Checklists of Parasites of Farm Fishes of Babylon Province, Iraq

Literature reviews of all references concerning the parasitic fauna of fishes in fish farms of Babylon province, middle of Iraq, showed that a total of 92 valid parasite species are so far known from the common carp (Cyprinus carpio), the grass carp (Ctenopharyngodon idella), and the silver carp (Hypophthalmichthys molitrix) as well as from three freshwater fish species (Carassius auratus, Liza abu, and Heteropneustes fossilis) which were found in some fish farms of the same province. The parasitic fauna included one mastigophoran, three apicomplexans, 13 ciliophorans, five myxozoans, five trematodes, 45 monogeneans, five cestodes, three nematodes, two acanthocephalans, nine arthropods, and one mollusc. The common carp was found to harbour 81 species of parasites, the grass carp 30 species, the silver carp 28 species, L. abu 13 species, C. auratus one species, and H. fossilis one species. A host-parasite list for each fish species was also provided.


Introduction
Although fish farming in Iraq started in 1955 with a small pond in Al-Zaafaraniya, south of Baghdad city [1], an advance was achieved in fish farming industry in Iraq during the seventies and early eighties of the last century when many fish farms were established especially in the middle of Iraq [2]. However, such achievement was hindered due to consequences of the war situations during 1980-1988 and 1991 as well as the economic sanction imposed by the UN against Iraq on August 6, 1990. During the last few years, a great advance was achieved in fish farming in general and fish cages in particular due to the increasing demand on fish protein as well as the increasing investment in fish-culture industry in most provinces of Iraq. According to the statistics, a total of 441 working fish farms are scattered in Iraq [3]. Of these farms, a total of 72 working fish farms are situated in Babylon province alone with a water area of 44.5% of the total water area of fish farms in Iraq.
Under extensive fish culture and inadequate administrative and control measures, fish farms are vulnerable to great hazards due to the infection with parasites and other disease agents [2,4,5]. Many parasite species can easily spread among fishes suffering from crowd and bad managements, especially those parasites with direct life cycles [6].
In connection with the parasites of cultured fishes of Babylon province, Mhaisen et al. [7] surveyed the literature on the parasitic fauna of fishes of Al-Furat Fish Farm (previously known as Babylon Fish Farm), which is the biggest fish farm in Babylon province, and showed that the parasitic fauna of fishes of that farm included 60 valid parasite species (10 protozoans, three myxozoans, one trematode, 29 monogeneans, five cestodes, three nematodes, two acanthocephalans, six crustaceans, and one mollusc larva). In addition, some investigations on other fish farms in Babylon province were done. Such data are scattered in different local journals, unpublished theses, and few other sources. Therefore, the present paper was aimed at gathering data from the literature concerning all fish farms of Babylon province and providing a list of parasite species according to their major groups as well as a host-parasite list for cultured fishes of these farms and some other fish species found in such farms. Such parasite list will help owners of fish farms and fish veterinarians to know what sort of parasites are found in their fish farms, which will help them later in taking appropriate measures for their control.

Results and Discussion
Surveying the literature concerning the parasites so far recorded from fish farms of Babylon province showed the presence of 92 parasite species. These parasites included one mastigophoran, three apicomplexans, 13 ciliophorans, five myxozoans, five trematodes, 45 monogeneans, five cestodes, three nematodes, two acanthocephalans, nine arthropods, and one mollusc. The common carp was found to harbour 81 species of parasites, the grass carp 30 species, the silver carp 28 species, L. abu 13 species, C. auratus one species, and H. fossilis one species. The layout and names of the major taxonomic groups (phyla and classes) followed a checklist of an FAO Fisheries Technical Paper [66]. These major groups represent the concerned phyla of the parasites, but due to the great numbers of parasite species of the phylum Platyhelminthes, its three classes (Trematoda, Monogenea, and Cestoda) were applied in addition to their phylum.

Major Groups of Parasitic Fauna: Parasite-Host List
The parasite-host list is arranged in the major groups (phyla or classes) of parasitic fauna according to Kirjušina and Vismanis [66]. For each major group, a list of species together with their hosts and concerned references is given.
