ANNALES • Ser. hist. nat. • 35 • 2002 • 1
original scientific paper	UDC 597.5(2623-11)
received: 11.3. 2002
ANALYSIS OF THE VERTEBRAL NUMBER IN GILT SARDINE SARD IN ELLA AURITA VALENCIENNES, 1847 AND ALLIS-SHAD ALOSA FALLAX NILOTICA (LACEPEDE, 1 803) FROM THE EASTERN CENTRAL ADRIATIC
lakov DULČiČ
Institute of Oceanography and Fisheries, HR-21000 Split, P.O. Box 500 E-mail: duicic@i20r.f1r
ABSTRACT
Samples of the gilt sardine catches with a total of 50 individuals from the channel area (Hvar Channel) and open waters (PalagtvZa island) of the central Adriatic were analysed with respect to their number of vertebrae. The vertebral number in gilt sardines ranged from 47 to 49. Modal value of 48 vertebrae was observed in all the samples of gilt sardine catches. Samples of (he allis shad catches with a total of 76 individuals from the inshore waters (Saldun and Marina Bays) and offshore waters (jabuka Island) were also analysed with respect to their number of veitebrae. The vertebra! number of allis shad ranged from 54 to 57. Modal value of 57 veitebrae was observed in all the sani-p/es of the allis shad catches. There was no significant difference between the mean values of vertebrae for both species. It could be concluded that the tested gift sardine and allis shad samples from the investigated regions belonged to the same populations as regards their number of vertebrae, respectively.
Key words: Sardinefla aurka, Alosa faliax nilotica, vertebral number, eastern central Adriatic
ANALISI DEL NUMERO DI VERTEBRE DI ALACCIA SARDINELLA AURITA (VALENCIENNES, 1847) E CHEPPIA ALOSA FALLAX NILOTICA (LACEPEDE, 1 803)
¡N ADRIATICO CENTRO-ORIENTALE
SINTESI
E stato analizzato il numero di vertebre di campioni di pes cate di alaccia, per un tota/e di 50 Individu!, proven-ienti da II'area del cana le (can a le di Lésinai e dal mare apeno (isola di Pelagosal. II numero di vertebre dell'alaccia è varíalo da 47 a 49. II valore modale di 48 vertebre è stato riscontrato in tutti i campioni di pescate di alaccie. É stato inoltre analizzato il numero di vertebre di campioni di pescate di cheppia, per un totale di 76 individui, proveniente da acqite vicine alla riva (baie di Saldun e Marina) e da aequo al largo (isola di labuka). II numero di vertebre della cheppia è varia to da 54 a 57. II valore modale di 57 vertebre è stato riscontrato in tutti i campioni di pescate di < heppie. Non l> stata regístrate alcuna differenza significativa tra i valori medí de lie vertebre di entxambe le specie. L'au tore conclude che, visto il numero di vertebre regis trato, i campioni di alaccia e cheppia analizzati apparten-gono rispe!tivamente alie stesse popolazioni.
Parole chiave: Sardinella aurita, Alosa fallax nilotica, numero di vertebre, Adriático centro-orientaie
ANNALES • Ser. hist. nat. • 12 • 2002 • 1
lakov DULCIO. ANALYSIS Of H It VCRUUJtAl WUM8CR IN CUT SARPINÍ SAUCMNRlA AURITAVALft4afWMtS, \ S4? .... JS-»
INTRODUCTION
The differences between the length distribution of gilt sardine Sardinella aurita Valenciennes, 1847 and aliis-sliarJ Alosa fa 11 ax nilotica (Lacepede, 1803) taken from the inshore and offshore waters of the central Adriatic (Kafici, 1975; Morovic, 1958) indicated a possibility of heterogeneous gilt sardine and aflis-shad populations existence.
The number of vertebrae is a meristic character previously used at population identification (Piccinetti, 1971; Krajnovic-Ozretie & 2ikid, 1978; Sinovcic, 1982; Dulcic ef al., 1994). The same meristic character was applied in this work.
Various experiments have shown thai the vertebral number is genetically fixed with narrow limits, and that minor aberrations are due to the influence of different environmental factors, especially temperature in the so-called sensitive time (Lindsay, 1954; Blaxter, 1957), which is different for each species. However, it is apparent that the statistic different number of vertebrae represents an independent population (Larrarieta, 1958).
The purpose of the present study is to analyse the number of vertebrae in gilt sardine and allis-shad from the inshore and offshore waters of the central Adriatic, since there are no precise data on the vertebral number of gilt sardine and allis-shad from the eastern Adriatic.
MATERIAL AND METHODS
Samples of the gilt sardine catches were taken from the channel area (Hvar Channel) and open waters (the region of Palagruza Island), while those of allis shad were obtained from the inshore (Saldun and Marina Bay) and open waters (the region of Jabuka Island) in the central Adriatic (Fig. 1). Six representative samples of catches with a total of 50 individuals of the gilt sardine and 76 individuals of the allis shad were taken during 1997. The number of individuals varied from 7 to 1 5 for the gilt sardine, and from 9 to 13 for the allis shad in some samples of the catches.
Fish were preserved in 4% formaldehyde and, after dissection, air-dried for one to two days. The vertebrae were counted by lens, from occipital condyle (not counted) to urostyle (included), as recommended by FAO Fisheries Division,
The samples were also analysed statistically, Mean numbers of vertebrae, standard deviation and standard errors of arithmetic means were calculated. Analyses of variance and Fisher's F test were also applied to determine the significant differences between variances, Obtained F values were compared to those of the limited values F, at a 5% significance level.
