Specimens of the snipefish, Macroramphosus scolopax (Linnaeus, 1758), from the middle and southern Adriatic were biometrically analyzed during the demersal communities research project, MEDITS. The specimens (n = 103) were caught at depths deeper than 100 m. Total length ranged 4.8-16.0 cm, with a mean of 9.45±2.796 cm. According to the length-weight relationship, positive
allometric growth was established (b = 3.23)

Barbara Zorica

Nedo Vrgoč

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ISSN: 0001-5113AADRAYACTA ADRIAT.,46 (1): 99 - 106, 2005UDC: 597.5(262.3)Original scientific paperBiometry and distribution of snipefish,Macroramphosus scolopax (Linnaeus, 1758), in the Adriatic SeaBarbara ZORICA and Nedo VRGOČInstitute of Oceanography and Fisheries, P.O. Box 500, 21 000 Split, Croatia Specimens of the snipefish, Macroramphosus scolopax (Linnaeus, 1758), from the middle and southern Adriatic were biometrically analyzed during the demersal communities research project, MEDITS. The specimens (n = 103) were caught at depths deeper than 100 m. Total length ranged 4.8-16.0 cm, with a mean of 9.45±2.796 cm. According to the length-weight relationship, positive allometric growth was established (b = 3.23).Key words: Macroramphosus scolpax, snipefish, biometry, Adriatic Seatrawl fishing was not well developed. However, snipefish was mentioned in fish identification keys (BINNI, 1968; ŠOLJAN, 1975; TORTONESE, 1975; JARDAS, 1996) and descriptions of Adriatic ichthyofauna (ŽUPANOVIĆ & JARDAS, 1989). Biometric analysis and the length-weight relationship of the Adriatic snipefish population remained to be studied. The present paper provides the first detailed description of the biometry and length-weight relationship of snipefish in the Adriatic Sea.   MATERIALS AND METHODS Macroramphosus scolopax specimens were collected by bottom trawlers during the MEDITS research cruises in the spring and summer of 1997 and 1998 (Fig. 1). Tows were carried out over the continental shelf at depths of 40-800 m for 30-60 min, depending on the depth. The mean trawl speed was 3 knots. Overall, 103 specimens were caught in 18 of INTRODUCTION The snipefish, Macroramphosus scolopax (Linnaeus, 1758), is a schooling demersal species. It is carnivorous, feeding on zooplankton and benthic invertebrates (MASUDA & ALLEN, 1993), and is usually found between the seabed and midwaters, on the lower continental shelf. The snipefish occurs mainly in temperate latitudes at 20-40°N, although it also occurs in the southern hemisphere to 43°S (BAUCHOT & PRAS, 1993). Reproduction takes place during January and February (EHRICH & JOHN, 1973). Several authors described the biometric characters and biology of snipefish from different localities: MORH (1937), EHRICH & JOHN (1976), BRÊTHES (1979) and BORGES (2000, 2001) for the Atlantic Ocean, ASSIS (1993) for the Mediterranean Sea, and CLARKE (1984) and MIYAZAKI et al. (2004) for the western Pacific Ocean. Prior to the early 20th century, the snipefish was rarely caught in the Adriatic Sea since 100  ACTA ADRIATICA, 45(1): 99-106, 2004127 hauls. The specimens were preserved in a 4% formaldehyde solution prior to examination. Lengths were measured to the nearest 0.1 cm and total weights to the nearest 0.01 g. Eighteen morphometric characters (Fig. 2) were measured according to JARDAS (1996). In addition, six meristic characters were counted: number of rays in the first dorsal, second dorsal, pectoral, pelvic, anal, and caudal fins.  