Indian Journal of Geo Marine Sciences Vol. 46 (06), June 2017, pp. 1175-1182 Metazoan parasites of Otolithes ruber (Perciforme: Sciaenidae) of the Persian Gulf off Hendijan Region, Iran Maryam Khosheghbal, Jamileh Pazooki* & Mohammad Reza Shokri Department of Marine Biology, Faculty of Biological Sciences, Shahid Beheshti University, G.C., Tehran, Iran *[E-mail: [email protected]] Received 29 June 2015 ; revised 16 December 2015 Totally, 110 fish specimens were seasonally caught by gill net and hook from summer 2013 to spring 2014. Parasites were Diplectanum spp. (Monogenea); Erilepturus hamati, Stephanostomum sp., Pleorchis sp. and Prosorhynchus sp. (Digenea); Philometra otolithi, Dichelyne spinigerus and Hysterothylacium sp. (Nematoda); Parabrachiella otolithi (Copepoda); and Gnathia sp. (Isopoda). No significant differences were found among the parasites analyzed with respect to the sex of the host except in digeneans. There were significant differences in parasites abundance among different seasons. No significant correlation was found between parasites abundance and total length of fish. [Keywords: Commercial fish, Khozestan Province, tigertooth croaker] Introduction which are polluted by majority of oil, gas and Fish parasitology is a significant study area in uncontrolled discharge of the sewage and aquatic sciences and fish parasites play a major industrial waste water. All these stresses and role in marine biodiversity. It is estimated that activities are posing a serious threat to the marine there are up to 100000 species of fish parasites1. environment and may be change and affect the As parasites may have negative effects on their parasitic fauna of marine organisms. Present hosts; thus, it is important to determine and study was undertaken to survey on metazoan identify the parasitic biodiversity2,3. Tiger tooth parasites of O. ruber one of commercially croaker Otolithes ruber (Bloch & Schneider, important fish from off Hendijan waters in the 1801) (Perciformes: Sciaenidae) with maximum northern Persian Gulf. Also effect of seasons, host length of 90 cm and maximum weight of 7 kg is a size and sex on incidence and occurrence of tropical commercial fish that occurs in marine and parasites were evaluated. brackish waters in Indo-West Pacific oceans. This benthopelagic species occurs mostly in coastal Material and Methods waters from East Africa, including Madagascar (excluding the Red Sea), eastward to the South A total of 110 specimens of O. ruber were China Sea and waters off Queensland, Australia4. seasonally caught by gill net and hook in Several investigations have been undertaken on Khozestan Province (off Hendijan), in the west parasitic fauna of different species of family northern Persian Gulf, Iran from 29° 45' to 30° 09' Sciaenidae in worldwide5-35. In spite of numerous N and 49° 30' to 50° 00' E (Fig. 1). Fish papers dealing with brackish and freshwater specimens were obtained from summer 2013 to parasitic fauna, only scanty information is spring 2014 and were immediately deep frozen available on parasites infesting marine fish until transfer to the Marine Parasitology Lab at species in Iran36-45. The Persian Gulf is one of Faculty of Biological Sciences of Shahid Beheshti commercially and economically important areas University, Tehran. 1176 INDIAN J. MAR. SCI., VOL. 46, NO. 06, JUNE 2017 parasites were embedded in permanent glycerine– gelatin preparations. Parasites identification carried out based on morphological features according to standard keys44-49. Identified parasites were deposited at Marine Parasitology Lab at Faculty of Biological Sciences of Shahid Beheshti University, Tehran. Because data was not normally distributed, significant differences in parasites abundance with respect to the fish gender were explored using non- parametric Mann- Whitney U test. The Fig. 1: Sampling location in Khozestan Province, off significant differences in parasites abundance Hendijan in the north western of the Persian Gulf. among various seasons were determined using After measuring weight and length of fish, all Kruskal-Wallis test with Mann- Whitney U test external and internal organs of the host were for pairwise comparisons. Non- parametric carefully examined by naked eye, stereo-and light Spearman correlation coefficient was used to microscopes for the presence of parasites based investigate the relationship between parasites on parasitology methods. Samples were studied abundance and total length of fish. Statistical using stereo microscopes NSZ-606 and light analyses were performed by the software package microscopes Nikon YS 100. isolated parasites of SPSS version 16.0. Prevalence, mean intensity were fixed and preserved in 4% formaldehyde and abundance were calculated based on Bush et Solution or in 70% ethanol. Monogeneans al. Table1- Prevalence, mean intensity (±SD), abundance and site of infection for the metazoan parasites in O. ruber at Hendijan Region in the north western of the Persian Gulf. Parasites Prevalence (%) Mean Intensity Abundance Site of Infection Monogenea Diplectanum sp1. 