Checklists of Gyrodactylus Species (Monogenea) from Fishes of Iraq

. Surveying the literature concerning the occurrence of the monogeneans of the genus Gyrodactylus parasitizing fishes of Iraq indicated that there are 25 nominated species of this genus on 29 fish species. These are: G. baicalensis , G. barbi , G. ctenopharyngodonti s, G. cyprini , G. derjavini , G. elegans , G. gobioninum , G. gussevi , G. katharineri , G. kherulensis , G. lavareti , G. longoacuminatus , G. macracanthus , G. malmbergi , G. markevitschi , G. medius , G. menschikowi , G. molnari , G. aff. mugili , G. salaris , G. shulmani , G. sprostonae , G. taimeni , G. vicinus and G. vimbi . All these species infected freshwater fishes, except G. aff. mugili which infected two marine fishes found in brackish waters. In addition to these species, some unidentified specimens of this genus were reported from 15 fish hosts among which five fish species showed no infection with any of the above nominated species of Gyrodactylus while the others showed mixed infection. Such unidentified Gyrodactylus species were recorded from 12 freshwater fishes as well as three marine fishes found within the freshwaters of Basrah province. Among Gyrodactylu s species, number of hosts ranged from one host for 15 Gyrodactylus species to a maximum of 23 hosts in case of G. elegans . The distribution of the infection ranged from one parasite species in 14 fish hosts to a maximum infection with 21 Gyrodactylus species in the common carp ( Cyprinus carpio )


Introduction
Monogeneans are small hermaphroditic worms that parasitize fishes and other aquatic animals.They infect fins, skin and gills of freshwater and marine fishes (59).The Class Monogenea includes 62 families, of which the family Gyrodactylidae has 34 genera.Among these genera, the genus Gyrodactylus has 518 nominated species of which 416 are valid species (91).However, number of Gyrodactylus species varies with varying references.
Gyrodactylids are amongst the smallest monogeneans and some are similar in size to oncomiracidium larvae (200mm).The fusiform body has a posterior opisthaptor armed with 16 marginal hooks and a pair of median hooks.Anteriorly, two conspicuous cephalic processes bearing adhesive glands are apparent with no eye spots.The transparent body is dominated by the F1 generation embryo curled within the uterus (50).They are remarkable in that they give birth to live young, which already have a developing embryo, in a 'Russian doll' arrangement (58).Gyrodactylids feed on mucus, epithelium and sometimes blood (66).Secondary infections of the epidermal lesions with bacteria or fungi may also play a significant role in the pathogenicity of Gyrodactylus (58).The pathogenicity of G. salaris on some strains of Atlantic salmon Salmo salar became clear in the early 1970s, when this parasite was introduced into Norway with juvenile Atlantic salmon imported from Sweden for aquaculture (94).
Information concerning gyrodactylids infecting fishes of Iraq are scattered in different local scientific journals, M. Sc. and Ph.D. theses as well as in few conference abstracts.Some of such parasites have been misidentified or given with wrong authorities and some parasite names are misspelled.Some of the infected fishes were given in synonymous names.For these reasons, it was decided to review these data in accordance with list of fishes of Iraq (57) and with up-to-date fish scientific names (61), to correct scientific names and authorities of the concerned gyrodactylids according to some major taxonomical references and a web site (62,96,91), and to provide a hostgyrodactylid checklist.

Sources and Methods
A total of 83 references (research papers, conference abstracts and M. Sc. and Ph.D. theses) dealing with gyrodactylids of fishes of Iraq were used to prepare the present review and checklists.Data from such references was gathered to provide gyrodactylid list and host-gyrodactylid list.Names and authorities of these gyrodactylids are checked with the list of nominal species of Gyrodactylus (64) as well as with two taxonomical accounts (62,96) and the well known specialized electronic sites (99, 91).For fishes, the scientific names were reported as they appeared in their original references and then checked with the recent account on freshwater fishes of Iraq (57).However, the valid names used here were based, with minor modifications, on a relevant electronic site (61).

