ON THE HELMINTH PARASITES OF THE RED SEA FISHES

Studies on host-parasite systems as bioindicators for monitoring trace metal pollution in marine environments are still scarce. Here, 11, 14 and 17 infrapopulations of Gyliauchen volubilis (Trematoda: Digenea), Procamallanus elatensis (Nematoda) and Sclerocollum rubrimaris (Acanthocephala), respectively, were collected from the fish Siganus rivulatus (Siganidae) in the Red Sea, from a chronically polluted small bay at Sharm El-Sheikh, South Sinai, Egypt. Water and sediment samples from the bay, tissue samples (intestines, liver, and muscle) from each fish, and samples from each parasite were taken for heavy metal analyses of cadmium and lead. Cadmium concentrations in intestines, liver and muscle of non-infected and infected fishes were much lower than those of lead, and both metal concentrations decreased in the order: liver > intestines > muscle. Cadmium and lead concentrations in the tissues of fishes infected with G. volubilis or P. elatensis were slightly lower than those in non-infected ones, while in the tissues of fishes infected with Sc. rubrimaris, they were much lower. Low concentrations of cadmium and lead in G. volubilis and P. elatensis are associated with their limited ability or capacity to accumulate trace metals. Therefore, bioconcentration factors corresponding to these species were relatively low, and both are herein considered as weak bioindicators. By contrast, high concentrations of cadmium and lead in S. rubrimaris are associated with its high ability to accumulate trace metals. Of the present three host–parasite systems, only the Siganus rivulatus–Sclerocollum rubrimaris system seems to be promising for biomonitoring of metal pollution in the Red Sea.

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First record of Pseudoterranova decipiens (Nematoda, Anisakidae) infecting the Red spot emperor Lethrinus lentjan in the Red Sea

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612019057 ◽

2019 ◽

Vol 28 (4) ◽

pp. 625-631 ◽

Cited By ~ 3

Author(s):

Saleh Al Quraishy ◽

Rewaida Abdel-Gaber ◽

Mohamed Abdel Monem Dkhil

Keyword(s):

Red Sea ◽

18S Rdna ◽

Morphological Characteristics ◽

First Record ◽

Gene Region ◽

Present Species ◽

Helminth Parasites ◽

Rdna Gene ◽

Pseudoterranova Decipiens ◽

18S Rdna Gene

Abstract The current parasitological study was carried out to investigate helminth parasites infecting the Red spot emperor Lethrinus lentjan inhabiting Hurghada City at the Gulf of Suez, Red Sea, Egypt. Third-stage larvae of nematode parasite was isolated from the intestine as well as body cavity of the examined fish. Light and scanning electron microscopy revealed that this parasite belonged to Anisakidae family within the genus Pseudoterranova. The present species is named Pseudoterranova decipiens based on the presence of triangular mouth aperture with prominent boring teeth and soft swellings of the cuticle, long muscular esophagus, ventrally excretory pore, and narrow transverse slit of anal opening followed by a short mucron. The morphological characteristics of this species were confirmed by molecular analysis of 18S rDNA gene region of the present parasite. It demonstrated a close identity ≥89% with taxa under family Anisakidae, 85% with Raphidascarididae, and 79-84% with Toxocaridae. A preliminary genetic comparison between gene sequence of the present parasite and other oxyurid species placeed it as a putative sister taxon to other Pseudoterranova decipiens described previously. This study demonstrated that the 18S rDNA gene region of Pseudoterranova decipiens yielded a unique sequence that confirmed its taxonomic position in Anisakidae.

