Preliminary report on freshwater oligochaetes from some districts of Tamil Nadu (India), along with DNA barcode sequence of a commercially important oligochaete in Chennai

A survey of aquatic Oligochaeta was conducted at Thiruvallur, Chennai, Kanchipuram, Villupuram and Nilgiris districts of Tamil Nadu from October 2015 to June 2016. Eleven taxa were recorded from a total of 922 specimens examined, eight of them were identified to species level. Five naidids identified during the present study: Branchiodrilus semperi, Dero dorsalis, Dero digitata, Dero indica and Dero zeylanica, and six tubificid taxa Branchiura sowerbyi, Tubificidae sp. 1, Tubificidae sp. 2, Tubificidae sp. 3, Limnodrilus hoffmeisteri and L. udekemianus. Dero dorsalis constitute the first report for Kanchipuram district. A DNA barcode sequence (GenBank accession no. MF125273) of the commercially important Limnodrilus hoffmeisteri, commonly known as ‘Tubifex worms’ in Chennai, was obtained and compared with other published COI sequences from that morphospecies from around the world.

Association of Aquatic worms and infected snails with Digenean larvae

Six species of aquatic snails were sorted from three sites, the irrigation canal of Baghdad University campus (S1), River Tigris at Al-Za'afaraniah district / Baghdad(S2) , and River Euphrates at Al-Haideriah district Al-Najaf province(S2). The species included Melanopsis nodosa ;Melanoides tuberculata ; Thaiodaxsas jordani ; Lymnaea auricularia ; Physa acuta and Bellamya bengalensis. The first specis recorded the highest total number and was found in high density in the R. Euphrates site (S3), while the last species was the most widely distributed species, and found in all study sites. The last three species were found in Tigris river (S2) , while the first and last species were collected from the irrigation canal (S1).The result revealed that the species M. nodosa, M. tuberculata and L. auricularia were infected with Digenean larval stages, and the first species recorded the highest infection percentage of 60.04%, and the lowest percentage of 5.70% was recorded in L. auriculari , while M. tuberculata recorded a percentage of 38.98%.The oligochaetes Chaetogaster limnaei was sorted from the mantle cavity of L. auriculari and P. acuta, and it was noted that the first species accommodated more worms numbers than the second species. Twelve Species of family Naididae worms (subfamily Naidinae and subfamily Pristininae) , in addition to Aeolosoma leidyi of family Aeolosomatidae were sorted from the specific aquarium of each snail species. The leech Glossiphonia heteroclite was also recorded. The Nematodes worms were recorded the highest number sorted from the aquarium of L.auricularia, which are the most associate species, and 10 species of 49 individuals of worms were sorted from its aquarium, specially Dero ( Dero)digitata. In general, the infected snails, M. nodusa, M. tuberculata, and L. auricularia showed the highest association with worms, and from their aquaria 48, 37 , and 49 individuals of worms . with a number of 8,3, and 18 species respectively.

Study of Naidid worms community associated with two species of aquatic plants in River Tigris inside Baghdad City / Iraq

The present study is concern with the interaction between the naidid worms diversity and the species of aquatic plant within which the worms found . For this purpose, two species of aquatic plant were used, Ceratophyllum demersum and Eichhornia crassipes. 12 samples of aquatic plants were collected , as one sample monthly for a period from September 2012 to September 2013 from different site on Tigris river within Baghdad City. From C. demersum, 1428 individuals, were sorted during the study period, related to 17 species. 12 species of subfamily Naidinae which are Chaetogaster limnaei , C. diastrophus , Ophidonais serpentine , Dero ( Dero) digitata. , D.(D.) evelinae , Nais pseudobtosa , N.simplex, N.stolci , N.Paradalis , N.elingius , N. variabilis and N. communis. In addition to five species of subfamily Pristininae, two species of Pristina , which are P. longiseta and . P. aequiseta, and three species of pristinella, which are P. . Jenkinae , P. sima , and P. osborni. Dero ( Dero) digitata was recorded the higher number of 430 individuals,with a percentage of 28.11% of the total sorted worms. About the aquatic plant Eichhornia crassipes, a total of 829 worms were sorted from it, which are related to six species of Naidinae , which are diaphanous , Ophidonais serpentine, Stylaria lacustris , Slavina appendiculata , N. variabilis and finally the species Allonais inaequalis. There was no any species of Pristininae sorted from this plant. The highest number of 467 individuals was recorded by the species Slavina appendiculata, with a percentage of 52.3% of the total number and 228 individual with a percentage of 25.5% was recorded by Allonais inaequalis.

