INTRODUCTION
Currently, the genus Sphyraena (barracudas) is thought to contain 27 species world-wide, with a distribution spanning temperate and tropical regions (Eschmeyer, Reference Eschmeyer2008). Individuals within this genus are typically found in shelf waters ranging to a depth of approximately 100 m (Robins & Ray, Reference Robins and Ray1986; Fischer et al., Reference Fischer, Bauchot and Schneider1987; de Silva, Reference de Sylva, Quero, Hureau, Karrer, Post and Saldanha1990; Demestre et al., Reference Demestre, Sánchez and Abelló2000). There appears to be some ontogenetic separation, however, with young individuals found in shallow waters (often > 1 m) (Okiyama, Reference Okiyama1988) forming numerous small schools, while adults tend to be solitary (de Silva, Reference de Sylva1975; de Silva & Williams, Reference de Sylva, Williams, Smith and Heemstra1986; Gasparini & Floeter, Reference Gasparini and Floeter2001; Barreiros et al., Reference Barreiros, Santos and de Borda2002).
In the Mediterranean Sea the genus Sphyraena comprises four species: (1) the lessepsian Sphyraena chrysotaenia (Klunzinger, 1884) (Spicer, Reference Spicer1931; Ben-Tuvia, Reference Ben-Tuvia1971, Reference Ben-Tuvia, Whitehead, Bauchot, Hureau and Tortonese1986; Golani & Ben-Tuvia, Reference Golani, Ben-Tuvia and Armantrout1995; Pallaoro & Dulcic, Reference Pallaoro and Dulcic2001); (2) S. flavicauda (Rüppell, 1838) (Golani, Reference Golani1992; Bilecenoglu et al., Reference Bilecenoglu, Taskavak and Kurt2002); and two Atlantic–Mediterranean species; (3) S. sphyraena (Linnaeus, 1758); and (4) S. viridensis (Cuvier & Valenciennes, Reference Cuvier and Valenciennes1829) (George et al., Reference George, Athanassiou and Tortonese1971; Tortonese, Reference Tortonese1975; Miniconi, Reference Miniconi1980; de Silva, Reference de Sylva, Quero, Hureau, Karrer, Post and Saldanha1990; Bizsel & Cihangir, Reference Bizsel and Cihangir1996; Ralini & Orsi Ralini, Reference Relini and Orsi Relini1997; Vacchi et al., Reference Vacchi, Boyer, Bussotti, Guidetti and La Mesa1999). Building on this long-established classification, this study puts forward morphological evidence for the existence of a previously undocumented fifth species within the region.
MATERIALS AND METHODS
Study sites and sample collection
Between July and October 2003 and May to November 2004, 78 barracudas were captured through a range of fishing techniques (gill-nets, trawl nets, seining and ‘lampara’ engine) in the Gulf of Taranto in the Mediterranean Sea at five sites: (1) Metaponto (40°22′2643″N–16° 5′5553″E); (2) Taranto (40°23′54 82″N–17°10′56 63″E); (3) Torre Columena (40°17′33 05″N–17° 44′32 62″E); (4) Porto Cesareo (40°15′16 98″N–17° 5′45 95″E); and (5) Gallipoli (40°02′38 10″N–17°55′40 44″E) (Figure 1).
Fig. 1. The fishing sites of barracudas in the Gulf of Taranto: Metaponto (1); Taranto (2); Torre Colimena (3); Porto Cesareo (4); Gallipoli (5).
Of these specimens collected, 28 individuals (15 males, 12 females and 1 juvenile without secondary sexual characteristics) were identified as S. sphyraena, 36 as S. viridensis (19 males and 17 females), with 19 individuals (6 males, 7 females and 6 juveniles) not-conforming to the taxonomic description of either species (later described as the new species S. intermedia). Figure 2 provides a visual comparison of S. intermedia with S. viridensis and the drawings of Figure 3 provide the different scaled pre-opercular and opercular areas.
Fig. 2. Two specimens of barracudas: Sphyraena intermedia (above) and Sphyraena viridensis (below), 60 cm SL.
Fig. 3. Heads of adult specimens: scaled areas on pre-operculum and operculum respectively in Sphyraena sphyraena (A), Sphyraena viridensis (B) and Sphyraena intermedia sp. nov. (C) (original drawings).
Morphometrics
The following morphometrics were recorded for each barracuda collected: total length (TL), standard length (SL), heat length (HL), pre-pelvic length (PPL), pre-dorsal length (PDL), body depth (BD), pre-pectoral length (PpL), pre-orbital length (POL), longitudinal eye diameter (LED) and jaw length (JL) (Figure 4). The number of lateral scales, and the distance to the first dorsal fin ray (D1), the second dorsal fin ray (D2), the pectoral fin ray (P), the pelvic fin rays (Pe), the anal fin rays (A) and vertebrae number were also considered. The number of vertebrae of each species was counted to be 22 between occiput and hypural plate. Otoliths were removed from five specimens of each S. sphyraena, S. viridensis and the new form (N = 15 fish in total) for comparison (Figure 5). The different anatomical feature of the jaws and dentition is given in Figure 6.
