1. Aquaculture and Fisheries, Marine Fisheries, Marine Science Center, University of Basrah, Iraq
2. Marine Invertebrate, Marine Fisheries, Marine Science Center, University of Basrah, Iraq
Author
Correspondence author
International Journal of Marine Science, 2015, Vol. 5, No. 15 doi: 10.5376/ijms.2015.05.0015
Received: 22 Feb., 2015 Accepted: 15 Mar., 2015 Published: 23 Mar., 2015
Digenetic trematodes represent the largest group of all internal metazoan parasites as they comprise about 18,000 nominal species (Cribb et al., 2001). The suborder Hemiurata is one of the most diverse groups of digeneans which usually occurs in the stomach and intestine of mainly marine teleost fishes (Gibson and Bray, 1979). This group has a wide geographical distribution, being found in the Great Barrier Reef of Australia, the Indian Ocean, and the Atlantic Ocean (Gibson and Bray, 1986). Life cycle of hemiuratids typically has marine gastropods as first intermediate hosts, crustaceans or some other invertebrates as second intermediate hosts and fishes as final hosts (Køie, 1979).
Members of Lepocreadiidae are recognizable as worms with widely distributed vitelline follicles, aspinous tegument, usually with a distinct external seminal vesicle and a typically I– shaped excretory vesicle (Bray, 2005).
The Lepocreadiidae fauna of the Arabian Gulf and the Iraq marine water is reported and discussed and a new host and locality records are presented, New host and locality records and a description were given of Lepocreadioides sp 1 and Lepocreadioides sp2 in Synaptura orinetalis by Bannai (2002) and new hosts and locality records of Lepocreadioides zebrini in Brachirus orientalis by (Bagherpour et al., 2011).
Material and Methods
Monthly fish samples were collected from Khor Abdullah, north west of the Arabian Gulf, from March to October 2013. A Total of 20 fish specimens of the two species were collected.
These fishes were kept in ice box and brought to the laboratory. The methods and techniques used for collection, relaxation, fixation, staining and mounting of helminthes are basically those described by Roberts (2001). Fishes were examined only for internal parasites, the abdominal cavity of each fish was opened and the intestine was separated from the other visceral organs and placed in a Petri-dish containing physiological saline and examined for parasites. The parasites were washed in a 0.6% saline solution and fixed in 70% ethanol. They were stained with alum carmine, dehydrated and then cleaned in xylene and mounted in Canada balsam. Drawings were prepared by camera Lucida.The specimens were deposited in the Department of Aquaculture and Marine Fisheries, Marine Science Center,University of Basrah, Iraq. Parasites identification was done with the aid of Yamaguti (1971).
Result and Discussion
As investigation was done for identification of the Trematoda fauna currently occurring in Psettodes erumei and Sillago sihama in Arabian Gulf, two parasites were found in the intestine of the dissected fishes.
Lepocreadioides orientalis Parker, 1939 Figure 1
Figure 1 Camera Lucida drawing and photograph of Lepocreadioides orientalis,ventral view. Scale bar 0.5mm
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Description based on two specimens.
Site of infection: Intestine.
The body is sub oval. Length 1.3-1.7 (1.5) and width 0.813-0.852 (0.832) mm. Cuticular spines are not present, sub terminal oral sucker measures 0.151-0.191(0.171) mm in diameter, the pre-pharynx is absent, but a pharynx is present and measures 0.197- 0.2 (0.198) mm length mm and 0.151-0.192 (0.171). The esophagus is smalland bifurcates into two, simple, wide caeca, which terminate blindly a little in front of the posterior extremity. Genital pore ventral to the anterior border of the acetabulum.
The acetabulum is oval-shaped and measures 0.303×0.30 mm in diameter. It is situated at the base of the anterior third of the body. The testes are two longitudinal and equal in size, one on either side of the body. They lie close behind the anterior half of body. The anterior testis measures 0.279-0.301 (0.29) mm in length. 0.162-0.201 (0.181) mm in width. The vitellaria are composed of small, irregular follicles extending along the caeca from the level of the intestinal bifurcation to their blind ends, where they turn round and extend up to the level of the seminal receptaculum. Many eggs spread throughout the level of acetabulum parasite body. Eggs are thick-shelled, operculated.
Lepocreadioides sp. Figure 2
Figure 2 Camera Lucida drawing and photograph of Lepocreadioides sp., ventral view, scale bar 0.5mm
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Description based on two specimens.
Site of infection: Intestines.
The body is sub oval and measures 1.2-1.6 (1.4) mm in length and 0.71-0.92 (0.82) mm in width. Cuticular spines are not present, terminal oral sucker measures 0.11× 0.10 mm in diameter, the pre-pharynx is absent, but a pharynx is present and measures 0.17 ×0.19 mm. Genital pore ventral to the anterior border of the acetabulum .The esophagus is small and bifurcates into two simple wide caeca, which terminate blindly a little in front of the posterior extremity.
The acetabulum is oval-shaped and measures 0.22× 0.21 mm in diameter. It is situated at the base of the anterior third of the body.
The testes are two, longitudinal and sub equal in size, one on either side of the body, and they lie close behind the anterior half of body and measuring 0.22 × 0.112. The vitellaria are composed of small, irregular follicles extending along the caeca from the level of the intestinal bifurcation to their blind ends, where they turn round and extend up to the level of the seminal receptaculum. Many eggs spread throughout the level of acetabulum parasite body. Eggs are thick-shelled, operculated.
In 1937, Yamaguti described a new parasite from a Japanese fish and created a new genus Lepocreadioides for its reception. The genus, with L. zebrine as the type species, was assigned to the subfamily Lepocreadiinae Odhner, 1905 of the family Allocreadiidae Stossich,1903.
Now the genus Lepocreadioides consists of nine valid species (WoRM S, 2014). These are:
Lepocreadioides branchiostegi Yamaguti, 1937
Lepocreadioides discum Wang, 1986
Lepocreadioides huanghauensis Qiu, Zang & Li, 1987
Lepocreadioides interruptus (Bilqees, 1973)
Lepocreadioides orientalis Park, 1939
Lepocreadioides otolithi (Bilqees, 1971)
Lepidocreadioides pagrosomi Wang, 1982
The excretory vesicles, winding between the testes, seem to relate the specimens to the genus Lepocreadioides (Yamaguti, 1936). Members of Lepocreadiidae are recognizable as worms with widely distributed vitelline follicles, aspinous tegument, usually with a distinct external seminal vesicle and a typically I–shaped excretory vesicle (Bray 2005). Lepocreadioides however, has a cirrus sac and a genital pore far to the left and far anterior. L. zebrini Yamaguti, 1936 and L. branchiostegi Yamaguti, 1937 both have excretory vesicles extending anterior to the acetabulum, but in L. indicum (Srivastava, 1941) ), which is a synonym of L. orientalis according to WoRMS (2014), the vesicle extends only to the ovary level (Manter, 1954).
According to Masaaki (2012) four new species of family Lepocreadiidae were described from the marine fishes of southern Japan and the Philippines, one of them is Lepidapedoides miharahanadai from the intestine of Giganthias immaculatus of southern Japan.
Lepocreadioides orientalis of the present study is very similar to those of Park (1939) specimens while Lepocreadioides sp. is different in the site of the oral sucker. The occurrence of these two species representstheir first record in the fishes of the Arabian Gulf.
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