MARINA
KAŠTELA BAY
B
INLAND JABUKA
Fig. 1: Location of sampling stations of the gilt sardine (A) and allis shad (B) in the eastern central Adriatic. SI. 7: Lokacije vzorčiščza veliko sardelo (A) in čepo (B) v vzhodnem srednjem Jadranu.
36
ANNALES • Ser. hist. nat. • 37 • 2002 • 1
lakov OUI.ČIČI ANALYSIS Of THE VÇfcHBKAl NUMBER IN Gll't SARDINE SAROIKiftlA AURH'A VALENOENNSS, ÎS17 ....35-38
RESULTS AND DISCUSSION
Total length of the gill sardines from the Hvar Channel used in ¡he analysis of the vertebral number varied from 197 to 279 mm (mean value - 248±0.44), and from 156 to 224 mm (mean value - 183+0.39) of those from open waters. Total length of all is shad from Saldun and Marina Bays varied from 137 to 425 mm (mean value = 289±0.77), and from 186 to 386 mm (mean value = 267+0.59) for those from jabuka Island.
The total vertebral number of gilt sardine from the channel area and open waters of the central Adriatic ranged from 47 to 49 (mean value = 48.2210.67, SE = 0.08, coefficient of variability - 1.39). The vertebral number in gilt sardines from the Hvar Channel ranged from 47 to 49 (48.20±0.84, SE - 0.07, coefficient of variability = 1.74), and from 48 to 49 (mean value ~ 48,25+0.50. SE = 0.06, coefficient of variability = 1.04) in those from Palagruza island. There was no significant difference between mean values (t = 0,11, P>0.05), so it can be concluded that there are no statistically significant differences in the vertebral number in gilt sardines from the channel area in relation to those from the open waters. There were no such differences between vertebral numbers in gilt sardines from the catch samples within the same regions. It could be concluded that the tested gilt sardine samples from both regions belonged to the same population as regards their number of vertebrae. Modal value of 48 vertebrae was observed in all samples of the gilt sardine catches. Besides that modal class, the class 48 showed the highest frequency and the class 49 appeared rarely just in the channel area. Similar vertebral number means in gift sardines have been ob-
served by several authors (Page, 1920; Navarro, 1927, 1932; Quignard & Kartas, 1974) for the Almeira region, Algerian coastal waters, Canarian archipelago and Tunisian waters. Navarro (1948) and Oliver & Navarro (1952) reported the -widest ranges of vertebrae (45-52 and 45-50) for Balearic Islands.
The total vertebral number in allis shad from the inshore and offshore waters of the centra! Adriatic ranged from 54 to 57 (mean value - 56.10+0.99, SE = 0.11, coefficient of variability = 1.76). The vertebral number of allis shad from Saldun and Marina Bays ranged from 55 to 57 (mean value = S6.25±0.94, SE = 0.06, coefficient of variability - 1.67) and from 54 to 57 (mean value - 56.14+1.27, SE - 0.1 3, coefficient of variability = 2.25) for those from Jabuka island. There was no significant difference between mean values it = 0.18, P>0 05), so it can be concluded that there are no statistically significant differences in the vertebral number of allis shad from inshore waters in relation to the allis shad from offshore waters. There were no such differences between vertebral numbers of allis shad from the catch samples within the same regions. It could be concluded that the tested allis shad samples from both regions belonged to the same population as regards their number of vertebrae. Modal value of 57 vertebrae was observed in all samples of the allis shad catches. There are no data about the vertebral number of allis shad from the Adriatic Sea, but there are some data from freshwaters. Vukovic (1961) reported the number of vertebrae for Skadar Lake (47-60), Badnska Lakes (4860) and River Neretva Estuary (53-60). Ivanovo (1973) noted that the total number of allis shad from the Skadar Lake ranged from 55 to 60.
ANALIZA ŠTEVILA VRETENC V VELIKIH SARDELAH SARDtNELLA AURITA VALENCiENNES, 1847 IN ČEPAH ALOSA FALLAK NILOTICA (LACEPEDE, 1 803) IZ VZHODNEGA SREDNJEGA JADRANA
Jakov OULČIČ inštitut za oceanografljo in ribištvo, HR-21000 Split, p.p. 500 F.-mail: dultic@izor.ht
POVZETEK
Avtor je ugotavljal število vretenc v velikih sardelah in čepah, ujetih v vzhodnem srednjem Jadranu. Pri analizi 50 primerkov velike s a rde le iz livarskega kanala in odprtega morja (iz okolice Palagružej se je število vretenc gibalo med 47 in 49, medtem ko je bilo modalno Število pri vseh primerkih 48 vretenc, Pri analizi 76 primerkov čep iz obalnih voda (zalivov Saldun in Marina) in odprtega morja (iz okolice jabuke) pa se je število vretenc gibalo med 54 in 57; modalno število pri vseh primerkih je bilo 57 vretenc. Avtor ni ugotovil nobene pomembne raziike med srednjimi vrednostmi pri obeh vrstah. Zatorej je bilo mogoče napraviti sklep, da so glede na število vretenc preučevani primerki velike sardele in čepe iz zgoraj omenjenih raziskanih območij pripadali istim populacijam.
Ključne besede: Sardinella aprila, Alosa fallas nilotica, število vretenc, vzhodni srednji Jadran
ANNALES • Ser. hist. nat. • 38 • 2002 • 1
lakov DUIČIČ ANALYSIS Or THE VRTČBKAI. NUMBER iN GILT SARD1NF SAKÜINEU.A AURITA VAUNCKNNES. 1847 .... 3S-3R
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