Epi- and mesopelagic fishes, acoustic data, and SST images collected off Lanzarote, Fuerteventura, and Gran Canaria, Canary Islands, during cruise "La Bocaina 04-97"

EPIANI> MESOPELAGIC FISHES, ACOUSTIC DATA, AND SST IMAGES COLLECTED OFF LANZAROTE, FUERTEVENTURA, AND GRAN CANARIA, CANARY ISLANDS, DURING CRUISE "LA BOCAINA 04-97" F. BORDESl, F. UIBLEIN2, R. CASTILLOl, A. BÁRRERAl, J.1. CASTR0 3, 1. COCA3 ,1. GOMEZ1, K. HANSEN4, V. HERNANDEZ3, N. MERRETT5, M. MIYA6, T. MOREN0 3, F. PEREZl, A. RAMOS3, T. SUTTON7, and M. YAMAGUCHI8 lInstituto Canario de Ciencias Marinas Aptdo. de Correos 56 / E-35200 Telde / Gran Canaria / SPAIN 2Institut f"tir Zoologie der Universitat Salzburg Hellbrunnerstr. 34/ A-5020 Salzburg / AUSTRIA 3Departamento de Biologia, Faculdad de Ciencias del Mar, Universidad de Las Palmas de Gran Canaria P.B. 550/ Las Palmas de Gran Canaria / SPAIN 4Institute of Marine Research Postboks 1870/ Nordness / N-5024 Bergen / NORW A y 5Department of Zoology, The Natural History Museum Cromwell Road / London SW7 5BD / U.K. 6Natural History Museum and Institute, Chiba Aoba-cho / Chuo-ku / Chiba 260 / JAPAN 7Department of Marine Science, U niversity of South Florida St. Petersburg / FL 33701 / USA 8Biology of Fisheries Resources, Ocean Research Institute, The U niversity of Tokyo. 1-15-1 Minami-dai/Nakano-ku / Tokyo 164/ JAPAN Original entregado en noviembre de 1998 INFORMES TÉCNICOS DEL INSTITUTO CANARIO DE CIENCIAS MARINAS Número 5, Telde (Gran Canaria), 1999 Inf. Téc.Inst. Canario Cienc.Mar. n05 RESUMEN Dunmte la campaña "La Bocaina 0497", se llevaron a cabo una serie de 14 lances con una red de arrastre pelágico de tipo comercial entre 20 y 700 m de profundidad y una prospección acústica con una ecosonda SIMRAD EK-500 en aguas neríticas y oceánicas adyacentes a Lanzarote, Fuerteventura y Gran Canaria, islas Canarias. Además, se obtuvieron imágenes SST para obtener información de las condiciones hidrológicas en el área de estudio. De los 14 lances, 10 tuvieron éxito y capturaron un total de 2166 peces pertenecientes a 81 especies, 53 géneros y 28 familias. Se comprueba que diez especies son nuevas citas para el área de las Islas Canarias. La prospección acústica cubrió un total de 2404 mn2 y permitió obtener una evaluación aproximada de la abundancia y biomasa de los peces. Tanto los resultados de las pescas como el estudio acústico mostraron que la caballa Scomber japonicus, una especie epipelágica de especial interés pesquero, presentaba gran variabilidad espacial en biomasa, con claras variaciones en la superioridad numérica de ciertas clases de edad o talla, entre las diferentes localidades muestreadas. Además, algunos juveniles en el primer año de vida aparecieron en la zona epipelágica oceánica durante la noche junto con peces mesopelágicos de migración vertical. Análisis preliminares del contenido estomacal e intestinal sugieren que estos juveniles se alimentaron cerca del fondo durante el día anterior y que pueden realizar migraciones horizontales entre la plataforma y las aguas oceáiücas adyacentes. Se concluye que la gran flexibilidad espacial de esta especie requiere más prospecciones de seguimiento a intervalos regulares para establecer un rendimiento sostenible de la pesquería. Los datos acústicos junto con los resultados de los arrastres demuestran la existencia de una densa capa profunda de reflexión entre 400 y 700 m de profundidad compuesta por peces mesopelágicos e invertebrados. Se encontraron indicaciones claras de migraciones verticales diurnas en varias especies formando una capa dispersa superficial a menos de 150 m de profundidad durante la noche. Juveniles de tres especies bentopelágicas, que durante su primera fase de vida tienen un comportamiento claramente pelágico, fueron capturadas junto con especies tipicamente mesopelágicas como estomiidos y mictófidos. Varios individuos de especies mesopelágicas fueron capturados sobre la plataforma, lo que puede reflejar la situación de la frontera ecológica en los bordes oceánicos típicos para las islas oceánicas y montañas submarinas. Algunas especies mesopelágicas recolectadas en este estudio pueden estar estrechamente asociadas con condiciones hidrográficas específicas, como el mictófido Ceratoscopelus maderensis que fue encontrado al SE de Fuerteventura en un área de posible afloramiento local. Este descubrimiento apunta la existencia de zonas micro-zoogeográficas en las islas Canarias que deben ser investigadas más profundamente a pequeña escala. 3 Inf.Téc.lnst.Canario Cienc.Mar. nOS ABSTRACT During cruise "La Bocaina 0497" a series of 14 tows with a commercial pelagic trawI at depths between 20 and 700 m and an acoustic survey with a SIMRAD EK-500 echosounder were carried out in neritic and adjacent oceanic waters off Lanzarote, Fuerteventura, and Gran Canaría, Canary islands. In addition, SST images were obtained to get some ínformations on the prevailing hydrological conditions in the studyarea. Of the 14 trawI tows ten were successful and resulted ih capture of a total of 2166 fishes belonging to 81 species, 53 genera and 28 farnilies. Ten species proved to be new record s for the area of the Canary Islands. The acoustic survey covered a total of2404 nm2 and allowed to obtain estimates ofthe abundance and biomass offíshes. Both the fishíng results and the acoustic study revealed considerable spatíal variability in biomass of chub rnackerel, Scomber japonicus, an epipelagic specíes of particular fisheries interest, showing clear variations in the nurnerical dominance of certain ageor size classes among different collecting localities. Furthermore, some juveniles in the fírst year of life occurred in the oceanic epipelagic during night together with vertically migrating mesopelagic fishes. Preliminary analyses of the stomach and intestinal content suggest that these juveniles fed c10se