Surveys Achieved on Gyrodactylids of Fishes in Iraq
The review of available literature indicated that since the first published account on fish parasites of Iraq (65) up till the first checklist of fish parasites of Iraq (78), no any gyrodactylid species was present from fishes of Iraq.Starting from 1984, when the first gyrodactylid species (G.elegans) was reported from two fish species (21) up to the present time, many surveys were achieved in different inland waters and fish farms and ponds which contributed in recording gyrodactylids from fishes of Iraq.These surveys can be grouped into nine major categories according to localities of inspected fishes.These are: 1-Tigris River (26,1,56,83,10,30,31,47) as well as some tributaries of Tigris River which included Greater and Lesser Zab rivers (4, 7), Lesser Zab River (75,76,93) and Diyala River (24,25,55,87,37).

Gyrodactylids Recorded from Fishes in Iraq
The review of literature indicated that a total of 25 nominated Gyrodactylus species are so far known from fishes of Iraq as well as some unidentified specimens of this genus.The following is an alphabetical list of such parasites.Gyrodactylid names and authorities are checked according to some major taxonomical accounts and web sites (62,64,96,99,91).The alphabetically arranged names of hosts for each parasite are quoted as they appeared in their original literature but the valid names have been updated according to Froese & Pauly (61) and the full authority of each valid fish host is shown in the host-gyrodactylid list.References of the records for each host within each gyrodactylid species are chronologically arranged but references of the same year are alphabetically arranged.

2-Gyrodactylus barbi Ergens, 1976:
This parasite was recorded for the first time in Iraq from C. carpio from Ainkawa fish hatchery, Erbil (75,76).No more records for this parasite in Iraq are available.

3-Gyrodactylus ctenopharyngodontis Ling in Gusev, 1962:
This parasite was recorded for the first time in Iraq from Ctenopharyngodon idella from Babylon (= Al-Furat) Fish Farm (84).It was then recorded only from the same fish of the same farm (43).It is appropriate to indicate here that the authority of this parasite was quoted as Lin, 1962 by the former reference (84) and as Ling, 1962 by the latter reference (43).Worldwide, PESI (95) quoted the authority as Ling, 1962, while MonoDB (91) quoted it as Ling Mo En, 1962 and Shin et al. (99) quoted it as Ling Mo-En, 1962.However, according to the personal communication between the senior author of this article and Dr. David I. Gibson of the British Museum (Natural History), it was decided to follow Harris et al. (64) who stated the authority as Ling in Gusev, 1962.Also, this parasite was quoted as G. ctenopharyngodonis instead of G. ctenopharyngodontis by some sources (96,60).

4-Gyrodactylus cyprini Diarova, 1964:
This parasite was recorded for the first time in Iraq from C. carpio from Ainkawa fish hatchery, Erbil (75,76).No more records for this parasite in Iraq are available.

5-Gyrodactylus derjavini Mikhailov, 1975
This parasite was recorded for the first time in Iraq from Aspius vorax from Hilla River (44).The authority of G. derjavini was given as Mikailov, 1975 by the researcher (44).
No more records for this parasite are available.
The rather long list of hosts recorded for G. elegans in Iraq comes in agreement with the statement that G. elegans represents one of the most widely cited Gyrodactylus species in the world and many host records are erroneous (64).

7-Gyrodactylus gobioninum Gusev, 1955:
This parasite was recorded for the first time in Iraq from C. carpio from Lesser Zab River (75,76).No more records for this parasite in Iraq are available.

8-Gyrodactylus gussevi Ling, 1962:
This parasite was recorded for the first time in Iraq from H. fossilis from Greater Zab River (4,7).Later on, it was reported only from the same fish from Euphrates River at Al-Musaib city (38).All the above references (4,7,38) quoted the authority of this species as Ling Mo-En, 1962 but the authority of Ling, 1962, used here, follows Harris et al. (64) and the personal correspondence with Dr. D. I. Gibson.

