Dear all, December 17, 1997
I received several interesting responses to my e-mail message regarding
"Morphotypes" in Kappaphycus/Eucheuma. As promised, I am now sharing them
with you. I should first comment that having worked on nutrients for now
quite some years (!), I am well aware that colours can change in seaweeds
due to environmental factors. What I am talking about here, however, is
plants that are, within a bracket of variations of shades, very stable in
their green, brown, and green-brown colorations. From the different
responses I received, I think I am now inclined to use the term "colour
variants"... interestingly, this was the term suggested to me by one of my
colleagues working on coral reefs, two doors down the hallway, before I
went to cyberspace to get your input! From the different responses, you
will also realize that the "business" of the so-called "morphotypes" in
Kappaphycus/Eucheuma seems presently to be another of these taxonomic
messes which make some phycologists happy and busy!
Thank you very much to all the people who contributed their thoughts, and
Season's Greetings to all of you.
From John Kessler:
Wouldn't be too good for cephalopods ... or some algae, e.g. Dunaliella
salina, that change colour depending on salinity, illumination..
From Edison Jose de Paula:
I prefer to call then as "color variants". But I have some other
interesting questions for you. I am growing Kappaphycus alvarezii, both
in laboratory and in the sea (S. Paulo, Brazil). I began my culture
experiments with a small branch brown in color (2,5 g fresh weight).
Them I propagated this branch in unialgal culture for 10 months and
after that I transferred to the sea. In the sea it appeared red and
green branches. This happened several times along the year in the sea
and once in the laboratory (one red branch). This was the way now I have
red and green variants. I do not have any information in the literature
that refers this finding, i.e. the high frequency of appearance of color
variants by vegetative propagation.
I also growth plants in the laboratory from tetraspores produced in the
sea. I found I high mortality rate of tetraspores. I grew only 21 plants
from tetraspores after a great efforts. All the 20 plants obtained are
very different one from another in morphology, color and growth rate.
Some of the best growing plants were transferred to the sea after 10
months and the remained very different one from another. Only two plants
survived all year round in the sea. They differed from the parent plants
also in growth rate and carragenan content. I am concluding that K.
alvarezii is an species of hybrid origin (at least the strain I am
studying). I will subscribe this paper to present at the ISS -
From Bill Henley:
I don't see any problem with referring to color variants as
morphotypes, assuming that they are genuine genetic variants (e.g. the
red/green genotypes of Gracilaria tikvahiae) and not just
physiologically acclimated to different light/nutrient regimes. Of
course, just by looking at them, there is no way to know which is the
case; for that controlled experiments are necessary.
From Larry Liddle:
Hi Thierry! When I was in Bali I went to a small
nearby island that cultivates Eucheuma (I believe).
Side by side in their harvested weed were dark red and
green plants with no other apparent morphological
differences. I thought it was interesting.
From Ralph Lewin:
Some chromoty-pes are induced by insolation or shade, others by one or more
genes. I'm sure you are aware of that already.
From Klaus Kowallik:
although I´m not a native English speaking person, the terms colourtypes and
colorotypes sound awkwardly to me. Secondly, as long as a morphological
character reflects environmental conditions (e.g. responds to changes in light
intensity and quality) and is not genetically inherited, the description of
morphotypes simply based upon coloration doesn´t make much sense. The reds are
particularly prone to such factors that influence the color of a population
at a single site (e.g. Laurencia pinnatifida or Gigartina stellata which
brownish green on the top of a rock, but dark red in the shadow).
From Eileen Cox:
I'm not sure we should use the term morphotype at all - strictly speaking it
refers to a SPECIMEN selected to represent a given intrapopulation variant.
We could as easily use the neutral term morph for the variants observed.
Another respondent implied that the variation should be genetically
controlled, not simply a result of environmental conditions, but it may not
be possible to determine that without longer investigation. Using morph to
describe what is seen permits recognition of variation and flags it for
I don't think it matters whether you are then referring to form or colour.
From Janet Kubler:
I would rather see them called colortypes or pigment- types if there
is no morphological distinction. There is a historical basis for
referring to naturally occurring color mutants in the work of John
Van de Meer. If there is a color linked morphological distinction I
would be extremely interested in hearing more about them.
From Mark Ragan:
(a) to what extent are these "types" really just clones, or strains? Do
they breed true? The idea of "type" seems like something out of the
Nineteenth century; why not try to move the discussion from phenetics to
(b) "there may be as many classifications of any series of natural, or
of other, bodies, as they have properties or relations to one another,
or to other things; or, again, as there are modes in which they may be
regarded by the mind." (Thomas Henry Huxley, An Introduction to the
Classification of Animals, 1869).
From Raul Rincones:
Kappaphycus alvarezii and E. denticulatum where introduced in Venezuela in
1995 from the Danajon Reef, Bohol, The Philippines. A total of 5 kgs of both
green and brown strains of each species arrived here and they have been
propagated vegetatively eversince. Now, we are in the commercial scale with
3 pilot farms in the NE coast of Venezuela. Our plan is to be able to
sustainable develop 200 Has using both the bottom and floating method.
I have been following their growing behaviour since their introduction and
have noticed the appearance of different morphotypes, not only in the colour
but on their growing characteristics,ramification, branching, thalli
diameter and elongation. These particular features are also linked with
their growing conditions such as light, nutrient, water motion, and
temperature to a lesser extent. Carrageenan yield has also been reported to
be different depending on the nutrients and light availability; conditions
that vary seasonally in different sites. This has made us conduct a research
in order to determine the optimal conditions and sites for commercial
farming, since growth rate and carrageenan yield are determinat parameters
It would be very interesting to exchange experiences and ideas on this
topic. We have to bear on mind the plasticity of both species, and define
what could be considered as a morphotype, due to the reversibility of
certain features that have been reported. For instance, K. alvarezii and E.
denticulatum are dark and brittle in one site and they drastically change
when they are grown in a more oligotrophic environment only 15 kms away!.
After less than 2 weeks, they start to look more flexible, loose their
strong pigmentation. On these new sites they have shown a higher carrageenan
content under conditions of lower nutrients and more light availability.
I would be more than glad to participate in the proposed discussion, even
better if we could exchange experiences. I am looking forward to hearing
from you soon
From Isabella Abbott:
I think that if you worked on Pacific Eucheumas, you would find a lot
of morphological morphotypes, some of which were handled by Doty in
Taxonomy of Economic Seaweeds, vol. 2, published by the California Sea
Grant Program (1988) where some previous morphotypes are given varietal
status--others are moved around in different species, etc. I don't have
the slightest interest myself in Eucheuma taxonomy (since it requires
extensive fieldwork which Doty had, and I don't have time for), but the
whole business came to a head when I had to write up Kappaphycus and
Eucheuma descriptions for the current Hawaiian red algal flora. That was
when push came to shove and the real morphotypes became realities. You
don't bother about chromotypes, color varieties, etc when you are swimming
around beds of things bigger than you are! What i am saying is that
there's a lot of morphology in Eucheuma that would make color differences
vanish! Best wishes anyway.
Dr. Thierry Chopin
Associate Professor and Associate Director of Graduate Studies
University of New Brunswick
Centre for Coastal Studies and Aquaculture
Department of Biology
P.O. Box 5050
Saint John, New Brunswick, E2L 4L5, Canada
Phone: (506) 648-5507
Fax: (506) 648-5650
E-mail: [log in to unmask]