to the bottom during the day before and hence may undertake diurnal horizontal migrations between the shelf and adjacent oceanic waters. It is conc1uded that the great spatial flexibility of this species requires further monitoring surveys at regular intervals as a basis for establishing a sustainable fisheries management. The acoustic data together wíth the trawling results demonstrate the existence of a dense deep scattering layer at depths between 400 and 700 m which is composed of mesopeIagic fishes and invertebrates. CIear indications of diurnal vertical migrations were found in severa! species with formation of a shallow scatteríng layer in less than 150 m depth during night. Together with typical mesopelagic species such as storniids and myctophids also juveniles of three benthopelagic species, which typically undergo a pelagic stage during early life, were collected. Several individuals of mesopelagic species were collected aboye the shelf what may reflect the ecological boundary situation at ocean rirns typical for oceanic islands and seamounts. Sorne mesopelagic species collected in thís study may be closely associated with distinct hydrological conditions such as the rnyctophid Ceratoscopelus maderensis which was discovered in the SE of Fuerteventura in an area of possible local upwelling. This finding points to the existence of rnicro-zoogeographic zones within the Canary islands which derserve further investigation using a small-scaled comparative approach. 4 1. INTRODUCTION 2. MATERlAL AND METHODS 2.1 Fish sampling 2.2. Acoustilc survey 2.3. Satellite data 3.RESULTS 3.1 Fish samples 3.2. Acousti.c data 3.3. SST images 4. DISCUSSION 5. ACKNOWLEDGEMENTS 6. REFERENCES 7. APPENDIX INDEX 5 lnfTéc.lnsLCanano Cienc.Mar. nOS 7 8 8 11 17 17 17 22 24 27 31 31 37 /ntTéc./nst.Canario Cienc.Mar. n05 1. INTRODUCTION The epiand mesopelagic fish fauna in the area of the Canary Islands, Eastern Central Atlantic, deserves increased research efforts both from a fisheries-oriented and a basic ecological viewpoint. During the last years fisheries for economically valuble epipelagic species has significantly increased (BAS et al. 1995, GONZÁLEZ and LOZANO 1996). At the same time, several ecological studies have been carried out aimed at investigating the population dynamics and feeding ecology of two of the most important species, skipjack tuna, Katsuwonus pelamis (LINNAEUS 1758), and chub mackerel, Scomber japonicus HOUTTUYN 1782 (CA-8TRO 1993, MORENO and CASTRO 1995, RAMOS et al. 1995). One ofthese studies clearly showed that young chub mackerel are the preferred food of skipjack (RAMOS et al. 1995). Therefore, chub mackerel has great value as bait for tuna fishing, too. However, young chub mackerels are quite difficult to study, as they are spatially and trophicalIy flexible and may frequently migrate between the coastal shelf and the open sea (CASTRO 1993). This migration activity may be facilitated by the rather narrow shelf, a typical feature for islands of vulcanic origino ~ jA first detailed study of the mesopelagic fishes from the Canary Islands has I been carried out based on material collected during the SOND cruise in 1965 ¡ (BADCOCK 1970). This investigation wa~ later followed by another one in adjacent ~ waters off NW Africa (BADCOCK and MERRETT, 1976). In recent years, during t ~ several cruises aimed at determining the abundance of epipelagic and benthic fishes ! with various fishing methods and acoustic devices (BORDES et al. 1987, 1991, 1995), i an intense scattering layer was discovered at between 400 and 700 m depth off several ~ islands. Like in other comparable areas, this layer is composed of large densities of! micronektonic and planktic organisms, among them also various species of ~. mesopelagic fishes. Many of these organisms show a strong affinity with shallow ~ waters, as they are diurnal migrators which ascend to the surface at sunset, stay there @ during night, and descend again to deeper, less illuminated levels at sunrise. Hence they may represent also a major food component for epipelagic predators. Lanternfishes (Myctophidae), for instance, are frequently listed as an important trophic source for tunas, chub mackerels, and other epipelagic fishes (e.g., ABRAMS et al. 1997), as welI as dolphins (e.g., FIEDLER et al. 1997). Mesopelagic fishes may vary in species composition among different geographic areas what indicates the existence of important ecological variations or barriers for dispersal. For instance, several studies on myctophids have suggested that the species composition of this group in various parts of the Atlantic represents distinct zoogeographic units (BACKUS et al. 1977, HULLEY 1981). In the area ofthe Canary Islands, rather complex hydrological conditions prevail with deep-water currents arriving from the North Atlantic, the Mediterranean, and the Antarctic (MITTELSTAEDT 1983). This may have lead to uneven distribution pattems aI1).c:>Ilg the different islands, as indicated in the study ofBACKUS et al. (1977) on who drew a line of zoogeographic separation of the Northem North 7 Inf. Téc.Inst Canario Oenc.Mar. nOS Subtropical Province from the Southern North African Subtropical Province between the two easternmost islands Lanzarote and Fuerteventura and the other five islands of the Canarian archipelago. More recently, ZELCK and KLEIN (1995), in a study ofthe spatial distribution of the lanternfish Ceratoscopelus maderensis (LOWE 1839) off NW Africa, reported a distributional gap in the east of the Canary Islands. They explained this finding by the lack of influence of Mediterranean water with which this species had been observed to be usually associated. In the present study on epiand mesopelagic fishes, acoustic data and SSTimages collected during a cruise financed by the V iceconsejería de Pesca, Consejería de Agricultura