Composition of Ichthyoplankton and Horizontal and Vertical Distribution of Fish Larvae in the Great Meteor Seamount Area in September 1998

Not to be cited without prior reference to the author

ICES/ASC CM 2002/M12 Theme Session on Oceanography and Ecology of Seamounts – Indications of Unique Ecosystems

Composition of ichthyoplankton and horizontal and vertical distribution of fish larvae in the Great Meteor Seamount area in September 1998

by Walter Nellen & Silke Ruseler Inst. of Hydrobiology and Fisheries Science Hamburg University

Abstract 24 stations above and near the Great Meteor Seamount, central north Atlantic, have been sampled at eight depth strata in late summer 1998 by a modified MOCNESS. Some 18.800 fish larvae were collected and specimens were identified to species and coarser systematic levels, respectively. Taxa typical of the high sea remote from coastal areas dominated the fish larvae assembly. But species which normally are found on the shelf or at the slope occurred as well in the plankton samples, mainly above and fairly close to the 300m deep seamount, obviously keeping away from the oceanic region several thousand meters deep. Eighteen of a total of more than 150 identified fish larvae taxa belonged to the neritic province. One of these species was the third most abundant larvae found so far during this investigation, namely Chlorophthalmus agassizii. Concentration and horizontal and vertical distribution of selected species are discussed as well as migration behaviour in dependence of day and night situation and sea bottom depth. It is considered whether this seamount may be regarded as an isolated, just 1465km² large shallow water area settled permanently by a coastal fish community. The question is treated why this may be so, i.e. which kind of non biotic and biotic factors could be responsible for such a situation.

1 Introduction At 30°00’N and 28°30’W the deep sea character typical for this area of the Atlantic Ocean is considerably disturbed by the Great Meteor Seamount. It is an isolated elevation rising from more than 4000m depth to less than 300m underneath the surface (Fig. 1). Conspicuous features of this seamount are on the one hand a elliptical plateau of 54 km length and 31 km width forming a shallow water area of 1465 km² within the 400m isobathic line and on the other hand very steep slopes. The mean inclination of the latter is about 13° in parts <20° and at the upper part of the slope the inclination is up to 45° (Ulrich, 1971).

Already in the late 60ies the question arose whether seamounts are settled by a peculiar community and whether they may be regarded as extremely isolated, more or less self-regulating marine ecosystems on their own. In 1967 and 1970 the Meteor Seamount and its surrounding were subject of several geological, physical, and biological investigations aiming, among other things, at the composition and abundance of fish larvae taxa in February 1970 (Nellen, 1973). A corresponding research program at the Meteor Seamount was carried out almost thirty years later, in September 1998 (Pfannkuche et al. 2000), allowing improved research methods and comparing inspections of former results as well.

The following hypotheses were proposed and tried to be proofed though the results of the present analysis are still to a certain extend preliminary and first of all descriptive. Actually, the data base my finally turn out as too small for far reaching statistical testing.

1. The Meteor Seamount is a marine biotope inhabited by a pronounced unique ichthyofauna 2. For the larvae of certain species the epipelagic zone above the seamount’s plateau is a retention area 3. Such larvae species do not make extended vertical migrations 4. One advantage of this behaviour is the avoidance of predators settling the plateau’s sea bottom 5. Ichthyoplankton species living in the vast oceanic surrounding off the seamount perform extended vertical day/night migrations down to water depths below the sea bottom depth of the plateau 6. Such fish larvae may get drifted above the plateau at night when they stay in the surface layer. At day time the may be the pray of benthos organisms settling at the seamount 7. Only relatively few fish species were able to settle the seamount as a niche area, but those which could are abundant there

Material and Methods. Between September 1st and 20th 1998 ichthyoplankton was sampled from R.V. METEOR during SEAMEC (Seamount Ecology) Survey M42-3 at 24 stations in the Meteor Seamount area. 12 stations were at shallow water positions, mean sea bottom depth 370m, 9 were at deep water positions, mean bottom depth 3280m, and the positions of 3 stations were above the slope, mean water depth 1330m (Fig. 2).

Plankton was sampled with a modified MOCNESS, width of opening rack 1m², netting 335 µm mesh aperture (Nellen et al.1996 and Fig. 3). Oblique step hauls were done from 290m water depth to the surface to allow discrete sampling of seven

2 water layers of defined depths at each station (Fig. 4). The water volume filtered in the respective depth layers was measured by an electrical flow meter when the gear was towed at a ship’s cruising speed of 3 knots while the hauling speed was 1m/s. The plankton was fixed in 4% formalin/seawater solution immediately when a haul was on deck.

In the laboratory total plankton displacement volume of the 148 samples obtained was determined and fish larvae were sorted from the entire sample after the formalin had been washed out. The fish larvae were stored later on in “sorting solution” (0,5% Propylen Phenoxetol, 5% Propandiol, 94,5% H20) and then identified to the lowest taxonomic level possible so far. This work was partly done at the U.S. National Marine Fisheries Service, South West Fisheries Science Center, La Jolla , California with help of Dr. G. Moser and his staff. Some specimens were sent to and identified by Dr. W. Richards, South East Fisheries Science Centre, Miami, Florida. Literature used for the taxonomic classification was mainly Fahay (1983), Moser (1984 and1996), Moser & Watson (2001), and Richards (2001)

Results. Larval Fish Identification: Altogether some 18 900 specimens of larval fish were found in the samples. 150 taxa were identified. Classification of specimens was successful down to different taxonomic levels: 56 to species (2 of these unknown but distinct species), 53 to genera, 34 to families, and 7 to higher taxonomic levels (Table 1).In all the material included fish larvae of 53 families. More specimens will probably be identified to species when further effort is put into the classification work. For the central issue of this paper, however, this is not deciding. It is likely that the 150 taxa listed in Table 1 correspond closely to the number of species which were actually present in the area in September ’98. All abundant taxa and those which are of specific ecological interest have been identified so far.

Description of Diversity: The ichthyoplankton was strongly dominated by larvae of. Gonostomatidae (4136 specimens = 22% of all larvae), Photichthydae (4093 specimens = 21%), the suborder Stomeoidei (390 specimens = 2%), Paralepididae (606 specimens = 3%), and Myctophidae (6047 specimens = 32%). Which genera and species, respectively, were most abundant in the area is shown by Fig. 5a. These seventeen taxa below the family level were reprented with at least 0,9% of all specimens found the rest of 137 taxa was less abundant. One of the very abundant taxa below the family level was Chlorophthalmus agassizii which larvae were found to be the third most abundant ones in September 1998 (6% of all specimens).

Samples from the shallow water and slope stations contained slightly more species on average than samples from oceanic stations (Fig. 5b).

Taxa of which more than 50 larvae specimens were found occurred at 19 to 24 (80 to 100%) of all stations Some 15 350 specimens or 80% of all larvae belonged to this category which means that the dominating taxa were quite evenly distributed in the research area.

