ANNALES 11/'97 original scientific paper UD C 597.5(262.3-11 ) OCCURRENC E O F F1NGERL1NGS O F GREYTRIGGERFISH , BALiSTES CAROLINENSIS GbAEUH, 1789 (PISCES: BALISTIDAE), iN TH E EASTERN ADRIATI C Jakov OULČIČ institute of Oceanography and fisheries, HR-210GG Split, Šetalište i. Meštroviča 63 Frano KRŠINIČ Biological institute, HR-200GG Dubrovnik, Kneza Damjana jucle 12 Miro KRALJEVIČ & Armin PALLAORO Institute of Oceanography and Fisheries, HR-210GQ Split, ŠetaliSte I. Meširoviča 63 ABSTRACT Three fingeriings of Baiistes carolinensis Gmelin, 1789, found under a floating wreckage near the coast of the is­let Gu'oavac (vicinity of the settlement Lumbarda, Korduia island)r in September 1994, provided the first occurrence of the grey triggerfish fingeriings in the eastern Adriatic. This occurrence shows that this species spawns in the south­eastern Adriatic. The main morphometric and meristic data are given. The status of the grey triggerfish needs to be evaluated on a continuous basis as it is becoming increasingly apparent that uncommon species, and particularly those on the edge of their distribution, can be essential indicators of environmental change. Key words: Balistes carolinensis, fingeriings, Eastern Adriatic, first occurrence INTRODUCTION MATERIAL AND METHODS The grey triggerfish, Balistes carolinensis Gmelin, Three fingeriings were found under a floating wreck­1789, occurs on reefs and in open waters in tropical and age near the coast of the islet of Gubavac in the vicinity subtropical seas, chiefly over rocky bottoms at 10-100 of the settlement Lumbarda (Korcula island) in the m. It is common in the Mediterranean Sea and on both southeastern Adriatic in September 1994 (Fig. 1). sides of the Atlantic (from the North Sea to Angola and The specimens were identified according to Soljan from Nova Scotia to Argentina) but rare in the Black Sea (1975) and Tortonese (1986). They are deposited in the (Tortonese, 1986). This species also occurs in the ichtbyo logical Collection of the institute of Oceanogra-Adriatic Sea, especially in its southern part (jardas, phy and Fisheries in Split. 1983, 1996; Pallaoro, 1988), and in warmer years it Specimens were preserved in 4% buffered formalin may be found in the northern Adriatic (Pallaoro, 1988). immediately after capture, subsequently measured to the There is no published information on biology and nearest 0.1 mm (Fig. 2) and weighed to the nearest 0.01 ecology of the grey triggerfish in the eastern Adriatic. g. Reduction in length caused by preservation depends The aim of this paper is to provide first data on the oc-on the initial lengths of the specimens and duration of currence of fingeriings of grey triggerfish in the eastern storage. Preservation in formalin causes an average 5% Adriatic and their morphometric and meristic character-loss in total length of larvae and fingeriings (Mc Gurk, istics. 1984). Meristic characteristics considered were dorsal, anal, pectoral, caudal fin rays and number of scales in the longitudinal line. 271 ANNALES 11/'97 I. DUt.ČI Č « .!i: OCCURRENCE O F FINGERUNCS OF GREY TRIGGERFISH 271-276 F/g. /: S/te where fingerlings of Balistes carolinensis were found (islet Gubavac). Si. I: Lokaliteta mladic balestre Baiistes carolinensis (ob otočku Gubavac). RESULTS AND DISCUSSION The grey triggerfish is relatively common in the $oii!!>'astern Adriatic and belongs to amphiatlantic bio. graphical elements {Tortonese, 1964, 1970; Jar­das, !LJ83, 1996). it is considered very rare in the north­ern areas, and only occurs in some years in the central Adriatic in the regions of Split and Zadar. The last occur­rence was recorded in 1986/87 when several adult, specimens were caught near the island of Ugljan and in Komati Archipelago. Specimens occurred around the island of Lošinj in the northern Adriatic (Pallaoro, 1988); in 1969 and again in 1978, specimens were reported from the extreme north of the Adriatic in the Gulf of Venice (Boldrin & Railo, 1980). Specimens were also recorded in Slovenian coastal waters (Piran Bay) and one is kept in the