156
C. Odebrecht and J.P. Castello
changes seasonally. Shelf and shelf break areas (about 200m depth) are
typical of adult Engraulis anchoita, Pomatomus saltatrix, Sarda sarda,
Scomber japonicus, Trachurus lathami, Katsuwonus pelamis, and three
species of Mugil. Tuna fish and similar species, mostly yellowfin ( Thunnus
albacares) and swordfish (Xiphias gladius) , pelagic sharks, and smaller
oceanic fishes (lantern fish, Maurolicus muelleri, Micthophidae, Lampanyctinae) occupy the slope and deeper waters.
The demersal, demersal-pelagic, and demersal-benthic communities
define different geographic assemblages (Angelescu and Prenski 1987;
Cousseau and Perrotta 1998). Between 34°S and 41 os down to 50 m depth
(Buenos Aires coastal assemblage) the white mouth croaker (Micropogonias furnieri) , weakfisk ( Cynoscion guatucupa = C. striatus) and the
narrownose smooth-hound (Mustelus schmitti) are dominant species. Less
abundant are black drum (Pogonias cromis), royal weakfish (Macrodon
ancylodon ), Argentine croaker ( Umbrina canosai), "burriqueta" (Menticirrhus americanus),Atlantic sea robins (Prionotus nudigula, P. punctatus),
marine catfish (Netuma sp.), red porgy (Pagrus pagrus), Brazilian codling
(Urophycis brasiliensis), red mullet (Mullus argentinae) , several flatfishes
(Paralichthys spp.), and small sharks and rays. In southern Brazil this
assemblage also includes Argentine conger (Conger orbignyanus), large
head hairtail (Trichiurus lepturus), the sciaenids Cynoscion jamaicensis
and Ctenosciaena gracilicirrhus, and horse mackerel (Trachurus lathami;
Haimovici 1997b). Between 34°S and 48°S at 50-225m depth (Buenos Aires
and Patagonia inner and outer shelf assemblage) the dominant hake (Merluccius hubbsi), followed by pink cuskeel ( Genypterus blacodes), spiny dogfish (Squalus acanthias), hawkfish ( Cheilodactylus bergi), flounders, and
notothenids are characteristic of SAW. The blackbelly rosefish (Helicolenus
dactilopterus lahillei), conger (Pseudoxenomystax albescens), "viuda"
(Iluocoetes fimbriatus), and six species of grenadiers (Macrouridae) are
present in northern areas. In the southern part, at less than 150m depth,
the Brazilian sandperch (Pseudopercis semifasciata), Brazilian flathead
(Percophis brasiliensis), elephant fish ( Callorhynchus callorynchus), and
the angel shark (Squatina argentina) occur. Finally, a cold water assemblage occurs along the slope between 220 and 2,300 m depth, with several
species performing daily vertical feeding migrations. A gulf assemblage
with reduced species number and density occurs between 42°S and 43°S,
while an austral assemblage of the Patagonian-Fueguian and Malvinas
shelf (up to 48°S and 200m depth) is in the domain of SAW of the Malvinas
Current.
A total of 3,193 and 3,300 species have been listed for coastal, shelf, and
slope areas between 30°S and 34°S (Seeliger et al. 1997) and the adjacent
Rio de la Plata region (Mendez 1998), respectively. Although tropical
C. Odebrecht and J.P. Castello
changes seasonally. Shelf and shelf break areas (about 200m depth) are
typical of adult Engraulis anchoita, Pomatomus saltatrix, Sarda sarda,
Scomber japonicus, Trachurus lathami, Katsuwonus pelamis, and three
species of Mugil. Tuna fish and similar species, mostly yellowfin ( Thunnus
albacares) and swordfish (Xiphias gladius) , pelagic sharks, and smaller
oceanic fishes (lantern fish, Maurolicus muelleri, Micthophidae, Lampanyctinae) occupy the slope and deeper waters.
The demersal, demersal-pelagic, and demersal-benthic communities
define different geographic assemblages (Angelescu and Prenski 1987;
Cousseau and Perrotta 1998). Between 34°S and 41 os down to 50 m depth
(Buenos Aires coastal assemblage) the white mouth croaker (Micropogonias furnieri) , weakfisk ( Cynoscion guatucupa = C. striatus) and the
narrownose smooth-hound (Mustelus schmitti) are dominant species. Less
abundant are black drum (Pogonias cromis), royal weakfish (Macrodon
ancylodon ), Argentine croaker ( Umbrina canosai), "burriqueta" (Menticirrhus americanus),Atlantic sea robins (Prionotus nudigula, P. punctatus),
marine catfish (Netuma sp.), red porgy (Pagrus pagrus), Brazilian codling
(Urophycis brasiliensis), red mullet (Mullus argentinae) , several flatfishes
(Paralichthys spp.), and small sharks and rays. In southern Brazil this
assemblage also includes Argentine conger (Conger orbignyanus), large
head hairtail (Trichiurus lepturus), the sciaenids Cynoscion jamaicensis
and Ctenosciaena gracilicirrhus, and horse mackerel (Trachurus lathami;
Haimovici 1997b). Between 34°S and 48°S at 50-225m depth (Buenos Aires
and Patagonia inner and outer shelf assemblage) the dominant hake (Merluccius hubbsi), followed by pink cuskeel ( Genypterus blacodes), spiny dogfish (Squalus acanthias), hawkfish ( Cheilodactylus bergi), flounders, and
notothenids are characteristic of SAW. The blackbelly rosefish (Helicolenus
dactilopterus lahillei), conger (Pseudoxenomystax albescens), "viuda"
(Iluocoetes fimbriatus), and six species of grenadiers (Macrouridae) are
present in northern areas. In the southern part, at less than 150m depth,
the Brazilian sandperch (Pseudopercis semifasciata), Brazilian flathead
(Percophis brasiliensis), elephant fish ( Callorhynchus callorynchus), and
the angel shark (Squatina argentina) occur. Finally, a cold water assemblage occurs along the slope between 220 and 2,300 m depth, with several
species performing daily vertical feeding migrations. A gulf assemblage
with reduced species number and density occurs between 42°S and 43°S,
while an austral assemblage of the Patagonian-Fueguian and Malvinas
shelf (up to 48°S and 200m depth) is in the domain of SAW of the Malvinas
Current.
A total of 3,193 and 3,300 species have been listed for coastal, shelf, and
slope areas between 30°S and 34°S (Seeliger et al. 1997) and the adjacent
Rio de la Plata region (Mendez 1998), respectively. Although tropical