Ecological groups. The fish larvae having been caught in the Meteor Seamount area in September 1998 can be placed into three different ecological groups: oceanic (83% of the taxa), slope bound (5% of the tax), and neritic (9% of the taxa) (Fig.6 a, Tab. 1). This finding corresponds closely to the results gained in the same area in

3 February1970 (Fig.6b) when at least 73 different taxa could be identified (Nellen 1973). Regarding the species of adult fish collected in 1998 (Uiblein et al., 1999, Pusch, this theme session) the respective ratio is different with only 62% oceanic taxa (55 species), 14% slope bound taxa (12 species) and 24% neritic ones (21 species, Fig.6c). When the total number of collected larvae specimens which ecological character could be classified is considered, even 90% (N=16242)were oceanic and only 1% (N=215) and 9% (N=1575) slope bound and neritic, respectively in September 1998; whereas in February 1970 92,2% (N=12 398) of some 14 100 fish larvae specimens were of the oceanic type and 7,2% (N=977) were shelf and just 0,5% (N=70) slope bound species (Figs: 6d and e).

Horizontal distribution of plankton biomass and of abundance of specific taxa. When looking at the quantities of plankton biomass and total number of fish larvae specimens as well as at the numbers of the more abundant taxa underneath a unit of water surface the influence of the seamount on the distribution seems to be not very conspicuous (Figs. 7-1 to 7-8). In each case positive catches resulted from any of the station groups, but quantities were heterogeneously distributed. For plankton biomass and fish larvae in general the highest concentrations were found outside of the seamount plateau whereas the two relatively abundant neritic species, Chlorophthalmus agassizii and Aulopus filamentosus (Whitehead et al., 1984), occurred mainly at stations on or near to the seamount shallows as did Trachurus picturatus larvae in February 1970 which then made up the main neritic element (Fig. 8, lower part). The other neritic as well as slope bound taxa found in 1998 and identified in Tab. 1 were all more or less closely associated with the seamount too (Fig. 7-9a-c). It was for this reason that the two unknown but distinct species “Maurolicine Type A”(see Moser, 1984, page 196) and “Species Nr. 130” (see Plate II) could be categorized as slope and shelf bound forms, respectively. Distinct oceanic taxa as Cyclothone spec., Vinciguerria spec. or Paralepididae larvae were found to be particularly abundant outside the seamount’s influence though the plateau area was not at all avoided by these forms (Figs. 7-5 to 7-7). When comparing the pictures of specimens distribution in February 1970 and in September 1998 (Fig. 8) the results from both cruises compare fairly good with each other. Fish larvae as a whole as well as oceanic taxa were usually more abundant outside the seamount area whereas the contrary is true for neritic species. Varying findings for the two years resulted for plankton biomass and leptocephali. Also higher numbers of Ceratoidei larvae above the plateau than above the deep ocean in 1998 is unexpected.

Vertical distribution of plankton biomass and specific taxa. Mean vertical distribution patterns are described for day and night situations and for grouped stations with bottom depths of < 370m (“shallow water stations”) and >1000m (“deep water stations”), respectively (Figs. 9a to 9h).

Usually night catches were richer than day catches and at any time there was a distinct reduction in plankton and ichthyoplankton concentrations below 150m water depth where the lower part of the thermocline was found (Mohn und Beckmann, 2001, submitted). The mean values for plankton biomass may indicate that the respective organisms above the seamount have a less pronounced day/night migration behaviour compared to plankton organisms of the deep water region. It may also be suggested that during daytime the zooplankton is less capable to avoid

4 the net by disappearing from the upper 300m into greater depths (Fig. 9a). A similar impression give the figures for ichthyoplankton in general (Fig. 9b).

By looking at distinct taxa larvae of the genus Cyclothone indicate again a more pronounced migration into the upper water layer when occurring at deep water stations (Fig. 9c), but the picture becomes a bit confusing when looking at the vertical distribution patterns of Vinciguerria larvae which frequency was in the same order of magnitude as Cyclothone larvae (Fig. 9d). At least the values for the day situation above the seamount differ very much from the respective values of Cyclothone. The Mctophids Lampanyctus alatus and Diaphus spec., both don’t reveal any particular vertical distribution pattern, aside that the larvae concentrate in the upper layers at night, they are distinctly reduced in the day samples, and become very rare in catches from water layers deeper than 150m (Figs. 9e and 9f). The most abundant larvae of a neritic fish species, Chlorophthalmus agassizii, were distributed in the water column at night in the same manner regardless of sea floor depth. The highest concentrations were found in the surface layer. Above the seamount these larvae were caught in almost equal numbers at night and day, but at day they had concentrated at greater depth, the few day catches at deep water stations were lacking Chlorophthalmus larvae almost completely (Fig. 9g). Another larvae of a neritic species which was much less abundant, however, was Aulopus filamentosus. Though its concentrations were found to be one order of magnitude lower compared to Chlorophthalmus larvae (at deep water stations even two orders of magnitude) the vertical distribution patterns of these larvae indicate a distinct upwards migration at night (Fig. 9h).

Discussion For the fish community the Great Meteor Seamount is a habitat which character seems to be markedly oceanic. This is at first obvious when the composition of larval fish is concerned. Two investigations of the ichthyoplankton in the area, February 1970 and September 1998, both gave similar results with oceanic species building the majority of the some 80 and some 150 taxa, respectively, identified in each of the two studies. But the occurrence of fish larvae species which one would not expect that their habitat is the deep high sea remote from the shallow areas of the continental shelf and slope or similar habitats off islands can’t be overlooked. Though only few of those species were found, the concentration in the water column of at least some of them was relatively high and in the same order of magnitude as found in low productive sea areas elsewhere. When the larvae of Trachurus picturatus or Chlorophthalmus agassizii were found with an average concentration of about 180 and 140 specimens per 100m² at the shallow water stations so does this compare, for instance, with figures for some neritic species given by Limouzy-Paris et al. (1994) who found Clupeidae larvae with N=100 x 100m-2 and Carangidae larvae with N=110 x 100m-2 in the Florida Keys in May/June 1989. The abundance of the additional 9 and 12 nertic fish larvae species found in 1970 and 1998, respectively, was much lower, but the reason that they were caught almost exclusively above the plateau of the seamount indicate that this is also a nursery ground for the early life stages of the respective species. The existence of larvae of fish species which are known to settle in slope biotopes gives evidence of a habitat with peculiar ichthyofaunistic elements as well. This is further supported by the results of the trawl catches (Uiblein et al., 1999) in which 21 of all species were shelf dwellers and 12 slope dwellers. Several of these were quite abundant with some 100 to 300 specimens caught (A. filamentosus, Ch. agassizii, A. capros, A. anthias, Callanthias ruber, and Scomber japonicus). Even

5 much more abundant was T. picturatus with about 3500 specimens found, and both, Capros aper and Macroramphosus scolopax, were in fact extremely abundant with >25.000 and >82 000 specimens counted. The larvae of most of these species were found in the area too, either in 1970 or in 1998 and some in high numbers as well (see Table 1). Others were missed, most likely because of specific spawning seasons which may not be taken for granted during the two different months when the investigations took place. This is strongly suggested for Scomber japonicus for instance, which is said to spawn off California & Baja California from March through October with peaks in April and August (Moser, 1996). So their larvae may just have been missed by our investigations. In February ‘70 the most abundant larvae of a species belonging to the neritic province was T. picturatus. In September ‘98 it was lacking completely in the samples very likely because the spawning time had ceased. John et al (1991) found the larvae of a closely related species, T. trachurs, off Mauretania to be abundant in January/February whereas their number decreased in March/April. The same is true for Scomberesox saurus which larvae were the second most abundant ones in 1970 when they were caught almost exclusively by the neuston net (Nellen & Hempel, 1970), whereas this gear did not catch any species of fish staying right underneath the water surface during its early life stage.

