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Byline: N.A.Birmani, A.M.Dharejo, M.M.Khan and A.M.Shaikh


During present studies on helminth parasites of black coot, Fulica atra (Gruiformes: Rallidae), in Sindh Province of Pakistan, twelve specimens (eight and four ) of Dendritobilharzia pulverulenta (Braun, 1901) Skrjabin, 1924 were collected from eleven hosts. Male D. pulverulenta were more frequent. This is first record of the genus Dendritobilharzia Skrjabin and Zakharow, 1920 from Pakistan.

Keywords: Dendritobilharzia pulverulenta, Fulica atra, Sindh, Pakistan.


Studies on schistosomes in waterfowl are valuable not only from veterinarian viewpoint but also as a tool to predict the risk of human infection by the schistosome larval stages (cercariae) which develop in water snails. The infection, known as swimmer's itch or cercarial dermatitis, is considered to be an emerging disease in human. The association between avian schistosomes and cercarial dermatitis in humans has been recognized for a long time. The disease seems to be most prominently distributed along the major flyways of migratory birds transporting the parasites to and from wintering areas and thus spreading the infection in all water reservoirs in which susceptible intermediate hosts live (Kolarova et al., 2006).

Flukes of the family Schistosomatidae are peculiar in that they mature in the blood vascular system of their definitive hosts and are dioecious. Several species that cause serious diseases to humans and their domestic animals are included in this family (Gibson et al., 2002). Family Schistosomatidae was described by Poche (1907). Mehra (1940) proposed two subfamilies Dendritobilharziinae and Gigantobilharziinae. He also described Dendritobilharzia asiaticus in Nettion crecca crecca of Allahabad, India. Later on, Farley (1971) synonymized Dendritobilharziinae with Gigantobilharziinae. Ulmer and Vande Vusse (1970) reported D. pulverulenta (Braun, 1901) Skrjabin, 1924 in Anseriformes and presented some previously undescribed features including presence of Laurer's canal and prostate gland cells. They also reported hermaphroditism in males. Vande Vusse (1979) described host parasite relationship of D. pulverulenta and birds of the family Anatidae.

Vande Vusse (1980) revised genus Dendritobilharzia Skrjabin et Zakharow, 1920 and specific diagnosis of D. pulverulenta (Braun, 1901) Skrjabin, 1924. He placed D. asiatica Mehra, 1940 as species inquirenda due to presence of only female worm. Rind (1989) reported D. pulverulenta (Braun, 1901) Skrjabin, 1924 in Anas superciliosa, Anas rhynchotis, Cygnus atratus, Tadorna variegata and Aythya novaeseelandiae with all new host records from New Zealand. He also listed avian hosts reported first time worldwide with Dendritobilharzia including Anas superciliosa superciliosa, Anas rhynchotis variegata, Cygnus atratus, Aythya novaeseelandiae and Tadorna variegata. Bayssade-Dufour et al. (2006) described D. pulverulenta (Braun, 1901) with improved species diagnosis confirmed with molecular analysis. Adult Dendritobilharzia species differ from other schistosomatids by having dendritic branches arising from common cecum and by inhibiting arterial system.

Fulica atra, a migratory game bird is popular food item in Sindh Province of Pakistan. Therefore, the interest was developed to investigate this bird for the presence of helminth parasites.


Live 101 black coot, Fulica atra Linnaeus (Gruiformes: Rallidae), collected from different water bodies of Sindh Province, Pakistan were examined for helminth parasites. Hosts were dissected without care of the worms. Twelve specimens (eight and four ) were collected from the aortal parts connected with the lung, kidney, intestines and gizzard of eleven hosts. Worms were fixed under slight cover glass pressure in 70% ethanol, stained with borax carmine, dehydrated in graded series of ethanol, cleared in clove oil and xylol and mounted in Canada balsam. Diagrams were made with the help of a camera lucida. Photographs were taken with camera Olympus DP12. All measurements are given in micrometer (u m) unless otherwise stated, as holotype is followed by range in parenthesis.


