Abstract:
One hundred and thirty-nine species of planktonic, edaphic, epioikotic, epiphytic
and epilithic green algae belonging to 3 phyla, 5 classes, 13 orders, 14 families and 26
genera have been collected from various freshwater habitats in the north-eastern areas of
Pakistan. For this purpose several districts of the Punjab e.g. Gujranwala, Jauharabad,
Jhang, Kasur, Lahore, Sargodha, Shiekhupura and Sialkot, certain areas of Attock and
Swat in N.W.F.P. like Bahrain and Kalam as well as Chenari, Muzaffarabad and Neelum
Valley in Azad Kashmir were surveyed during December 2003 and July 2005. They have
been morphologically and cytologically investigated, taxonomically determined and
described on the basis of such characters. Although all of them appeared to be
taxonomically known species, but most of them were described for the first time from
their area of collection.
As a result of taxonomic studies members of the phylum Chlorophyta with 22
genera and 127 species were found to be more prevalent than other two phyla of green
algae, while Vaucheriophyta included 3 genera and 10 species and Charophyta contained
only 1 genus with 2 species and thus appeared to be the smallest phylum in diversity.
Zygnemales was the most commonly distributed order with 5 genera and 63 species (45.3
%). It was followed by the order Oedogoniales with 2 genera and 28 species (20.1 %),
while Prasiolales, Sphaeropleales and Botrydiales were poorly distributed orders with
only 1 genus and 1 species each (0.7 %). As a result of that Zygnemophyceae appeared to
be the most highly distributed class with 7 genera and 91 species (65.5 %) as compared to
others. It was followed by the class Ulvophyceae with 11 genera and 25 species (20.1 %).
The class Siphonocladophyceae appeared to be the least distributed class of the phylum
Chlorophyta having 4 genera and 8 species (5 %).
Spirogyra with its 42 species was the most commonly occurring genus. It was
followed by the genera Oedogonium with 26 species and Zygnema with 10 species. Next
common were the genera Ulothrix with 8 species and Zygnemopsis with 6 species. Except
Ulothrix all these genera belong to the class Zygnemophyceae. Poorly distributed genera
were Binuclearia, Chaetophora, Cylindrocapsa, Geminella and Heterothrichopsis among
class
Ulvophyceae,
Hallasia
among
Zygnemophyceae,
Sphaeroplea
among
Siphonocladophyceae and Botrydium among class Vaucheriophyceae, which were
represented by a single species each. Aphanochaete, Bulbochaete, Chara, Cladophora,
Coleochaete, Pithophora, Tribonema and Uronema were slightly better in their diversity,
as each of them was represented by two species each.
An overwhelming amount of the collected species was found in the free-floating
or planktonic condition (75. 5 %). Next category of habitats, in which they were
collected, is epiphytic condition (15. 8 %). Only a few species occurred in the edaphic
and epilithic conditions (3.6 %), and epioikotic condition was the least occurring habitat
(1.4 %). No epipsammic or epipelic alga was collected. These conditions were mainly
represented by species of the phylum Chlorophyta. In the phylum Vaucheriophyta no
species was found in the epioikotic or epilithic condition. Among Charophyta, apart from
epilithic and epiphytic habitats all the other categories were missing.
Largest number of species was found in the Lahore District (17. 3 %), which was
followed by the collections made from Sheikhupura District (14 %). This was further
followed by Kasur and Sialkot districts (12.1 % each). The cold areas of Swat and Azad
Kashmir also displayed an appreciable number of species (9.3 & 9.8 % respectively). The
areas of Attock and Pasroor were quite poor in the distribution of algae (3.3 %). Smallest
number of species was observed in Sargodha and Jauharabad districts (1.9 & 2.3 %)
respectively). The class Zygnemophyceae was well represented at all the 12 localities, but
the
class
Ulvophyceae
was
not
found
at
Sargodha
District.
The
class
Siphonocladophyceae was not present at several localities. The phyla Vaucheriophyta
and Charophyta were found to be poorly represented at several localities, due to small
number of species collected.
Spirogyra was the most commonly collected genus, found at all the investigated
localities except Sargodha District. Next to it was Zygnema, which was further absent at
Jauharabad District. Further next were Ulothrix and Oedogonium, which were collected
from
different
localities.
Binuclearia,
Botrydium,
Geminella,
Hallasia,
Heterothrichopsis and Sphaeroplea were the least occurring genera, they were collected
from one locality only. While Aphanochaete, Bulbochaete, Chaetophora, Chara,
Coleochaete, Cylindrocapsa, Tribonema and Uronema were slightly better, as they
occurred at two different localities.
The largest number of collected species was found in spring (31.6 %), their
frequency of occurrence remained almost the same during summer and winter (24.6 &
26. 3 % respectively), and they were collected in smallest number in autumn (17.5 %). It
appeared that they started growing in winter, reached to a maximum growth during spring
and began to disappear in autumn. The seasonally resistant most common genera were
Oedognium, Pithophora, Spirogyra, Stigeoclonium, Ulothrix and Zygnema, which were
found to grow in all the four seasons. Binuclearia, Cylindrocapsa, Geminella and
Hallasia were only collected during spring, Heterothrichopsis was only found in
summer, Chaetophora and Chara occurred only during autumn, while Aphanochaete,
Botrydium and Sphaeroplea thrived only in winter. Species of these genera could not be
collected during other seasons. The remaining genera were found in certain seasons of the
year but remained absent during others.