Piran Aquaria (Lipej, pers. comm.) Studies on larval and juvenile stages of fish are of particular importance to population dynamics, espe­cially to recruitment and biological models incorporat­ing environmental parameters (Houde, 1986; Myers & Cadigan, 1993). There ate no previous records of the grey triggerfish fingerlings in the eastern Adriatic al­though several studies and investigations on fish juve­nile stages were carried out between 1975 and 1995 in the eastern Adriatic. Fingerlings of the grey triggerfish has short and deep body. Eyes are near dorsal edge. Mouth are small and jaws short and strong with two rows of few incisor-like teeth (Randall, 1968; Tortonese, 1986). Specimens have two dorsal fins; the anterior fin is equipped with three spines (Tortonese, 1986). Pelvic fins are replaced by-short spine at end of long and movable pelvic bone. Gill openings are very small. There were no blue stripes be­low the eye (a pair of blue side stripes below the eye is characteristics of Balistes vetula L., 1758). It is indicative that all specimens were found under a floating wreck­age, which is in agreement with the findings of Tor­tonese (1986). All specimens are without elongated caudal rays, which are characteristics of adult species (Bini, 1968; Tortonese, 1986). In Table 1 the main morphometric and meristic data of the three specimens are presented. Specimens 1 2 3 Total length 40.0 46,9 48.6 Standard length 33.1 38,9 40.8 Predorsal length 10.0 12,5 13.3 Preanal length 23.1 25.5 27.3 Preventral length 21.1 22.3 22.5 First dorsal fin, length 7.6 8.4 9. 0 Second dorsal fin, length 11.4 12.2 13.0 Anal fin, length 6.2 6.7 7.0 Pectoral fin, length 6.6 6.9 6.9 Body depth (max) 18.2 19.1 21.3 Body depth (rnin) 4.4 4.5 4.8 Head length 13.8 14.9 15.7 Ocular diameter 3.4 3.9 4.3 Preorbitai length 7.5 8.0 8.2 Postorbital length 3.3 3.8 3.9 First dorsal fin rays (Di } lit Iti 111 Second dorsal fin rays (Dj ) 27 27 27 Anal fin rays (A) 25 25 26 Pectoral fin rays (P) 14 14 14 Caudal fin rays (C) 11 11 11 Scales 54 54 55 Tab. 1; Morphometric and meristic data (in mm) of the grey triggerfish fingerlings in the south-eastern Adriatic (islet Gubavac). Tab. 1: Morfometrični in meristični podatki (v mm) mladic balestre v jugovzodnem Jadranu (otoček Guba­vac). 272 ANNALES 11/'97 DULČ1 Č el el.: OCCURRENC E O F FINGERLING S O F GRE Y TRIGGERFISH , ..., 271-276 The meristic characteristics of fingerlings (Table t) closely correspond with data by Bini (1968), i.e. D^ HI, D2 27-28, A 25-27, P 14, C 10-12, but differ from data by Tortonese (1986) i.e. D !!1+2, 2*2-25, A 2-3, 22-23. Even several adult stages were caught and since there are no previous records of larva! and fingerling stages, the following question was raised: "Does the grey triggerfish spawn in the eastern Adriatic?" This Septem­ber record shows that, this species probably spawns in the southeastern Adriatic or even more the south, espe­cially when we take into consideration that the grey triggerfish spawns in summer in the Mediterranean (Tor­tonese, 1986). We suppose that this specimens are about 3 or 4 months old according to the spawning time. Ofori-Danson (1990) defined the breeding season of the grey triggerfish as October to December (warmer months) in the Ghanaian coastal waters (Africa). The same author noted that the spawning of this species was characterized by relatively short preceding period of av­erage minimum sea-surface temperature of 22.6°C. First time spawners were 13,3-15.7 cm in fork length (mean length L=14.4 cm, about 50.0-70.5 g in weight and one year of age) (Ofori-Danson, 1989, 1990). Wheeler (pers. comm., after Quigiey et a!., 1993), based on unsubstan­tiated reports on the occurrence of very small "young" triggerfish in Irish waters, speculated that the species may be "breeding quite close to Irish coasts (perhaps in Biscay)". It should be emphasized that in 1994 the east­ern Adriatic was characterized by frequent records of larvae and juveniles, for example, larva of a mesopeia­gic species Trachipterus trachypterus (Dulčič, 1996) and juvenile of Trachinotus ovatus (Dulčič, et al., 1997). Fig. 2: Body measurements of Batistes carolinensis fingerlings. L! - total length; l.s - standard length; Lp. - predorsal length; Lpv - pre ventral length; /./, - head length; O - eye diameter, Lpo - preorbital length; Lpp0 -postorbital length; .di - first dorsal fin length; L42 - second dorsal fin length; Lp - pectoral fin length; Lv - ventral fin length; La - anal fin length; lpa - preanal length; Hm!