9-Gyrodactylus katharineri Malmberg, 1964:
This parasite was recorded for the first time in Iraq from C. carpio from Lesser Zab River (93).No more records for this parasite in Iraq are available.According to personal communication with Prof. Phil Harris of the Natural History Museum, University of Oslo, the scientific name was erroneously given as G. katherineri by MonoDB (91).

11-Gyrodactylus lavareti Malmberg, 1957:
This parasite was recorded for the first time in Iraq from C. carpio from different fish markets in Baghdad city (2).No more records for this parasite in Iraq are available.

12-Gyrodactylus longoacuminatus Zitnan, 1964:
This parasite was recorded for the first time in Iraq from C. carpio from Ainkawa fish hatchery, Erbil (75,76).No more records for this parasite in Iraq are available.

14-Gyrodactylus malmbergi Ergens, 1961:
This parasite was recorded for the first time in Iraq from both C. carpio and H. molitrix from Babylon (= Al-Furat) Fish Farm (43).No more records for this parasite in Iraq are available.

16-Gyrodactylus medius Kathariner, 1895:
This parasite was recorded for the first time in Iraq from C. carpio from Babylon (= Al-Furat) Fish Farm (43).The year of authority of this parasite was erroneously given as 1893 instead of 1895 by the four concerned references (43,4,7,38).Also, the authorship of this parasite was given as Katheriner instead of Kathariner (91).Now, this species has two hosts in Iraq.These are B. luteus, which is a synonym of C. luteus (38) and C. carpio (43,4,7).

17-Gyrodactylus menschikowi Gvosdev, 1950:
This parasite was recorded for the first time in Iraq from both C. carpio and L. abu from Hilla River (44).Later on, it was recorded only from C. carpio (40).

18-Gyrodactylus molnari Ergens, 1978:
This parasite was recorded for the first time in Iraq from both C. carpio from Darbandikhan Lake (8).No more records for this parasite in Iraq are available.

19-Gyrodactylus aff. mugili Zhukov, 1970:
This parasite was recorded from Chelon subviridis from the brackish waters of Shatt Al-Arab Estuary near Al-Fao town and from Valamugil speigleri near the dam on the Shatt Al-Basrah Canal (74).This is the only Gyrodactylus species which was so far recorded from marine fishes of Iraq within the brackish waters of Basrah province.

20-Gyrodactylus salaris Malmberg 1957:
This parasite was recorded for the first time in Iraq from C. carpio from Babylon (= Al-Furat) Fish Farm (43).Later on, it was reported only from the same host and the same fish farm (28).Both researchers (43,28) reported the year of authority of this parasite as 1956 instead of 1957.

21-Gyrodactylus shulmani Ling, 1962:
This parasite was recorded for the first time in Iraq from C. carpio from Lesser Zab River (93).No more records for this parasite in Iraq are available.The authorship of this parasite was given as Ling Mo En (99, 91) but according to the personal communication with Dr. David I. Gibson), it was decided to follow Harris et al. (64) who stated the authority as Ling, 1962.

23-Gyrodactylus taimeni Ergens, 1971:
This parasite was recorded for the first time in Iraq from C. carpio from different fish markets in Baghdad city (3).No more records for this parasite in Iraq are available.

25-Gyrodactylus vimbi Shulman, 1954:
This parasite was recorded for the first time in Iraq from S. triostegus from Al-Hammar marsh (71).The researcher (71) reported the year of authority of this parasite as Shul'man, 1953 instead of Shulman, 1954.No more records for this parasite in Iraq are available.

Fish-Gyrodactylid List:
The following list shows which gyrodactylids are so far recorded from fishes of Iraq.Fish scientific names, both valid and synonymous, are alphabetically arranged.The full authorities of the valid hosts only are also cited according to Froese & Pauly (61).Gyrodactylid species reported from each valid fish species, together with gyrodactylids of fish synonym (when applicable) were gathered within the valid host and also alphabetically arranged.To minimize the size of this article, references for each gyrodactylid species from each host are not provided here.Such references can be easily obtained from the relevant gyrodactylid species mentioned earlier in this paper.