Assiut university researches
Studies on Taxonomic and Morphology of
Marine Ostracods (Crustacea) in the Red Sea
Egypt
Studies on Taxonomic and Morphology of
Marine Ostracods (Crustacea) in the Red Sea
Egypt
Studies on Taxonomic and Morphology of
Marine Ostracods (Crustacea) in the Red Sea
Egypt
‫درا سات ت ص ن ي ف ية ومورف ول وج ية ع لى ب عض ان واع‬
‫األو س تراك ودا ال بحري ة (ال ق شري ات) ف ى ال بحر‬
‫األح مر م صر‬
Ebtsam Ahmed Youseif Abu Taleb
‫أب ت سام أحمد ي و سف أب وطال ب‬
Mohamed Ahmed Hussein, Ahmed Hamid Obuid-Allah, Azhar
Hussein Mohamed
‫أزهار ح س ين محمد‬
،‫ أحمد حامد ع بدهللا‬،‫محمد أحمد ح س ين‬
Abstract:
The Ostracoda are a class of small Crustaceans which occur
in practically every aquatic environment. In today`s oceans,
they are found living from the abyssal depths to the shoreline.
They also inhabit estuaries, lagoons, freshwater, lakes, ponds
and streams, salt lakes, hot spring and damp vegetation.The
most distinctive feature of the Ostracoda is the calcareous
bivalved carapace which can totally envelop the body and
limbs, but from which various appendages are protruded for
locomotion, feeding and reproduction. The shell or carapace
has numerous morphological characters which allow
taxonomic and phylogenetic studies to be made on living and
fossil specimens. Ostracods play an important role an
important role in the food web of aquatic environment, since
they are considere, with other zooplankton organisms, as
intermediate link between higher consumers and producers.
In recent years, interest in ostracods has greatly increased as
a result of the applications of micropaleontology to oil and gas
exploration. On reviewing literature and as can be
ascertained, it was noticed that the previous records on
Indopacific region and the Red Sea Coast of Egypt ostracods
are relatively scarce and nearly all the studies were carried
out by paleontologists and focused on the shell and fossils
only but the soft parts were neglected although they are used
in taxonomy of these animals. It is well known that the
majority of the Red Sea fauna are endemic, since it is
considered as a closed sea. This point adds to the important
of study of the unknown species. The present work was
designed to study the taxonomy and morphology of common
ostracods of the Red Sea Coast of Egypt. The preliminary
study and information indicated that the marine ostracod
species are associated in their distribution with macroalgae.
Samples were collected from nine sites; and one of them was
chosen as the main site for collecting seasonal samples
during a period, extending from June 2000 to March 2001;
872 specimens were collected. During collecting, some
ecological factors were measured including pH, salinity,
temperature of air and water and dissolved oxygen. The
scanning electron microscope was used to study the details
of the shell of the investigated species. The details of
appendages were drawn with the help of Camera Lucida. The
present investigation revealed that 8 common ostracod
species were collected with considerable numbers and about
12 species were collected with few numbers. So, the study
was focused on the common eight species. The study
indicated that eight common species belong to order:
Prdocopida from six families. These families are: (1)
Bairdiidae including one species (Neonesidea schulzi). (2)
Loxoconchidae including two species (Loxoconcha
ghardaqensis and Lpxoconchella dorsobullata). (3)
Xestoleberidae including one species (Xestoleberis rotunda).
(4) Hemicytheridae including one species (Tenedocythere
borchesi). (5) Trachylebrididae including one species
(Caudites sublves). (6) Paradoxostomatidae including two
species (Paradoxostoma altecaudatum and Paradoxostoma
transiens) The morphology of the above mentioned eight
species was studied in details including the shell and
appendages. The shells were compared with other studies
carried out in the Red Sea region and it was concluded that
slight differences exist between the same species. So, such
differences could be considered as intraspecific variations.
The original descriptions of some investigated species were
based only on the shell. So, the present study represent a
new contribution concerning the description in details of the
appendages.The distribution of the investigated species at
the nine sites of collection along the Red Sea Coast was
illustrated. The study revealed that the species Loxoconchra
ghardaqensis and Neonesidea schulzi are widely distributed.
The seasonal coleection of ostracods in the present study
indicated that the maximum total density of the ostrcod
species collected was recorded in Summer (350), while the
lowest was recorded in Winter (86). The ostracod namely
Loxoconcha gharadaqensis recorded the greatest density
during the wholew year (450 individuals) constituting 51.6%
of the total catch. This was also true during the different
seasons of collection. The minimum value of density during
the whole year was recorded for the species Caudites
sublevis (24 individuals) constituting 2.8% of the total catch.
The remarked increase of ostracods in Summer may be due
to the effect of temperature, since it was the only fluctuated
factor measured but pH, salinity, and dissolved oxygen were
nearly constant during collection. The study also revealed
that the distribution and the presence of the collected
ostracod species were strongly associated with algae. The
dominant species of algae collected were Bathrathospermum
sp.; Sargassum hornschuchil Sargassum vulgare sp. and
nereia filiform.