„ - minimal body depth; Hmax - maximal body depth at dorsal fin. SI. 2: Mere mladic balestre Batistes carolinensis : Lt -skupna dolžina; Ls -standardna dolžina; Lpc! -predhrbtna dol­žina; Lpv - predtrebušna dolžina; Z./, - dolžina glave; O - premer očesa, L„0 - predorbitalna dolžina; Lppo -po­storbitalna dolžina; . - dolžina druge hrbtne plavuti; Lp - dolžina prsne plavuti; Lv -dolžina trebušne plavuti; La - dolžina analne plavuti; Lpa -predanalna dolžina; Hm!n -najmanjša višina; Hmax ­ največja višina pri hrbtni plavuti. 273 ANNALES 11 /'97 I. DUI.Ct C etal.: OCCURRENC E O f EINGERLING S O F GRE Y TRIGGERFIS H 271-276 Quigiey et al. (1993) noted, from the biogeo­graphics! review, that B. carolinensis has been exten­ding its range and abundance on both sides of the North and South Atlantic during recent decades, especially for Irish waters. During the 1960's and 1970's the triggerfish increase in frequency and range in British waters (Wbc­eler etal., 1975; Dobson, 1984). During the 1970fs they occurred in numbers in the North Sea (Blacker, 1981) and penetrated even into the Thames estuary (Andrews & Wheeler, 1985). During the same period, it was recorded from the coasts of Denmark (Neilsen, pers. comm. from Ouigley ei' a!., 1993), The Netherlands (de Groot, 1973), and Belgium (De Clerk, 1975). Wheeler (1978) considered that the triggerfish appeared to make regular annual migrations into northern European wa­ters, where its relative abundance varied from year to year. During the 1980's and early 1990!s triggerfish numbers appeared to increase further. In 1983, two spe­cimens were recorded from the Dtitch coast (de Groot, 1986), while in 1984 several specimens were recorded from as far north as Scotland (Dobson, 1984). Large numbers of triggerfish were also captured by anglers off the southwest coast of England in 1984 and 1989 (Cooling, 1989). During 1991, triggerfish appear to have occurred more frequently than usual in UK waters, paricularly in the west and northwest of Scotland (Gill, 1991). Wheeler (pers. comm. from Quigiey etal., 1993) remarked that "the triggerfish had become so common in English waters that it is probably the most striking change in the fauna of this century". In 1976, the triggerfish was regarded as rare north of the Gulf of Gascony in southwest France (Harambillet et a!., 1976). However, during the 1960's, 1970's and 1980's, the species was recorded with increasing frequency as far north as northwest France (Quero et al., 1986; Delmas et al., 1986). The greater geographical range and gene­ral abundance of triggerfish may be related to the changes in climate and/or oceanographical conditions (Quigiey, 1985). Global temperatures, for example, have risen by about 0.5"C in this century (Sweeney, 1989). Some changes in oceanographical conditions were noted for the central Adriatic (Marasovic et al., 1996). The penetration of the grey triggerfish in the central and northern Adriatic and, according to our data, probably for its spawning in the southeastern Adriatic might be connected with some special climatological and oce­anographical conditions in 1994 and input of inter-median waters (50-100 m) in the central Adriatic which influenced the increase in salinity and temperature (Marasovid et al., 1996). Pallaoro (1988) also stated that the Adriatic ingressions caused more rare species (Centracanthus cirrus, Aulopus filamenlosus, Pseudo­charartx dentex, Synodus saurus, Centrolophus nlger) to appear in the central Adriatic region in 1986-87 period. An unusual abundance of such rarely found fish species compared to the non-ingression periods gives