To ensure that any impact of the formaldehyde on the measurements was eliminated, morphometric characters were expressed as a percent of the total or head length. To compare growth, length-length relationships were established using linear regression analysis (BINOHLAN et al., 1998). Sex was determined according to the shape and appearance of the gonads. Statistical differences between mean lengths of males and females were determined by Student’s t test, and differences between their distributions by χ2 test. The length-weight relationship was calcu-lated by the function W = aLb (RICKER, 1975), where W is the total weight measured in g, L is total length measured in cm, and a and b are constants. The hypothetical isometric growth was tested by STUDENT’s t test.RESULTS AND DISCUSSION According to the pattern of occurrence, this species is distributed along the continental shelf at depths deeper than 100 m. Depth appeared to be the main factor determining the spatial distribution of snipefish. Total length ranged 4.8-16.0 cm with a mean of 9.45±2.796 cm. Sex was determined for 33 specimens: 14 were male (42%) and 19 were female (58%). The ratio of males to females did not significantly differ from the expected 1:1 ratio (χ2 = 0.758; p>0.05). As the length frequency distribution for both sexes resulted in a single mode, mean lengths represent the length frequencies for each sex. Total length ranged 9.7-16.0 cm in females (χ2 = 13.12±1.743 cm) Fig. 1. Sampling stations of the MEDITS survey (1997-1998) in the Adriatic Sea. Squares and triangles indicate sampling stations according to the number of Macroramphosus scolopax collected101ZORICA & VRGOČ: Biometry and distribution of snipefish in the Adriatic Seaand 9.1-13.8 cm in males (χ2 = 11.74±1.334 cm). Morphometric characters are displayed in Table 1. In general, there were no significant differences (p<0.05) between sexes except in mean postocular head length, but the coefficient of determination was very low (r2 = 0.4776). Percent of total length Sex Range χ2±SD       tFork length (FL) Males 94.90-98.90 97.19±1.040Females 96.64-97.74 97.42±0.607Total 93.50-99.09 97.25±1.060 0.821Standard length (SL) Males 87.50-91.10 88.33±1.220Females 85.37-91.04 88.75±1.520Total 84.21-91.58 87.86±1.700 0.867Head length (CL) Males 43.88-47.46 45.40±1.290Females 31.64-48.52 43.45±4.270Total 31.64-48.53 44.95±2.350 1.878Predorsal distance (PD) Males 66.30-70.00 67.90±1.320Females 65.04-70.30 68.09±1.440Total 60.01-71.30 66.53±2.390 0.394Fig. 2. Measured body proportions: CL = head length, ED = eye diameter, FL = fork length, h = minimum body height, H = maximum body height, Hray = length of the second spine in first dorsal fin, LA = length of anal fin base, LD1 = length of first dorsal fin base, LD2 = length of the second dorsal fin base, LP = length of pectoral fin, LV = length of pelvic fin, PD = predorsal distance, POC = preocular head length, PP = prepectoral distance, PV = prepelvic distance, SL = standard length, TL = total length, ZOC = postocular head lengthTable 1. Morphological characters of Macroramphosus scolopax (n = 103; males = 14, females = 19, undetermined sex = 70), from the Adriatic Sea in spring-summer, 1997 and 1998102  ACTA ADRIATICA, 45(1): 99-106, 2004Prepectoral distance (PP) Males 43.88-47.64 45.38±1.270Females 31.64-48.52 43.50±4.290Total 31.64-48.52 44.99±2.360 1.808Prepelvic distance (PV) Males 54.60-65.60 57.50±3.150Females 53.00-64.90 57.40±3.060Total 41.60-65.60 56.42±4.970 0.093Maximum height (H) Males 23.26-26.98 25.45±1.180Females 20.79-29.46 26.07±1.740Total 18.18-30.83 24.74±2.260 1.170Minimum height (h) Males 3.20-5.70 4.17±0.751Females 3.26-5.97 4.53±0.553Total 3.20-5.97 4.37±0.659 1.589Length of 1st dorsal fin (LD1) Males 7.69-10.10 8.86±0.693Females 7.81-11.36 9.33±1.006Total 7.69-11.36 9.13±0.907 