Introduction 13 CLASSIFICATION AND SYSTEMATIC ARRANGEMENT Considering that the purpose of this document is to Class Chondrichthyes (cartilaginous fishes) provide a simple user-friendly guide for species identification, no reference will be found here to Subclass Holocephali (chimaeras) dichotomy keys for single species. It is important that the classification used in this guide be defined, Order Chimaeriformes (chimaera and silver sharks) as available literature is not always in agreement Subclass Elasmobranchii (sharks) with this presentation. The classification of this group is still under review as no consensus has Superorder Squalomorphi (squalomorph sharks) been found to reconcile different authors’ positions. Order Hexanchiformes (cow and frilled sharks) For more information and further specific details on the taxonomy and biology of cartilaginous fish Order Squaliformes (dogfish sharks) species, refer to Tortonese, 1956; Hureau and Monod 1979; Whitehead et al., 1984; Fischer et al., Order Squatiniformes (angel sharks) 1987; Fredj and Maurin, 1987; Compagno, 1988, 2005; Nelson, 1994; Shirai, 1996; Mould, 1998. The Order Pristiophoriformes (sawsharks) * consultation of FishBase http://www.fishbase.org Order Rajiformes (batoids) (Froese and Pauly, 2000) proved very useful. The most fundamental references are Compagno’s Superorder Galeomorphi (galeomorph sharks) catalogues issued in 1984 and his recent revision partially issued in 2001. Order Heterodontiformes (bullhead sharks) * This guide follows the systematic organization Order Lamniformes (mackerel sharks) proposed by Compagno (1999, 2001) and the classification reflects a cladogram attempt where a Order Orectolobiformes (carpet sharks) * new concept of cladistic classification is used. For instance, the batoids are raised to the order Order Carcharhiniformes (ground sharks) (Rajiformes) belonging to the superorder of the The species inside the families and in the orders Squalomorphi, even if perhaps a more suitable are mentioned in alphabetical order according to name should be found to indicate both Rajiformes genus. For both orders and families, some and Squaliformes. At the same time the sawsharks summary descriptions with their most significant group is raised to the order Pristiophoriformes. So characteristics are included. The current status is the batoids have been diversely allocated with described for each single species on an individual respect to the previous taxonomic organizations. sheet where, in addition to a drawing, scientific However, even if this new phylogenetic name and more recent synonyms and significant classification is considered valid, for practical misidentifications in some important cases, other reasons sharks and batoids are described synthetic information is given, i.e. FAO common separately in the text. names, maximum size, habitat and biology, Taking only modern sharks into consideration, we methods of capture and, when available, can adopt the following, simplified classification exploitation and conservation status. Arrows are (the orders with no representatives in the superimposed on the drawings to indicate features Mediterranean Sea are indicated by an asterisk): that help in species identification. 14 Field Identification Guide to the Sharks and Rays of the Mediterranean and Black Sea When possible the type of spiral valve which – Raja rondeleti Bougis, 1959 is probably based on characterizes the intestine of cartilaginous fishes is an abnormal specimen of R. fullonica and shown. There are large variations in the anatomy of considered as Leucoraja cfr. fullonica.The the spiral valve, three different types have been taxonomic status of four specimens from French described: columnar spiral with funnels pointing and Italian coasts is doubtful (Séret, pers. comm.). either backward or forward; spiral ring valve and cylindrical (scroll) valve (Compagno, 1988; How to use this guide Hamlett, 1999). Readers are advised to follow these simple steps in order to successfully identify any sharks, batoids Local names are not included considering the large and chimaera found in the region. First, refer to the number of names used in the various picture key of shark-like and batoid fishes then Mediterranean countries. Feeding behaviour is read carefully through the description of key indicated only in some cases. Remarks are characters listed under each order and family. Use indicated for species whose taxonomic status or the illustrations of the families under each order or presences are dubious. suborder only as a secondary aid in making certain For the purpose of this guide, a number of dubious that the right order or suborder has been found. species have not been considered as valid for the Then proceed to narrow down the family