indication of their interdependence. The moving of some southern Adriatic tbermophile (Balistes carolirtensis) and bathi­phile (Lepidopus caudatus) species to a greater extent towards the North has been ascertained in 1986/87, which is a possible result of the effect of the ingression waters (Pallaoro, 1988). As quoted by Harmelin (1991), some species with southern affinities like Seiiola dume­rill, Diplodus cervinus, Balistes carolirsensis, Epine­phelus alexandrinus and Epinephelus marginatus are being found more commonly along the northwestern Mediterranean coasts, juveniles of these species were observed at relatively high latitudes such as Caivi and Barcelona (Spain). Changes in the physical properties of the water and natural fluctuations in space and time are perhaps responsible for the mentioned occurrences (Saldanha, 1992). Sazonov and Galaktionova (1987) found that the quasi-synchronous increase in abundance of Sardina pilchardus, Macroramphosus scolopax and Balistes carolinensis in different climatic zones of the Central east Atlantic can more likely be attributed to global weather processes rather than to fishery impact since the exploitation rate of these species is quite different. The status of the grey triggerfish needs to be evaluated on a continuous basis because it is becoming increasingly apparent that uncommon species, and particularly those on the edge of their distribution, can be essential indicators of environmental change (Swaby & Potts, 1990). 274 ANNALES 11/"97 J DULČtČ c( si: OCCURRIiNCE OF FÍNCERUNCS OF GREY TRJGCERFISH, ....271-276 POJAVLJANJE MLADI C BALESTRE BAUSTES CAROUNENSIS GMEUN , 1 789 (PiSCES: BALiSTIDAE) V VZHODNE M JADRANSKEM MORJU Jakov DULČIČ lnstitut za oceanografiju i ribarstvo, HR-21000 Split, ŠetalBte 1. Meštrovica 63, p.p. 500 Fran o KRŠINiČ Biološki zavod, HR-20000 Dubrovnik, Kneza Damjana Jude 12 Miro KRALJEVIČ & Armin PALLAORO Institut za oceanografiju t ribarstvo, HR-21000 Split, Šetalište i. MeStroviča 63, p.p. 500 POVZETEK Baiestra Bal !síes caroiinensis Cmelin, 1789 naseljuje grebene odprtih voda tropskih in subtropskih morij, pred­vsem kamnito dno v globinah med 10 in 100 metri. Pogosta je v Sredozemskem morju in na obeh straneh Atlantika (od Severnega morja do Angole in od Nove Škotske do Argentine); v- Črnem morju je redka (Tortonese, 1986). Živi tudi v jadranskem morju, predvsem v njegovem južnem delu (Jardas, 1983, 1996; Pallaoro, 1988); v toplejših letih jo utegnemo opaziti tudi v severnem Jadranu (Pallaoro, 1988). Tri balestrine mladice, odkrite septembra 1994 pod ladijskimi razbitinami ob obrežju otočka Gubavac (v bližini naselja Lumbarda na Korčuli), so prvi podatek o pojav­ljanju mladic te vrste v vzhodnem Jadranu. To odkritje potrjuje, da se baiestra drsti v jugovzhodnem Jadranu; v član­ku so nanizani glavni morfometrični in meri stični podatki, zbrani o tej vrsti. Sicer pa avtorji članka ugotavljajo, da je treba položaj balestre vJadranu oceniti na osnovi trajnejšega raziskovanja, saj postaja vse bolj očitno, da so tako nenavadne vrste - in posebno vrste z roba svoje razširjenosti -pomemben kazalec sprememb v morskem okolju. Ključne besede: Balistes caroiinensis, mladice, vzhodni !adran, pi vo pojavljanje REFERENCES Andrews, M.J. & A, Wheeler. 1985. Rare and little- known fishes in the Thames Estuary, j. Fish. 8toi., 27: 59-71. Bini, G. 1968. Atlante dei pesci delie coste Italians. Vol. IV, Osteiti. Mondo Somerso Editrice, 164 pp. Blacker, R.W. Recent occurrences of blue whiting, Micromesistius poutassou, and Norway pout, Triso­pterus esmarkii, in the English Channel and southern North Sea. j. Mar. Biol. Assoc. U.K., 61: 307-313. Boldrin, A. & G. Ralio. 1980. Reperti interessanti di osteichthyes nel Veneto e nef Gulfo di Venezta. Lavori. Soc. Ven. Sc. Nat., 5: 42-48. Cooling, D. 1989. Year of the Trigger. Angler's mail, 23/30 December 1989. De Clerk, R. 1975. Belgian observations on rare fish in 1 973. Annl. bioL Copenh., 30: 210. de Groot, S.J. 1973. Dutch observations on rare fish in 1973. Annl. biol. Copenh., 30: 209-210. de Groot, S.J. 1986. Dutch observations on rare fish in 1983. Annl. biol. Copenh., 40: 188. Delmas, G., M.H. Du Buit, A. Lafon, J.P. Minet & J.C. Quero. 