1.511Length of 2nd dorsal fin (LD2) Males 6.50-8.81 7.55±0.689Females 6.64-9.70 7.85±0.795Total 6.49-9.70 7.72±0.755 1.132Length of anal fin (LA) Males 13.56-17.62 15.39±1.167Females 10.40-16.49 14.93±1.386Total 10.39-17.62 15.124±1.299 1.018Length of pectoral fin (LP) Males 14.41-18.46 15.95±1.099Females 12.42-16.83 15.09±1.280Total 12.42-18.45 15.46±1.265 2.024Length of pelvic fin (LV) Males 5.98-9.34 7.39±1.029Females 3.78-8.91 7.10±1.162Total 3.76-9.35 7.22±1.100 0.671Length of 2nd spine in 1st dorsal fin Males 24.35-35.70 28.70±3.310(Hray) Females 21.92-31.68 27.36±2.370Total 21.92-36.47 29.50±2.950 1.381Percent of head length Preocular head length (POC) Males 65.79-73.17 69.46±2.420Females 63.46-72.05 71.29±6.100Total 54.16-73.17 67.20±5.190 1.188Eye diamete (ED)r Males 14.63-22.02 18.28±1.970Females 16.79-26.19 20.00±2.900Total 11.61-28.30 17.07±2.940 1.946Postocular head length* Males 16.00-19.50 17.90±1.060(ZOC) Females 16.05-28.30 19.38±2.850Total 12.12-28.30 18.13±2.740 2.085Table 1. cont’d* p<0.05103ZORICA & VRGOČ: Biometry and distribution of snipefish in the Adriatic Sea All length-length relationships were linear (Fig. 3). The estimated equations for the length-length relationships and coefficients of determination r2 are presented in Table 2. Increase of the second spine length was slower than that of other lengths. There were no significant differences between meristic characters of males and females (Table 3).   The length-weight relationship was W = 0.2 x 10-5L3.23 (r2 = 0.975, n = 103) and allometric growth was positive. According to results of the STUDENT’s t test (p<0.05), the hypothesized Fig. 3. Relationships of total length (TL) to head length (CL) fork length (FL), maximum body height (H), length of the second spine in first dorsal fin (Hray), predorsal distance (PD), prepectoral distance (PP), prepelvic distance (PV), and standard length (SL) of Macroramphosus scolopax (n = 103) from the Adriatic SeaTable 2. Estimated coefficients for relationship between total length (TL) and other lengths for Macroramphosus scolopax  (n = 103) from the Adriatic SeaEquation r2Fork length (FL) = 0.9639TL + 0.1714 0.9653Standard length (SL) = 0.8925TL - 0.0302 0.9498Head length (CL) = 0.3990TL + 0.5619 0.6805Predorsal distance (PD) = 0.6869TL - 0.0405 0.9337Prepectoral distance (PP) = 0.4015TL + 0.5347 0.6826Prepelvic distance (PV) = 0.6575TL - 0.9879 0.8753Maximum body height (H) = 0.2618TL - 0.0292 0.8267Height of 2nd spine in 1st dorsal fin (Hray) = 0.1241TL + 1.9157 0.4776104  ACTA ADRIATICA, 45(1): 99-106, 2004isometric growth for this species was rejected. The b-value was generally in agreement with results found by other authors. In the western Mediterranean, the length-weight relationship for this species was W = 0.004L3.15 (MERELLA et al., 1997) while in Portuguese continental waters it was W = 0.004L3.127 (BORGES, 2000). The biometry findings for snipefish habituating this part of the Adriatic Sea are presented here for the first time and therefore significant. The biology of snipefish should be further studied, especially of older specimens. ACKNOWLEDGMENTS The authors are grateful to Dr. sc G. SINOVČIĆ and two anonymous reviewers for their critical and useful comments on the manuscript.Table 3. Meristic characters of Macroramphosus scolopax (n = 103, males = 14, females = 19, undetermined sex = 70) from the Adriatic Sea in the 1997 and 1998 spring-summer periodMeristical character SexRange(no.)X  ±SD tFirst dorsal fin rays (D1) Males V-VI 5.14±0.36Females V-VI 5.16±0.38Total IV-VII 5.14±0.40 0.155Second dorsal fin rays (D2) Males I+(10-14) 11.4±1.08Females I+(10-13) 11.4±0.68Total