Pesca y Alimentación del Gobierno de Canarias in April 1997, we examined the following questions in particular: (1) Which fish species are the major components of the deep scattering layer and to which extent do they show diurnal vertical migrations? (2) Where and at which abundance do young chub mackerels, an important food resource for tuna accumulate and what are the possible implications for a proper management of this species? (3) Are there any indications of trophic and/or spatial relationships between migratory mesopelagic organisms and epipelagic fishes? (4) Can any further evidence be gathered for the zoogeographic distribution patterns described in earlier studies and to which extent can the distribution of mesopelagic fishes be related to specific hydrological conditions? For this latter purpose two sampling localities of particular ecological interest were included in this cruise: an eddy in the SW off Gran Canaria (HERNANDEZ LEON 1991, ARÍSTIGUI et al. 1994) and an area of possible local upwelling activity in the SE off Fuerteventura (UIBLEIN et al. 1998). 2. MATERlALAND METHODS Cruise "La Bocaina 04/97" was carried out from 3 to 12 April 1997. The distance covered was 730 nm. The course of the cruise included a circumnavigation of the islands Umzarote, Fuerteventura, and Gran Canaria and an eddy SW off Gran Canaria. Fig. 1 shows an overview map of the course with the sampling stations. The zig-zag pattern allowed to investigate a wide area of the shelf with acoustic methods. The research vessel used in this cruise BIE "La Bocaina" (Fig. 2) belongs to the Canarian government and is based at the port of Arrecife, Lanzarote. It has the following characteristics: 29.7 m length, 8 m width, 3.1 m draught, 205 tons registered brutto weight, and the principal motor equipped with 705 H.P. at 1200 r/min. 2.1. Fish sampling For the fishing operations a comercial trawl was used. The dimensions of the net are shown in Fig. 3. Fourteen trawI tows were performed between the surface and 700 m depth aboye different bottom depths and during different dayor nighttimes. The duration of the tmwI tows which started after the descend and ended before the 8 hauling-in operation was approximately one hour, The characteristics operations are shown in Table 1, lB' Ir _ la- .. 15' .. 14"; '" 30' 011' ANAl YIS .ANDI ..-.. .. ¡".,.. J ...., í 011 .. 'O ~ l '" ....- D-J ". .r h. B ~ L - ~~ r; ~ ... ... fOIl 211 2B "N LANZAROn """"""l"""""""''''''''''f'''''''''''''''''''''''¡'''''' B' 011. Ir 011 l' OO' 5' OO' 4'11 '" """Il.Ja' .... _ 30' . .. . ... 1 ....................... 1" ..................... j ..... .f.~E!~~E!~~.'!Y~A .. 28°N ......... .. . .... ; ........................ : .............. . p_~,riil'._~. . 30' " ..... ... ".".~:-:- ... : ......... " .... " ....... , ...................... J ....................... ; ....................... i, ....................... ~ ....................... , ........ . ; : Á EPlPELAGI~ TRAWL TOW (G-100 m) SAHARA : • MESOPEuh¡C TRAWL TOW:(400-'700 m) : : . :.: 30' 16 30' 30' Fig. 1. Overview map of the course of the cruise, Fig. 2. BIE "La Bocaina" , 9 /nf.Téc./nstCanano Cienc.Mar. nOS Table 1. Characterístics of the trawl hauls plus catch per unít effort (CPUE, in kglh) for the fishes collected. Tow Date 1 03. Apr97 2 03 , Apr97 3 05 , Apr97 4 05 , Apr97 5 07, Apr97 6 07, Apr97 7 OS , Apr97 8 10 , Apr 97 9 11. Apr97 10 ILApr97 11 ILApr97 12 12 , Apr 97 13 12 , Apr97 14 12 , Apr97 Time {h} lnitial ~sition 18:37-19:37 27°34. 6N W26.4W 21:10-22: 00 27°36.5N 16°3L4W 13:52-15:00 27°53,3'N ls o S3TW 20:35-20:55 28°02.3N 15°49. 8W 10 : 51-11 :36 28°02,6'N W21.5'W 23:54-01 :35 27"43,7'N Is o46,9'W 03:00-03: 51 27°38, 6'N 15°4S , 9W 05 :11-06:05 29°23, 3N \3°32, 7W 10:45-11 :50 29°11. 9'N 13°33.5 W 04:57-05:55 2s050,3'N I3"52, 2W 07:41-08:40 2s051.8'N 13°57.0'W 00:42-01:3:> 28"08,2'N 14°12, TW 04:42-05:40 28°0S,2'N 14°0L2'W 07:48-08:44 28°08,2'N 14°02.2'W Rte. mm 6 (PA) 3, .180 (PA) ,3.180 300 (PA) 2. 600 200 (PA) 2. 600 150 (PA) 2, 600 120 (PA) 3.180 80 Final ~sition 27°35.3N 16°30. 7W 27°37, 9N J6°36, 3W 27°49,9'N Is oS1A'W 28°04.3N 15°465'W 27°59,6'N 15°20.2'W 27°4I.S'N 1'5°44.5'W 27°36,8N Is 0 42.4W 29°19,2N I3"32, 9W 29°09.4N 13°37, 6W 2s047.1 N I3°54, 6W 2s047,2'N 14°00.4'W 28°05,2'N 14°15.4'W 28°06,3'N 14°04, TW 2so06,O'N 14°07, TW (PA) 3,400 40 250 z Fig. 3. Dimensions of the net used. 10 Mean Bottom de2th NlUlIber WeiE!!t CPUE 538m 1258m 935 667,5 0,78 23m 3400 m 135 149.5 0. 18 89m 94m O 64m 79m O 40m 93 m O 75m 98m 219 24007 14,29 522 m 9S6m 37 169 ,2 0, 21 57m 295 m 102 1517.3 1.67 41 m 88m O 44m 115m, 81 1478 1.48 624 m 1258m 195 255.5 0,24 36m 187m 14 S54 ,7 0,93 75m 1120 m 128 405,7 0,33 520 m 1156 m 320 157.1 0,14 Inf. Téc.InsL Canario Cienc.Mar. n05 AH tows were perfonned at a speed between 2.4 and 4.1 knots in a distinct depth stratum either between the surface and 100 m or between 400 and 700 m (Figs. 1,4, 5). A netsounder positioned at the mouth of the net during aH operations aHowed to control the position of the net (Fig. 6). As no opening-c1osing mechanism was used, the net sounder also served to assure that the aperture of the net was minimal during the descend and ascend of the trawl. The best results in this respect were accomplished by keeping the net in a vertical position during lowering and by folding of the net through an increase of the speed immediately followed by a stopping of the ship, before the hauling-in operation was started. During the towing of the gear, it was repeatedly necessary to adjust the speed of the vessel to keep the net in a distinct depth stratum. To illustrate this, the vertical pathways of two trawl tows and the speed of the vessel are shown in Fig. 5. Length and weight of the collected fishes were detennined. The size measures of common epipelagic fishes such as chub mackerel, round sardinella, Sardinella