Especially interesting is the species Macroramphosus scolopax. The adults are known for living close to the bottom (normally 50 to 150 m depth). The juveniles to about 10 cm live pelagically in oceanic water (Whitehead et al., 1986). The larvae were caught mainly off the Meteor Seamount only in February as the reproduction takes place mainly from October to March. They were by far the most abundant fish larvae in 1970. With almost 700 specimens per 100m² outside the seamount plateau when they outnumbered every other larvae species in number. This dominance of the Macroramphosus larvae in 1970 and the adults in 1998 correspond very well with each other.

Several observations seem to indicate that the seamount under discussion is a permanent residence of several shelf/slope dwelling fish species. This is concluded from the co-occurrence of the respective larvae and adults on and in the surrounding of the Meteor Seamount and from the fact that within an interval of almost 30 years the picture of species composition did not fundamentally chance though in 1998 more species of fish larvae as well as adults were found because of a more intensive sampling. For the occurrence of larvae it is without doubt very important to take the reproduction time of the adults into account.

There is much evidence that the first hypothesis (page 2) comes true.

As the larvae of the shelf/slope dwelling fish species concentrate over the summit plain and are found in the upper water layers (>150m) at similarly high concentration during day and night hypotheses 2 and 3 seem to come true as well. Beckmann and Mohn (2001, submitted) say on account of a numerical ocean circulation model: “These tracer simulation lead us to conclude that there is a strong retention potential above Meteor Seamount. The results indicate the areas of retention, as well as the existence of an inner regime in areas with water depth of less than 350m as well as vertically separated regimes above the summit plain” (page 11).

The findings for the vertical distribution of oceanic fish larvae species let us strongly suggest that most of them disappear out of the upper part of the water column during

6 the day and migrate to depths >290m which were not fished by the gear any more. The same seems be true for some zooplankton organisms (Fig. 9a) which indicates that some species specific differences between the occurrence at shallow and deep water stations exist for this group as well. These observations would mean that the respective ichthyo and zooplankton organisms get caught at night in the surface layer of 0 to 150m, but not between 150 to 290m during the day. Some pictures made from the sonar screen indicate that organisms performing long distance vertical migration actually end up on the seamount bottom when it happened that they got drifted over the plateau at night (Plate I). The diverse bottom fauna described by Benke and by Piepenburg (this symposium) as inhabiting the summit plain likely finds a main food resource in the migrating organisms whereas the less active migrating shelf/slope species keep away from the near bottom area. This is in accordance with hypotheses 4 to 6.

The number of some 150 different taxa which were found so far for the fish larvae fauna of the Meteor Seamount may be compared with other subtropical/tropical sea regions where as well oceanic and neritic larvae occur together. One of such an area is off Key West, Florida where Limouzy-Paris et al. (1994) identified 263 taxa in samples from 29 stations collected in May and June 1989 when they had analysed a total number of 20 236 individuals. This amount of taxa is considerable higher than it was found in the Meteor Seamount region which would confirm the validity of the seventh hypothesis, especially as much more taxa typical for shelf areas were found off Key West aside many Mytophids and Stomiiformes with both being more or less entirely oceanic groups. This hypothesis has to be followed, however, further. The fish larvae collections of Nellen (1973) and Röpke (1992) in the Arabian Sea, for instance, were also not extraordinarily rich in taxa, with a maximum of 135 species found along the coast of East Africa (Sokotra to Mombasa) in Dec./Jan. 1965/65 (Nellen, 1973a) and another maximum of only64 species off Pakistan in May/June 1987 (Röpke, 1992). But because of the peculiar hydrographical situation in the Arabian Sea it may be not easily compared with the well mixed Atlantic Ocean.

Nevertheless the diversity of non oceanic taxa for which the Meteor Seamount is an isolates habitat is low. The species concerned seem to be adapted in different ways to the situation. Macroramphosus scolopax certainly takes most advantage from being oceanic as larvae and neritic as adult. So there should be good reason for this species to settle the seamount in very high numbers as long as the juveniles find back from their oceanic living space to the seamount. This mechanism is but not understood yet. The early life stages of other shelf/slope bound fish species may profit in the one or other specific way from the living conditions at the seamount; how, is hard to say. As in both years, 1979 and 1998, fish larvae concentrations at shallow water stations were less than at deep water stations some taxa may take advantage of that, no matter how. Plankton biomass was much reduced above the plateau compared to the oceanic station in February ’70 and generally low at the same time. In September ‘98 about three times as much plankton biomass was measured and no difference between shallow and deep water areas existed anymore. This may indicate that also the zooplankton develops differently in both regions and specific fish larvae may take specific advantage from this. A peculiarly strange life strategy is suggested for the not identified “Species Nr. 130” which had been caught in relatively high numbers at only five shallow water stations where it concentrated in the deepest water layer fished (>250m). This is in sharp contrast to all the other larvae.

7 Conclusion Many open questions how fish species cope with the environmental regime of the Meteor Seamount still exist. As the present fish larvae material has not been analysed with regard to age and length of larvae such data may give future and further information about the fate of oceanic species being drifted into the shallow water area. In 1970 the larger larvae of some of the respective species were found to be reduced above the seamount.

To learn more about the fish community and the life strategy and situation, respectively, of certain species additional investigations would be of advantage. First of all data should be completed by sampling and measuring in Dec./Jan. and May/June. The vertical migration pattern of oceanic species should be studies more completely by sampling water layers down to about 500 to 600m. In case the catches are biased by the influence of daylight enough night samples should be made to be able to relate on a sufficient data base for a far reaching statistical analysis.