Distribution and Diversity of Oligochaetes in Selected Ponds of Thiruvananthapuram District, Kerala, South India

The present study was carried out to evaluate the distribution and diversity of oligochaete fauna in selected ponds of Thiruvananthapuram district in Kerala, South India. The sediment samples were collected from three ponds seasonally during the period December 2006 to November 2008. In the study, 10 oligochaete species which belong to 8 genera were identified in three selected ponds. These include Dero digitata, Dero nivea, Dero obtusa, Pristina longiseta, Aulophorus furcatus, Stylaria fossularis, Chaetogaster spp., Aeolosoma spp., Tubifex tubifex and Limnodrilus hoffmeisteri. Tubifex tubifex and Limnodrilus hoffmeisteri are the pollution-indicator oligochaete species identified in the fresh water ponds, which reveals that the studied ponds are subjected to pollution.

Preliminary survey of aquatic oligochaetes in Eastern Tamil Nadu, India

A random survey of aquatic Oligochaeta was conducted in Chennai, Villupuram, Dindugal, Thiruvallur, and Sivagangai districts of Tamil Nadu from November 2010 to March 2012. Thirteen taxa were identified from a total of 644 aquatic oligochaetes examined from various qualitative samples of aquatic vegetation and sediments. Chennai district had 3 families: Naididae, Pristinidae and Tubificidae along with a polychaete. The naidids were most diverse with 5 species: Branchiodrilus semperi, Aulophorus furcatus, Dero digitata, Dero indica and Dero zeylanica, the pristinids were represented by Pristina brevichaeta and Pristina jenkinae and the tubificids by 2 species, Branchiura sowerbyi and Limnodrilus hoffmeisteri. The nine aquatic oligochaetes collected from Chennai were already reported from this region. Two naidids, Branchiodrilus semperi and D. indica, along with the tubificid Branchiura sowerbyi, were collected from Villupuram district and they constitute the first reports for that district. Limnodrilus udekemianus from Kodaikanal, Dindugal district constitutes the first report for that region of Tamil Nadu. Megadriles belonging to the family Octochaetidae (Dichogaster bolaui?) and unidentified Megascolecidae collected from Thiruvallur and Sivaganga districts respectively were found to occur in aquatic habitats.

Aquatic Oligochaetes of Iraq's Southern Marshes

Aquatic Oligochaetes community in the Iraqi southern marshes, Al- Hawiezah, Al-Chibayish and Al-Hammar, have been studied for the period from July 2006 to June 2007. Two sites within each marsh, in addition to a reference site located at Shatt Al-Garma, have been chosen for sample collection using Ekman dredge. The results revealed that the highest average annual density was 16800 individual / m2 recorded in Al-Hawiezah marsh, while in Al-Chibayish and al-Hammar marsh the density did not exceed 5111 individual/m2. In contrast, the density of Oligochaetes recorded in Shatt Al-Garma was about 10500 individual / m2. The highest monthly density was recorded in April 2007.The highest local percentage occurrence was 96% recorded in Al-Hawiezah marsh, while the highest average monthly percentage occurrence was recorded in January 2007.The study revealed the presence of 19 Oligochaetes species belonging to 14 genera and 4 families. Naididae was represented by 8 spp.; Tubuficidae 8 spp.; Lumbriculidae 2 spp. and Lumbricidae 1 spp. Tubificid worms formed about 73% of the total count while Naididae formed 15%, Lumbriculidae 8% and Lumbricidae 4%.Among Tubificidae, Limnodrilus was the most abundant genus composed about 35% of L. hoffmeisteri; 11.5% L. claparedianus; 8% L. profundicola and 4.7% L. maumeensis, followed by Tubifex tubifex 23%. Other species were Branchuira sowerbyi formed 15%; 2.8 and 2 % for Peloscolex velutinus and Aulodrilus pigueti respectively. Naididae worms comprised 8 species including 32% of Dero digitata, 24% of Nais variabilis, 14% of Amphichaeta sp. and 11% of each of D.obtuse and Pristina longiseta. However, D. dorsalis represented only 7.5% of the total Naididae. Few individuals of B. sowerbyi and Lumbriculus variegates, with two regenerated parts at the posterior end were also detected in some samples. This case was considered a rare observation within the population of these worms in this particular area.