Author name:
الهام عبيد صالح الجنابي
Supervisor name:
هيفاء جواد جوير
Abstract:
تعد ديدان قليلة الاهلاب المائية مجموعة حيوانية تضم انواعا مهمة من الناحية الاقتصادية والعلمية كونها غذاء جيدا للاسماك، ودورها في النظام البيئي بوصفها مؤشرات حياتية معروفة في تقييم نوعية المياه ودرجة تلوثها. وبسبب قلة الدراسات التشخيصية وعدم وجود قائمة خ | Aquatic oligochaete worms is an animal group that contains important species, economically speaking as its being a good fish food, and its scientific role in the ecosystem as well known bio - indicator for assessment water quality and evaluate the degree of water pollution. Due to little identification studies available about this group, and the absence of Iraqi checklist of species, the idea of the current study came, which concerned with the community of aquatic oligochaetes worms in the middle sector of the Euphrates River. Three sites have been chosen for this purpose, the first site is on the Euphrates River in the district of River at Al - Mussayab city (S1) and two streams branched from it, including Al - Mashroo'a stream (S2) and Abu - alasafeer stream (S3).These sites are characterized by sediment texture ranged from silt - sandy sediment in S1, sandy in S2 and Sandy - Clay in S3, the percentage of organic matter in the sediment ranged between1.8 - 2.6 % in S1, 0.7 - 1.9% in S2, and 4.8 - 6.4 % in S3. As far as plants concern, the presence of reed plant Phragmites australis, Potamgeton crispus plant, Hydrilla verticellata plant, and some filamentous algae in all study sites.Total of 1720 individuals of aquatic oligochaeta have been sorted out during the study period from all sites representing 37 species belong to the family Lumbricidae, Tubificoid naidid worms, Naidid worms of subfamily Naidinae and subfamily Pristininae, and finally, family Aeolosomatidae. Eleven species were considered as new records for Iraq. Regarding study sites, S2 recorded a least number of individuals and number of species, while the number of individuals and number of species were converged at S1 and S3. Results of the Species Richness Index showed that the highest value was recorded at the S3 and reached 8.37, while Species Uniformity Index, ranged between the highest value of 1.88 at the S3 and lowest value of 1.60 in S2, and finally in S1 it was 0.85. Shannon - Weiner diversity Index, recorded its highest value of 6.33 bits / individual in the S3, and lowest value has in of 2.78bits/individual in S1, but it was 4.80 bit / individual in S2. The Results of Jacquard Presence - Community values of similarity showed that the highest degree of similarity is (58.62%) recorded betwen S1 and S2. One species of family Lumbricidae was recorded that is Eiseniella tetraedra in S2.This family recorded a percentage of 3% of the total isolated worms. Total of 584 individuals of Tubificoid naidid worms were sorted with a percentage 34% of the total number of worms and they were identify as nine species included Limnodrilus hoffmeisteri, L. profundicola, L.claparedeanus, Tubifex tubifex, Aulodrilus pigueti, Peloescolex tenuis, Potamothrix hammoniensi, Rhyacodrilus coccineus, and finally Branchiura sowerbyi which recorded the highest percentage of 65.24% of the total tubificoid naidid worms with the highest frequency of 100%, followed by L. hoffmeisteri with a percentage of 16.95% and the frequency percentage of 85.19%, while the remaining species recorded close proportions ranged between 1 - 2%. Peloscolex tenuis was considered as a new record for Iraq, where10 individuals of this species were sorted with a percentage of 1.71%, and a frequency percentage of 3.70 %.Total of 47 individuals of subfamily Pristininae, were sorted, represented five species, including two species of genus Pristinella, P obsorni, and P. sima, and three species of genus Pristina, identified as, P. longiseta, P. aequiseta, and P. foreli, with a highest percentage of 53.19%, and a highest frequency of 14.81% were recorded by P. longiseta. A total of 788 individuals of subfamily Naidinae were sorted represent 20 specie includes Chaetogaster diastrophus, Stephensoniana trivandrana Paranais litoralis, P.frici, Ophidonais serpentina, Slavina appendiculata, S.isochaeta, Specaria josinae, Stylaria lacustris S. fossularis, Dero(Dero) evelinae, D.(D.) nivea, D. (Aulophorus) furcatus, Nais simplex, N.pseudobtusa, N. stolci, N. variabilis, N. elinguis, N. pardalis, Allonais inaequalis. Nine species of which were recorded for the first time in Iraq (in Bold). Species S. lacustris recorded the highest frequency percentage of 59.25%, and the highest individuals number 0f 187 was recorded by both S. lacustris and O. serpentine. Finally, 207 individuals of family Aeolosomatidae were identified into two species, Aeolosoma variegate and A. hemprichi. The first species recorded the highest percentage of 82.61% and a frequency percentage of 33.33%, and the second species recorded a percentage of 17.39% and a frequency percentage of 29.64%. The study also included a description of the identified species with photos illustrations of the identification characteristics of each species.