1.81 1±0.13 0.01 Gills and operculum Diplectanum sp2. 80.90 6.22±8.10 5.03 Gills and operculum Digenea Pleorchis sp. Stephanostomum 0.90 1±0.09 0.01 Intestine sp. 54.54 3.13±2.46 1.70 Intestine Erilepturus hamati 84.54 5.96±6.21 5.03 Gill- Stomach Prosorhynchus sp. 6.36 2±0.52 0.12 Gill- Stomach Nematoda Philometra otolithi 12.72 12±7.71 1.52 Gonad Dichelyne spinigerus 46.36 2.98±2.33 1.38 Intestine Hysterothylacium sp. 13.63 1.40±0.55 0.19 Stomach, Intestine and Mesenteries Copepoda Parabrachiella otolithi 7.27 1.25±0.34 0.09 Gill Isopoda Gnathia sp. 2.72 1±0.16 0.02 Gill PAZOOKI et al.: METAZOAN PARASITES OF OTOLITHES RUBER (PERCIFORME: SCIAENIDAE) 1177 Results autumn and winter. The most infected organs were gills and stomach with 48.0% and 23.1%, Eleven species of metazoan parasites were respectively; while, they were less in operculum identified representing by two species of and mesenteries with 3.5% and 0.1%, respectively Monogenea, four species of Digenea, three (Fig. 7). species of Nematoda, one species of Copepoda and one species of Isopoda (Fig. 2−4, Table 1). The result of non- parametric Mann- Whitney U test showed no significant difference between the The results of this study showed that parasites analyzed with respect to the sex of the monogeneans and digeneans had the highest host except for digenetic trematodes (Z= -1.99; df occurrences on the host with 45.1% and 37.2%, = 1; P = 0.04). The result of Kruskal-Wallis test respectively, while copepod and isopod were less revealed significant differences among abundant with 0.8% and 0.1%, respectively (Fig. monogenean, nematode and copepod parasites in 5). As shown in Fig. 6, monogenean parasites different seasons (Table 2) and the Mann- were minimized in summer; while, frequently Whitney U test indicated pairwise comparison of recorded in spring. Highest infection rate of seasons with different parasites (Table 3). No trematodes was detected in winter and the lowest significant correlation was found between was in spring. Among the nematodes, peak parasites abundance and total length of fish. infection occurred in summer and spring, low in Table 2- The results of Kruskal-Wallis test to determine significant differences among parasites in different season Mon Dig Nem Cop Iso Chi-square 14.188 5.367 21.006 16.778 3.169 df 3 3 3 3 3 P- value 0.003 0.147 0.000 0.001 0.366 Fig. 2: A. Parabrachiella otolithi B. Gnathia sp. C. Fig. 3: A. Prosorhynchus sp. B. Erilepturus hamati C . Diplectanum sp1. D. Opisthaptor of Diplectanum sp1. E. Pleorchis sp. D. Stephanostomum sp. E. Anterior part Diplectanum sp2. F. Opisthaptor of Diplectanum sp2. of Philometra otolithi, male F. posterior part of P. otolithi, male. 1178 INDIAN J. MAR. SCI., VOL. 46, NO. 06, JUNE 2017 Fig. 5: Occurrence of parasites on O. ruber (%) Fig. 4: A. Anterior part of P. otolithi, female B. posterior part of P. otolithi, female C. Anterior part of Hysterothylacium sp. D. posterior part of Hysterothylacium sp. E. Anterior part of Dichelyne spinigerus, female F. posterior part of D. Fig. 6: Occurrence of parasites in different seasons (%) spinigerus, female G. Anterior part of D. spinigerus, male H. posterior part of D. spinigerus, male. Fig.7: Parasitic infection in different organs of O. ruber (%) Mesen: Mesenteries, Operc: Operculum Table 3- The results of pairwise comparisons among seasons obtained from Mann- Whitney U test * P<0.05; 1: summer, 2: autumn, 3: winter, 4: spring mongen digen nematode copepod isopod 1 vs. 2 0.92 0.78 0.41 0.08 0.24 1 vs. 3 0.31 0.29 0.06 0.33 1.00 1 vs. 4 0.006* 0.28 0.05 0.08 0.41 2 vs. 3 0.42 0.49 0.24 0.31 0.15 2 vs. 4 0.01* 0.15 0.001* 0.001* 0.55 3 vs. 4 0.001* 0.02* 0.000* 0.006* 0.31 PAZOOKI et al.: METAZOAN PARASITES OF OTOLITHES RUBER (PERCIFORME: SCIAENIDAE) 1179 Discussion et al.56 described different species of Prosorhynchus spp. from some families of fish Fish is one of the important sources of protein in such as Serranidae, Carangidae and Trichuridae in the world. Due to limited marine resources and the off coast of Kuwait. In the current study O. need to artificial aquaculture, parasitic infection ruber was introduced as a new host for this of fish is a serious threat and should not be species and Prosorhynchus sp. was reported for neglected. Parasites are known to potentially the first time in Iran. Peyghan et al.37 reported decrease the survival or the reproduction of host Elythrophallus sp., Lecithocladium sp. and 51 populations , so parasitism is largely considered Alloceraadium sp. from this host in Khozestan in studies of biodiversity. Province, Iran. None of the mentioned trematodes by Peyghan et al.37 were found in this study.