6 - Sphaeromatidae::“Cute As Buttons”

Zoogeography
FAUNAL PROVINCES
The area under discussion has been divided into several faunal regions or
provinces, of which the Caribbean, West Indian, and Brazilian are the major
ones (Briggs, 1974). The extent and boundaries of the provinces have been
variously defined depending on the group of organisms under discussion.
Inevitably, zones of overlap exist, but for the purposes of this discussion, the
following rough limits have been used.
Brazilian Province: This province stretches from Cape Frio near Rio de
Janeiro in Brazil to the mouth of the Orinoco River in Venezuela. The out­
flow of freshwater from the major rivers of this region has probably contrib­
uted to the isolation of the Brazilian coral reefs and their associated fauna
from those of the Caribbean. This isolation is demonstrated by the consider­
able endemism of the Brazilian reef fauna and that of the Caribbean reef
fauna, with very few species being common to both.
Caribbean Province: This province has two components, a northern part
in peninsular Florida, that stretches from around Cape Kennedy on the east
coast to Tampa or Sanibel Island on the west coast, and a southern compo­
nent that runs from the mouth of the Orinoco River to around Cabo Rojo or
Tampico on the gulf coast of Mexico. The northern Gulf of Mexico is ex­
cluded from this province and is characterized as being warm-temperate,
rather than subtropical (Briggs, 1974:66).
West Indian Province: This includes all the islands of the West Indian
chain, the Bahamas, and the isolated outrider, Bermuda. The West Indian
Province closely approaches the Caribbean Province in the Yucatan Penin­
sula to the north, and between Grenada and Trinidad in the south. There is
also some indication of the isolating effect on the Bahamas of the Florida
Current through the Straits of Florida.
It has been suggested, on the basis of the molluscan fauna, that a relict of
the Neogene Gatunian Province exists around northern Venezuela and Col­
ombia (Petuch, 1982). While several isopod species have been recorded only
from this area, these are all described in a single paper that covers a very
small part of this region (Paul and Menzies, 1971). There is as yet too little
evidence to explore the idea of this relict fauna further.
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