LITERATURE CITED

BECKMANN, A. & C. Mohn, 2001: The upper ocean circulation at the Great Meteor Seamount. Part II: Retention potential of the seamount induced circulation. Submitted, 20 p

JOHN, H.-C., B. KLENZ, R. HERMES, 1991: Distribution and drift of horse mackerel larvae (genus Trachurus) off Mauretania January to April 1983. Int. Counc. Expl. Sea, Counc. Meeting. H:13, 22 p

FAHAY, M.P., 1983: Guide to the early stages of marine fishes occurring in the western north Atlantic Ocean, Cape Hatteras to the southern Scotian Shelf. J. Northw. Atlantic Fish. Science, 4, 423 p

LIMOUZY-PARIS, C., M.F. McGOWAN, W.J. RICHARDS, J.P. UMARAN, & S.S. CHA, 1994: Diversity of fish larvae in the Florida Keys: Results from SEFCAR. Bull. Mar. Science, 54, 857-870

MOHN, C. & A. BECKMANN 2001: The upper ocean circulation at Great Meteor Seamount. Part I: Structure of density and flow fields. Submitted, 26 p

MOSER, H.G. (ed. in Chief), 1984: Ontogeny and Systematics of Fishes. Spec. Public. No. 1, American Soc. Ichthyologists & Herpetologists, USA, 759 p

MOSER, H.G, 1996: The early stages of fishes in the California Current Region. Cal. Coop. Oceanic Fish. Invest., Atlas No. 33, 1505 p

MOSER, H.G, & W. WATSON, 2001: Preliminary Guide to the identification of the early life history stages of Myctophiform fishes of the westewrn central Atlantic. U.S. Dept. of Commerce, NOAA, Nat. Mar. Fish. Serv., Miami, Florida, 118 p

NELLEN; W., 1973a: Fischlarven des Indischen Ozeans. „Meteor“ Forsch.- Ergebnisse, Reihe D, 14, 1-66

8 NELLEN, W. 1973b: Untersuchungen zur Verteilung von Fischlarven und Plankton im Gebeit der Großen Meteorbank. „Meteor“ Forsch.-Ergebnisse, D, 13, 47 – 69

NELLEN, W., W. BETTAC, W. ROETHER, D. SCHNACK, H. THIEL, H. WEIKERT und B. ZEITZSCHEL 1996 (eds.): MINDIK, Reise Nr. 5, 2. Januar 1987 bis 24. September 1987, METEOR-BERICHTE 96-2, Leitstelle METEOR, Universität Hamburg, 179 p

NELLEN, W. & G. HEMPEL, 1970: Beobachtungen am Ichthyoneuston der Nordsee. – Observations on the ichthyoneuston of the North Sea. Ber. Dt. Wiss. Komm. Meeresforsch., 21, 311 – 348

PFANNKUCHE, O., T. MÜLLER, W. NELLEN. G. WEFER (eds.), 2000: Ostatlantic 1998, Cruise No. 42, 16. June – 26 October 1998. METEOR-BERICHTE 00-1, Leitstelle METEOR, Hamburg, 259 p

RICHARDS, W.J., Draft edition 2002: Preliminary Guide to the identification of early life history stages of ichthyoplankton of the western central Atlantic, Part 1. U.S. Dept. of Commerce NOAA, Nat. Mar. Fish. Serv., Miami, Florida, 111 p

RÖPKE, A., 1992: Eine vergleichende Studie zur Vertikalverteilung von Fischlarven in Relation zur physikalischen Stratifikation der Wassersäule im nördlichen Arabischen Meer. Ber. Zentr. Meeres- und Klimaforsch., Reihe E, Univ. Hamburg, 159 p

F. UIBLEIN, A. GELDMACHER, F. KÖSTER, W. NELLEN, & G. KRAUS, 1999: Species composition and depth distribution of fish species collected in the area of the Great Meteor Seamount, eastern central Atlantic, during Cruise M42/3, with seventeen new records. Informes Técnicos del Instituto Canario de Ciencias Marinas, No. 5, Telde (Gran Canaria), 47 - 85

ULRICH, J. 1971: Zur Topographie und Morphologie der Großen Meteorbank. „Meteor“ Forsch.-Ergebnisse, C, 6, 48 – 68.

WHITEHEAD, P.J.P., M.-L. BAUCHOT, J.-C. HUREAU, J. NIELSEN, E. TORTONESE (eds.), 1984 - 1986: Fishes of the North-eastern Atlantic and the Mediterranean, Vol. I - III. UNESCO, Paris,1473 p

ACKNOWLEDGEMENT

This research was part of the Cruise No. 42 of R.V. METEOR, Ostatlantic 1998, and of the science project Pelagische Seebergbiozönose, DFG/Ne 99-25/1&2. Both were funded by the Deutsche Forschungsgemeinschaft which financial help is highly appreciated. Many thanks are due also to Dr. Geoff Moser and his collaborators D.A. AMBROSE; S.R. CHARTER,and W. WATSON, U.S. National Marine Fisheries Service, South West Fisheries Science Center, La Jolla , California where the first author spent four weeks to be retrained in fish larvae identification. Dr. William RICHARDS, South East Fisheries Science Center, Miami, Florida helped with the identification of some more specimens of fish larvae which had been sent to his laboratory. We are very grateful to all U.S. colleagues who did not hesitate to offer their uncomplicated and patient help.

9 Table 1: List of fish larvae and adult fish collected in the Meteor Seamount area during cruises of R.V. METEOR in September 1998 and in February 1970 ecotypes: blue = oceanic, purple = slope bound, green = shelf bound A 1998 B 1970 C 1998 Serial fih larva specim. % requen- mean fih larva adult fish cy of abund./ No. caught 2 (Nellen, 1973b) occurr. 100m (Uiblein et al., 1999; positive positiv Pusch, this theme Stations Stations session)