aurita V ALENCIENNES 1847, and horse mackerel, Trachurus picturatus (T.E. BOWDICH 1825) were carried out on bord immediately after capture. To compare the length distribution among different trawl tows, statistical comparisons of different size c1asses were perfonned using G-test with subsequent multiple comparisons (SOKAL and ROHLF 1981). The mesopelagic fishes were conserved in ethanol for later use in DNA studies. Species identification was based on the following literature: BIGELOW et al. 1964, NAFPAKTITIS et al. 1977, POST 1973, NIELSEN and SMITH 1978, HULLEY 1981, WHITEHEAD et al. 1984-86, MIYA 1994, NELSON 1994, ESCHMEYER 1998. The stomach and gut contents of several specimens of young chub mackerel were examined. For this diet analysis, the entire digestive tract was removed and dissected. Diet items were assigned to one of several food categories inc1uding copepod crustaceans, decapod and bivalve larvae, and fish remains. Non-digested bottom material (e.g ., sand grains and large pennate diatoms) was also noted when it occurred. 2.2. Acoustic survey The acoustic survey covered a total of 2404 nm2. To obtain proper Act ..... ua .. fish and plankton densities in this area, a SIMRAD EK-500 split beam acoustio was used. It was connected to a SUN SP ARC 10 station (Fig. 6) into acoustic data were entered together with the position and velocity data MLR 03 plotter. These data were then processed for each navigated mile. divided into sectors in order to estimate the abundance in each island (north, east, south and west) and these sectors were three subareas with respect to bottom depth. The first subarea r!lntr." 11 /nf.Téc./nstCanario Cümc.Mar. n05 Table 3. List of the families and species collected during cruise "La Bocaina 0497" indicating tow number, number ofindividuals (n), and standard length (SL) FamilX or Order Species Townr. n SL~mml Nemíchthvidae Nemichthvs curvirostris (STROMMAN 1896) 2,11,13,14 7 274-788 Nemichthys sc%paceus RICHARDSON 1848 14 1 206 Semvomeridae SelTÍvomer beani GILL and RYDER 1884 1,2,11,12,14 52 133-388 Clupeidae Sardinella aurita VALENCIENNES 1847 12,13 9 161-222 Bathylagidae J3athylagus sp. 2,11 3 31-56 Gonostomatidae Cyclothone braueri JESPERSEN and TANING 1926 1, 11, 14 543 12-28 Cyclothone pallida BRAUER 1902 11 1 28 Cyclothone pseudopallida MUKHACHEVA 1964 1,11 41 20-33 Diplophos taenia GüN1HER 1873 1 3 88-107 Gonostoma denudatum RAFINESQUE 1810 l,lI, \3 7 22-120 Gonostoma e/ongatum GüN1HER 1878 1,2,7,11,14 258 17-115 Margrethia obtusirostra JESPERSEN and TANING 1919 1 • 1 47 Sternoptychidae Argyropelecus aculeatus V ALENCIENNES 1850 1,7,11 5 53-74 Argyrope/ecus gigas NORMAN 1930 1 4 64-111 Argyrope/ecus hemigymnus COCCO 1829 1,7,11,14 28 17-33 Argyrope/ecus o/fersi CUVlER 1829 14 1 18 Stemoptyx diaphana HERMANN 1781 7 1 27 Phosichthyidae Vinciguerria nimbaria (JORDAN and WILLIAMS 1895) 2,13 5 24-33 Stomiidae (Astronesthinae) Astranesthes gemmifer GOODE and BEAN 1896 1,13,14 7 2~5 Astranesthes indicus BRAUER 1902 1 2 26-30 Astranesthes macropagon GOODYEAR and GlBBS 1970 1 I 32 Astranesthes micropogon GOODYEAR and GIBBS 1970 I 3 21-38 Astranesthes neopogon REGAN and TREWA V AS 1929 I3 I 73 Rhadinesthes decimus (ZUGMA YER 1911) 11 I 46 Stomiidae (Stomiinae) Chauliodus danae REGAN and TREWA VAS 1929 1,2,7,11,13,14 57 45-132 ! Chau/iodus sloani BLOCH and SCHNEIDER 1801 7,11,14 13 46-238 I Stomias boa (RISSO 1810) 1,2,7,11,13,14 138 26-230 ! Stomiidae (Melanostomiinae) Bathophilus vaillanti (ZUGMA YER 1911) 1,7,14 7 83-126 Chirostomias pliopterus REGAN and TREWA VAS 1930 1,14 4 39-54 :> Eustomias obscurus VAILLANT 1884 2,7,13 13 124-214 j Eustomias tetronema ZUGMA YER 1913 11 2 126 Flagellostomias boureei (ZUGMA YER 1913) II I 70 o " Grommatostomiasflage//ibarba HOLT and BRYNE 19IO 1I I 97 ~ Leptostomias gladiator (ZUGMA YER 1911) 14 I 143 ¡¡ Melanostomias biseriatus REGAN and TREWA VAS 1930 1,14 2 64-84 . Me/anostomias tentaculatus.(REGAN and TREWAVAS 1930) 1,7,14 7 62-138 f Photonectes braueri (ZUGMA YER 1913) 1 I 37 " Stomiidae (Idiacanthinae) ldiacanthus fasciola PETERS 1877 1,7,11,13,14 90 41-276 ~ StoInÜdae (MaIacosteinae) Aristostomias lunifer REGAN and TREWA VAS 1930 1 1 72 i Photostomias guemei COLLETT 1889 1,7,11,14 106 31-118 Notosudidae Ahliesaurus benyi BERTELSEN, KREFT and MARSHALL 1976 1 2 36-38 j Scopelosaurus argenteus (MAUL 1954) 1 3 32-39 ParaJepididae Macroparalepis nigro (MAUL 1965) 2 1 172 .1l Myctophidae Benthosema suborbitale (GILBERT 1913) 1,2 2 28,4 f Bolinichthys indicus (NAFPAKTII1S and NAFPAKTII1S 1969) I 2 36 -38,9 ~ Ceratoscopelus maderensis (LOWE 1839) 2,8,13 11 52 - 58 Ceratoscopelus warmingii (LÜTKEN 1892) 2,7,13 42 24 -62 t'l " Diaphus adenomus GILBERT 1905 11 1 104 Diaphus metopoclampus (COCCO 1829) 1,14 39 53 -78 Diaphus mollis TANlNG 1928 2 3 39 -46 Diaphus perspicillatus (OGILBY 1898) 14,2 8 48 -58 Diaphus rafinesquii (COCCO 1838) 1,7,11,14 19 60 -83 Hygaphum benoiti(COCCO 1838) 2 I 44 Hygophum hygomi (LÜTKEN 1892) 1,2,13 l3 29 -63 Hygophum reinhardti (LüTKEN 1892) 2 I 45 Lampadena urophaos atlantica MAUL 1969 1,14 4 92 -125 Lampanyctus alatus GOODE and BEAN 1896 1,7,13,14 48 19 - 51 Lampanyctus ater TANING 1928 11,14 4 25 -57 LampanyctusfestillUs TÁNlNG 1928 11 1 63 Lampanyctus lineatus TANING 1928 11 1 41 Lampanyctus photonotus PARR 1928 13,14 4 21 -62 Lampanyctus pusi//us (JOHNSON 1890) 1, 13, 14 7 25 -35 Lepidophanes gaussi (BRAUER 1906) 1,2,11 19 20-42 Lcbianchia dofleini (ZUGMA YER 1911) 1,2, l3 13 22 -58 Lobianchia gemellarii (COCeO 1838) 1,7,11,14 5 50-76 Notolychnus valdiviae (BRAUER 1904) 11 1 22 Notoscopelus caudispinosus (JOHNSON 1863) 2 1 31 Notoscopelus resplendens (RICHARDSON 1845) 2,8,13 11 27 -75 Symbolophorus veranyi ~U 1888) 13 1 96 Melanocetidae Melanocetusjohnsoni G R 1864 7 1 44 Diretmidae Diretmus argenteus JOHNSON 1864 1,7 2 63-67 Caproidae Capros aper (LINNAEUS 