1986. Observations françaises sur les poissons rares en 1983. Annl. biol. Copenh., 40: 188-189. Dobson, J. 1984. Trigger-fish off western Scotland. Glasgow Nat, 20 (5): 486-488. Dul&d, J. 1996. First record of ribbon fish Trachipterus trachypterus (Gmelin, 1789} larva from the eastern Adriatic. Cybiurn, 20: 101-102. DulciL, )., A. Pallaoro & M. Kraljevid 1997. Note on the first record of juvenile derbio, Trachinotus ovatus (Linnaeus, 1758) (Pisces: Carangidae) in the eastern middle Adriatic. Nat. Croatica, 1: 61-65. Gill, K. 1991. Fish warms to Scots offering. Times, 30th October, 1991, HarambilJet, G.f A. Pererer, & j.C. Quero. 1975. Re- marques sur la faune ichthyologique de la Cote Basque Française. Bull. Cent. Etud. Rech. sci. Biarritz, 11 (1): 23-34. Harmelin, J.G. 1991, Statut du corb (Sciaena umbra) en Méditerranée, in: C.F. Boudorescque, M. Avon & V. Gravez (Eds.): Les Espec.es Marines a Proteger en Mediterranee, 219-227. GIS Posidonie Pub!., Marseille, France. 275 ANNALES 11/'97 J. DUlCiCe ; ^'..'OCCURRENCE OF F1NCERUNCS O F GREY TRIGGERFISH,..., 2/1-276 Houde, E.D. 1986. Potential for growth, duration of early life stages and regulation of recruitment in marine fish. Int. Count. Explor. Sea ICES CM 1986/L, 28 pp. Jardas, I. 1983. Analiticki pregled ihtiofaune jadranskog mora, ichthyologia, vol. I S (1): 15-35. Jardas, I. 1996. ladranska ihtiofauna. Skolska knjiga, Zagreb, 533 pp. Marasovid, i., B. Grbec & M. Morovici. 1995. Long-term production changes in the Adriatic. Neth. j. Sea Res. 34(4): 267-273. McGurk, M.D. 1984. Ring deposition in the otoliths of larva! Pacific herring, Clupea harengus pallasi. Fish. Bull., 82: 113-120. Myers, R.A. & N.G. Cadigan. 1993. Density-dependent juvenile mortality in marine demersal fish. Can. J. Fish. Aquat. Sci., 50: 1576-1590. Ofori-Danson, P.K. 1989. Growth of grey triggerfish, BaH5t.es capriscus, based on growth checks of the dorsal Spine. Fishhbyte, 7 (3): 11-1 2. Ofori-Danson, P.K. 1990. Reproductive ecology of the triggerfish, Balistes capriscus from the Ghanaian coastal waters. Trop. Ecol., 31 (1): 1-11. Pallaoro, A. 1988. O mogucnosti pojave nekih rijetkih vrsta riba na srednjejadranskom podrucju u vezi s jad­ranskom ingresijom 1986/87. godine. Morsko ribarstvo, 3: 82-87. Randal!, I.E. 1968. Caribbean reef fishes. T.F.H. Publi­cations, jersey City, New jersey, 318 pp. Saldanha, L. 1992. Marine fishes, habitats and con­servation. Neth. j. Zool., 42 (2-3): 190-199. Quero, J.C., G. Deimas, M.H. Du Buit, J. Fonteneau & A. Lafon. 1986. Observations ichthyologiques effectuees en 1985. Ann. Soc. Sci. nat. Charente-Maritime, 7(4): 493-498. Quigley, D.T.G. 1985. Specimens of trigger fish Balistes carolinerisis Gmelin 1789 (B. capriscus Gmelin) from Achill Island, Co. Mayo, and a review of the Irish records. Ir. Nat. j., 21 (1 1), 474-476. Quigley, D.T.G., K. Flannery & }. O'Shea. 1993. Trigger fish in Irish waters: a biogeographical review. -Bio­geography of Ireland: past, present and future. M.j. Costello and K.S. Kelly (eds.) Occ. Publ. Ir. biogeog. • Soc., 2: 127-140. Swaby, S.E. & G.W. Potts. 1990. Rare British marine fishes -identification and conservation, j. Fish. Biol., 37: 133-143. Sweeney, J. 1989. The greenhouse effect and Ireland. Technology Ireland, July/August 1989: 30-32. S>oijan, T. 1975. I pesci dell'Adriatico. Officine grafiche di Verona, 522 pp. Tortonese, E. 1964, The main biogeographical features- and problems of the Mediterranean fish fauna. -Copeia,;: 1:98-107. Tortonese, E. 1970. Osteichthyes (Pesci ossei), I. Fauna • Ital., 10. Ed. Calderini, Bologna: 565 p. Tortonese, E. 1986. Baiistidae. -In: Whitehead, P.j.P./ M.-L. Bauchot, j.-C. Hureau, ]. Nielsen & E. Tortonese, ;' eds.: Fishes of the North-eastern Atlantic and the Me--.­diterranean, 3. 1335-1338. UNESCO. Paris. Wheeler, A.C., R.W. Blacker & S.F, Pirie. 1975. Rare and little-known fishes in British seas in 1970 and 1971-...­ j. Fish. Biol., 7: 183-201.