I NOTACANTHIFORMES 1 Notacanthidae 1 0,01 1 -- -- 2 II ANGUILLIFORMES 51 0,27 15 11 ++ CONGROIDEI 3 Congridae 19 0,10 10 6 4 Conger spec. 16 0,08 7 5 C. conger Gnathophys mystax 5 Conger triporiceps 3 0,02 2 -- -- 6 Derichthyidae 10 0,05 8 -- -- 7 Derichthys serpentinus 13 0,07 5 3 -- -- 8 Nessorhamphus ingolfianus 22 0,12 8 7 - -- 9 Nemichthyidae 12 0,06 3 8 -- -- 10 Nemichthys spec. 17 0,09 9 8 -- N. curvirostis 11 Labichthys carinatus (?) 1 0,01 1 -- -- Serrivomeridae -- 12 Serrivomer spec. 3 0,02 2 -- -- 13 Synaphobranchidae 1 0,01 1 -- -- S. caupi Gymnothorax maderensis Nettastomatidae -- --- 14 Facciolella spec. 1 0,01 1 -- -- III SACCOPHARYNGIFOR.. -- Cyematidae -- 15 Cyema spec 6 0,03 6 7 -- -- 16 Cyema atrum 1 0,01 1 -- -- Clupeidae? IV SALMONIFORMES -- ARGENTINOIDEI -- -- 17 Bathylagidae 20,01 1 ++ -- 18 Bathylagus longirostris 6 0,03 5 9 -- -- Glossanodon leioglossus 19 Microstomatidae 14 0,07 4 15 -- -- V STOMIIFORMES 20 Gonostomatidae 343 1,82 16 58 ++ -- 21 Bonapartia spec. 62 0,03 11 12 ++ -- 22 Cyclothone spec. 3677 19,47 24 604 ++ -- 23 Diplophos taenia 90,05 7 6++ ++- 24 Gonostoma spec 38 0,20 13 8 ++ ++ 25 Gonostoma elongatum 2 0,01 1 -- ++ 26 Margrethia obtusirostra 50,03 4 2++ ++ ∑ Gonostomatidae 4136 22 N = 1186 (8%) -- Photichthyidae 27 Vinciguerria spec. 3334 17,65 24 550 ++ ++ 28 Ichthyococcus ovatus 40,02 4 5++ ++ 29 Sternoptychidae 148 0,78 11 30 ++ 30 Argyropelecus spec 47 0,25 7 15 -- A. aculeatus 10 31 Sternoptyx spec. 278 1,47 23 39 -- ++ 32 Valenciennellus 72 0.38 9 18 ++ ++ tripunctulatus 33 Maurolicus muelleri 130 0,69 19 20 ++ -- 34 Maurolicine Type A 80 0,42 18 10 -- ∑ Photichthyidae 4093 21 N = 603 (4%) STOMIOIDEI Chauliodontidae 35 Chauliodus spec. 207 1,10 22 32 ++ -- Ch. danae 36 Astronestidae 21 0,11 11 7 ++ ++ Stomiatidae -- Stomias spec. -- 37 Melanostomiidae 18 0,10 17 4 ++ 38 Bathophilus spec. 15 0,08 7 6 ++ B. longiceps B. vaillant 39 Eustomias spec. 28 0,15 14 9 -- ++ 40 Leptostomias spec. 13 0,07 6 6 ++ L. gladiator 41 Melanostomias spec. 3 0,02 1 -- -- 42 Photonectes spec. 2 0,01 1 -- -- 43 Malacosteidae 2 0,01 2 -- 44 Aristostomias spec. 10 0,05 5 5 -- -- 45 Photostomias guernei 7 0,04 2 1 -- ++ Idiacanthidae 46 Idiacanthus fasciola 64 0,34 19 11 ++ ++ ∑ STOMIOIDEI 390 2 N = 65 (0,5%) 47 VI AULOPIFORMES 14 0,07 4 8 48 AULOPOIDEI ? 2 0,01 6 9 -- -- 49 Aulopidae ? 8 0,04 2 16 -- -- 50 Aulopus filamentosus 110 0,58 14 25 -- ++ 51 SCOPELARCHOIDEI 5 0,03 1 -- 52 Scopelarchidae 30 0,16 6 14 ++ -- 53 Scopelarchus spec. 171 0,91 23 23 spec. a -- spec b -- 54 Scopelarchus michaelsarsi ?) 37 0,20 10 10 -- -- 55 Benthalbella infans 19 0,10 6 9 -- -- 56 Rosenblattichthys hubbsi 22 0,12 8 7 -- -- Notosudidae/ Scopelosaurid. 57 Scopelosaurus spec. 48 0,25 13 10 -- -- 58 Paralepididae 82 0,43 15 18 ++ 59 Lestidiops jayakari 100 0,53 18 20 -- ++ 60 Lestidium atlanticum 5 0,03 1 -- -- 61 Magnisudis atlantica 154 0,82 24 20 -- -- 62 Macroparalepis spec. 51 0,27 8 23 ++ 63 Macroparalepis breve 6 0,03 1 -- ++ 64 Stemonosudis spec. 25 0,13 8 9 -- -- 65 Sudis spec. 183 0,97 21 27 ++ S. hyalina ∑ Paralepididae 606 3 N = 130 (0,9%) 66 Evermanellidae 7 0,04 4 4 -- ++ 67 Evermanella indica 32 0,17 16 9 -- ++ 68 ALEPISAUROIDEI 119 0,63 19 16 -- -- 69 Alepisauridae 7 0,04 5 6 -- -- 70 Alepisaurus ferox 30 0,16 11 8 -- -- 71 Omosudidae 12 0,06 4 7 -- -- VII MYCTOPHIFORMES Chlorophthalmidae 72 Chlorophthalmus agassizii 1072 6 21 210 -- ++ Neoscopelidae --

11 73 Neoscopelus micochir 44 0,23 12 16 -- -- 74 Myctophidae 837 4,43 20 168 ++ - 75 Benthosema suborbitale 49 0,26 18 8 ++ ++ 76 Bolinichthys spec. 475 2,51 24 72 -- 77 Centrobr. nigroocellatus 21 0,11 14 4 ++ -- Centrobr. spec. 78 Ceratoscopelus warmingi 138 0,73 18 25 ++ ++ Cerat. spec. -- Cerat. townsendi -- 79 Diaphus spec. 820 4,34 24 140 ++ ++- 80 Diogenichthys atlanticus 265 1,40 24 38 ++ ++ Electrona spec. -- 81 Gonichthys cocco 17 0,09 10 5 ++ -- 82 Hygophum reinhardtii 256 1,36 23 43 ++ ++ 83 Hygophum taaningi 546 2,89 23 89 ++ ++ 84 Hygophum spec. 10,01 1 ++ -- H. hygomi ++ 85 Lampadena spec. 89 0,47 21 18 ++ ++ 86 Lampadena chavesi (?) 38 0,20 15 8 ++ L. uraphaos 87 Lampanyctus alatus 1026 5,43 24 150 -- -- 88 Lampanyctus pusillus 1 0,01 1 -- -- L. spec. ++ -- L. festivus -- L. phototonus 89 Lepidophanes gaussi 371 1,96 21 72 ++ ++ -- -- Lep. guentheri Lep. spec. 90 Lobianchia spec. 35 0,19 12 9 Lob. gemellari ++ -- Lob. dofleini ++ 91 Loweina rara 65 0,34 22 10 ++ -- 92 Loweina interrupta (?) 20,01 1 -- -- 93 Myctophum nitidulum 73 0,39 22 12 -- ++ 94 Myctophum punctatum 1 0,01 1 -- -- 95 Myctophum selenops 50 0,26 19 10 --. -- Myctophum spec. -- 96 Nannobrachium cuprarium 385 2,04 24 52 -- ++ 97 Nannobrachium lineatum 28 0,15 13 8 -- ++ 98 Notolychnus valdiviae 324 1,72 24 45 ++ ++ Notolychnus spec. -- N. caudispinosus -- N. resplendens 99 Symbolopherus rufinus 134 0.71 21 22 -- ++ -- Symbolopher. spec. -- Taningichthys. spec. ++ ∑ Myctophidae 6047 32 N = 1859 (13%) -- VIII GADIFORMES Gadidae -- ++ -- Phycis phycis Moridae -- -- Laemonema yarrelli Physiculus dalwigki Gadella maraldi 100 Macrouridae 24 0,13 11 5 ++ -- Hymenocephalus gracilis 101 IX OPHIDIIFORMES 5 0,03 3 -- 102 Ophidiidae 3 0,02 2 -- ++ Carapidae/Fierasferidae -- ++ Echiodon dentatus 103 Bythitidae 5 0,03 5 -- --