To economize space, names of fish farms are not given here as they can be easily detected from the previous subtitle "Parasitological Investigations Achieved on Fish Farms of Babylon Province." Also the systematic account of all major groups is given down to the specific name of all parasites. For each parasite species, all records in farm fishes in Babylon province are given together with the first record of each concerned parasite in Iraq as well as the present number of all hosts so far known in Iraq for each concerned species based on the index-catalogue of parasites and disease agents of fishes of Iraq [17]. Ichthyobodo necator (Henneguy, 1884) Pinto, 1928, was erroneously reported as Costia necatrix from the skin and gills of C. carpio [27]. The first record of C. necatrix in Iraq was from body surface of H. fossilis from Al-Ashar Canal at Basrah [67]. Seven fish host species are so far known for this parasite (as C. necatrix) in Iraq [17].

Phylum
Apicomplexa. The phylum Apicomplexa, which is known as phylum Myzozoa according to WoRMS [12], is represented in farm fishes of Babylon province with three species; two of them belonged to the genus Eimeria and one unspecified species to the genus Haemogregarina.  [27]. So far, this is the only record of E. dogieli from fishes of Iraq [17].
Eimeria mylopharyngodoni Chen, 1956, was recorded from C. carpio [49]. The specific name was misspelled as mylopharyngodon and no authority, site of infection, parasite description, and illustration were given for this parasite by Hussain et al. [49]. So this record is considered as questionable especially if we take in consideration that Hussain et al. [49] examined C. carpio externally while E. mylopharyngodoni is known to infect intestine, kidneys, and liver of fishes [68]. This is the only record of E. mylopharyngodoni from fishes of Iraq [17].
Haemogregarina sp. was found on gills of C. carpio [49]. In Iraq, three species of Haemogregarina were so far recorded from blood of three fish species in Basrah province only [17]. So we think that the record of Haemogregarina sp. from gills of C. carpio by Hussain et al. [49] with neither description nor a good illustration is considered as questionable.  [27,29,43,51], skin, fins, buccal cavity, and gills of C. carpio [27,30,43,51,53], and skin and gills of H. molitrix [27,43,51]. The first record of C. cyprini in Iraq was from skin, buccal cavity, and gills of Mystus pelusius from Tigris River at Baghdad [69]. So far 13 fish host species are known for this parasite in Iraq [17].
Apiosoma amoebae (Grenfell, 1887) Lom, 1966, was reported from skin, buccal cavity, and gills of C. idella [20,24,27], skin and buccal cavity of C. carpio [27,55], and gills and buccal cavity of H. molitrix [20,27]. It is appropriate to mention here that A. amoebae was reported as Glossatella amoebae [27,55]. The first record of A. amoebae in Iraq was from the skin, buccal cavity, and gills of C. idella from Babylon Fish Farm [20]. So far this parasite has five fish host species in Iraq [17].
Apiosoma minuta (Chen, 1961) Lom, 1966, was recorded from skin of C. carpio [45,47]. This was its first record in Iraq. So far, A. minuta has two fish host species in Iraq as it was recently recorded from Luciobarbus xanthopterus by Al-Salmany [71].
Apiosoma poteriformis (Timofeev, 1962) Lom, 1966, was recorded from skin and gills of C. idella [20,24,27] and buccal cavity and gills of C. carpio [27]. It is appropriate to mention here that A. poteriformis was reported as Glossatella poteriformis by Al-Zubaidy [27]. A. poteriformis was recorded for the first time in Iraq from gills of C. idella from Babylon Fish Farm [20]. So far, this parasite has three fish host species in Iraq [17].

Journal of Parasitology Research
Trichodina cottidarum Dogiel, 1948, was recorded from skin and gills of C. carpio [45,47,49,54,59,60] and skin and gills of H. molitrix [45,47]. T. cottidarum was recorded for the first time in Iraq from gills of C. carpio from a manmade lake at Baghdad city [72]. So far, this parasite has 13 fish host species in Iraq [17].
Trichodina gracilis Polyanskii, 1955, was recorded from skin of C. carpio [45,47]. This was its first record in Iraq. So far, it has three fish host species in Iraq [17].
