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Seed shrimps
1. ““Freshwater seed shrimps (Ostracoda:Freshwater seed shrimps (Ostracoda:
Podocopida) from lakes of Sindh, Pakistan”Podocopida) from lakes of Sindh, Pakistan”
Mukhtiar Ahmed MaharMukhtiar Ahmed MaharMukhtiar Ahmed MaharMukhtiar Ahmed Mahar
Department of Fresh Water Biology and Fisheries,Department of Fresh Water Biology and Fisheries,
University of Sindh, Jamshoro, Sindh, Pakistan.University of Sindh, Jamshoro, Sindh, Pakistan.
2. IntroductionIntroduction
Ostracodes are referred as “seed Shrimps” because due to their shapeOstracodes are referred as “seed Shrimps” because due to their shape
and small size, they look like small seeds.and small size, they look like small seeds.
The body is enclosed in a bivalve, calcified shell (carapace).The body is enclosed in a bivalve, calcified shell (carapace).
They are found in marine, brackish and freshwaters.They are found in marine, brackish and freshwaters.
Order Ostracoda is divided into three suborders (i) Myodocopida (ii)Order Ostracoda is divided into three suborders (i) Myodocopida (ii)
Platycopida and (iii) Podocopida. First two suborders are represented inPlatycopida and (iii) Podocopida. First two suborders are represented in
marine and members of the third are found in freshwater (Pennak,marine and members of the third are found in freshwater (Pennak,
2001). About 5000 species of Ostracodes are known from various2001). About 5000 species of Ostracodes are known from various
habitats (Oliverhabitats (Oliver et al.et al., 2000)., 2000).
They play important role in aquatic ecosystem as source of natural food forThey play important role in aquatic ecosystem as source of natural food for
benthivorous fish.benthivorous fish.
As there is paucity of data on Ostracodes of Pakistan, present study wasAs there is paucity of data on Ostracodes of Pakistan, present study was
initiated to supply baseline information for future research.initiated to supply baseline information for future research.
3. MATERIALS AND METHODSMATERIALS AND METHODS
Three lakes of Sindh, Keenjhar (Distt: Thatta), Manchhar (Distt: Dadu) andThree lakes of Sindh, Keenjhar (Distt: Thatta), Manchhar (Distt: Dadu) and
Chotiari (Distt: Sanghar) were surveyed for the collection of seed shrimpsChotiari (Distt: Sanghar) were surveyed for the collection of seed shrimps
during 2008-09.during 2008-09.
Random sampling was carried-out by using No. 25 plankton net (mesh sizeRandom sampling was carried-out by using No. 25 plankton net (mesh size
55µm).55µm).
Some specimens were also collected from algal mates in shallow, weedySome specimens were also collected from algal mates in shallow, weedy
marginal areas.marginal areas.
The samples were preserved in 5% formalin solution for studies in theThe samples were preserved in 5% formalin solution for studies in the
laboratory.laboratory.
Identification was carried with the help of taxonomic keys (Ward andIdentification was carried with the help of taxonomic keys (Ward and
Whipple, 1976, Bronshtein, 1988 and Pennak, 2001).Whipple, 1976, Bronshtein, 1988 and Pennak, 2001).
Photographs were taken with a digital camera DCM 35 (350 K Pixels, USBPhotographs were taken with a digital camera DCM 35 (350 K Pixels, USB
1.0, mounted on the trinocular microscope (Nikon, Eclips E-200 and Swift1.0, mounted on the trinocular microscope (Nikon, Eclips E-200 and Swift
300-D).300-D).
4. ResultsResults
Five genera and species of seed shrimpsFive genera and species of seed shrimps
recorded from Pakistan in the presentrecorded from Pakistan in the present
study.study.
6. Cypris subglobosaCypris subglobosa (Sowerby, 1840)(Sowerby, 1840)
Shell some what globular in dorsal view,Shell some what globular in dorsal view,
length 1.19 mm,length 1.19 mm,
height 0.7mm,height 0.7mm,
width 0.62mm,width 0.62mm,
8. Dolerocypris simensisDolerocypris simensis (Sars, 1903)(Sars, 1903)
Shell elongated, slightlyShell elongated, slightly
convex dorsally, ventral marginconvex dorsally, ventral margin
straight.straight.
Length 2.02mm, widthLength 2.02mm, width
0.72mm. Anterior margin more0.72mm. Anterior margin more
rounded then posterior.rounded then posterior.
Anterior margin bears marginalAnterior margin bears marginal
bristles.bristles.
Shell fairly transparent,Shell fairly transparent,
yellowish brown in colour, ayellowish brown in colour, a
yellowish green spot extendsyellowish green spot extends
across the shell. Six,across the shell. Six,
elongated muscle attachmentelongated muscle attachment
scars visible in the centre ofscars visible in the centre of
shellshell
9. Herpetocyperis fontinalisHerpetocyperis fontinalis (Bronshtein, 1928)(Bronshtein, 1928)
Shell elongated, surfaceShell elongated, surface
covered with small setae.covered with small setae.
Length 1.49 mm, widthLength 1.49 mm, width
0.49 mm and height 0.540.49 mm and height 0.54
mm.mm.
Anterior portion of shellAnterior portion of shell
broadly rounded, whilebroadly rounded, while
posterior portion distinctlyposterior portion distinctly
narrow.narrow.
10. Cypridopsis obesaCypridopsis obesa (Brady and Robertson, 1877)(Brady and Robertson, 1877)
Shell roughly sub-globular,Shell roughly sub-globular,
anterior side broadly roundedanterior side broadly rounded
while posterior end truncated.while posterior end truncated.
Length 0.67 mm, width 0.4 mmLength 0.67 mm, width 0.4 mm
and height 0.34 mm.and height 0.34 mm.
11. ConclusionConclusion
Gurney (1920) reported six species from westernGurney (1920) reported six species from western
Balochistan, while Arora (1931, 1935) recorded 10Balochistan, while Arora (1931, 1935) recorded 10
species from Lahore city and 6 species from Karachispecies from Lahore city and 6 species from Karachi
area respectively. Later on, one speciearea respectively. Later on, one specie StenocyprisStenocypris
fontinalisfontinalis was reported from Lahore area (Mahoon andwas reported from Lahore area (Mahoon and
Sultana, 1977; ChowdhrySultana, 1977; Chowdhry et alet al., 1986). As two species., 1986). As two species
are common from Sindh and Balochistan, in all 21are common from Sindh and Balochistan, in all 21
species have already been reported from Pakistan thespecies have already been reported from Pakistan the
present new record of 5 species from Pakistan (Lowerpresent new record of 5 species from Pakistan (Lower
Sindh) is an addition to already known freshwaterSindh) is an addition to already known freshwater
Ostracod fauna of Pakistan.Ostracod fauna of Pakistan.