12 X LOPHIIFORMES ANTENNAROIDEI Chaunacidae -- -- Chaunax pictus CERATOIDEI Melanocetidae 104 Melanocetus spec. 34 0,18 17 7 -- -- Himantolophidae -- -- 105 Himantolophus spec. 13 0,07 8 7 -- -- 106 Oneirodidae 62 0,33 16 16 -- -- 107 Dolopichthys spec. 18 0,10 9 7 -- -- 108 Oneirodes spec. 48 0,25 12 20 -- -- Gigantactinidae -- 109 Gigantactis spec. 39 0,21 15 8 -- G. vahoeffeni Ceratiidae 110 Ceratias spec. 40,02 4 4++ ? -- XI BELONIFORMES Exocoetidae -- 111 Cypselurus spec. 1 0,01 1 -- -- 112 Exocetus spec. 1 0,01 1 -- -- 113 Scomberesocidae 60,03 5 5++. -- Sc. saurus N = 2061 (14%) XII SYNGNATHIFORMES Macrorhamphosidae M. scolopax N = 5018 (35%) M. scolopax XII BERYCIFORMES Polymixidae -- P. nobilis Diretmidae D. argenteus -- 114 Melamphaidae 13 0,06 8 5 ++ -- 115 Melamphaes spec. 1 0,01 1 -- -- 116 Scopeloberyx spec. 10,01 1 -- -- XIII ZEIFORMES Zeidae ------Cyttopsis roseus-- -- Zenopsis conchifer Grammicolepididae -- -- G. brachiusculus Caproidae -- 117 Antigonia capros 36 0,19 5 27 -- ++ Capros aper ++ XIV SCORPAENIFORMES 118 Scorpaenidae 10 0,05 5 8 ++ Pontinus kuhli Scorpaena loppei Helicolenus dactylopterus Setarches guenteri 119 XV PERCIFORMES 10 0,05 5 ++ PERCOIDEI 120 Serranidae 20,01 2 ++ 121 Anthias anthias 17 0,09 6 14 -- ++ Callanthias ruber Sciaenidae Carandidae Trachurus picturatus ++ Coryphaenidae -- 122 Coryphaena spec. 27 0,14 15 8 -- C. hippurus 123 Bramidae 1 0,01 1 ++ 124 Pteraclis spec. 4 0,02 4 5 -- P. carolinus

13 Howellidae 125 Howella spec. 86 0,46 20 17 -- H. sherborni MUGIOIDEI Mugilidae ++ ? -- TRACHINOIDEI 126 Chiasmodontidae 60,03 6 5++ 127 Chiasmodon spec. 23 0,12 11 8 -- Ch. niger 128 Dysalotus spec. 1 0,01 1 -- -- 129 Kali spec. 8 0,04 4 9 -- -- 130 Pseudoscopelus spec. (?) 3 0,02 3 3 -- --i 131 Sydoscopelus spec. (?) 1 0,01 1 -- --i BLENNIOIDEI Blenniidae ++ ? -- CALLIONYMOIDEI 132 Callionymidae 15 0,08 8 5 -- Synchirop. phaeton GOBIOIDEI 133 Gobiidae 1 0,01 1 -- --

TRICHIUROIDEI Trichiuridae ++ 134 Gempylidae 80,04 5 5++ -- 135 Gempylus serpens 2 0,01 2 2 --? -- 136 Diplosinus multistriatus 163 0,86 23 25 -- ++ 137 Nealotus tripes 4 0,02 3 4 -- -- 138 Prometichth. prometheus (?) 2 0,01 1 -- -- SCOMBROIDEI SCOMBROIDEI Scombridae ++ 139 Acanthocybium spec. 3 0,02 2 6 -- -- 140 Katsuwonus pelamis 3 0,02 2 4 -- -- Auxis spec. -- 141 Ruvettus spec. 40,02 2 -- R. pretiosus Scomber japonicus 142 Thunnus spec. 11 0,06 7 6 -- 143 Benthodesmus spec. (?) 8 0,04 7 3 -- B. simonyi Xiphiidae 144 Xiphias gladius 1 0,01 1 -- -- 145 Istiophoridae 1 0,01 1 -- -- STROMATEOIDEI Nomeidae -- -- 146 Psenes spec. (?) 8 0,04 5 6 -- -- XVI PLEURONECTIFORM. PLEURONECTOIDEI 147 Bothidae 7 0,04 4 5 -- 148 Bothus spec. 11 0,06 4 8 spec. a -- spec. b -- 149 Arnoglossus spec 39 0,21 11 12 -- A. ruepelii XVII ECHENEIFORMES Echeneidae ++ Unknown 67 0,35 20 150 Species No. 130 264 1,40 5 130 -- damaged 493 2,61 24 A B C Total Σ of specimens 18 984 Total Σ of specimens 14149 ecological group % N ecological group % N ecological group % N oceanic 84 126 oceanic 70 57 oceanic 62 55 slope 5 7 slope 6 5 slope 14 12 neritic 9 13 neritic 12 10 neritic 24 21 unidentified 2 4 unidentified 11 9 unidentified 0

Fig. 1: Position of study area

15 558 449 30.5 30.5

30.4 505 30.4

30.3 30.3 506 30.2 30.2 559 451 509 523 524 30.1 452 30.1 467 492 30 491 30

552 29.9 551 550 29.9 461563 456 29.8 459 29.8 455 29.7 29.7 454

29.6 504 29.6

29.5 29.5 484 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332

Fig. 2: Station grid and station types

Shallow water stations, mean water depth: 370m Slope stations, mean water depth: 1330m

Deep water stations, mean water depth: 3280m

Fig. 3: Modified MOCNESS used

17 0 m 7. net change 10 m 0.3 m/s 0.7 m/s 50 m 0.3 m/s 6. net change 100 m 0.3 m/s 5. net change 150 m 0.3 m/s 4. net change

0.3 m/s 200 m 3. net change 250 m 0.3 m/s 2. net change 290 m 1. net change

Fig. 4: Diagramm of a MOCNESS haul

x103 4 t

h 3 g 60 cau

s 50 2

men 40 ci e

p 30 s 1 N 20

10 . . i 0 . . . . e . . s 0 i s s c t 0 c gi c c m c y a si u i ec d 3 e n t u ec s ec h i r v t p pe

1 n.B. B. pe a pe p pe mu u p us . m i n a l hi l s h s r sp s s di s s s c a u a l c h i a c a zi i t i N s a i g s s s r a a a n i h x s t i n y s t ne r v us a s N species/station di y r u e s a r en br h h hu t h du l e r t es s u i a p p ho pt c p o t c ue um i r at S og no yc o o l a ch i an o nu r i e g i a ag cu l n n i u um h h o D ph n c D c a l i a el c p l er y Sp n p t h p Nan y ph i o go l C S o Ch o C do m V y B o i c t g H p o S y La e N H L a b Fig 5: a: The most abundant fish larvae taxa in the Great Meteor Seamount area in September 1998, b: Number of species found at oceanic (n B) and at shallow water and slope stations (B) F