Unidentified specimen of Trichodina was recorded from L. abu [50] with no mention to site of infection. In addition to 24 recognized Trichodina species so far recorded from fishes of Iraq, some unidentified species of Trichodina were so far recorded from six fish species [17].
Tripartiella amurensis (Chan, 1961) was recorded from skin of C. carpio [45,47]. This was its first record in Iraq. No more records are so far known for T. amurensis in Iraq [17]. Myxobilatus legeri (Cépède, 1905), erroneously reported as Myxobllatus legerl, with no given authority, description, and illustration, was recorded from skin and gills of C. carpio [54]. This was the only record of M. legeri in Iraq [17].

Phylum
Myxobolus dogieli Bykhovskaya-Pavlovskaya & Bykhovski, 1940, was recorded from kidneys and gallbladder of L. abu [56]. The first record of M. dogieli in Iraq was mainly from the external surface of heart, liver, and ovaries of L. abu from Tigris River at Baiji town [74]. So far, M. dogieli has nine host species in Iraq [17].
Myxobolus muelleri Bütschli, 1882, was recorded from intestine and liver of C. carpio [27] with the specific name spelled as mülleri. The first record of M. muelleri in Iraq was from gills of Luciobarbus xanthopterus, reported as B. xanthopterus [70]. So far, M. muelleri has eight host species in Iraq [17].
Myxobolus oviformis Thélohan, 1892, was recorded from skin, intestine, and kidneys of C. carpio [27,54,59]. The first report of M. oviformis in Iraq was from gill arches and heart of four fish species [70]. So far, M. oviformis has 20 fish host species in Iraq [17].

Phylum Platyhelminthes: Class Trematoda. The class
Trematoda of the phylum Platyhelminthes is represented in farm fishes of Babylon province with five species; two species belonged to the genera Apharyngostrigea and Ascocotyle and three species to the genus Diplostomum. Apharyngostrigea cornu (Zeder, 1800) was recorded as metacercaria from mesentery, coelom and liver of C. carpio [52]. This was its first report in Iraq. No more records are so far known on the occurrence of A. cornu from fishes of Iraq [17]. The adult worm of this parasite was detected from the Journal of Parasitology Research 5 intestine of the purple heron Ardea purpurea in Bahr Al-Najaf Depression [76].
Ascocotyle coleostoma (Looss, 1896) Looss, 1899, was recorded as metacercaria from gills of H. fossilis [56]. This parasite was reported for the first time in Iraq from gills of H. fossilis and L. abu from Diyala River [77]. A. coleostoma has so far 34 fish host species in Iraq [17]. The adult worm of A. coleostoma was detected from the grey heron A. cinerea in Babylon (now Al-Furat) Fish Farm [78].
Diplostomum indistinctum (Guberlet, 1923) Hughes, 1929, was recorded as metacercaria from eyes of H. molitrix [43]. The first occurrence of metacercariae of D. indistinctum was from eyes of Luciobarbus esocinus, reported as B. esocinus from fish market in Mosul city [79]. No more records are so far known on the occurrence of this parasite from fishes of Iraq [17].
Diplostomum paraspathaceum Schigin, 1965, was recorded as metacercaria from eyes of both C. idella [43] and C. carpio [43]. This was its first record in Iraq. No more hosts are so far known for this parasite in Iraq [17].
Diplostomum spathaceum (Rudolphi, 1819) Olsson, 1876, was recorded as metacercaria from eyes of the three carp species: C. idella [43,56], C. carpio [29,43], and H. molitrix [43,56]. The first occurrence of metacercariae of D. spathaceum was from eyes of C. luteus, reported as B. luteus, Cyprinion macrostomum, and C. carpio from Dokan Lake [80]. Thirty-four hosts are so far known for this parasite in fishes of Iraq [17]. Metacercariae of Diplostomum spp. are responsible for worm cataract which causes fish blindness [81]. Adult worms of this parasite were found in the intestine of some fish-eating birds such as the silver gull Larus argentatus in Bahr Al-Najaf Depression [76].