1758) 1, II 3 24-29 Syngnathidae ? Syngnathus sp. I3 1 77 Carangidae Trachurus picturatus (T.E. BOWDICH 1825) 6,8 I3 210-280 Gernpylidae Diplospinus multistriatus MAUL 1948 1,14 2 101-161 Trichiuridae Aphanopus intermedius PARIN 1983 I I 154 Trichiuridae Lepidopus caudatus (EUPHRASEN 1788) 12 1 70 Scombridae Scomber japonicus HOUTfUYN 1782 6,8, 10, 12, 13 417 72-318 Anguilliformes various genera 1,2 28 33-194 Total 2166 18 Inf.Téc.lnstCanario Cienc.Mar. nOS With tow 13 a considerable number ofyoung chub mackerels and one round sardinella were collected, too (Tab. 5). With tow 2, which was located in the area of the eddy, severalleptocephali were collected. The mesopelagic tows resulted in capture of high numbers of mesopelagic fishes. The most numerous mesopelagic species collected was Cyclothone braueri, followed by Gonostoma elongatum, both belonging to the family Gonostomatidae (Tab. 4, 5). Quite abundant were also the stomiids Stomias boa, Idiacanthus fasciola, Photostomias guernei, and Chauliodus danae. Among the myctophids, Diaphus metapoclampus and D. raflnesquii occurred most freque!ltIy. Quite common were also serrivomerid eels of the species Serrivomer beani and the sternoptychid Argyropelecus hemigymnus. In the area of the eddy (tow 1), several leptocephali occured together with a juvenile of the benthopelagic trichiurid Aphanopus intermedius and two small juveniles of Capros apero The length distribution of 368 chub mackerel, the most common epipelagic species in the samples, is shown in Fig. 9a. While in tow 6 mainly adult ~ specimens were collected, only juveniles occurred in the other tows. There were i significant differences in size distribution of chub mackerel between tow 6 and all 1 ~ other tows (G=538.3, df=48, p<O.OO 1). Furthermore, specimens caught by tow 13 were ¡ significantly smaller than those caught by tow 8 and 10, repectively (G=132.6, df=12, g p<O.OOI). The specimens caught with tow 12 (n=4; 107-125 mm TL) were exc1uded i from this analysis due to the small sample size. The length-weight relationship of 365 t mackerels caught by tows 6,8, 10, 12, and 13 is shown in Fig. 9b. I f Table 4. Results of each trawl tow with the number of individuals of each family t indicated. The three different types of trawl tows, neritic epipelagic, oceanic j epipelagic, and oceanic mesopelagic are shown separated with further· indications of ~ time of day, towing depth range and bottom depth range. ~ Townr (, I 11 I 10 I 12 I 2 I 13 I 1 I 7 I 11 14 Timeofdav N 1 N ~ N ~ N ~ N ~ N ~ D ~ N ~ D ~ D Towin2 deoth 20-100 m .~ 400-700 m Bottom deoth 90-300 m 950-3400 m Nemichthvidae I 2 2 3 Senivomeridae I 6 40 3 2 Clupeidae 8 1 Bathylagidae 2 I Gonostomatidae 4 4 534 3 79 230 Sternoptychidae 10 14 2 \3 Phosichthyidae I 4 Stomiidae 20 15 262 14 98 50 Notosudidae 5 Paralepididae 1 Myctophidae 5 85 72 66 4 9 21 Melanocetidae I Diretmidae 1 1 Caproidae 2 I Syngnathidae 1 Carangidae 12 I Gempylidae 1 1 T richiuridae I 1 Scombridae 207 96 81 4 29 IAnguilliformes 15 \3 Total 219 \02 81 14 135 128 935 37 195 320 19 Inf. Téc.lnsL Canario Cienc.Mar. nOS Table 5. Species collected ordered according to trawl tow type and ecological group (I=epipelagic species, II=mesopelagic species, IIT=juveniles of benthopelagic species). e nUf Dr_ 6 11 jil 17 T ., 13 1 -7 i1 -14 Ttmeofdav N N N N T N 1 N I D N T D OWUt~deoth 20 -100 m I 400 -700m Hottom deoth 90 - 300m 9503400 ro I Sardinel/a aurita Trachurus piclU7YlIW 12 1 Scomhe,. japonicus 207 96 81 4 29 JI Nemichtlrvs curviroslrls I 2 2 2 Nemichthys sc%paceus 1 Serrlvomer beani 1 6 40 3 2 8athy/agw sp. 2 I Cydolhcne braueri 273 44 226 Cyc/o/hone pallido . I Cyclo/hone pseudo¡xrllida 10 31 Dip/ophos /aenia 3 Gorwsloma denudan"" 4 2 I Gorws/oma e/ongalUrn 4 245 3 2 4 Margre/hia obOOi1'O"/1'O 1 Argyrope/ecus acule,ÚIlS 2 2 1 Argy1'Ope/ecus gigas 4 Argyropelecus hemigyrmu.< 4 11 1 12 Argyropelecus olfers! 1 SlemoplyX dlaphana 1 Vinciguema nirnharia 1 4 Astrones/hes gemmi/c,r 2 2 3 Astrones1hes indicus 2 Astrones/hes macropogon 1 Astronesthes micropogon 3 Asl1'onesthes neopogon 1 Rhadines1hes decimus 1 Chau/iodus danae 3 1 44 2 2 5 Chauliodus sloani 2 8 3 Stomiasboa 7 6 104 1 10 10 Bathophilus vaillanti 3 3 1 Chi1'Ostomias pliopterus 3 I Eustomtas obscurus 10 2 1 Euslomias lelr"anema 2 F7agel/oslomias houreei I Grammatos/omiasj/ogelliba,.ba I Leptos/omias g/adia/or I Me/anos/amias bisen'aOO I I Melanostomias teniaculatus 4 1 2 Ph%nectes braueri 1 ldiacanthu.s fascJo/a 3 65 2 12 8 Arisloslomias lunifer I Photos/omias gueme l 28 2 61 15 Ah/iesau1'US berryi 2 Scope/osaurus argenteus 3 Macropa,.a/epis nigr .. 1 Benthosema suboro/lale 1 1 Bo/lnichthys indicus 2 Ceraloscopelu.s madenmsis 3 1 7 Ceraloscopelus wanrningil 38 3 1 Dlaphus adenomus 1 Dlaphus melapoc/ampus 37 2 Diaphus mol/ls 3 Diaphus perspicillatus 7 1 D!aphus roftnesquH 15 1 1 2 Hygophum benoiti 1 Hygoplrum hygomi 11 1 I Hygoplrum relnhardti 1 Lampadena urophaos a/lantica I 3 Lampanycoo a/aoo 38 5 I 4 LampanycOO ater 2 2 Lampanycoo fost/vus 1 Lampanycoo /ineatus I LampanycOO photonotus 3 1 LampanycOO pustl/us 2 1 4 Lepldophanes gaussi 17 1 1 Lobianchia dofleinl 1 II 1 Loblanchia gernel/aril 1 1 1 2 Nololychnus va/divla.' I Notoscope/us caudisp/nosus 1 Notoscope/us resp/enden.s 2 3 6 Symh%pho1'US veranyl 1 Me/IJ1IOCeOO johnsonl I Diretmus orgenteus I 1 ? Syngnathus .p. I Dip/osplnus mu/tistriaOO 1 1 Anguiflifonne. (Lcotoccohali) IS 13 In Caorosaoer 2 1 Aphanopus intermedius 1 Lepldopus caudooo J 20 60 40 20 O 100 80 60 40 20 o 100 - t::: 80 11» (.1 60 ... <U o... 40 20 O 100 80 60 40 20 O b.() feO Inf. Téc./nst Canario Cienc.Md/ii1 Tow 6 (n=207) Tow 8 (n=95) Tow 10 (n=81) Tow 13 (n=29) 'b0 \.()() \'l-() \.b. 0 \fe() \'b() 'l-()() 'l-'}.() 'l-b.() "fe() ,,'b() ,,()() ,,'l-() "Cl.O "fe() ,,'bO b.()() b.'l-0 Totallength (mm) Fig. 9.a. Length distribution of chub mackerel with the tow number indicated. r I I 400 - C) - ~ 300 .s::. .