Taxonomia, distribuição geográfica e filogenia do gênero Codium

Oliveira-Carvalho, M. F. Taxonomia, distribuição geográfica e filogenia ... 4
ABSTRACT
Codium Stackhouse is a genus exclusively marine which is represented by 125 taxa
and it is distributed in the seas of almost the whole world, except for the polar
regions. The highest infrageneric diversity is found in the temperate and subtropical
zone seas. In Brazil, there are few informations about the genus, and the majority of
the studies deals with floristic surveys from many localities, with just few publications.
The aim of this work is to present the survey of this genus with emphasis to its
taxonomy and the distribution of its representatives. The morphological studies were
based in material collected from many Brazilian states (PB, PE, BA, ES, RJ, SP, SC
and RS), in the intertidal region, during the low tides, with the help of spatulas and
when necessary through diving in the reef ponds. The specimens were preserved
with formalin (4%). For a better comprehension of the phenotypical variations and
aiming to contemplate a number of samples as high as possible in the Brazilian
states, the material of Codium was studied in the following indexed national herbaria:
JPB, PEUFR, ALCB, HUEFS, RB, R, HB, RFA, SP, SPF and FLOR. They were also
analyzed the exsiccates of the specimens collected by the Almirante Saldanha,
Canopus and Recife Commission oceanographic expeditions. Besides, were
analyzed as exsiccates of Codium from Brazil deposited in the Herbarium of the
University of California, Berkeley (UC). All the exsiccates were carefully analyzed and
confirmed and/or corrected as for the identifications. The identification of the taxa
was based in morphological characters (habit, ramification pattern and the
dimensions of the stalks), anatomical (diameter of the medular filaments, morphology
and dimensions of the utricula and disposition of the hairs or scars) and reproductive
(morphology, dimentions and insertions of the gametangia). In the Brazilian coast, it
was registered the occurrence of seven infrageneric taxa, distributed in the following
sections: Adhaerentia (C. Intertextum), Spongiosa (C. spongiosum), Tomentosa (C.
isthmocladum, C. repens and Codium sp.) and Elongata (C. decorticatum and C.
taylorii). From this work, C. tomentosum is considered as a doubtful species to the
Brazilian littoral and C. profundum as “nome nudum” and because of this, cited as
Codium sp. As for the great morphological plasticity the species C. decorticatum, C.
isthmocladum and C. taylorii were those which showed the greatest difficulties in the
taxonomical identification. Three species of straight habit as C. isthmocladum, C.
decorticatum and C. taylorii and prostrate habit C. intertextum were those which
presented the highest distribution in the Brazilian coast. Through the present study,