M.P.OIivar <strong>and</strong> I.Palomera 43 41 39 43 41 39 43 41 39 1000' II I 1 I •
<strong>Ontogeny</strong> <strong>and</strong> <strong>distribution</strong> <strong>of</strong> H.<strong>benoiti</strong> in NW Mediterranean During June/July 1992, two patterns <strong>of</strong> <strong>distribution</strong> <strong>of</strong> H.<strong>benoiti</strong> larvae were obvious. Larvae were most abundant in deep waters <strong>of</strong>f the Catalan coast, but were largely absent from the Gulf <strong>of</strong> Lions in the northern part <strong>of</strong> the survey region. This difference could not be related to differences in temperature <strong>and</strong> salinity between the Catalan <strong>and</strong> French coasts, since these environmental factors showed little variation between the slope areas <strong>of</strong> the two sectors. The main concentrations <strong>of</strong> H.<strong>benoiti</strong> larvae at deeper stations <strong>of</strong>f the Catalan coast match the oceanic habits <strong>of</strong> the adults (Taning, 1918; Goodyear et al., 1972; Hulley, 1981). As pointed out by Sabates <strong>and</strong> Maso (1990), the circulating pattern in the area has a major effect on the <strong>distribution</strong> <strong>of</strong> mesopelagic larvae. Current flow in the region is southwesterly along the edge <strong>of</strong> the continental shelf. Associated with this current is a typical shelf-slope front separating less saline inshore waters from the open sea (Font et al., 1988). Just north <strong>of</strong> the Ebro Delta, the current penetrates to the wide continental shelf (Font et al., 1990), <strong>and</strong> the concentration <strong>of</strong> larvae closer to the coast in this area is probably related to this circulation pattern. Thus, the nearshore <strong>distribution</strong> <strong>of</strong> H.<strong>benoiti</strong> observed in this study may be closely related to both hydrographic <strong>and</strong> topographic features in the area. Acknowledgements The authors wish to thank Dr H.G.Moser for the revisions <strong>and</strong> useful comments on the manuscript, <strong>and</strong> advice in its preparation. Larvae used for comparison were generously made available by the following persons, to whom we are especially grateful: A.Aboussouan (Faculte des Sciences de Luminy, Marseille), L.Beckley (Oceanographic Research Institute, Durban), K.E.Hartel (Museum <strong>of</strong> Comparative Zoology, Cambridge), W.F.H<strong>of</strong>fman (National Museum <strong>of</strong> Natural History, Smithsonian Institution), H.Ch.John <strong>and</strong> C.Zelck (Zoologisches Institut <strong>and</strong> Museum, Hamburg), J.Leis <strong>and</strong> T.Trnski (Australian Museum, Sydney), T.Ozawa (Kagashima University), P.Rubies <strong>and</strong> A.SabatSs (Instituto de Ciencias del Mar, Barcelona), R.Zeidane (Centre de Recherches Marines, Lebanon). We are also grateful to G.Fuster <strong>and</strong> A.Carpena for sorting the samples. We also appreciate the comments <strong>and</strong> suggestions made by P.Rubies while preparing the manuscript. J.Corbera prepared the figures <strong>of</strong> the larvae. References Backus.R.J., Craddock.J.E., Haedrich.R.L. <strong>and</strong> Robison.B.H. (1977) Atlantic mesopelagic zoogeography. In Gibbs.R.H. Jr (ed.), Fishes <strong>of</strong> the Western North Atlantic, Sears Found. Mar. Res. Yale Univ. Mem., 1, 266-287. Balbontin.F. <strong>and</strong> Orellana.M.C. (1983) Descripci6n de las larvas del pez linterna <strong>Hygophum</strong> bruuni del 4rea de Valparaiso, Chile (<strong>Pisces</strong>: Myctophidae). Rev. Biol. Mar., 19, 205-216. Beckley.LE. <strong>and</strong> van Ballegooyen.R.C. (1992) Oceanographic conditions during three ichthyoplankton surveys <strong>of</strong> the Agulhas current in 1990/91. In Payne,A.I.L., Brink,K.H., Mann.K.H. <strong>and</strong> Hilborn.R. (eds), Benguela Trophic Functioning. S. Afr. J. Mar. Sci., 12, 83-93. Berdar.A. <strong>and</strong> Cavaliere.A. (1979) Stadi larvali e postlarvali di mict<strong>of</strong>idi: <strong>Hygophum</strong> hygomi (Lutken). Mem. Biol. Mar. Ocean., 9, 167-173. 989
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