Turbellarian taxonomic database

Symsagittifera bifoveolata Notes


Gschwentner R, Baric S, Rieger R 2002 (citation)- New species and description of Symsagittifera corsicae; study
of formation and function of sagittosysts; body-wall musculature, morphological features and 18S rDNA
sequencing.  Discusses other species including: Symsagittifera sagittifera, Symsagittifera bifoveolata,
Praesagittifera shikoki, Convolutriloba longifissura, Symsagittifera poenicea.  

Kostenko AG, Mamkaev YuV 1990 (citation)- p 21, "Green convoluts possessing symbiotic algae and sagittocysts
are
isolated into a genus Simsagittifera [Symsagittifera] which is also characterized by a weakly pronounced
ciliated antrum, ciliated vagina, and a thin sclerotized nozzle of bursa; the seminal vesicle does not have
its own walls.  Seven species are referred to the genus, they are:  S. schultzei (O. Schmidt, 1852), S.
roscoffensis (Graff, 1891), S. japonica (Kato, 1951), S. macnaei (Du Bois Reymond Marcus, 1957), S.
psammophila (Beklemischev, 1957), S. bifoveolata (Mamkaev, 1971), S. nitidae (Yamasu, 1982).  A detailed
revision of S. psammophila is given.  The comparative description of its reproductive apparatus contains new
data on S. bifoveolata and S. schultzei."

Mamkaev YuV, Kostenko AG 1991 (citation)- "On the phylogenetic significance of sagittocysts and copulatory
organs in acoel turbellarians."

[from Mamkaev, 1971 (citation), translated by Anatoly Petrov]
Convoluta bifoveolata was first encountered by I. B. Raikov in summer 1962
in the Adreev bight (Ussuriiski Bay). This species was observed there in
large numbers at a depth of about 60 cm in clean medium sand (the average
size of sand grains is 0.5 mm). In the Posiet (Pos'yet) Bay this species
was found off the eastern coast of the Expedition Bay (to the north from
the Cape Shelekh and at the cliffs which mark the end of the Churhado
spit). Near Cape Shelekh, it lives at a depth of 1-2 m, inhabiting in vast
numbers coarse sand with detritus; at a depth of 3-4 m it could no longer
be found. At the Churhado spit, C. bifoveolata was encountered in clean
sand at a depth of 3-4 m. It was also found at the shoal (depth of ca. 50
cm) off the western shore of the Churhado spit, but in small numbers. C.
bifoveolata was also found in the Sivuch'ya Bay and near the Furugelm
Island. In the Sivuch'ya Bay it was observed in the mouth of the creek
flowing out of the salt Lake Tal'mi (depth of 1-1.5 m, large clean sand),
and at the Cape Fal'shivyy Ostrovok (False Islet) predominantly at a depth
of 3-4 m; at a depth of about 5 m these convolutas are more scarce. At the
Furugelm Island, this species populates in vast numbers the coarse sand
with gravel at a depth of 2-5 m; it disappears toward the depth of 8-10 m.

Several characteristic features for the biotope of this species emerge from
our data. The species inhabits a relatively coarse-grained substratum (from
medium-grain sand to coarse sand with gravel), clean or with a bit of
detritus, but it never lives in the intertidal zone of open beaches. Also,
it cannot withstand any significant increase in detrital content and
siltation, which occurs with increasing depth. As a result, it inhabits a
deeper zone on open shores than in closed bays, where it can live in the
shallowest areas. Thus, for instance, near the Furugelm Island it is
numerous at a depth of 2-6 m and in the open Sivuch'ya Bay at the depth of
3-4 m, while in more quiet stretch of the bay, in the mouth of the creek,
it rises higher (up to 1 m depth). In an inner, relatively quiet region of
the Pos'et Bay it never reaches deeper than 2 m; near the end of the
Churhado spit, where there are strong currents it descends much deeper,
while in the closed area near the cliffs it rises up to 0.5 m depth. These
features of the biotopes of C.  bifoveolata suggest that the limiting
ecological factors for the given species are strong water turbulence,
on one side, and siltation of the sediments, on the other.

In comparing the biotopes of C. bifoveolata, it should be taken into
account that in the open areas of the coast, where it occurs at greater
depth, the water is much clearer, than in closed areas, e.g. in Expedition
Bay. It may be assumed that this factor also has considerable importance
for C. bifoveolata, as it contains symbiotic algae, zoochlorellae, that
need a sufficient irradiation for photosynthesis.  However, the lower
border of the biotopes of the given species is probably not determined by
irradiation. This assumption is supported by the fact, that C.  furugelmi,
found near the Furugelm Island in close proximity with C.  bifoveolata,
lives at such depth (6-8 m), where the latter is never encontered.

Notes from synonyms

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