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level appropriate to two distinct, though
closelyrelated, species. The researchers
conclude that the Indonesian specimen is a
new species, and have named it Latimeria
menadoensisafter the island where it was
discovered.
Using a 'molecular clock' (determining the
rate of ta gene's evolution by plotting
percentage differences in base sequence
against time) they believe the two species
diverged about 1.5 million years ago. This is
a relatively recent event, considering
coelacanths' long history.
The Indonesian coelacanth was taken
from the submarine slopes of a geologically
young volcanic island, a similar environment
to the habitat of the Comorean species.
Crevices in the lava make ideal refuges for
the nocturnal fish. Recent studies have
shown that although coelacanths can move
several dozens of kilometres between caves,
as semi-sedentary fish, they are unlikely to
have migrated nearly 10,000km, negotiating
the abyssal troughs on that way from the
Comoros to the Indonesian coast. Speciation
probably occurred as a result of long
geographical isolation.
Latimeria menadoensismay not be limited
to the area to the north of Celebes.
Coelacanth sightings have been reported from
elsewhere in the Indonesian archipelago.
Erdmann M.V., Caldwell R.L. & Kasim Moosa
M. 1998. Indonesian "king of the sea"
discovered. Nature395, p. 335.
Forey P. 1998. A home from home for
coelacanths. Nature395, p. 319-320.
Pouyaud, L., S. Wirjoatmodjo, I. Rachmatika,
A. Tjakrawidjaja, R. Hadiaty, W. Hadiaty,
W. Hadie; A new species of coelacanth.
C. Combes; Coelacanths : metapopulation
or clade? Both in Comptes Rendus de
l'Académie des Sciences, 4 April 1999.
The Times 25.3.99, p13
Weinburg, Samantha 1999. A fish Caught in
Time. The Search for the Coelacanth.
Fourth estate, Lond 239pp [St 13.99
[see also Final reflections below]
*****************
CONODONT CORNER
CON-NEXUS
In August 1998 the Pander Society
sponsored thelaunch of an international e-
mail discussion group dedicated to conodonts
and all conodont-related matters. As well as
providing a forum for discussion between
conodont workers, con-nexus is used to
circulate Pander Society information rapidly to
conodont specialists.
Anyone wishing to subscribe to con-nexus
should simply send the message: subscribe
con-nexus xxxx@xxxx.xx.xx (where
xxxx@xxxx.xx.xx is your e-mail address) to
listserv@le.ac.uk.
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THE PANDER SOCIETY (for people
interested in conodonts) IS ON THE WEB
AND CONTACT VIA
'pandersoc@le.ac.uk'
*****************
Anne Kemp, Centre for Microscopy and
Microanalysis, University of Queensland,
St. Lucia, Queensland 4072, AUSTRALIA.
Ichthyolith Issues20: A Refined Method
for the Staining of Organic Remnants in
Conodont Elements
Attempts to demonstrate that conodonts
are or are not vertebrates have applied
many different techniques, including the
use of histochemical dyes that are
specific for certain components of
mammalian tissues (Kemp & Nicoll 1996,
Savage et al. 1990). Detailed biochemical
analyses have confirmed that amino acids
found in collagen are present in the
hyaline tissue of conodont elements, but
attempts to isolate peptide fragments from
well preserved conodonts have not been
successful. This has prompted a
modification of the techniques used to
demonstrate the presence in conodont
elements of remnants of molecules such
as collagen, as well as a reanalysis of the
results. In addition, a method for making
permanent preparations of stained
conodonts has been designed, to improve
histological analysis of elements.
Clean, unaltered conodonts are
placed on a glass slide and decalcified
with 0.1M HCl in 10% formalin for 10-20
minutes, depending on the specimen. The
decalcification process is monitored under
a microscope. When the conodont element
begins to show evidence of decalcification
around the edges, the formalin acid
mixture is carefully drawn off and the
element is covered with stain, without first
washing the element. Stain is applied to
the decalcified element at a concentration
of 0.1% in a suitable buffer for up to 20
minutes to detect residues of organic
matter. Contamination with extraneous
material during handling is prevented by
using clean containers and slides and by
filtering solutions before use.
Staining must be monitored under a
microscope because of the acidic nature
of many of the chemicals used. Thorough
washing in distilled water follows staining,
until all free stain is removed. Stained
elements are dehydrated in a graded
series of alcohols, cleared in xylene and
mounted in DePeX. These preparations
are permanent, and the stain is stable.
The most effective stain is Sirius red,
dissolved in saturated picric acid. This is
considered specific for collagen in
mammalian material.Alcian blue, a stain
for chondroitin sulphate found in cartilage,
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