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Sclerocollum saudii Al-Jahdali, 2010 (Acanthocephala: Cavisomidae) as a sentinel for heavy-metal pollution in the Red Sea

Journal of Helminthology ◽

10.1017/s0022149x18000044 ◽

2018 ◽

Vol 93 (2) ◽

pp. 177-186 ◽

Cited By ~ 2

Author(s):

R.M. El-S. Hassanine ◽

Z.M. Al-Hasawi ◽

M.S. Hariri ◽

H. El-S. Touliabah

Keyword(s):

Red Sea ◽

Metal Pollution ◽

Infected Fish ◽

Fish Host ◽

Helminth Parasites ◽

Metal Concentrations ◽

Fish Intestine ◽

Fish Samples ◽

Siganus Rivulatus ◽

Acanthocephalan Parasite

AbstractCurrently, fish helminth parasites, especially cestodes and acanthocephalans, are regarded as sentinel organisms to elucidate metal pollution in aquatic ecosystems. Here, 34 specimens of the fish Siganus rivulatus were collected in the Red Sea, from a seriously polluted, small lagoon named Sharm-Elmaya Bay, at Sharm El-Sheikh, South Sinai, Egypt; 22 (64.7%) were infected by Sclerocollum saudii (Acanthocephala: Cavisomidae). Thus, 22 natural infrapopulations (26–245 individuals) of this parasite were collected from infected fish. Samples of water and sediments from the bay, samples of muscle, intestine and liver from each fish, and samples from the parasite were taken for analysis of heavy metals (cadmium (Cd) and lead (Pb)). Both Cd and Pb concentrations in sediments were higher than those in water. The concentration of these metals were significantly higher in tissues (intestine, liver and muscle) of non-infected fish than those in infected fish, with Pb concentrations consistently higher than those of Cd, and both were drastically decreased in the order: liver > intestine > muscle. Metal concentrations in this acanthocephalan were much higher than those in its fish host. There were strong negative relationships between metal concentrations in tissues (intestine, liver and muscle) of infected fish and infrapopulation size, and between metal concentrations in the acanthocephalan and its infrapopulation size. These relationships strongly suggest competition for these metals between the fish host and its acanthocephalan parasite, and intraspecific competition among acanthocephalan individuals for available metals in the fish intestine. Bioconcentration factors were relatively high, since the mean Cd concentration in S. saudii was 239, 68 and 329 times higher than those in intestine, liver and muscle tissues, respectively, of its fish host. Also, mean Pb concentration was 55, 13 and 289 times higher than those in these tissues, respectively. The host–parasite system described here seems to be promising for biomonitoring of metal pollution in the Red Sea.

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Helminth parasites from Red Sea fishes: Neowardula brayi gen. nov., sp. nov. (Trematoda: Mesometridae Poche, 1926) and Sclerocollum saudii sp. nov. (Acanthocephala: Cavisomidae Meyer, 1932)

Zootaxa ◽

10.11646/zootaxa.2681.1.5 ◽

2010 ◽

Vol 2681 (1) ◽

pp. 57 ◽

Cited By ~ 5

Author(s):

MOHAMMED O. AL-JAHDALI

Keyword(s):

Red Sea ◽

Type Species ◽

Egg Size ◽

Developmental Stages ◽

Ventral Surface ◽

Helminth Parasites ◽

Intestinal Helminths ◽

The Family ◽

Siganus Rivulatus ◽

Proboscis Receptacle

Specimens of the fishes Acanthopagrus bifasciatus Forsskål (Sparidae) and Siganus rivulatus Forsskål (Siganidae) were caught in the Red Sea off the coast of Rabigh, Saudi Arabia. Four (25%) and 24 (80%) of these fishes, respectively, were found to harbour intestinal helminths. Acanthopagrus bifasciatus was parasitised by Neowardula brayi gen. nov., sp. nov. (Trematoda: Mesometridae) and S. rivulatus by Sclerocollum saudii sp. nov. (Acanthocephala: Cavisomidae). Neowardula brayi gen. nov. is similar to Wardula Poche, 1926, but clearly differs from it and from the other four genera of the family Mesometridae Poche, 1926 in having a ventral surface anterior to the intestinal bifurcation greatly modified into a well-developed, relatively deep pouch encircling the genital pore and constantly diagonal testes. Sclerocollum saudii sp. nov. is similar to S. rubrimaris Schmidt et Paprena, 1978 (type species), but clearly differs in having a proboscis only armed with 10 rows of hooks, smaller proboscis hooks, lemnisci much longer than proboscis receptacle and much smaller egg size. The developmental stages of this acanthocephalan (cystacanths, juveniles and immature worms) are also described and figured.

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