Gorgonocephalus chilensis and Astrotoma agassizzi. The order Ophiurida is well
represented, with eight families and 18 genera. Family Amphiuridae is the most
speciose with 13, of which seven in the genus Amphiura. A complete taxonomic
revision, based upon additional benthic samples, is needed (Brogger et al. 2008).
Echinoidea
Sixteen known species of sea urchins are present (Mortensen 1910, 1936;
Bernasconi 1924, 1925, 1941c, 1947, 1953, 1964c, 1966b, 1970). Two are
members of the Subclass Cidaroidea and 12 belong to the Subclass Euechinoidea.
Spatangoida is well represented, with eight species, followed by Camarodonta (4),
Cidaroida (2), Clypeasteroida (1) and Arbacioida (1). There is a marked predominance of Magellanic species. Some Magellanic species have a wide distribution (e.g., Pseudechinus magellanicus and Arbacia dusfresnii) reaching low
latitudes (*35°S) but only in deeper waters (Bernasconi 1947, 1957).
Holothuroidea
Twenty-six species of holothurians occur in the Argentine Sea (Martinez et al.
2009). Records of holothurians from South of Argentina are scarce, but they
increase northward in the Magellanic Province (Pawson 1969). There are a great
number of species from cold waters that also occur off Buenos Aires (35°–38°S).
At these latitudes, holothurians are found only in deep waters (Bernasconi 1941b;
Hernández 1981; Martinez 2008). Holothurians from the Argentine Province are
restricted to the North (Deichmann 1947). Overall, cold water species
predominate.
Dendrochirotida is well representated by 18 species, followed by Apodida (5)
and Molpadiida (3). The fauna has the closest similarity with those of Chile
(Pawson 1969) and Antarctica (Deichmann 1947).
The diversity of substrates in ACS provides suitable habitats for several species
of holothurians. Some are infaunal, and others are epifaunal on rocky bottoms,
while others live on Macrocystis sp. holdfasts and fronds or on hard substrata
provided by other invertebrates (Bernasconi 1941b; Deichmann 1947; Hernández
1981; Zaixso and Lizarralde 2000; Martinez 2008).
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represented, with eight families and 18 genera. Family Amphiuridae is the most
speciose with 13, of which seven in the genus Amphiura. A complete taxonomic
revision, based upon additional benthic samples, is needed (Brogger et al. 2008).
Echinoidea
Sixteen known species of sea urchins are present (Mortensen 1910, 1936;
Bernasconi 1924, 1925, 1941c, 1947, 1953, 1964c, 1966b, 1970). Two are
members of the Subclass Cidaroidea and 12 belong to the Subclass Euechinoidea.
Spatangoida is well represented, with eight species, followed by Camarodonta (4),
Cidaroida (2), Clypeasteroida (1) and Arbacioida (1). There is a marked predominance of Magellanic species. Some Magellanic species have a wide distribution (e.g., Pseudechinus magellanicus and Arbacia dusfresnii) reaching low
latitudes (*35°S) but only in deeper waters (Bernasconi 1947, 1957).
Holothuroidea
Twenty-six species of holothurians occur in the Argentine Sea (Martinez et al.
2009). Records of holothurians from South of Argentina are scarce, but they
increase northward in the Magellanic Province (Pawson 1969). There are a great
number of species from cold waters that also occur off Buenos Aires (35°–38°S).
At these latitudes, holothurians are found only in deep waters (Bernasconi 1941b;
Hernández 1981; Martinez 2008). Holothurians from the Argentine Province are
restricted to the North (Deichmann 1947). Overall, cold water species
predominate.
Dendrochirotida is well representated by 18 species, followed by Apodida (5)
and Molpadiida (3). The fauna has the closest similarity with those of Chile
(Pawson 1969) and Antarctica (Deichmann 1947).
The diversity of substrates in ACS provides suitable habitats for several species
of holothurians. Some are infaunal, and others are epifaunal on rocky bottoms,
while others live on Macrocystis sp. holdfasts and fronds or on hard substrata
provided by other invertebrates (Bernasconi 1941b; Deichmann 1947; Hernández
1981; Zaixso and Lizarralde 2000; Martinez 2008).
368
M. I. Brogger et al.