Fig. 4. Sphyraenidae body measures: TL, total length; LF, length to the furca; SL, standard length; LL, lateral line; POL, pre-orbital length; ED, eye diameter; HL, heat length; PPL, pre-pelvic length; PDL, pre-dorsal length; PPcL, pre-pectoral length; BD, body depth (partially modified draw referred to Sphyraena sphyraena from FAO Fishes (Fisher et al., 1981)).
Fig. 5. Otoliths, image 10×: left, Sphyraena sphyraena, 320 mm standard length (SL); middle, Sphyraena intermedia, 320 mm SL; right, Sphyraena viridensis, 330 mm SL.
Fig. 6. Bone jaws and dentition in the 3 forms: A, A1, A2 Sphyraena sphyraena; B, B1 and B2, Sphyraena viridensis; C, C1 and C2 Sphyraena intermedia.
Lastly, a brief morphometric comparison was made with records of previously documented lessepsian migrants (S. chrysotaenia and S. flavicauda) and with other potential lessepsian migrants such as Sphyraena qenie, S. jello and S. putnamae to prevent misidentification of the unidentified barracuda collected from the Gulf of Taranto.
Fig. 7. Intestinal villi of Sphyraena sphyraena (5a), Sphyraena viridensis (5b) and Sphyraena intermedia (5c).
SPECIMENS COLLECTED
Holotype: adult female, 745 mm SL, preserved with formalin (catalogue No. 3274, Mar Grande, Gulf of Taranto, trawl, 40°23′54 82″N–17°10′56 63″E, August 2004, Pastore, IAMC–CNR, Fish Collection).
Paratype: a male specimen 375 mm SL (catalogue No. 3255, Torre Columena, Gulf of Taranto, 40°17′33 05″N–17°44′32 62″E, seining, from a fish-shop, August 2004, IAMC–CNR, Fish Collection).
Other specimens: 1 mature ♂ (79 cm SL), 5 immature ♂♂ (respectively: 42–59.5–63.5–64.5–75 cm SL), 4 mature ♀♀ (respectively: 34.5–35.5–36.5–39.5 cm SL), 3 immature ♀♀ (30.5–32.7–34 cm SL), 4 young (20.5–20.8–21–21 cm SL).
DESCRIPTION
Body slender, tapering, weakly compressed, with conical, hydrodynamic snout; body depth 12.8% SL. Mouth long, with low protractile capacity and with prognathic lower jaw and a moderate fleshy excrescence on top (less than in S. viridensis). Eye diameter 4 times the POL. Pre-operculum and operculum not completely scaled (however not like in S. viridensis) (Figure 3c). Maxilla reaching to below anterior margin of eye. Minute teeth on the entire premaxillary bone, and 2–3 strong canine-like teeth on the superior symphysis, the second nearly double than the first. The upper jaw (Figure 6C, C1, C2) with 3 acute teeth, the second stronger than the other two, after them there is a row of minute and crooked behind denticles, 1 very strong canine-like tooth on the symphysis; lower jaw with a first acute tooth and an arrow of teeth, increasing in length; palatine with 2 teeth, the second stronger than the first and after these a row of minute denticles.
Lateral scale series 118–135 (127–154 in S. sphyraena and 137–163 in S. viridensis). First dorsal fin (D1) with 5 rays and origin lightly before the pelvic fin; second dorsal (D2) with 10 rays; pectoral fin (P) with 11–13 rays not reaching the origin of the first dorsal fin; anal fin (A) with 10 rays gives rise lightly after second dorsal fin; pelvic fin (Pe) with 6 rays; lobes of caudal fin with internal margins weakly concave (right in S. sphyraena and falcate in S. viridensis).
A lengthening index of the sagittae (Il = W × 100/SL) is calculated how Il = 28.95 (Il = 26.83 in S. sphyraena, and Il = 31.43 in S. viridensis) (Figure 5 middle). Vertebral bodies, 22; intestinal villi, 30–32 (Figure 7c).
Colours: blue-darkish on back, from the snout until the caudal fin; 22 bars on body, with the bars 1 to 7 crossing the lateral line; 4th–7th longer than others; first and second dorsal fins brownish; pelvic fin white in young specimens and brownish with white tip in adults; anal fin ever white; caudal fin almost black. Mouth with inferior jaw borders orange and tongue with a longitudinal red-brownish medial line.
Remarks: stomach contents of 11 specimens consist of rest of cephalopods, Sardina pilchardus or Sardinella aurita, from 5 specimens; a young S. sphyraena in the stomach of a male; 2 empty guts and 4 guts with fluidified materials.
Some specimens affected on the outer face of stomach and on the gonads by the anisakid nematode Anisakis sp. Two specimens had regressive male gonads in favour of female gonads in development.
DISCUSSION
Table 1 shows the main differences of S. intermedia in comparison with S. sphyraena and S. viridensis, such as: the intermedial body depth between the other two species; the eye longitudinal diameter/POL; the scale numbers on the lateral line relatively reduced; the intestinal villi, the number of which is less than in the other two species; the size, intermedial in comparison with the sizes of the two other species.
