Leucos aula (Bonaparte, 1841)

Bianco, Pier Giorgio & Ketmaier, Valerio, 2014, A revision of the Rutilus complex from Mediterranean Europe with description of a new genus, Sarmarutilus, and a new species, Rutilus stoumboudae (Teleostei: Cyprinidae), Zootaxa 3841 (3), pp. 379-402 : 382-384

Leucos aula (Bonaparte, 1841)

( Fig. 2 A, 3A)

Squalius aula Bonaparte, 1841 : Fauna It., fasc. XXX, Tav. 116, fig. 3: type locality; Padua Province; north-eastern Italy

Examined material: All from Italy: ANSP 6434-6445, 12 (types of Squalius aula Bp ), ANSP 6467-6468, 2 (types of S. elatus Bp ), NE Italy.— IZA 8361, 2, R. Sile at Jesolo, G. Delmastro, 10 August 1980.— IZA 8361, 14, small canal near Jesolo, G. Delmastro, 10 August 1980.— IZA 83138, 12, R. Tartaro near Lazise, C. Oppi, 20 May 1975.- IZA 83139, 6, R. Tartaro near Isola della Scala, C. Oppi, 20 November 1978.— IZA 83140, 4, Le Porte del Menago, Verona, G. Togni, 1 May 1978.— IZA 8412, 25, R. Tartaro, Isola della Scala, C. Oppi, May 1978.— IZA 8345, 14, L. Major, P.G. Bianco, 18 April 1982.— IZA 8365,10, R. Po near Cuneo, G. Delmastro, 8 August 1980.— IZA 8368, Canal Moneta (R. Po basin), 10, G. Delmastro, 5 October 1977.— IZA 8377, 8, Rio Stellone (R. Po basin), G. Delmastro, 22 May 1980.— IZA 8349, 10, L. Piediluco near Terni, P.G. Bianco, 1 May 1983 (introduced).— IZA 8372, 9, L. Monticchio, Basilicata, P.G. Bianco, 18 June 1977 (introduced).— IZA 0 198, 2, L. Massaciuccoli near Pisa, E. Baldaccini, 7 April 2001 (introduced).— IZA 8837, 14, R. Foglia, P.G. Bianco, 22 June 1988.— IZA 0 425, 7, R. Bacchiglione, 4 April 1996, E. Marconato.

Diagnosis. The species can be distinguished from all others species of Leucos for the presence of a middle lateral band, and a smaller head length, which in fish of comparable size is less than 4.5 times in the SL, except L. panosi , and more than 4.0 times in the others species. Additionally, L. aula differs from in the modal number of circum-peduncular scales, which is 12 as opposed to 14 in other species.

Description. General appearance in Fig. 2 A. A small-medium sized, not exceeding 180 mm, usually 80–120 mm SL. A species of Leucos characterized by a quite marked mid-lateral band, extending from the operculum (sometimes from the tip of the snout) to the end of the caudal peduncle: on caudal peduncle the band is sometimes enlarged to form an oval spot; body moderately elongate, dorsal profile convex; sometimes a small hump in largest specimens; posterior mouth corner placed beyond the vertical crossing the anterior margin of orbital cavity; snout blunt; mouth opening oblique and terminal to slightly sub-terminal; lips smooth; horizontal diameter of eye, less or equal than pre-orbital length; head small, its length about 3.8–4.2 times in the SL; body quite deep, its depth about 2.6–3.0 times in the SL; origin of the D at same level or slightly below the insertion of the P2; free margin of D and A, slightly concave; caudal fin moderately forked; LL complete, with 35–42 pored scales, placed below the middle of the body, slightly concave and extending from the upper margin of opercular membranae, to the end of caudal peduncle; modally 3 un-branched and 9 branched rays both in the D and A; P1 with 1 un-branched and 14–15 branched rays; P2 with 1 un-branched ray and constantly 8 branched rays; about 8–10 total GR; color of eye in life from yellowish to a brilliant red; fins yellowish; peritoneal membranae silvery sometimes with few scattered melanophores. Adult reproductive males may have minute, granular tubercles on head, check, upper side of paired fins and fan-shaped on the free border of scales of the body. For additional description and shape, see Fig. 2 A and Tables 1, 2.