Phylum Platyhelminthes: Class Monogenea. The class
Monogenea of the phylum Platyhelminthes is represented in farm fishes of Babylon province with 45 species: 12 species of the genus Gyrodactylus, 26 species of Dactylogyrus, and one species of each of the genera Pseudacolpenteron, Diplozoon, Eudiplozoon, Paradiplozoon, and Microcotyle in addition to some unidentified species of Dactylogyrus and Diplozoon. It is appropriate to mention here that this group is considered as Monogenea by some electronic sites [9][10][11][12] but as Monogenoidea in some references [14,66]. Gyrodactylus baicalensis Bogolepova, 1950, was recorded from skin, fins, and gills of C. carpio [25,27,29,52]. The first report of G. baicalensis in Iraq was from skin, buccal cavity, and gills of C. carpio from Al-Suwaira and Al-Latifiya Fish Farms [52]. So far, G. baicalensis has eight fish host species in Iraq [17].
Gyrodactylus ctenopharngodontis Ling in Gusev, 1952, was recorded from skin, fins, buccal cavity, and gills of C. idella [24,27]. The first report of G. ctenopharngodontis in Iraq was from gills of C. idella from Babylon Fish Farm [24]. No more hosts are so far recorded for this parasite in Iraq [17].
Gyrodactylus kherulensis Ergens, 1974, was recorded from skin and gills of C. idella [27] and skin, fins, and gills of C. carpio [18,27]. The first report of G. kherulensis in Iraq was from gills of C. carpio from Babylon Fish Farm [18]. So far, G. kherulensis has four fish host species in Iraq [17].
Gyrodactylus macracanthus Hukuda, 1940 (reported as G. paralatus Gusev, 1955), was recorded from skin and gills of C. carpio [27] and skin, fins, and buccal cavity of H. molitrix [27]. This was its first report in Iraq. Later on, it was reported from both hosts [82] as G. paralatus also. According to Gussev [83] and Pugachev et al. [14], G. paralatus is a synonym of G. macracanthus. No more hosts are so far known for G. macracanthus or its synonym G. paralatus from fishes of Iraq [17].
Gyrodactylus malmbergi Ergens, 1961, was recorded from skin, fins, and gills of C. carpio [27] and from skin and gills of H. molitrix [27]. This was its first report in Iraq and no more hosts are so far known for G. malmbergi from fishes of Iraq [17].
Gyrodactylus medius Kathariner, 1895, was recorded from skin and fins of C. carpio [27]. This was its first record in Iraq. The year of authority of this parasite was erroneously given as 1893 instead of 1895 by Al-Zubaidy [27] as well as by three other references according to Mhaisen and Abdul-Ameer [15]. Also the authorship of this parasite was given as Katheriner instead of Kathariner according to MonoDB [10]. Now, this parasite has three host species in Iraq [17].
Gyrodactylus menschikowi Gvosdev, 1950, was recorded from skin and gills of C. carpio [60]. The first report of this parasite in Iraq was from gills and skin of C. carpio and skin, fins, and gills of L. abu both from Hilla River [84]. So far, no more hosts for this parasite are known in Iraq [17].
Gyrodactylus salaris Malmberg, 1957, was recorded from skin and gills of C. carpio [27,29]. The first report of this parasite in Iraq was from gills and skin of C. carpio from Al-Furat Fish Farm [27]. The year of authority of this parasite was reported as 1956 instead of 1957 by Al-Zubaidy [27] and Al-Jadoaa [29]. No more hosts for this parasite are so far known in Iraq [17].
Gyrodactylus sprostonae Ling, 1962, was recorded fromskin and fins of C. carpio [27]. This was its first report in Iraq. Now, this parasite has seven host species in Iraq [17].
Gyrodactylus vicinus Bychowsky, 1957, was recorded from skin, fins, and gills of C. carpio [27,35]. The first report of this parasite in Iraq was from skin, fins, and gills of C. carpio from Al-Furat Fish Farm [27]. Now, it has three host species in Iraq [17].
Finally, the unidentified Gyrodactylus species reported from C. carpio [34,38] were the same 11 species which had been recorded in Al-Zubaidy [27]. In Iraq, so far 15 fish host species were reported for some unspecified Gyrodactylus species [17].