~ ; 200 - ftS 100 ~ O 150 100 Tw = O 0000037 TI 3,116 , N = 365 150 200 250 300 Totallength (mm) Fig. 9.b. Length-weight relationship in chub mackerel. 21 350 400 Inf. Téc.Inst Canario Cienc.Mar. nOS Among the ten juvenile chub mackerels (93~135 mm TL; four from tow 12 and six from tow 13) examined for their stomach and gut contents, five did not show any food or other remains. In the other five specimens, the stomachs were mostly empty and only the intestines were fiHed. The latter contained numerous prey items, among them copepods belonging to the genera Candacia, Corycaeus, Microsetel/a, Oncaea, and Pleuromamma (Appendix, Plate V). Especially Oncaea and Microsetella occurred at high frequencies of between 100 to 10000 specimens per gut. In addition, decapod and bivalve larvae, fish eggs, and ~ in one case - a smalI fish bone were found. In addition, sand grains and pennate diatoms were found in two individuals collected with tow 13. Size measures of the gut remains indicate that small copepods of a mean metasome length of about 60 microns were the dominant prey category. 3.2. Acoustic dalta Estimates of the abundance and biomass of pelagic fishes ca1culated by the echo~integration method are provided in Table 6. For the three islands a total of 61546 tons was ca1culated with much higher abundance, density, and biomass values for Lanzarote and Fuerteventura. Within the shelf area (0-100 m) a high spatial variability of acoustic signal pattems occurred with particularly dense concentrations in the NW of Lanzarote, in tbe "La Bocaina" strait between Lanzarote and Fuerteventura, and off Puerto de Mogan in the south of Gran Canaria (Fig. 10). Two examples of echograms indicating aggregations of epipelagic and epibenthic fishes are provided in Fig. 11. Table 6. Estimates of total abundance and biomass of pelagic fishes calculated by the echo-integration analysis. Surveyed nautical miles 198 215 210 623 Covered area (0-1000 m) (nm 2) 626,0 949,9 826,9 2403,8 Mean intefation value (m 2 /nm) 55,0 486,5 282,8 302,9 Mean fish length (cm) 24,5 12,7 13,2 16,8 Abundance (nOoffish) 55,9 x 106 2326,3 X 10 6 1658,6 X 10 6 4040,8 X 106 Density (nO offish/ nm2) 0,1 x 106 3,2 X 10 6 1,7 X 10 6 1,7 X 106 Biomass (tons) 5753 30925 24868 61546 1(%) (9,35%) (50,25%) (40,41%) 000%) , \ 22 Inf.Téc./nst.Canario Cienc.Mar. n05 15'W 45' 30' 15' 14" 45' 30' 15' 30' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~o' 15' 29' INTEGRATED ECHO LEVEL ~ ·10-99 ,. :100-499 . :> 500 45' .... . ... .. .. .... ... ..... ... .. .... .. .. .. 30' ...... ... .. .. .. • .. . ¡ . • 15' 28'N i : i 15'W 45' 30' 28'N 16'W . .. ..... . ... . 15' 14· .. 29' .. ...... . ... ...... ................ ..... 30' 15' .. ........... .... .. .. . ... , .. 28"N SCALE ° s ID " 20 (Km} 45' 30' 15' ID' , •..•.. 1- .. ·+· .. .. .... ··· .... ·· ·· ··· 1""· LEVEL Fig. 10. 'Acoustic estimates for the abundance of epipelagic fishes off Lanzarote and Fuerteventura (on top), and Gran Canaria (bottom). 23 Inf.Téc.lnstCanario Cienc.Mar. nOS For the epipelagic neritic tow 6 (Fig. 12) which resulted in the capture of a considerable number of epipelagic fishes, biomass calculations with respect to chub mackerel and hors~~ mackerel were carried out based on mean total lengths of 25.1 cm and 24.5 cm, for each of the two species, respectively. The mean integrator value during the four miles towing distance was 168 m2/nm2. Chub mackerel had an estimated biomass of 28.5 tons/nm2 and a mean density of 276959 fish/nm2 or 0.06 fish/m2. In comparison, horsemackerel occured at a much lower density of estimated 0.003 fish/m2. Clear evidence for diurnal vertical migration of mesopelagic fishes comes from the results of an echogram produced during the night of 11 to 12 April and the following morning in combination with the collecting data. Parallel to this echogram tows 13 and 14 were carried out successively at the surface during late night and in midwater during the morning (see Fig. 5). The echogram gathered during and between these tows is shown in Fig. 13. In the transect carried out the contours ofthe shelf and slope, the nocturnal formation of the deep and shallow scattering layers at 400-700 m and at less than 150 m depth, respectively, and the downwards migratíon towards the deep scattering layer in the morning can be clearly recognized. The descent of the migrating mesopelagic fauna started with the sunrise at about 6:30 a.m. just after tow 13 had been hauled in. Tow 14 started at 7:48 a.m. when the descending process was already considerably advanced. One nemichthyid (Nemichthys curvirostris), four stomiids (Astronesthes gemmifer, Chauliodus danae, Stomias boa, Idiacanthus fasciola), and three myctophid species (Lampanyctus alatus, L. photonotus, L. pusillus) co-occurred in the collections ofboth tows (Table 5). 3.3. SST images Sea-surface temperature (SST) images taken during the cruise from 7th to 12th April and immediately afterwards for the periods from 14th to 15th and from 27th to 30th April are shown in the Appendix (Plates VI, VII). During the period of the cruise, surface temperatures of 19 to 21°C prevailed in the study area with warmer water between Tenerife and Gran Canaria and in the south of both islands. Later, water temperature increased in the northern area of the Canary Islands, too, with maximum va]ues of 24.5 oC in the centre of warm-water pockets. These pockets moved from the north to south along the east of Lanzarote, Fuerteventura, and Gran Canaria or were formed in the southwest of Gran Canaria and Tenerife. At the same time, with the general increase in surface temperature, the upwelling activity off NE Africa becomes evident. In one ca')e, on 29th April, a cooler water mass appears off the southeastern coast of Fuerteventura which is surrounded by two warm-water pockets towards the south and southeast. On the next· day, this situation has completely changed with another warm-water body aITiving in the east. Between 27th and 30th April, weak anticyclonic displacements of surface waters can be observed in the southwest or south ofGran Canaria close to the location ofthe eddy (ARÍSTEGUI et al. 1994). 