Event Abstract

Distribution of Opecoeloides furcatus (Digenea, Opecoelidae) from the red mullet (Mullus barbatus barbatus) (L.1758) off the northern Sicilian coasts (Southern Tyrrhenian Sea)

  • 1 Institute for Coastal Marine Environment (IAMC), Italy
  • 2 Università degli studi di Messina, Scienze Biologiche ed Ambientali, Italy
  • 3 Institute for Coastal Marine Environment (IAMC), Italy

Opecoeloides furcatus (Bremser in Rudolphi, 1819) is an opecoeliid digenean infecting the digestive tract of the two mullidae Mullus barbatus barbatus and M. surmuletus (Carreras-Aubets et al., 2012). The Opecoelidae constitute a large and cosmopolitan family of digeneans characterised by a series of complex life-cycles involving two or three hosts and several developmental stages (Jousson et al., 1999). The specialist O. furcatus uses the gastropod Mitrella scripta (L.) as first intermediate host and, probably a decapod as second intermediate host (Jousson & Bartoli, 2000). The present study aims to assess the potential impact of O. furcatus on M. barbatus barbatus specimens inhabiting the seabed off the northern Sicilian coasts (Southern Tyrrhenian Sea). The distributional pattern as well as the influence on host growth have been evaluated. Samples have been collected from Cape Rasocolmo (Messina) to Cape S. Vito (Palermo) encompassing two Fishery Exclusion Zones: the Gulfs of Patti and the Gulf of Castellammare. A total of 10 hauls have been performed between 32 and 110 meters depth during an experimental otter trawl survey performed in May 2012. On board only red mullets of total length ranging from 110 and 150 mm were sorted and frozen. In the laboratory samples were defrosted, measured, weighed and dissected in order to macroscopically evaluate their sex. The entire digestive tract was removed and examined under a stereomicroscope for the presence of O. furcatus. The three epidemiological indices: prevalence of infestation (P%), mean intensity and mean abundance were calculated according to Bush et al. (1997). Fisher's exact test and Bootstrap t-test were applied to test for sex and sampling site factors (Reiczigel & Ròzsa, 2005). To test for correlation between prevalence and mean intensity vs depth the Spearman test was applied. The values of prevalence of infestation were additionally mapped by using GIS software. The parasitic effect on host growth was evaluated applying the length-weight relationship separately for infected and uninfected specimens. Differences between infected and uninfected specimens were tested using an analysis of covariance. The prevalence and intensity of infestation did not differ significantly between sexes (Table 1); consequently, the spatial distribution of this parasite in the study area was examined computing the parasitic prevalence in each haul for combined sexes. A total of 53 out of 251 M. barbatus barbatus were parasitized (Table 1). Each infected fish was parasitized by one to seventeen parasites. Generally the parasitic prevalence was 21.1 % and the mean intensity was 2.06. The parasite occurred throughout the study area with wide fluctuations of prevalence values ranging between 0 and 40 % (Figure 1). The parasitic prevalence values were significantly higher inside the Fishery Exclusion Zones (P = 32.3 %) than in the fishing zones (P = 14.2 %) (Fischer exact test, p value< 0.01). Mean intensity and abundance were not significantly different between fished and un-fished areas (Bootstrap 2-sample t-test, p >0.05). No significant correlation was found between prevalence and mean intensity vs. depth factor (rs = 0.22, p > 0.05; rs = 0.07, p > 0.5). The length-weight relationships showed a positive allometry for both uninfected and infected specimens, with a b value of uninfected specimens (b = 3.330) even lower than that of infected ones (b = 3.505); however the difference between infected and uninfected specimens was not significant (F = 0.903, p > 0.05). Although to date specimens of O. furcatus have been reported in M. barbatus barbatus from various localities in the Mediterranean Sea (Paggi et al., 1998; Martinez-Vicaria et al., 2000), the obtained value of prevalence of the parasite from our study area was lower than from the north African and from the Mediterranean Spanish coasts (Martinez-Vicaria et al., 2000; Carreras-Aubets et al., 2012; Derbel et al., 2012;). The comparison of length-weight relationships of infected and uninfected specimens and the low intensity of infection allow us to assume that, for the moment, there is no severe effect on the host population dynamic: O. furcatus does not affect the general-being of its host. Interestingly the spatial distribution on O. furcatus along the study area is not related to the depth appearing rather influenced by the presence of the two Exclusion Fishery Zones. Future studies will be performed in order to clarify this latter observation in relation to the seabed features and habitat integrity status among fished and un-fished areas as well as about the identification of intermediate crustaceans hosts (Mangano et al., 2014). Figure caption Figure 1. Prevalence of infestation (P%) of Opecoeloides furcatus in red mullets (Mullus barbatus barbatus) off the northern Sicilian coasts.