Dactylogyrus amurensis Akhmerov, 1952, was recorded from gills of C. carpio [55]. This was its first report in Iraq. However, neither description and measurements nor illustration was given. So far, this parasite has two host species in Iraq [17].
Dactylogyrus cornu Linstow, 1878, was recorded from gills of C. carpio [27,59]. D. cornu was recorded for the first time in Iraq from gills of five fish species from Diyala River [88]. So far, it has 13 fish host species in Iraq [17].
Dactylogyrus crassus Kulwiec, 1927, was recorded from gills of C. carpio [45,47,55,60]. D. crassus was recorded for the first time in Iraq from gills of C. carpio from Al-Shark Al-Awsat Fish Farm [45]. It is appropriate to mention here that the specific name crassus was misspelled as carassus by Al-Rubaie et al. [55]. No more hosts are so far known for this parasite in Iraq [17].
Dactylogyrus ctenopharyngodonis Achmerow, 1952, was recorded from gills of C. idella from Al-Shark Al-Awsat Fish Farm [43]. This is the only report on the occurrence of D. ctenopharyngodonis in fishes of Iraq [17].
Dactylogyrus dogieli Gusev, 1953, was recorded from gills of C. carpio in fish cages and an earthen pond in Sadat Al-Hindiya [60]. The first report of D. dogieli was from five fish species from Euphrates River at Al-Musaib city [89] and its full description and illustration were published later by Al-Sa'adi et al. [90]. Six host species are so far known for D. dogieli in Iraq [17].
Dactylogyrus ergensi Molnár, 1964, was recorded from gills of C. carpio from Al-Furat Fish Farm [27]. This was its first report in Iraq. No more hosts were reported for D. ergensi in Iraq [17].
Dactylogyrus gobii Gvosdev, 1950, was recorded from skin and gills of C. carpio [45,47,60]. D. gobii was recorded for the first time in Iraq from gills of C. carpio from Al-Shark Al-Awsat Fish Farm [45]. Now, it has three host species in Iraq [17].
Dactylogyrus jamansajensis Osmanov, 1958, was recorded from gills of C. carpio [45,47]. The first report of D. jamansajensis in Iraq was from gills of C. luteus from manmade lakes, north of Baghdad [91]. Now, it has five host species in Iraq [17].
Dactylogyrus latituba Gusev, 1955, was recorded from gills of both C. idella [27] and C. carpio [25,27] as well as from the buccal cavity and gills of H. molitrix [27]. The first report of D. latituba in Iraq was from gills of C. luteus from manmade lakes, north of Baghdad [91]. Now, it has four host species in Iraq [17].
Dactylogyrus lopuchinae Jukhimenko, 1981, was recorded from gills of C. carpio [45,47,54]. D. lopuchinae was recorded for the first time in Iraq from gills of C. carpio from Al-Shark Al-Awsat Fish Farm [45]. No more hosts are so far known for this parasite in Iraq [17].
Dactylogyrus navicularis A. Gusev, 1955, was recorded from fins, buccal cavity, and gills of C. carpio [27,35,60]. The first report of D. navicularis in Iraq was from the buccal cavity, fins, and gills of C. carpio from Al-Furat Fish Farm [27]. C. carpio is the only host so far known for D. navicularis in Iraq [17].
Dactylogyrus phoxini Malevitskaia, 1949, was recorded from skin and gills of C. carpio [45,47,60]. The first record of D. phoxini in Iraq was in June 1995 from gills of C. carpio from Tigris River at Al-Zaafaraniya but the report was published later by Balasem et al. [92]. This parasite has so far only two host species in Iraq [17].
Dactylogyrus propinquus Bychowsky, 1931, was recorded from gills of C. carpio [27,35,49]. The first report of D. propinquus in Iraq was from gills of C. carpio from Al-Furat Fish Farm [27]. C. carpio is the only host so far known for D. propinquus in Iraq [17].
Dactylogyrus sahuensis Ling in Chen et al., 1973, was recorded from fins and gills of C. carpio [27]. The first report of D. sahuensis in Iraq was from fins and gills of C. carpio from Al-Furat Fish Farm [27]. C. carpio is the only host so far known for D. sahuensis in Iraq [17].
