468 
PACIFIC SCIENCE, Vol. XVIII, October 1964 
Antipodean Province Islands: The holothurian 
fauna of southern Chile bears no close relation- 
ship to that of New Zealand and Australia. A 
single species, Paracaudina chilensis, is common 
to New Zealand and southern Chile, and this 
species is a circum-Pacific eurybath form. Ocnus 
calcareus is known from New Zealand and Juan 
Fernandez, but has not as yet been recorded 
from the Chilean coast. The Antipodean Prov- 
ince Islands ( Auckland Is., Campbell Is. in par- 
ticular) of New Zealand support a holothurian 
fauna of New Zealand character, and thus the 
fauna differs fundamentally from that of other 
southern islands such as Kerguelen, Macquarie, 
South Georgia. However, one Antipodean Prov- 
ince species, Stereoderma leoninoides (Mor- 
tensen) is a close relative of Stereoderma 
laevigata from southern Chile, and it is quite 
possible that these two species may have been 
derived from some common source. 
B. With that of Antarctica: Some species, in- 
cluding Cladodactyla crocea, Stereoderma laevi- 
gata , Trachythyone parva, and P solus antarcticus, 
are shared with the fauna of Antarctica. Fell 
(1961), in discussing the Ophiuroidea of Ant- 
arctica, stated that the Magellanic ophiuroid 
fauna is predominantly of southern American 
type, mingled with a few Antarctic species 
which are eurythermal. The four species men- 
tioned above are probably eurythermal and can 
readily survive the difference in temperature be- 
tween Antarctica and southern Chile. 
C. With that of the Subantarctic Islands: The 
Falkland Islands ( Islas Malvinas) have a holo- 
thurian fauna which is scarcely distinguishable 
from that of southern Chile. This is understand- 
able when one considers that the islands are but 
300 miles east of Tierra del Fuego, in a good 
position to accept species carried from southern 
South America by the westwind drift. 
Among the Kerguelen Island holothurians 
are Cladodactyla crocea, Stereoderma laevigata, 
Trachythyone parva, and Taenio gyrus contortus. 
Thus the fauna here also bears a remarkable 
likeness to that of southern Chile. 
South Georgia, regarded as a separate biotic 
province by Knox (I960), shares Cladodactyla 
crocea, Trachythyone parva, Stereoderma laevi- 
gata, Neopsolidium convergens, Taenio gyrus 
contortus, and (with doubt) Anapta fallax with 
.southern Chile. 
Stereoderma laevigata is also known in the 
fauna of Marion Island and the Crozets. 
When considered overall, these islands have 
faunas which are similar to that of southern 
Chile, and the similarity is at the specific level. 
The dispersal of species to these widely sepa- 
rated areas is probably effected epiplanktonically 
(perhaps on rafts of seaweed), with the aid of 
the westwind drift. This is quite conceivable 
for such species as Stereoderma laevigata and 
Cladodactyla crocea, which commonly live on 
the fronds and holdfasts of Macrocystis, a brown 
seaweed which is found on all of the islands 
mentioned above. The westwind drift dispersal 
mechanism for echinoderms has already been 
discussed by Mortensen (1925), Fell (1953, 
1962 ) , and Ekman ( 1953 ) , and others. 
The holothurian fauna of southern Chile is a 
generalised fauna, containing few restricted spe- 
cies, and notable because of the number of spe- 
cies which are shared with distant islands, and 
the Antarctic continent. 
REFERENCES 
Bell, F. J. 1881. Echinodermata. In: Account 
of the Zoological Collections made during the 
Survey of the H.M.S. "Alert” in the Straits of 
Magellan and on the coast of Patagonia. Proc. 
Zool. Soc. London., 1881:100-101. 
1908. Echinoderma. National Antarctic 
Expedition 1901-04. Nat. Hist. IV. London. 
Brandt, J. Fr. 1835. Prodromus Descriptionus 
Animalium ab H. Mertensio Observatorum. 
Fasc. I. Petropoli. 
Clark, H. L. 1907. The Apodous Holothurians. 
A Monograph of the Synaptidae and Mol- 
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pis. I-XIII. 
1921. The Echinoderm Fauna of Torres 
Strait: Its Composition and Origin. Carnegie 
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1946. The Echinoderm Fauna of Aus- 
tralia: Its Composition and Origin. Carnegie 
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