Family Schistosomatidae Poche, 1907

Subfamily Gigantobilharziinae Mehra, 1940

Genus Dendritobilharzia Skrjabin and Zakharow, 1920

Dendritobilharzia pulverulenta (Braun, 1901) Skrjabin, 1924 (Fig. 1-2)

DESCRIPTION: Body in both sexes is flat, leaf-like, tapering at both ends. Females larger than males. Tegument smooth without ornamental structures. Digestive tract starts from oral opening situated subterminally, leading into esophagus which is surrounded by esophageal glands. Esophagus bifurcates into intestinal crura at level of genital pore in males and at level of uterus in females, which reunites posteriorly running up to posterior end in zigzag lateral branches. In both sexes suckers not observed. Vitellaria commencing from level of union of intestinal crura up to hindbody.


(Based on 8 specimens): Body 7.94 mm (4.62-7.94) long by 1.48 mm (0.77-1.48) wide. Oral opening sub terminal. Esophagus 460 (450-580) long, surrounded by esophageal glands at its distal part. Esophagus bifurcates into intestinal crura, which reunites posteriorly at a distance of 770 (610-880) from esophageal bifurcation.

A high number of testes 80-100 not uniform in shape and arrangement, starting from union of intestinal crura up to posterior extremity of body. Seminal vesicle long. Cirrus well developed 350 (18-350) long by 230 (100-230) wide with bulbous distal end. Genital pore dextral at a distance of 630 (500-640) from anterior extremity.


(Based on 4 specimens): Body 9.41 mm (5.85-9.48) long by 1.51 mm (1.08-1.52) wide. Digestive tract similar to males. Esophagus 270 (210-580) long. Intestinal crura reunite posteriorly at a distance of 2000 (1240-2000) from esophageal bifurcation running posteriorly in zigzag lateral branches. Ovary submedian, long, coiled within crura. Seminal receptacle median, immediately posterior to ovary, 170 (170-650) long by 70 (70-150) wide. Vitellaria in spaces between dendritic branches of gut. mehli's gland 300 (300-350) long by 360 (360-390) wide. Reprouctive organs; ovary, oviduct, Mehlis' gland and uterus entirely intercaecal. Uterus filled with numerous eggs. Eggs 39-57 long by 31-47 wide.


Schistosomes are considered to be highly pathogenic for migratory waterfowls (Kolarova et al., 2006). Genus Dendritobilharzia Skrjabin and Zakharow, 1920 was proposed to accommodate schistosomes from birds. Type species is Dendritobilharzia pulverulenta (Braun, 1901) Skrjabin, 1924 reported from the blood vessels of Querquedula querquedula, Anas platyrhynchos, Fulica atra, Nyroca, Aythya fuligula (Yamaguti, 1971). Other species include D. asiatica Mehra, 1940 in Nettion crecca from India; D. anatinarum Cheatum, 1941 in Anas platyrhynchos from New York and D. loosi Skrjabin, 1924 in Pelecanus onocrotalus from Russia.

Dendritobilharzia species have been reported from avian hosts including Aix sponsa, Anas creca, Anas discors, Anas platyrhynchos, Anas querquedula, Anas rhynchotis, Anas superciliosa superciliosa, Aythya affinis, Aythya americana, Aythya ferina, Aythya novaeseelandiae, Bucephala albeola, Bucephala clangula, Cygnus olor, Cygnus atratus, Cygnus columbianus, Mergus merganser, Mergus serrator, Nettion crecca and Tadorna variegate from Poland (Sulgostowska, 1972; Khalifa, 1976), New Zealand (Rind, 1989), North America (Ulmer and Vande Vusse, 1970), Brazil (Freitas and Costa, 1972), Czech Republic (Kalarova et al., 1989, 1997), Germany (Palm, 1965); Texas (Canaris et al., 1981), India (Chauhan et al., 1973 and France (Bayssade-Dufour et al., 2006).

Previously there is no record of avian schistosome belonging to the genus Dendritobilharzia Skrjabin and Zakharow, 1920 form Pakistan. This report constitutes first record of the genus Dendritobilharzia Skrjabin and Zakharow, 1920 from Pakistan.


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Department of Zoology, Shah Abdul Latif University, Khairpur, Sindh, Pakistan. Department of Zoology, University of Sindh, Jamshoro, Sindh, Pakistan. Corresponding author email:
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Publication:Journal of Animal and Plant Sciences
Geographic Code:9PAKI
Date:Aug 31, 2013

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