Dactylogyrus simplex Bychowsky, 1936, was recorded from C. carpio [49] with no mention to site of infection. The first report of D. simplex in Iraq was from gills of C. carpio from the new fish farm of the Fish Research Center at Al-Zaafaraniya [93]. D. simplex has so far three host species in Iraq [17].
Unidentified Dactylogyrus species were recorded from skin and gills of C. idella [56] and from skin, buccal cavity, and gills of C. carpio [34,38,56]. Some of these specimens were larval stages [56], while the unidentified Dactylogyrus species of Al-Zubaidy et al. [34,38] were the same 15 species which were recorded in Al-Zubaidy [27]. In Iraq, so far nine fish host species were reported for some unspecified Dactylogyrus species [17].
Pseudacolpenteron pavlovskii Bychowsky & Gussev, 1955, was recorded from fins and gills of C. carpio [25,27,45,47] and gills of H. molitrix [27]. The first report of P. pavlovskii from Iraq was from skin and gills of C. carpio from Babylon Fish Farm [25]. This species has so far only two host species in Iraq [17].
Diplozoon paradoxum Nordmann, 1832, was recorded from gills of C. carpio [60]. This parasite was reported for the first time in Iraq from gills of Carasobarbus luteus, reported as Barbus luteus, from Al-Husainia creek, Karbala province [95]. Now, it has five fish hosts in Iraq [17].
Unidentified Diplozoon species were recorded from gills of C. carpio [43]. Some other unidentified Diplozoon species occurred as larvae in 12 fish host species in Iraq [17].
Eudiplozoon nipponicum (Goto, 1891) was recorded from gills of C. carpio [60]. This parasite was recorded for the first time in Iraq from gills of C. carpio from a manmade lake in Baghdad [96] as Diplozoon nipponicum but then it was reported by its valid name E. nipponicum by all subsequent researchers. So far, three host species are known for E. nipponicum in Iraq [17].
Paradiplozoon barbi (Reichenbach-Klinke, 1951) was recorded from gills of C. carpio [27] as Diplozoon barbi. This parasite was reported for the first time in Iraq from gills of Chondrostoma nasus, C. regium, and C. carpio from Tigris River at Baghdad [97] as Diplozoon barbi. Also, all the subsequent records in the Iraqi literature, except the checklists of Mhaisen and Abdul-Ameer [16], referred to this parasite as D. barbi. According to Khotenovsky [98], D. barbi is a synonym of P. barbi. Eight host species are so far known for this parasite in Iraq [17].
Microcotyle donavini van Beneden & Hesse, 1863, was recorded from gills of L. abu from Babylon Fish Farm [22]. This was its first report in Iraq. Ten host species are so far known for M. donavini in Iraq [17]. Bothriocephalus acheilognathi Yamaguti, 1934, was recorded from the intestine of both C. idella [24,56] and C. carpio [25-27, 52, 53, 62]. It is appropriate to mention here that this worm was reported by its synonym B. opsariichthydis by Salih et al. [52] and Al-Zubaidy [27]. The first report of B. acheilognathi in Iraq was from the intestine of C. carpio from different fish farms near Baghdad [99]. Two other species of Bothriocephalus, B. gowkongensis Yeh, 1955, and B. opsariichthydis Yamaguti, 1934, were also reported from Iraq [17]. According to Molnár [100], both these two species are considered as synonyms of B. acheilognathi. At the present time, B. acheilognathi and both of its above-named synonyms has so far a total of 21 host species in Iraq [17].

Phylum
Ligula intestinalis (L., 1758) Bloch, 1782, was recorded from the body cavity of both C. idella [24,27,29] and C. carpio [27]. L. intestinalis was reported for the first time in Iraq as a plerocercoid from the body cavity of Leuciscus vorax (reported as A. vorax) from Shatt Al-Arab River [101]. So far, this species has 13 fish host species in Iraq [17]. In Iraq, the adult stage of L. intestinalis was reported from the intestine of the moorhen Gallinula chloropus chloropus from around Baghdad [102].