Distribution. The species was endemic in the Padany-Venetian ichthyogeographic district, including all the river basins tributary of the upper Adriatic Sea, from Croatia, in basins near the town of Zara ( Mačrovcić et al., 2006), Slovenia and down, in Italy, to the River Reno in the Marche Region. It was introduced in several basins of central and southern Italy: at least lakes of Monticchio, Massaciuccoli, Bracciano, Piediluco and rivers Tiber, Arno, Mignone ( Bianco & Taraborelli, 1985; Bianco & Santoro, 2011; P.G. Bianco, pers observ).

Lectotype designation for Leucos aula (Bonaparte, 1841) . The syntypes series of Leucos aula (Bomparte’s original catalogue number 438) in ANSP includes two species: 11 individuals are L. aula (ANSP 6434-6444, 55– 101 mm SL), and 1 is Scardinius hesperidicus (ANSP 6445, 43.0 mm SL). Among the 11 syntypes, the specimen ANSP 6434, 74 mm SL, in very good condition, is designated as lectotype ( Fig. 3A ). It has 39 scales on the LL; 9 branched rays in D and 9 in A; 7.5 rows of scales above LL and 3.5 below LL; total GR, 9; 14 circumpeduncular scales; pharyngeal teeth formula, 5-5. The 10 paralectotypes, ANSP 6435-6444, 43– 101 mm SL, show the following ranges of meristic counts: LL, 38–40; 7.5–8.5 rows of scales above and 2.5–3.5 below LL; 9–11 total GR. D constantly with 9 branched rays; A with 9–11 branched rays (modal value, 9); 12–14 circum-peduncular scales; 5-5, 5-4 pharyngeal teeth. The single specimen of Scardinius hesperidicus has 38 scales on LL; 9 branched rays in D, 11 in A, 14 circum-peduncular scales and 14 total GR. Pharyngeal teeth formula: 5.3-3.5.

Remark on the Bonaparte fish collection. Several question were raised about the value of the syntypes of the Bonaparte collection housed in ANSP and catalogued by Böhlke (1984) by Dr. Maurice Kottelat (pers. comm.). Kottelat’s point of views were followed by several ichthyologists and, among them, one of the reviewers of the first version of this contribution, originally submitted to Zootaxa. The study was rejected mainly on the grounds that there are no proof that syntypes of Bonaparte housed in ANSP were used for the original description. But this controversy was recently solved and the collection of Bonaparte’s new cyprinid species are confirmed to be syntypes ( Bianco, 2014a).

Remarks on ecology, biology and conservation. Preferential habitats: lakes and still waters of rivers. Not thriving in moderately to fast flowing rivers. This species strongly competes and tends to eliminate Sarmarutilus rubilio in still waters. It is responsible for the extinction of S. rubilio in central and southern Italian lakes and rivers ( Bianco & Ketmaier, 2001). The reproductive season extends from April to August, peaking in May–June. Age at first reproduction is 1+ or 2+ for males and 2+ for females. Maximum age observed, 7+ ( Bianco & Taraborelli, 1985). Its conservation status is of “Low Concern” according to the IUCN (2013) red list.

Figures

FIGURE 2. Native species of the Rutilus complex in southern Mediterranean Europe: A) Leucos aula, 115 mm SL, R. Bacchiglione, northern Italy, April 1996 (IZA 0425); B) Leucos basak, 95 mm SL, Lake Ohrid, FYROM, August 1987, (IZA 0429); C) Leucos ylikiensis, 120 mm SL, Lake Yliki, April 1987 (IZA 8733); D) Leucos panosi, 130 mm SL, canal to Lake Trichonis, May 1987 (IZA 8766); E) Leucos albus, 98 mm SL, River Moraca, Montenegro, November 1999 (IZA 0421); F) Sarmarutilus rubilio, 100 mm SL, River Ofanto, southern Italy, February 2002 (IZA 02183); G) Rutilus pigus, 230 mm SL, Lake Major, northern Italy, (IZA 0474); H) Holotype of Rutilus stoumboudae new species, 148 mm SL, October 1998, Lake Volvi, Greece (IZA 02107).

FIGURE 3. A) Lectotype of Leucos aula, 74 mm SL (ANSP 6434), Padua Province, northern Italy; B) Lectotype of Leucos basak, 117 mm SL (NMW 50723 - 1), Vergoraz and Lake Drusino near Imotsky, Croatia; C) Lectotype of Sarmarutilus rubilio, 93 mm SL (ANSP 6509), Lake Nemi, Central Italy.