24 1nm /nf.Téc./nstCanario Cienc.Mar. nOS ~ ___ !!!!!!!!!!!_!!!!!!!!!!!!"!""I" __ r Om Botton ~::~~~~~~54m 10m above bottom ~ j- ~ :> i ~ 8. ~ - 250m~ Fig. 11. Examples of echograms showing accumulations of epipelagic and epibenthic I fishes. West of Fuerteventura; 11 April 1997. i ¡ Om .1l f 50m ~ ¡;¡ " 100m 150m - 200m - 250m Om 50m 100m . ,- 150m - 200m Fig. 12: Echogram oftow m. 6. South ofGran Canaria; 8 April1997. 25 900Z 'B!JI1j!SJ3A!Un EOa 10!1Q! 8 ' ::>9 dl n 100 epez!Je~J UQp e z!IE!l!6! O ' SólJO lne SOl ' Ol U3U H'IOO p ¡sa O Inf. Téc.lnst Canario Cienc.Mar. n05 El O O O O O O O O O O O O N • <O cg ... 1, ; 'V ' ~'~!L 1 I I l· I,.: . ~,, ; ~ '- '-' . ~-:' : ' . .. ... _ .. _- ._, .. :"'~".,., ...... _el O O O N H.Ld3G O O • O O <O O O cg O O O .... ,.,.r ~~:;;. , El O O O N Fig. 13. Echograms taken before, during and after trawI tows 13 and 14. 26 O O • o o <O O O cg O O O .... Inf. Téc.Inst Canario Cienc.Mar. nOS; 4. DISCUSSION AH epipelagic trawl tows carried out in daylight or dawn were without fishing success. This result may be due to active, visually mediated avoidance of vessels and/or fishing gears by epipelagic fishes and/or too slow trawling speed (e.g., WARDLE 1993). During night, with the same gear and speed, epipelagic as well as mesopelagic fishes were collected, partly at high numbers. Mesopelagic tows were successful both during day and night. The following ten species have not been cited in the most recent species catalogue of the fish fauna of the Canary archipelago (BRITO 1991) or in any other relevant zoogeographic account (e.g., BADCOCK 1965, KOTTHAUS 1972, QUERO et al. 1990), and hence can be regarded as new records for this area: Astronesthes macropogon, Astronesthes micropogon, Astronesthes neopogon, Grammatostomias flagellibarba, Melanostomias tentaculatus (aH Stomiidae), Ahliesaurus berryi (Notosudidae), Macroparalapis nigra (Paralepididae), Diaphus adenomus (Myctophidae), Diplospinus multistriatus (Gempylidae), and Aphanopus intermedius ~ (Trichiuridae). The latter species probably co-occurs with A. carbo in the study areat (cf UIBLEIN et al. 1998). However, further taxonomic studies on comparative ~ material are required to examine this assumption. Another interesting aspect of this i finding is that only few juveniles of the genus Aphanopus have been coHected in this ~ and adjacent areas. Off Madeira, for instance, only two specimens of 60 and 100 mm t SL were caught at about 400 -450 m depth in the open water (KOTTHAUS 1972). For ) the Canaries, our record is the first for a juvenile of this genus. j g Sorne of the dominant stomiiform and myctophid species in the study area occur ! " at particular high frequencies also in other regions, such as, for instance, Cyclothone I braueri off the NW African coast (BADCOCK and MERRETT 1976) and ~ " Lampanyctus alatus and Ceratoscopelus warmingii in the Gulf of Mexico (GARTNER et al. 1987). In the earlier study off Lanzarote and Fuerteventura by BADCOCK (1970), Cyclothone braueri, Ceratoscopelus warmingii, Lobianchia dofleini, and Argyropelecus hemigymnus occurred at the highest frequencies in the catches. Numeric dominance of Cyclothone species in mesopelagic layers has be en observed at a worldwide scale. This genus is said to include the most abundant vertebrates on earth (MIYA and NISHIDA 1997). The species of the genus Cyclothone do not show diurnal vertical migrations and remain in deep layers during night. Similar to the observations made by BADCOCK and MERRETT (1976), Cyclothone specimens clinged in the mesh ofthe net and could not be completely removed after each mesopelagic tow. Therefore, if the trawl was towed in the epipelagic immediately afterwards, Cyclothone specimens appeared in the net as "pollution". The vertical migrations observed covered considerable depth ranges. For instance, the eight species collected before sunrise in the epipelagic and immediately 27 Inf. Téc.lnst. Canario Cienc.Mar. nOS HOPKINS, TL., SUTTON, TT and LANCRAFT, TM. (1996). The trophic structure and predation impact of a low latitude myctophid community. Prog. Oceanog., 38, 205-239. HOPKINS, TL. and SUTTON, TT (1998). Midwater fishes and shrimps as competitors and resource partitioning in low latitude oligotrophic systems. Mar. Ecol. Prog. Ser., 164,37-45. HULLEY, P.A. (1981). Results of the research cruises of FRV "Walther Herwig" to South America. LVIII. Family Myctophidae (Osteichthyes, Myctophiformes). Arch.Fisch. Wiss., 31, 1-300. KERSTAN, S.L. (1989). The food of silver roughy (Hoplostethus mediterraneus, Beryciformes, Trachichthyidae). Meeresforsch., 32,241-247. KNUDSEN, H.P. (1990). The Bergen Echo Integrator: an introduction. J.Cons.int.Explor.Mer,47, 167-174. KOTTHAUS, A. (1972). Die mesound bathypelagischen Fische der "Meteor"- RoBbreiten-Expedition 1970 (2. und 3. Fahrtabschnitt). Meteor-Forsch.-Ergebnisse, D 11~ 1-28. LORENZO, 1M. (1992). Crecimiento de la caballa Scomber japonicus (Houttuyn, 1782) en aguas de Canarias. Ph.D.thesis, Univ. ofIas Palmas de Gran Canaria. LORENZO, lM. and CASTRO, J.J. (1996). Determinación de un cambio de hábitat en los juveniles de caballa. In Oceanografía y Recursos Marinos en el Atlántico Centro-Oriental, Llínás, O., Gonzáles, lA. and Rueda, MJ. (eds). Gobierno de Canarias, Las Palmas, 297-309. MAGNÚSSON, l, 1996. The deep scattering layers in the Irminger Sea. J. Fish Bio/., 49 (Suppl.A), 182-19l. MAUCHLINE, J. and GORDON, lD.M. (1991). Oceanic pelagic prey of benthopelagic fish in the benthic boundary layer of a marginal oceanic regíon. Mar.Ecol.Prog.Ser., 74, 109-115. MERRETT, N.R., (1986). Biogeography and the ocean rim: a poorly known zone of ichthyofaunal intf~raction. In Pelagic Biogeography, Pierrot-Bults, A.C. van Spoel, S., Zahuranec, BJ. and BJ. Johnson, BJ. (eds), UNESCO Technical Papers in Marine Science 49: 201-209. MITTELSTAEDT, E. (1983). The upwelling area offnorthwest Africa - a description ofphenomena related to coastal upwelling. Prog.Oceanog., 12,307-331. 