Table 1. Main distinctive features of 3 forms.
POL, pre-orbital length; SL, standard length.
The livery differs also among the three species: no vertical bars in S. sphyraena and with 22 bars in S. viridensis and in the new species; caudal fin decidedly black, while it is blackish in S. viridensis.
The main differences between the two lessepsian species S. chrysotaenia and S. flavicauda are relative to the size (S. chrysotaenia is a small species and S. flavidauda is a medium-sized species); lateral scale series 118–135 (82–87 in S. Chrysotaenia and 84–91 in S. flavicauda); body with longitudinal bars (no bars or stripes and blotches in S. chrysotaenia, and with 2 brown or brownish yellow longitudinal stripes in S. flavicauda); caudal fin dark (yellowish in S. chrysotaenia and in S. flavicauda).
According to the literature (de Sylva & Williams, Reference de Sylva, Williams, Smith and Heemstra1986), the main differences with the three Indo-Pacific species S. putnamae, S. qenie and S. jello are: S. qenie is a large species (maximum total length 115 cm); lateral-line scales 127 to 130; origin of pelvic fins before first dorsal-fin origin. Caudal fin forked, in adults with a pair of small lobes at posterior margin. Colour: many dark bars crossing lateral line on body, each bar oblique in upper half, but nearly vertical in lower half; caudal fin largely blackish; S. jello is a large species (maximun total length 125 cm); lateral-line scales 130 to 140; origin of pelvic fins before first dorsal-fin origin. Caudal fin typically forked in all stages. Colour: many dark bars crossing lateral line on body, each bar oblique in upper half, but nearly vertical in lower half; caudal fin largely yellowish without white tips; S. putnamae is a large species (maximum total length 87 cm); lateral-line scales 123 to 136; origin of pelvic fins before first dorsal-fin origin. Caudal fin forked, in large adults with a pair of indistinct lobes at posterior margin. Colour: many characteristic dark chevron markings crossing lateral line on body; caudal fin largely blackish without white tips.
CONCLUSION
Sphyraena intermedia differs, in comparison with the other two native species S. sphyraena and S. viridensis for a certain number of relevant emphasized differences as shown in Table 1 and Figures 3, 5, 6 & 7. The species differs too from the lessepsian migrants and the Indo-Pacific species. For the three species (Sphyraena sphyraena, S. viridensis and S. intermedia sp. nov.) a DNA collateral study has been made that confirms the separation of them. The reason to believe that S. intermedia is a distinct species in comparison with S. sphyraena and S. viridensis is that the morphological characters are steadily distinct among the three forms in all stages, so we must believe S. intermedia is not a hybrid S. sphyraena × S. viridensis.
In the Gulf of Taranto the new species appears sympatric with the other two. The exact distribution and abundance of S. viridensis are unknown because most published records do not separate it from S. sphyraena and perhaps have confused this form with the new species.
The ‘yellow mouth barracuda’ name given to Sphyraena viridensis is not correct because also S. sphyraena and S. intermedia have almost the internal part of the mouth, yellowish the first and orange the second, so that it is not a good distinguishing character.
To distinguish the three native Mediterranean species a key is given.
KEY TO THE THREE NATIVE MEDITERRANEAN SEA BARRACUDAS:
Body depth less than 12% of SL; pre-operculum and operculum entirely scaled; eye diameter 3.5 times the pre-orbital length; no prominent fleshy excrescence on top of the lower jaw; top of the pre-pectoral fin far from the origin of the first dorsal fin; caudal fin with internal margins right in each lobe … … … … … … … … … … … . S. sphyraena
Body depth more than 12% of SL; pre-operculum and operculum not completely scaled; eye diameter 4 or more times the pre-orbital length … … … … … … … … … . 2
Body depth 14.1% of SL; a prominent fleshy excrescence on top of the lower jaw; eye diameter 4–5 times the pre-orbital length; pectoral fin top reaches the origin of the ID fin; lateral scales 137–163; internal margin of caudal fin falcate in each lobe; intestinal villi 37–40 … … … … . . S. viridensis
Body depth 12.8% of the SL; a moderate fleshy excrescence on top of the lower jaw; eye diameter 4 times the pre-orbital length; pectoral fin top does not reach the origin of the ID fin; lateral scales 118–135; internal margin of caudal fin weakly concave in each lobe; intestinal villi 30–32. … … … … … … … … … … … … … … … … S. intermedia
ACKNOWLEDGEMENTS
Thanks to all the people who made possible this work: E. Saller and A. Guida of the Library of Stazione Zoologica in Naples; G. Ugolini of ‘La Sapienza’ University, Rome, and M. Filippi, librarian in the IAMC–CNR Institute, for furnishing the current literature on Atlantic–Mediterranean species. A particular thanks to L. Relini Orsi for his useful opinions on the presence of S. viridensis in the Mediterranean Sea; to C. Saba of the ‘Barracuda spinning club’, for some pictures of specimens caught in Sardinian waters; to M.L. Fioravanti, Health Department, University of Bologna, for the Nematoda classification.