Figure 1

Acknowledgements

This work has been carried out in the framework of Ritmare Project SP2_WP1_AZ4_UO06 "Use of parasite as biological tags for fish stock identification” funded by the Italian Ministry of University and Research.

References

Bush A.O., Lafferty K.D., Lotz J.M., Shostak A.W. (1997) Parasitology meets ecology on its own terms: Margolis et al. revisited. Journal of Parasitology, 83: 575-583.
Carreras-Aubets M., Montero F.E., Kostadinova A., Carrassòn M. (2012) Parasites communities in the red mullet, Mullus barbatus L., respond to small-scale variation in the levels of polychlorinated byphenyls in the western Mediterranean. Marine Pollution Bulletin, 64: 1853-1860.
Derbel H., Châaari M., Neifar L. (2012) Digenean species diversity in teleost fishes from the Gulf of Gabes, Tunisia (Western Mediterranean). Parasite, 19: 129-135.
Jousson O., Bartoli P., Pawlowski J. (1999) Molecular identification of developmental stages in Opecoelidae (Digenea). International Journal for Parasitology, 29(11): 1853-1858.
Jousson O., Bartoli P. (2000) The life cycle of Opecoeloides columbellae (Pagenstecher, 1863) n. comb, (Digenea, Opecoelidae): evidence from molecules and morphology. International Journal for Parasitology, 30: 747-760.
Mangano M.C., Porporato E.M.D., Caridi F., Kaiser M.J., Spanò N., Bottari T. (2014). Assessing the effects of trawling disturbance on the diet of red mullet, Mullus barbatus barbatus (L. 1758), in the Southern Tyrrhenian Sea. Fishery Dependent Information Symposium (Rome 2014). Book of Abstract pp 61.
Martinez-Vicaria A., Martin-Sanchez J., Illescas P., Lara A.M., Jimenez-Albarran M., Valero A. (2000). The occurrence of two opecoeliid digeneans in Mullus barbatus and M. surmuletus from the Spanish South-Eastern Mediterranean. Journal of Helminthology, 74(2): 161-164.
Paggi L., Mariniello M., Ortis M., Mattiucci S., D’Amelio, Di Cave D., Orecchia P. (1998) Indagine parassitologica su specie ittiche di interesse economico dei mari italiani. Biologia Marina Mediterranea, 5(3): 1483-1492.
Reiczigel J., Rózsa L. (2005) Quantitative Parasitology 3.0. Budapest.

Keywords: Fishes, Parasitism, digenea, exclusion fishery zone, central Mediterranean Sea

Conference: IMMR | International Meeting on Marine Research 2014, Peniche, Portugal, 10 Jul - 11 Jul, 2014.

Presentation Type: Poster Presentation

Topic: FISHERIES AND MANAGEMENT

Citation: Bottari T, Mangano M, Busalacchi B, Porporato E, Rinelli P, Garofalo G and Fiorentino F (2014). Distribution of Opecoeloides furcatus (Digenea, Opecoelidae) from the red mullet (Mullus barbatus barbatus) (L.1758) off the northern Sicilian coasts (Southern Tyrrhenian Sea). Front. Mar. Sci. Conference Abstract: IMMR | International Meeting on Marine Research 2014. doi: 10.3389/conf.fmars.2014.02.00121

Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.

The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.

Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.

For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.

Received: 10 May 2014; Published Online: 18 Jul 2014.

* Correspondence: Dr. Teresa Bottari, Institute for Coastal Marine Environment (IAMC), Messina, Messina, 98122, Italy, teresa.bottari@iamc.cnr.it