The first cave dwelling fish was discovered in the 1820s and the first named
species (Amblyopsis spelaea) was described from Mammoth Cave in 1842. Since
then cave fishes have been discovered in 27 countries world wide and there
are now 79 described species. At the turn of the millennium there will be
roughly 100 known cave fishes. What will happen to these in the next few
decades and how might these numbers change? It seems certain that the number
of known species will increase. In 1960 there were 27 species, 1970 35, 1980
39, and 1990 59 and in 1998 79. If this rate of discovery remains constant
there will be 85 species by 2000, 125 by 2010 and 200 by 2020. At the same
time it is possible that known species will become extinct. Three
species(Clarias cavernicola, Namibia; Speoplatyrhinus poulsoni, USA;
Glossogobius ankaranensis, Madagascar) are assessed as critically endangered
by IUCN. Two are assessed as endangered (Prietella phreatophila and
Ophisternon infernale, both in Mexico) and no less than 46 as vulnerable.
This is 63% of all known species. One of the critical needs of the next few
years therefore is for conservation assessments so that conservation effort
is directed to the right places. A central plank of this must be accurate
population assessment. A second will be an examination of the molecular
genetics of demes. Sbordoni et al., working on Somali species, Noltie et al.
on Amblyopsids, and Borowsky on Mexican and Thai animals, have all shown
that morphological species are in fact several to many isolated populations
all of which may merit specific identity. If this assessment is accepted it
makes the conservation task more difficult if we wish to preserve the
genotypes of these populations as well as the phenotype. Over 50% of all
known species are from only five countries (China, Mexico, Brazil, USA and
Thailand) and in all of these human population pressure will continue to
increase. In summary the next few decades will see a large increase in the
number of described morphological species (and perhaps many more "molecular"
species). One or two species may well become extinct and a great many more
will suffer declines in population or in habitat quality. Ideally we would
like to protect many or all of these in situ but it does not seem realistic
that we can achieve this. Perhaps the most critical need in the next few
decades is to start captive breeding of as many as we can. This is a
daunting task.
Graham S. Proudlove
Department of Language Engineering
UMIST Manchester M60 1QD
United Kingdom
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