18 24% 8% 3% 9% 10% 83% 75% 5% 7% 62% 14%

6a: Portion of oceanic-, shelf- and 6b: Portion of oceanic-, shelf- and 6c: Portion of oceanic-, shelf- and slope-bound fish larvae species slope-bound fish larvae species slope-bound fish species in plankton catches 1998 in plankton catches 1970 in trawl catches 1998

977 65 shelf 1575

slope 215

oceanic

unidentified 16242

12389 6d: Absolute abundance of specimens of 6e: Absolute abundance of specimens of oceanic-, shelf- and slope-bound fish larvae oceanic-, shelf- and slope-bound fish larvae in plankton catches 1998 in plankton catches 1970

Fig. 6: Findings of taxa belonging to different ecological groups in the Great Meteor Seamount area

19 961

711 30.5 30.5

30.4 327 30.4

30.3 30.3 257 1081 30.2 390 587 30.2 456 364 723 30.1 423 30.1 518

30 332 30 557 552 559 29.9 29.9 647 580 559 917 29.8 29.8 724

29.7 762 29.7

29.6 264 29.6

29.5 29.5 277 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 -2 Fig. 7-1: Distribution of plankton biomass ml x 100m

8603

3977 30.5 30.5

30.4 1598 30.4

30.3 30.3 1182 3501 30.2 2299 30.2 946 1121 1415 890 30.1 2863 30.1 2954 30 1276 30

1460 2152 29.9 1640 29.9 41173501 6636 1714 29.8 29.8 3177 29.7 29.7 1979

29.6 1533 29.6

29.5 29.5 1276 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Fig. 7-2: Σ fish larvae N x 100m-2

20 49 5 30.5 30.5

30.4 3 30.4

30.3 30.3 19 30.2 298 30.2 1 123 73 30.1 30.1 94 296

30 19 30

7237 29.9 91 29.9 235 735 251 47 29.8 29.8 215

29.7 148 29.7

29.6 29.6

29.5 29.5 12 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Fig. 7- 3: Chlorophthalmus agassizi N x 100m-2

30.5 30.5

30.4 30.4

30.3 30.3

30.2 30.2 5 4 3 30.1 3 30.1 14 55

30 4 30 115 23 27 29.9 29.9 62 48 13 29.8 29.8

29.7 29.7 3 29.6 29.6

29.5 29.5

29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Fig. 7-4: Aulopus filamentosus N x 100m-2

21 1706

1676 30.5 30.5

30.4 223 30.4

30.3 30.3 76 611 30.2 347 30.2 6 314 94 101 30.1 4031182 30.1

30 306 30

170 285 29.9 171 29.9 1047560 398 1374 29.8 29.8 878 29.7 29.7 136

29.6 233 29.6

29.5 29.5 389 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Fig. 7-5: Cyclothone spec. N x 100m-2 1952

715 30.5 30.5

30.4 585 30.4

30.3 30.3 393

30.2 365 30.2 336 242 209 101 106 30.1 503 30.1 256

30 115 30

245 29.9 250 233 29.9 834 907 1325 189 29.8 29.8 339 29.7 29.7 362

29.6 502 29.6

29.5 29.5 234 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Fig. 7-6: Vinciguerria spec. N x 100 m-2

22 144

80 30.5 30.5

30.4 33 30.4

30.3 30.3 39 82 30.2 107 66 30.2 34 52 59 30.1 69 30.1 17 30 15 30 43 55 40 29.9 29.9 77 60 30 107 29.8 29.8 23 29.7 29.7 33

29.6 43 29.6

29.5 29.5 53 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Fig. 7-7: Paralepididae larvae N x 100m-2

21 29 30.5 30.5

30.4 13 30.4

30.3 30.3 21 49 30.2 25 30.2 34 2 18 24 30.1 65 30.1 16 24 30 30

10 23 29.9 7 29.9 43 33 17 45 29.8 29.8 26 29.7 29.7 9

29.6 6 29.6

29.5 29.5 19 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Fig. 7-8: Eel larvae (Leptocephali) x 100 m-2

23 558 449 30.5 30.5

30.4 505 30.4

30.3 30.3 506 30.2 30.2 559 451 509 523 524 30.1 452 30.1 467 492

30 491 30

552 29.9 551 550 29.9

461 563 456 29.8 459 29.8

455 29.7 29.7 454 29.6 29.6 504

29.5 29.5

484 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Margrethia obtusirostra

558 449 30.5 30.5

30.4 505 30.4

30.3 30.3

506 30.2 559 30.2 451 509 523 524 30.1 452 30.1 467 492 30 491 30 552 29.9 551 550 29.9 461563 456 563 29.8 459 29.8 455 29.7 29.7 454 29.6 29.6 504

29.5 29.5 484 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 “Maurolicine Type A”

558 449 30.5 30.5

30.4 505 30.4

30.3 30.3

506 30.2 559 30.2 451 509 523 524 30.1 452 30.1 467 492 30 491 30

552 29.9 551 550 29.9

461 563 456 29.8 459 29.8 455 29.7 29.7 454 29.6 29.6 504

29.5 29.5

484 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Antigonia capros

Fig. 7-9a: Occurrence of larvae of neritic and slope bound fish species

24 558 449 30.5 30.5

30.4 505 30.4

30.3 30.3

506 30.2 559 30.2 451 509 523 524 30.1 452 30.1 467 492

30 491 30

552 29.9 551 550 29.9 461563 456 29.8 459 29.8 455 29.7 29.7 454 29.6 29.6 504

29.5 29.5

484 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Anthias anthias

558 449 30.5 30.5

30.4 505 30.4

30.3 30.3 506 30.2 30.2 559 451 509 523 524 30.1 452 30.1 467 492

30 491 30 552 29.9 551 550 29.9 461563 456 29.8 459 29.8

455 29.7 29.7 454 29.6 29.6 504

29.5 29.5

484 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Bothidae

558 449 30.5 30.5

30.4 505 30.4

30.3 30.3

506 30.2 30.2 559 451 509 523 524 30.1 452 30.1 467 492

30 491 30

552 29.9 551 550 29.9 456 461 563 29.8 459 29.8

455 29.7 29.7 454 29.6 29.6 504

29.5 29.5

484 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 ”Species Nr. 130”

Fig. 7-9b: Occurrence of larvae of neritic and slope bound fish species

25 558 449 30.5 30.5

30.4 505 30.4

30.3 30.3

506 30.2 559 30.2 451 509 523 524 30.1 452 30.1 467 492

30 491 30 552 29.9 551 550 29.9 461563 456 29.8 459 29.8

455 29.7 29.7 454 29.6 29.6 504

29.5 29.5

484 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Callionymidae

558 449 30.5 30.5

30.4 505 30.4

30.3 30.3 506 30.2 559 30.2 451 509 523 524 30.1 452 30.1 467 492

30 491 30

552 29.9 551 550 29.9

461 563 456 29.8 459 29.8 455 29.7 29.7 454 29.6 29.6 504

29.5 29.5

484 29.4 29.4

29.3 29.3

330.6 330.8 331 331.2 331.4 331.6 331.8 332 Neoscopelus microchir

Fig. 7-9c: Occurrence of larvae of neritic and slope bound fish species

600 700 700 70 30 30 150 3000 600 600 60 500 20 1000 500 500 50 400 20 20 100 2000 400 400 40 300 300 300 30 10 500 200 10 10 50 1000 200 200 20 100 100 100 10 0 0 0 0 0 0 0 0 0 0 n.B. B. n.B. B. n.B. B. n.B. B. n.B. B. n.B. B. n.B. B. n.B. B. n.B. B. n.B. B. mlPlankton Sa fishlarvae Cyclothone Vinciguerria Myctophidae Paralepididae Leptocephali Ceratoidei Chl.agassizii A.filamentosus 1998