Proteocephalus osculatus (Goeze, 1782) Nybelin, 1942, was recorded from the intestine of C. carpio [27]. The first report of this parasite in Iraq was from the intestine of L. vorax (reported as A. vorax) from Al-Tharthar Lake [103]. So far, this species has eight fish host species in Iraq [17].
Proteocephalus torulosus (Batsch, 1786) Nufer, 1905, was recorded from intestine of C. carpio [27]. The first report of this parasite in Iraq was from the intestine of C. carpio from a fish farm near Baghdad city [99]. So far, this species has two fish host species in Iraq [17].
Neogryporhynchus cheilancristrotus (Wedl, 1855) Baer & Bona, 1960, was recorded from the intestine of C. carpio by Al-Zubaidy [27] as Gryporhynchus cheilancristrotus. The first report of N. cheilancristrotus in Iraq was from the intestine of L. abu from Diyala River [104]. So far, this species has four fish host species in Iraq [17]. Unidentified larval species of Contracaecum was recorded from the intestinal wall, body cavity, liver, spleen, heart, and gonads of C. carpio [27,29] and intestinal wall of L. abu [22,37,42]. The first report of Contracaecum spp. larvae in Iraq was from the body cavity and different viscera of 10 fish species from different inland waters of Iraq [70]. Contracaecum spp. larvae have so far 40 fish host species in Iraq [17]. Adult worms of Contracaecum spp. were detected from six species of aquatic birds in Iraq, Egretta alba, E. garzetta, Ardeola ralloides, Botaurus stellaris, Ardea purpurea, and Ceryle rudis, from Bahr Al-Najaf Depression [76].

Phylum
Cucullanus cyprini Yamaguti, 1941, was recorded from the intestine of C. carpio [27]. The first report of this parasite in Iraq was from the intestine of Alburnus caeruleus and Luciobarbus xanthopterus (reported as B. xanthopterus) from Al-Tharthar Lake [103]. So far, this species has 15 fish host species in Iraq [17].
Dermoergasilus varicoleus Ho, Jayarajan & Radhakrishnan, 1992, was recorded from gills of L. abu [31,40]. This crustacean was reported for the first time in Iraq from gills of L. abu from Shatt Al-Arab River [109]. D. varicoleus has so far nine fish host species in Iraq [17].
Ergasilus barbi Rahemo, 1982, was recorded from gills of L. abu [46]. This crustacean was firstly detected from gills of B. grypus from Tigris River at Mosul city by Fattohy [75] and its full description as a new species was achieved by Rahemo [110]. E. barbi has so far 13 fish host species in Iraq [17].
Ergasilus mosulensis Rahemo, 1982, was recorded from gills of the three carp species, C. idella [27], C. carpio [27], and H. molitrix [27] as well as gills of L. abu [46]. This crustacean was firstly detected from gills of L. abu from Tigris River at Mosul city by Fattohy [75] and its full description as a new species was achieved by Rahemo [110]. E. mosulensis has so far 23 fish host species in Iraq [17].
Ergasilus sp. was recorded from L. abu [50] with no mention to site of infection. In addition to 11 species of Ergasilus so far recorded from fishes of Iraq, some specimens of unidentified Ergasilus species were also reported from 12 fish species in Iraq [17].
Paraergasilus inflatus Ho, Khamees & Mhaisen, 1996, was recorded from gills of H. molitrix [27]. This crustacean was reported as a new species from gill rakers of L. abu from Shatt Al-Arab River [111]. D. varicoleus has so far seven fish host species in Iraq [17].
Lamproglena pulchella von Nordmann, 1832, was recorded from gills of C. carpio [27]. The first report of L. pulchella in Iraq was from gills of Chondrostoma regium and Capoeta trutta (reported as Varicorhinus trutta) from Tigris River at Mosul city [112]. L. pulchella has so far 19 fish host species in Iraq [17].

Host-Parasite List
The following host-parasite list for fish parasites in fish farms of Babylon province is compiled. For each host, the scientific names of all recorded parasites are alphabetically enlisted under their major parasitic groups. To economize space, references of previous records for each parasite species are not given here. These can be obtained from the account of each concerned parasite species in the part of major groups of parasitic fauna within the results and discussion part.