I+(10-14) 11.3±0.74 0.000Pectoral fin rays (P) Males 14-17 15.4±0.85Females 14-17 15.7±0.95Total 13-18 15.3±0.93 0.952Pelvic fin rays (V) Males I+(5-6) 5.2±0.43Females I+(5-6) 5.3±0.45Total I+(4-6) 15.3±0.93 0.654Anal fin rays (A) Males 17-19 18.4±0.65Females 17-19 18.6±0.60Total 17-20 18.4±0.64 0.465Caudal fin rays (C) Males 14-17 15.1±0.83Females 12-17 15.3±1.15Total 12-17 14.9±0.91 0.562105ZORICA & VRGOČ: Biometry and distribution of snipefish in the Adriatic SeaREFERENCESASSIS, C.A. 1993. On the systematics of Macroramphosus scolopax (Linnaeus, 1978) and Macroramphosus gracilis (Lowe, 1839). II. Multivariate morphometric analysis. Arquivos do Museu Bocage (new series), 2(22): 383-402.BAUCHOT, M.L. & A. PRAS. 1993. Guía de los Peces de Mar de España y de Europa. Ediciones Omega, Barcelona, p. 227. BINNI, G. 1968. Atlante dei pesci delle coste Italiane. V Mondo Sommerso, Milano, 175 pp. BINOHLAN, C., R. FROESE & D. PAULY. 1998. The length-length table. In: R. Froese, D. Pauly (Editors). Fishbase 1998: Concept, Design and Data Sources. ICLARM, Manila, pp. 124.BORGES, L. 2000. Age and growth of the snipefish, Macroramphosus spp., in the Portuguese continental waters. J. Mar. Biol. Ass. U.K., 80: 147-153.BORGES, L. 2001. A new maximum length for the snipefish Macroramphosus scolopax. Cybium, 25(2): 191-192.BRÊTHES, J.C. 1979. Contribution à l’étude des populations de Macroramphosus scolopax (Linnaeus, 1978) et Macroramphosus gracilis (Lowe, 1839) des côtes Atlantiques marocaines. Bull. de l’Institut de Pêches Maritimes, 24: 62.CLARKE, T.A. 1984. 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Length-weight relationship of fishes and cephalopods from the Balearic Islands (western Mediterranean). Naga ICLARM Q., 20(3/4): 66-68.MIYAZAKI, E., K. SASAKI, T. MITANI, M. ISHIDA & S. UEHARA. 2004. The occurrence of two species of Macroramphosus (Gasterosteiformes: Macroramphosidae) in Japan: morphological and ecological observations on larvae, juveniles, and adults. Ichthyol. Res., 51:256-262.MOHR, E. 1937. Revision der Centriscidae (Acanthopterygii, Centrisciformes). Dana Rep., 13:1-69.RICKER, W.E. 1975. Computation and interpretation of biological statistics of fish populations. Bull. Fish. Res. Board Can., 191: 382.ŠOLJAN, T. 1975. I pesci dell’Adriatico. A. Mondadori (Editor). Verona, Italy, 522 pp.TORTONESE, E. 1975. Osteichtyes (Pesci ossei). Fauna d’Italia. XI Calderini, Bologna, 636 pp.ŽUPANOVIĆ, Š. & I. JARDAS. 1987. Fauna i flora Jadrana, Jabučka kotlina, II dio. Logos, Split, 526 pp.Received: 27 October 2003Accepted: 30 March 2005106  ACTA ADRIATICA, 45(1): 99-106, 2004Biometrija i rasprostranjenost šljuke,Macroramphosus scolopax (Linnaeus, 1758), u Jadranskom moruBarbara ZORICA i Nedo VRGOČInstitut za oceanografiju i ribarstvo, P. P. 500, 21 000 Split, HrvatskaE-mail: zorica@izor.hrSAŽETAK U radu je prikazana rasprostranjenost i biometrija 103 primjerka šljuke, Macroramphosus scolopax (Linnaeus, 1758), koji su prikupljeni tijekom istraživanja pridnenih naselja Jadranskog mora, na dubinama većim od 100 m, a u sklopu projekta MEDITS, tijekom proljetno-ljetnog razdoblja  1997. i 1998. godine. Analizirano je 18 morfometrijskih i 6 merističkih obilježja ove vrste. Nisu nađene morfološke i merističke razlike između mužjaka i ženki. Analizom dužinsko – masenog odnosa je utvrđena pozitivna alometrija (b=3,23); šljuka je pokazala proporcionalno brži maseni nego dužinski rast.Ključne riječi: Macroramphosus scolopax, šljuka, biometrija, Jadransko more

Biometry and distribution of snipefish, Macroramphosus scolopax(Linnaeus, 1758), in the Adriatic Sea

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