34 Inf. Téc.lnst Canario Cienc.Mar. nOS MIYA, M. (1994). 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The eel family Nemichthyidae (Pisces: Anguilliformes). Dana Rep., 88, 1-71. OWRE, H.B. and FOYO, M. (1967). Copepods olthe Florida Current. Fauna Caribea No. 1. Institute ofMarine Science, University ofMiami, Florida. PASTOR, X. and DELGADO DE MOLINA, A., (1985). Acoustic abundance estimation of mackerel, pilchard and bogue in Canary Island waters. ICES, Pelagic Fish Commitee (ApriI1984), 5218, 1-24. POST, A. (1973). Ergebnisse der Forschungsreisen des FFS "Walther Herwig" nach Südamerika XXVIT. Macroparalepis Ege, 1933 (Osteichthyes, Myctophoidei, Paralepididae). Revision der Gattung und Beschreibung zweier neuer Arten. Arch.Fischereiwiss., 23, 202-242. QUERO, J.-C., HUREAU, J.-C., KARRER, C., POST, A. and SALDANHA, L. (1990). Check-list olthefishes olthe eastem tropical Atlantic. Paris, UNESCO. RAMOS, A., LORENZO, J.M. and PAJUELO, J. (1995). Trophic habits of skipjack tuna Katsuwonus pelamis Linnaeus 1758 offthe Canary Islands. Scientia Marina, 59, 365-369. 35 Inf. Téc.lnst Canario Cie,,,c.Mar. n05 ROE, H.S.J. and BADCOCK, 1. (1984). The diel migrations and distributions within a mesope1agic community in the North East Atalantic. 5. Vertical migrations and feeding offish. Prog.Oceanog., 13,389-424. RUDJAKOV, lA. (1979). Diurnal vertical migrations of pelagic animal s in the Canary Islands area. Oceanology, 19, 196-199. SIMRAD, 1992: Simrad EK500 scientific echo sounder instruction manual. Simrad Subsea, Horten. SOKAL, R.R. ami ROHLF, F.J. 1981. Biometry. 2nd. edition. W.H. Freeman & Company, San Francisco. UIBLEIN, F., BORDES, F. and CASTILLO, R. (1996). Diversity and depth distribution of demersal deep-water fishes off Lanzarote and Fuerteventura, Canary Islands. J.Fish Bio/., 46 (Suppl. A), 75-90. UIBLEIN, F., F. BORDES, R. CASTILLO and RAMOS, A.G. (1998). Spatial distribution of shelfand slope-dwelling fishes collected by bottom longline off Lanzarote and Fue:rteventura, Canary Islands. Mar.Eco/., 19, 53-66. UlBLEIN, F., GELDMACHER, A., KOSTER, F., NELLEN, W. and KRAUS, G. (1999). Species composition and depth distribution of fish species collected in the area of the Great Meteor Seamount, Eastern Central Atlantic, duríng cruise M42/3, with seventeen new records. Inf. Téc. ICCM, 5, 47-85. W ALSH, M., REID, D.G. and TURRELL, W.R. (1995). Understanding mackerel migration off S<:otland: tracking with echosounders and commercial data, and including environmental correlates and behaviour. ICES J. mar. Sci. , 52, 925-939. W ARDLE, C.S. (1993). Fish behaviour and fishing gear. In Behaviour 01 Te/eost Fishes, 2nd ed., Pitcher, T.J. (ed.). Chapman and Hall, London, 609-643. WORNER, F.G. (1979). Nahrungsbiologie dreier Myctophidenarten, Benthosema glaciale (Reinhardt, 1837), Ceratoscope/us maderensis (Lowe 1839) und Myctophum (M) punctatum Rafinesque, 1810, des nordwestafrikanischen Auftriebsgebietes. Meteor Forsch.-Ergebnisse, D 30, 41-61. WHITEHEAD, P.J.P., BEAUCHOT, M.L., HUREAU, J.c., NIELSEN, J.G. and TORTONESE, E. (eds) 1984-1986. Fishes 01 the north-eastern Atlantic and the Mediterranean. 3 vol. UNESCO, Paris. ZELCK, C. and KLEIN, B. (1995). Distribution of lanternfish Ceratoscopelus maderensis (Lowe 1839) off northwest Africa and its relation to water mass. Deep-Sea Research, 42, 1411-1422. 36 Inf.Téc.lnst.Canario Cienc.Mar. n05 APPENDIX Plates I-IV. Photos ofspecies collected during cruise "La Bocaina 0497". Plate V. Photos of the remains of food items found in the stomachs of juvenile chub mackerels. Top (from left to right): Candacia pereiopod, Microsetalla sp. Bottom (from left to right): Oncaea sp., Corycaeus sp. Plates VI, VII: SST images collected in April 1997 during and after cruise "La Bocaina 0497". 37 ¡ni Téc.lnst. ((mario Cienc.Ma r. n05 Plate 1 :"¡ emicÍJlhvs ( un !:\ ). ,; " ;, ' Nemichthys sc%paceus C)ciOlhone pseudopa/lida : cm. Diplophos iaerlÍC: Gonostoma elongatum 39 Inf Téc./nst.Canario Cienc.Mar. n05 .,..-- ---'-- Cm'\. lv[argrethia ohtusirostra Argyropeiqcus hemigymnus Vinciguen'ia nimbaria I J I J 11 J 1 J 1I11111111 1111 ¡ 11 J J 11 ¡ 11111 1111 1 11111111111" ,-, '-' -, e Rh(1li;ne.stes derimus 11 -, ,- ::' cm. J 'Plate TI ArgyropeJecus aculeatus Astrollesthes macr o pog on ._. ----- ---- -_---:: Chauliodus danae 40 Plate ID Stomiashoa Bathophilus vailJanti Eustomias tetranema Grammatostomias flageOiharba Leptostom;as gladiator MeJanostomias tentaculatus Idiacanthus ¡aseloJa Photonom¡~ guernei 41 In! Téc./nst Canario Cienc.Mar. n05 Plate IV j,-, "1';:1111'[;1111 11 . S cm Scope/osaurus argenteus Macropara/epis nigra -' --------------- Diaphus adenomus Me/anocetus johnsoni ..... Diretmus argenteus Caprosaper f.- .---......:.... ->á .,')llllll¡:11111 1111111111111111 1'111Itj!11 Lepidopus caudatus Leptocephali 42 /nf Téc./mt. ((mario Cienc.Mar. n05 Plate V 43 lnl Téc. Inst. Canario Ci.enc.May. n05 PI ate VI 7th Apríl 1997 8th April 1997 -17 -16 ·15 -14 -13 -17 -16 -15 -14 -13 29 2' 28 28 27 21 -17 -16 -15 -14 -13 9th Apríl 1997 10th Apríl 1997 -17 -16 -15 -14 -13 -17 -16 -15 -14 -13 29 29 28 28 27 27 -17 -16 -15 -14 -13 11th Apríl 1997 12th April 1997 -17 -16 -15 -14 -13 -17 -16 -15 -14 -13 29 29 28 28 27 27 -17 -16 -15 -14 -13 -17 -16 -15 -14 -13 SST oC 17.0 !lI 18.0 l!I19.0 ~ 20.0 • 21.0 lI'i!l 22.0 23.0 ® 24.0 ¡¡¡ "17 .5w 18.5 i~ 19.5 11 20.5 III 21.5 22.5 23.5 24.5 44