500 30 80 200 3000 400 100 200 70 80 400 300 60 150 2000 20 50 60 300 100 200 40 100 40 200 30 1000 10 20 50 100 20 100 10 0 0 0 0 0 0 0 0 n.B. B. n.B. B. n.B. B. n.B. B. n.B. B. n.B. B. n.B. B. n.B. B. mlPlankton Sa fishlarvae Cyclothone Vinciguerria Myctophidae Paralepididae Leptocephali T. picturatus

1970

Fig.8: Mean amount of plankton biomass and number of specimens x 100m-2 of some fish larvae taxa at deep water (n B) and at shallow water (B) stations in the Meteor Seamount area in September 1998 and in February 1970.

ml x 100m-3 0123456 m

0-10

10-50

50-100 r e y

h l 100-150 pt

de 3

150-200 00m

e x 2

um l 200-250 o

onv t k 1 an Night (N stations = 6) l P n a >2 50 e 0 Day (N stati ons = 3) m Nig ht Day

shallow water stations

-3 ml x 100m 01234567 m 0- 10

10-50

r 50-100 e

y a l 100-150 h

pt 3 m de 0

0 1

150-200 x

e 2

m lu o v n o

t 200-250 k 1 an Night (N stations = 9) l ean P

m 0 >250 Day (N stat ions = 3) Night Da y

deep water stations

Fig. 9a: Mean vertical distribution of plankton biomass

-3 N x 100m

0 5 10 15 20 25 30 35 m

0-10

10-50

r e 50-100 y a l h 100-150

pt 10

150-200 0m 8

10 6 x N 4 200-250 an e 2 m Night (N stations = 6) 0 >250 Day (N stations = 6) Nigh t Day

shallow water stations

-3 N x 100m

m 0 5 10 15 20 25 30

0- 10

10-50

r 50-100 e y

h l 100-150

pt 15

de 150-200 m

0 10 0 1 x

N n 200-250 a 5 Night (N stations = 9) me 0 >2 50 Day (N stations = 3) Nig ht D ay

deep water stations

Fig. 9b: Mean vertical distribution of Σ fish larvae

-3 N x 100m

m 01234567

0-10

10-50

e 50-100 y a

h 100-150 t p

de 150-200 3 200-250 2 Night (N stations = 6) 1 0 >250 Night Day Day (N stations = 6)

shallow water stations

-3 N x 100m

m 0123456

0-10

10-50

r r e e 50-100 y y a a

h l h l 100-150 t t p p

de 150-200

200-250 Night (N stations = 9) >250 Night Day Day (N stations = 3)

deep water stations

Fig. 9c: Mean vertical distribution of Cyclothone spec.

-3 N x 100m

0246810 m

0- 10

10-50

r e 50-100

h lay

t 100-150

p 3 -3 m de 150-200 2 100

N 1 200-250 n a Night (N stations = 6) e m 0 >250 Day (N stations = 6) Night Day

shallow water stations

-3 N x 100m

012345 m

0-10

10-50

r r

e 50-100 y

a l

h 100-150 t 3

dep 150-200 0m 2 10

N 1 200-250 an e Night (N stations = 9) m 0 >250 Day (N stations = 3) Night Day

deep water stations

Fig. 9d: Mean vertical distribution of Vinciguerria spec.

31 -3 N x 100m

m 00,511,522,5

0-10

10-50

e 50-100 y

a l

h 100-150 t 1

-3 dep 150-200 0m 0,8 10

0,6 x

N 0,4 200-250 n a Night (N stations = 6) e 0,2 m 0 >25 0 Day (N stations = 6) Night Day

shallow water stations

-3 N x 100m

m 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6

0-10

10-50

e 50-100 y

h l 100-150 t p 1 de 150-200 0,8 0,6 200-250 0,4

Night (N stations = 9) 0,2

>250 0 Day (N stations = 3) Night Day

deep water stations

Fig. 9e: Mean vertical distribution of Lampanyctus alatus

32 -3 N x 100m

m 01234

0-10

10-50

50-100 yer a

h 100-150

pt 1

de 150-200 0m 0,8

10 0,6 x

0,4 N

200-250 n

e 0,2 Night (N stations = 6) m >250 0 Day (N stations = 6) Night Day

shallow water stations

N x 100m-3

m 0 0,5 1 1,5 2

0-10

10-50

50-100

layer

h 100-150

pt 0, 8

de 150-200 0, 6

0, 4 200-250 0, 2 Ni ght (N stations = 9) >250 0 Day (N stations = 3) Night Day

deep water stations

Fig. 9f: Mean vertical distribution of Diaphus spec.

33 N x 100m-3

m 00,511,522,5

0-10

10-50

e 50-100 y

h l 100-150

pt 0,6

0 0 de 150-200 1

x 0,4 N

a 0,2 200-250 Night (N stations = 6) me 0 >250 Day (N st ati ons = 6) Ni g ht Day

shallow water stations

N x 100m-3

m 012345

0-10

10-50 r r

e 50-100

y a 1, 2

h l 100-150 1 pt 0, 8 de 150-200 0, 6 0, 4 200-250 Night (N stations = 9) 0, 2 0 >250 Day (N stations = 3) Ni ght Dayay

deep water stations

Fig. 9g: Mean vertical distribution of Chlorophthalmus agassizii

N x 100m-3

m 0 0,10,20,30,40,5

0-10

10-50

r e 50-100 y a l h 100-150 t

de 150-200 0,2

200-250 Night (N stations = 6) 0,1

>250 Day (N stations = 6) 0 Night Day

shallow water stations

N x 100m-3

m 0 0,01 0,02 0,03 0,04 0,05 0,06

0-10

10-50

e 50-100

y a

h 100-150 t p

de 150-200

200-250 Night (N stati ons = 9) >250 Day (N stations = 3)

deep water stations

Fig. 9h: Mean vertical distribution of Auolpus filamentosus

35 Plate Ia: Upper picture: 06.09.98, 19.25 hours., between 300 and 500 m strong sound reflections of migrating organisms. Lower picture; 13.09.98, early morning, down migrating organisms at the steep slope of the seamount, depth of seamount plateau 300m

Plate Ib: 02.09.98, 13.07 hours., organisms concentrating in a depression at 400m depth

Plate II: The not identified species “Species Nr. 130”