اسم المؤلف:
افراح محمد علوان الجبوري
اسم المشرف:
هيفاء جواد جوير
المستخلص:
انواع تحت العائلة Tubificinae ديدان مائية حمراء اللون يتراوح طولها مابين 1سم الى عدة سنتمترات وقطرها حوالي 1ملم تنتمي الى العائلة Naidiadae، الصنف الثانوي قليلة الاهلاب، صنف السرجيات التابع لشعبة الديدان الحلقية، وتسمى عاميا" بديدان الوحل. تقطن هذه المجم | Species of Subfamily Tubificinae are aquatic red worms, their length ranged between 1cm to several centimeters, and their diameter about I mm, and they are classified with Family Naididae, subclass Oligochaeta, class Clitellata, phylum Annelida. They are commonly called "sludge worms". This group inhabit the rivers, lakes and ponds sediment, and some species also found in marine habitat, they are considered as one of the main benthos components specially in freshwater, with increase abundance in soft sediment rich in organic matters. Sludge worms individuals are hermaphrodite, reproduced sexually by cross - fertilization, eggs led in cocoon and hatched directly without any larval stage. They are also reproducing asexually by ArchitomyAccording to the economic importance of this worms as good food for fish, their ecological role as well known bio - indicators, little studies about their identification were available and absence of check list of their species in Iraq, the present investigation idea was come to concern primarily with sorting and identification of subfamily Tubificinae from River Tigris and some water surface in Baghdad /Iraq. For this purpose six study sites were chosen, including a drainage canal, North Baghdad (S1); three sites on the shore of River Tigris (S2, S3 & S4) ; in addition to site in Al - Jeish canal, East Baghdad (S5), finally the sixth site was from pond in Al - Zawra'a park, within the center of Baghdad (S6). These sites were characterized by sedimenet rang from clay, silty - clay to silty with a percentage of organic matter ranged between higher percentage of 9.9% in site S5 and 0.7% as a lowest percentage in site S1. According to water temperature, salinity and pH values, they were identical in all study sites.3628 individuals were sorted from 24 samples collected from all study sites. The sorting results revealed that the highest number of worms (1346 ind.) recorded in site S5, while the lowest number (326ind.) recorded in site S4. Twelve species were identified belonging to seven genera, and Limnodrilus was the most dominant genus. Five species were considered as new records to Iraq, which are L. silvani in S6, P. hammoniensis & Monopylophorus irroratus in P. moravicus in S2 and Rhyacodrilus cocciensis in S6.Five species of Limnodrilus were recorded, including L. hoffmeisteri, L. claparadienus, L. profundicola, L. udekemianus, and L. silvani with a percentage of 52%, 1.40%, 4%, 10.03% and 0.35% for each species respectively. Two species of Potamothrix were recorded which are P. bavaricus and P. hammoniensis with a percentage of 2% and 2.05% respectively, in addition to Branchiura sowerbyi, Psammoryctides moravicus, Tubifex tubifes, Rhyacodrilus cocciensis, and Monopylophorus irroratus with a percentage of 26.07%, 0.33%, 3%, 0.27, and 0.24 respectively. The higher frequency percentage of 100% was recorded by L. hoffmeisteri and B. sowerbyi.High densities of Tubificinae were recorded during all study period. Higher density of 6882 ind./m2 was recorded during in site S1; 4296 ind/m2 in site S2 ; 4496 ind/ m2, ind/ m2in site S3; 3730 ind/ m2 in site S4; 15218 ind/ m2 in site S5 and 7026 ind/ m2 in site S6.The results of relative abundance revealed that L. hoffmeisteri was the dominant species in site S3 and abundant in other study sites. B. sowerbyi was abundant in all study sites, while other species were recorded between few to rare species except L. udekemianus which was abundant in site S5, and T. tubifex in site S4. It was clear from species richness index, Shannon - Wiener diversity index, and species uniformity index, that the highest value for each index was recorded during cold months (Dec. - Feb.), 1.47, 2.83bit/ind, and 1.17 respectively, while the result of cluster analysis depending on Jaccard index of similarity revealed that the highest similarity of 80% found between S1& S6.The investigation also includes description of identified species and photos of identification criteria for each species. B. sowerbyi was easily recognized from other species by having gill filaments at the posterior end of the body. Species of Limnodrilus were characterized by the absence of hair chaetae, and they are differentiated by the shape of penis sheath, due to the close similarity of chaetal shapes, with the exception of L. udekemianus in which its anterior chaetae characterized by long and curved dorsal tooth. Species of Potamothrix were recognized by the presence of a pair of spermathecal chaetae, its shape was used to differentiate between P. hammoniensis, which have long gutter - shape and P. bavaricus, which have plade - like shape with triangle base. P. moravicus also have spermathecal chaetae but it was differed from that of Pomatothrix species by its long and narrow shape. T. tubifex was identified by its tub - shaped penis sheath, while R. cocciensis, was recognized by their penial chaetae in segment NO. XI, and M. irroratus by the presence of pseudopenis and its sheath.