of the Mediterranean: specimen using the illustration for each family and key characters annotated in each illustration; make – Carcharhinus leucas (Valenciennes, 1841) is a use of the size data included for each family. Once doubtful species; it is neither recognized by the family has been identified, move to the Compagno nor in this guide. corresponding pages where the species for that family are illustrated. These illustrations and the – Carcharhinus longimanus (Poey, 1865) is a key characters indicated should allow proper doubtful species; it is considered “probable” by identification for all sharks and batoids known for Compagno but is not included in this guide. the area. – Rhinobatos halavi (Forsskål, 1775) was recorded In a few cases the considered area is wider than by Tortonese (1951a) from the Egyptian part of the the Mediterranean basin; it refers to the CLOFNAM Mediterranean Sea but Ben-Tuvia (1966) noted area (Hureau and Monod, 1979): Mediterranean that no specimens of this species were available to and northeastern Atlantic between 30° and 80° of confirm its presence in this sea. Latitude north, -30° and +60° of Longitude, Azores and Madeira Islands included (Whitehead et al., – Torpedo alexandrinsis Mazhar, 1982 and 1984). Torpedo fuscomaculata Peters, 1855 are not Although (Linnaeus, 1758) is considered a valid species. Torpedo alexandrinsis Chimaera monstrosa represented in the sharks cladogram as indicated is known by only five syntypes mentioned in the by Compagno, 2001, the species account is original paper from Alexandria (Egypt) (Séret, inserted at the end of the guide to follow the pers. comm.); therefore its taxonomic status is taxonomic sense. Eventhough there is only one doubtful. The second species recorded Torpedo chimaera species in the Mediterranean Sea, the only once in Alexandria (Egypt) needs to be author thought it was important to illustrate the verified and is probably synonymous of Torpedo technical terms and description of this order. (Torpedo) marmorata (Séret, pers. comm.). – The species Raja africana Capapé, 1977, previously defined as dubious by Compagno (1999), is now indicated as not a valid species (syntypes lost). Sharks and Chimaeras - Picture Key of Shark-like Fishes 15 SHARKS AND CHIMAERAS HOLOCEPHALI 1 gill slit CHIMAERIFORMES mouth ventral, pectoral fins attached to sides of head RAJIFORMES body flattened, ray-like SHARK-LIKE FISHES mouth terminal, pectoral fins not attached to head no anal fin SQUATINIFORMES snout elongated, saw-like body not ray-like PRISTIOPHORIFORMES* 5 to 7 gill slits snout short, not saw-like ELASMOBRANCHII SQUALIFORMES 6 or 7 gill slits, 1 dorsal fin HEXANCHIFORMES nictitating eyelids, spiral or scroll intestinal valve mouth behind front of eyes CARCHARHINIFORMES anal fin present no nictitating eyelids, ring no fin spines intestinal valve 5 gill slits, LAMNIFORMES 2 dorsal fins mouth well in front of eyes Orders with an asterisk are not represented in the Mediterranean ORECTOLOBIFORMES* PICTURE KEY OF SHARK-LIKE FISHES dorsal-fin spines (not a cladogram) HETERODONTIFORMES* (from Compagno, 2001) 16 Field Identification Guide to the Sharks and Rays of the Mediterranean and Black Sea SHARKS TECHNICAL TERMS AND MEASUREMENTS dorsal-fin spine (if present) st 1 dorsal fin nd 2 dorsal fin precaudal pit spiracle gill slits interdorsal space snout nostril keel labial caudal peduncle subterminal furrows pelvic fin notch clasper pectoral fin (male sex organ) caudal fin pectoral-fin length anal fin head trunk tail gill slits precaudal tail nostril caudal fin snout anal fin trunk preanal ridges anal opening pelvic fin pectoral fin (female, no claspers) underside view interdorsal-fin ridge location of intestinal valve total length (caudal fin depressed to body axis) Sharks - Technical Terms and Measurements 17 terminal lobe posterior tip dorsal lobe dorsal margin terminal margin upper origin subterminal margin subterminal notch upper postventral margin postventral notch lower origin lower postventral margin preventral margin ventral tip lower (ventral) lobe caudal fin apex fin insertion inner margin free rear tip spine posterior margin base anterior margin fin origin height free posterior rear margin tip anterior margin base apex insertion fin origin dorsal fin pectoral fin preoral length internasal mouth distance width head (ventral view) upper eyelid labial furrow notch incurrent nictitating aperture lower secondary eyelid lower anterior eyelid nasal flap labial excurrent posterior fold aperture nasal flap subocular eyes pocket mouth corner nostril 18 Field Identification Guide to the Sharks and Rays of the Mediterranean and Black Sea LIST OF ORDERS, FAMILIES AND SPECIES OCCURRING IN THE AREA A question mark (?) before the scientific name indicates