Checklist of helminth parasites of Striped Red Mullet , Mullus surmuletus ( Linnaeus , 1758 ) ( Perciformes : Mullidae ) , caught in the Bay of Kristel , Algeria ( western Mediterranean )

This investigation on the parasitic biodiversity of Striped Red Mullet, Mullus surmuletus, revealed the presence of 14 parasite species, including seven species of Digenea, four species of Nematoda, two species of Acanthocephala, and one Cestoda. Opecoelides furcatus and Proctotrema bacilliovatum are the most prevalent digenean species, present in 70% and 17% of the fish specimens analyzed, respectively. Concerning nematode species, Hysterothylacium fabri, Ascarophis valentina and Cucullanus longicollis have shown a prevalence of 66%, 17% and 8% respectively, among all specimens of M. surmuletus analyzed.


INTRODUCTION
The parasite fauna of Striped Red Mullet, Mullus surmuletus (Linnaeus, 1758) (Perciformes: Mullidae), has aroused the interest of numerous parasitologists, mainly due to economic value of this species (Boudaoued-Krissat 1979).According to Le Pommelet et al. (1997) the system helminths-Mullus would undoubtedly be one of the richest and most diversified of the Mediterranean.
Although many authors have studied the helminth parasites of M. surmuletus (Bayoumi et al. 2004;Ferrer et al. 2005Ferrer et al. , 2007;;Neifar et al. 2007;Ternengo et al. 2009) few studies have focused on Algerian coast.To better characterize the distribution of helminth parasites here, an epidemiological survey of helminths was carried out on 100 specimens of M. surmulentus from September 2009 to July 2010 in the Bay of Kristel on the west coast of Algeria.

MATERIALS AND METHODS
The samples were collected from the Bay of Kristel on the coast of western Algeria.The coordinates of the sampling point were (35°43' N, 00°37' W) (Figure 1).One hundred fish were captured with trammel net.Their length ranged from 16 to 24 cm.The fish were dissected by making an incision along the ventral line from the anus to the buccal aperture, then the whole body cavity was carefully dissected, and their walls scraped and rinsed several times in physiological saline water and thoroughly examined.Parasites were fixed and preserved in ethanol (70%).For light microscopy studies, Digenea and Cestoda were stained in carmin and mounted in Eukitt and Acanthocephala and Nematoda were clarified in Lactophenol (Ash and Orihel 1991).For identification of the parasites, papers of Anderson (1992) and Moravec (1994Moravec ( , 1998) ) were used for Nematoda, Gibson and Bray (2002) for Digenea, Khallil et al. (1994) for Cestoda, and Amin (1987) for Acanthocephala.

RESULTS
A total of 1758 specimens of helminth parasites were recovered from the host species, representing 14 species and 12 genera, as listed below:

DISCUSSION
Our studies show high degree of infestation, which is however not uncommon in Striped Red Mullet populations of the Mediterranean Sea (Hristovski et al. 1989;Arculeo et al. 1997;Figus et al. 2004).The most prevalent parasites were the digeneans, among them Opecoeloides furcatus, Poracanthium furcatum and Proctotrema bacilliovatum, and the nematodes Hysterothylacium fabri, Ascarophis valentina, Cucullanus longicollis and Hysterothylacium sp.The present study reports the occurrence of Ascarophis valentina from the west coast of Algeria.Cestoda and Acanthocephala were rare.
The high diversity of digenean species in M. surmuletus was reported by Le Pommelet et al. (1997), who listed 18 species.However, many of these species have a restricted distribution in the western Mediterranean and the Adriatic Seas and were not recorded elsewhere.Neiffar et al. (2007) found that M. surmuletus from Tunisia hosted significantly fewer parasite taxa than those from Spanish coasts (16 species in the Spanish Mediterranean vs. 9 in Tunisia).Lasiotocus mulli, Lecithocladium excisum and Ascarophis valentina were found only in Spain and, in contrast, no taxa were exclusive to Tunisian coasts.Klimpel et al. (2008) demonstrated that the parasite fauna of mullets from the North Sea (North Atlantic) was richer than from mullets from the Mediterranean.Opecoeloides furcatus and Ascarophis valentinea were isolated only from the Mediterranean Sea while Capillaria gracilis and Anisakis simplex were found only in the North Sea.These results suggest historical (post-Messinian history) and geographical reasons for the differences observed in the parasite fauna composition of the mullets from different localities.Ferrer et al. (2007) published similar results and identified these species with a similar high prevalence and abundances.
Parasite species from M. surmuletus and other teleost fishes were correlated to the sites located inside or outside the Bonifacio Strait Marine Reserve (Corsica Island) and their distribution seemed to be most influenced by host specificity than by the protected status of the site (Ternengo 2009).
Species composition herein resembles those in the western Mediterranean, suggesting that species composition and richness of parasite communities of M. surmuletus appear to vary significantly at a large geographical scale.Further studies with other sampling sites are needed to explore the role of the natural barriers (e.g., Strait of Gibraltar) to restrict metazoan parasite populations within and outside the Mediterranean Sea.

Figure 1 .
Figure 1.Geographical location of the studied area.