Barrull & I. Mate) 23' I: and 41° IV N - 2° 20' F. The specimen was identified according to Compagno (1984b). The rnorphome-tric measurements were made following Compagno (1984a). It was preserved in 70% ethyl alcohol and deposited in the Ichthyological Collection of the Zoology Museum of Barcelona, with catalogue number MZB-2000-1312. The small-spotted catshark was examined for parasites. Stomach was dissected and the contents identified. The reproductive tract was examined to determine maturity according to Moreno & Hoyos (1982). Tab. 1: Proportional dimensions (% TOT) of small-spotted catshark, Scyliorhinus canicula, caughi off Barcelona. Tab. 1: Proporcionalne mere (% celotne iztegnjene dolžine) male morske mačke Scyliorhinus canicula, ujete v bližini Barcelone. MZB-2000-131 2 SEX F TOTAL LENGTH (mm) TOT 435 PRFCAUOAL LENGTH PRC 78.6 PftÉ-FtRST DORSAL LENGTH PD1 3(3.6 PRE-SECOND DOR5AL LENGTH PD2 67.6 riRST DORSAL Sl'NGTl l D1L 7.1 SECOND DORSAL 1 LNGTH Ü2L 4.4 FIRST DORSAL BASE D1B 4.4 SECOND DORSAL BASE D2B 4.4 HRST DOR5AL INNER MARGIN D11 - SECOND DORSAL INNER MARGIN 02I 2.7 HRST DORSAL HEIGHT DIH - SECOND DORSAL HEIGHT D2H 3.2 DORSAL CAUDAL MARGfN CDM 21.4 PREVENTRAL CAUDAL MARGIN CPV 7.8 TERMINAL CAUDAL LOSE CTL 7.G PREFECTORAL LENGTH PPt 16.1 Pi.CI ORAL ANTERIOR MARGIN P1A 14.0 PECTORAL POSTERIOR MARGIN PIP 9.2 PECTORAL BASE FIB 4.6 PECTORAL INNER MARGIN P11 6.9 PREPET.VÍC LENGTH PP2 40.2 PELVIC LENGTH P2L 11.3 PELVIC ANTERIOR MARGIN P2A 5.7 í'RI"ANAt LENGTH PAL 53.3 ANAL LENGTH AN L 14.0 AÑAL BASE ANB 12.2 ANAL INNER MARGIN ANI ...... "" 1.3 ANAL HIUGHT ANH 3.2 MOUTH WIDTH MOW 7.1 PREORAL LENGTH POÍT 3.9 NOSTRIL WIDTH NOW 1.6 INTERNARIA!. SPACE INW 4.4 PRENARIAL LENGTH PRN 4.4 PRESPIRACÜLAR LENGTH PSP ft5 PRE ORBITAL LENGTH POB 4.6 { EYE LENGTH EYL 3.4 EYE HEIGHT £YH 1.8 INTERGILL LENGTH INC 6.0 FIRST GILL SLIT HEIGHT GS1 2.7 FIFTH GILL SLIT HEIGHT GSS I.I RESULTS AND DISCUSSION The female small-spotted catshark Scyliorhinus canicula measured 435 mm in total length and weighed 292 g. The main morphometry data of the specimen are presented in Table 1. The femaie was an adult, with intense vitellogenesis, the ovary containing a clutch of maturing 24 ANNAl.ES • Ser. hist. nat. • 12 • 2002 • 1 Fig. 2: Detail of the catshark's deformed first dorsal fin. (Photo: J. Barnill & I. Mate) SI 2: Detajl machine deformirane prve hrbtne plavuti. (Foto: J. Barrutl & I. Mate) oocytes. No external parasites were found. Internal stomach parasitic nematodes of species Proleptus obtusus Dujardin, 1845 were found. The examination of the stomach content revealed only fragments of bony fish. Its body marks and diagnostic features presented no particular differences from that observed in other adults of this species, except for the first dorsal (fig. 2) and caudal fins (Fig. 3). The first dorsal fin was only a vestige and the terminal lobe of the caudal fin was not differentiated. The authors considered the possibility that these abnormalities could be due to genetic mutation, or because of a bite made by a congener or some other predator. After a detailed examination of both fins it seemed there were marks of shark bites similar to those found in other works (Lopez et a/., 1996). Therefore, the abnormalities could be a result of a genetic factor. It is possible that these abnormalities could decrease the biological efficiency of the animal due to the absence of the two important elements for its self-propulsion and stability. However, the examination of the digestive and reproductive tracts seemed to confirm that the characteristics described about the first dorsal fin and the tail have not deprived the animal to achieve a considerable Fig. 3: Detail of (he deformed caudal lobe. (Photo: }. Barrull & I. Mate) SI. 3: Detajl tnackine deformirane repne krpice. (Foto: j. Barruil & I. Mate) size and sexual maturity. Probably, the second dorsal fin with a regular dimension and placed near the caudal fin acted as a substitutive stabilising element. Moreover, this second dorsal fin and the lower caudal lobe acted as propellers to the preys capture and so let the animal grow normally as indicated by the necropsy. The abnormalities in sharks are relatively rare. Wc have detected very few cases of malformations after examining thousands of individuals of different species all over the Catalan Sea. Although these differences have, a priori, a limited interest for the biological and systematic knowledge of the species, they can offer some additional genetic and embryologies! data, and about the individuals' biological efficiency. ACKNOWLEDGEMENTS We wish to thank Mr. David Albiol and the "Maireta II" crew for their help in collecting sharks. Special thanks are due to Dr. Christian Capape who was especially helpful in providing information and articles. We would also like to thank Dr. Alessandro De Maddalena for translating the abstract into Italian. POSEBNOSTI, UGOTOVLJENE PRI MALI MORSKI MAČKI SCYUORHÍNUS CANICULA (LINNAEUS, 1758), UJETI V SREDOZEMSKEM MORJU loan BARRULL, Isabel MATE & ManeI BUENO Lab. Verte btats, Secció Ictiología, Museu Zoología vulgaris. Proc. Roy. Soc. (B), 69, 2-26. Quero, |. Cv (1978): Sur une rnonstruosité de l'aiguillat (Squalus ¿tea nth i as Linné, 1758). Ann. Soc. Sci. Nal. Charente-Maritime, 6 (5), 440-441. Taniuchi, T. & F. Yanagisawa (1987): Albinism and lack of second dorsal in an aduit tawny nurse shark, Nebrius concolor, from japan, jap. |. Ichthyol., 34 (3), 393-395. 26