Brackish-Water Algae from Hawaii—A bbott 
OCCURRENCE OF ALGAE 
The ubiquitous Enteromorpha appeared 
in all stations of the ponds, in water ranging 
in salinity from that of the open ocean to 
almost fresh. Two distinct species, showing 
much variability, were recognized. The two 
species of Ulva present, on the other hand, 
showed distinct preference for the more 
saline portions. Cladophora, that trouble¬ 
some entity, was present in all situations; 
such distribution would lead one to believe 
that variations of marine and fresh-water 
forms are to be found mixed in the ponds. 
Other green algae did not occur in great 
quantity, as did the three just mentioned. 
True fresh-water algae (Spirogyra, des- 
mids) were recorded from the fresh-water 
ponds. 
The only brown alga found was Ectocar- 
pus indicus, which occurred as a common 
epiphyte on other algae as well as on other 
plants. The variation shown by this species 
led to a critical examination of all species 
which might be growing in this area. The 
results, which are included with the species 
description, require placing in synonymy 
two species, one of which was so placed 
quite independently of Boergesen (1941). 
The red alga collected most frequently 
(from all but two ponds) was a species of 
Polysiphonia, described here as new to sci¬ 
ence. Another species of Polysiphonia found 
abundantly in fresh water could not be iden¬ 
tified with the foregoing species, nor with 
any other, as it lacked reproductive organs. 
This seems to be a new record for the occur¬ 
rence of this genus in fresh water (chlorin- 
ity values were 2.48 to 2.54 parts per thou¬ 
sand). This species was found in a fresh¬ 
water pond, strangely called Salt Lake, which 
is apparently fed by subterranean wells. An 
old connection with the sea has apparently 
been sealed off. Other red algae found in 
some quantity are Erythrotrichia carnea, 
Centroceras clavulatum, and species of Cera- 
195 
mium. The red algal species were nearly in 
contact with the ocean and thus may be 
thought to be marine, with the exception of 
the fresh-water Polysiphonia. 
KEY TO THE ALGAE 
A simple key is presented to aid the inter¬ 
ested reader with some botanical training to 
identify as far as genera the algae found in 
the fishponds. Technical terms have there¬ 
fore been reduced to a minimum. 
PartI. Chlorophyceae. The grass-green 
algae. 
1. Plants with uninucleate cells.2 
1. Plants multinucleate or with multi- 
nucleate cells ...4 
2. Parenchymatous .3 
2. Filamentous, unbranched, free- 
floating, with spiral chloroplasts 
. Spiro gyra, p. 196 
3. Tubular plants, one layer thick in 
section ... Enteromorpha, p. 196 
3. Foliose plants, membranous, with 
simple to cleft margins, two layers 
thick in section. Ulva, p. 197 
4. Filaments unbranched .5 
4. Filaments profusely branched.7 
5. Entangled.6 
5. Attached, rhizoids only from the 
basal cell, cells often bulbous. 
. Chaetomorpha, p. 197 
6. Floating, or if attached with short 
rhizoidal branches along the en¬ 
tire attaching length, with few to 
several nucl eL.Rhizoclonium, p. 197 
6. Matted, completely multinucleate, 
non-septate except at the location 
of reproductive organs. 
. Vaucheria, p. 198 
7. Plants in bushy soft tufts, the 
branches lateral, opposite, alternate, 
or fascicled, cut ofif from the main 
axis .. Cladophora, p. 198 
7. Branches not cut ofif from the main 
axis 
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