In Atlantis and Hydrographer Canyons, and to a lesser extent in 

 Veatch Canyon, at about 40 m there was a temperature inversion 

 where temperatures increased with depth to 150 m but thereafter 

 decreased. Below 400 m temperatures changed only slightly (4.8- 

 7°C ) . Salinities were not measured. 



RESULTS 



Thirty-eight species of gelatinous macrozooplankton were 

 observed and collected (Table 1). Medusae, with 16 taxa, 

 represented the largest group. Of these, two species of 

 hydromedusae, Pantachogon haeckeli and Halicreas minimum , were 

 most abundant. No new species were found, however two rare 

 medusae were collected i.e., Poralia ruf escens and Halitrephes 

 maasi . 



Siphonophores were represented by 13 species, several of 

 which are undescribed. Nanomia cara and Forskalia spp. dominated. 

 N. cara was the most numerous coelenterate observed. It was 

 sometimes very abundant in midwater strata and near the bottom. 

 The physonect Agalma okenii was the only coelenterate that was 

 commonly seen in the surface waters by scuba divers. 



Ctenophores were represented by 9 species. Several species 

 are new to science. Bathocyroe fosteri and Beroe cucumis were 

 most common. 



Macro-crustaceans were dominated by three species, the 

 euphausiid Meganyctiphanes norvegica . The sergestid shrimp 

 Sergestes sp. and the amphipod Themisto ( Parathemisto ) 

 gaudichaudii . M. norvegica was often very numerous in well 

 defined depth strata and near the bottom. Neither Themisto nor 

 Sergestes were limited to specific depth strata although their 

 abundance was depth dependent. Large calanoid copepods were 

 seen, mostly below 600 m but were not collected or identified. 



Pelagic molluscs were represented by a number of 

 unidentified squids and the commonly seen cranchiid 

 Megalocranchia sp. and by the pteropods Clione limacina , Limacina 

 helicoides , and ? Cymbulia . 



Representatives of at least 13 families and many genera and 

 numerous species of fishes were seen, video taped, and or 

 collected. Myctophids (many taxa), hatchet fishes 

 ( Sternoptychidae, several taxa), paralepidids (mostly Notolepis 

 rissoi ) , and snipe eels ( Nemichthyidae, mostly Nemichthys 

 scolopaceus ) were most abundant. Other important taxa were 

 Stomias boa ferox (Stomiidae) and Melanostigma atlanticum 

 ( Zoarcidae) . 



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