Prevalence of copepod parasite(Lernaeenicus polynemi)infestation on Eleutheronema tetradactylum from Pazhayar coastal waters,southeast coast of India

Objective:To study the prevalence and mean intensity of copepod parasite Lernaeenicus polynemi infestation on Eleutheronema tetradactylum from Pazayar,Tamil Nadu,southeast coast of India.Methods:The fish was collected from Pazhayar landing centre from January to December 2012 and their biometric measurements were examined.Toal number of infected fish and total number of parasites were recorded.Results:Higher prevalence and mean intensity of infestation of 35.23%and 3.1 were respectively reported during monsoon season of 2012.The parasitic infestations were scattered over the entire body of the host and targeted the different internal organs such as liver and the dorsal aorta.The highest intensity was reported to be 66 parasites in a single host.Conclusions:Due to the heavy parasitic attack the fish will suffer and its economical value or the marketability may reduce.

Isolation and identification of marine fish tumour(odontoma)associated bacteria

Objective:To identify fish tumour associated bacteria.Methods:The marine fish Sphyraena jello with odontoma was collected from in Tamil Nadu(Southeast India),and tumour associated bacteria were isolated.Then the isolated bacteria were identified based on molecular characters.Results:A total of 4 different bacterial species were isolated from tumour tissue.The bacterial species were Bacillus sp.,Pontibacter sp.,Burkholderia sp.and Macrococcus sp.,and the sequences were submitted in DNA Data Bank of Japan with accession numbers of AB859240,AB859241,AB859242 and AB859243 respectively.Conclusions:Four different bacterial species were isolated from Sphyraena jello,but the role of bacteria within tumour needs to be further investigated.

Four types of neoplasms in Asian sea bass(Lates calcarifer)

Objective:To describe and observe four types of neoplasms on different parts(external and internal organs)of an Asian sea bass(Lates calcarifer).Methods:The sample was collected from local fish landing center(south east coast of India).Histopathology of normal and tumour tissues were analyzed.Results:A total of 83 tumour masses(neoplasm)were recorded on the fish skin,also the neoplasms were recorded in internal organs of fish such as liver,stomach and ovary.Conclusions:Aetiology of such neoplasm’s are unknown,further more researches need to confirm the causative agent for this type of neoplasm.

Acanthocephalan(Echinorhynchus sp.)infection of yellowfin tuna(Thunnus albacares)from Nagapattinam,south east coast of India

Objective:To recored the infection of Acanthocephalan parasite,(Echinorhynchus sp.)in adult yellowfin tuna(Thunnus albacares).This is the first report of acanthocephalan Echinirhynchus sp attached to yellowfin tuna and moreover prevalence,mean intensity and mean abundance was observed.Methods:Totally 1001 yellowfin tuna fishes were collected throughout the year of 2012 from the coast of Nagapattinam(10°45'36.25"N and 79°50'59.54"E),Tamil Nadu,India.The collected fishes were washed with fresh water to remove debris and immediately stored in ice,and brought to the laboratory.Intestines were placed in normal saline(0.85%NaCl).The worms were fixed in alcohol/formalin/(AFA)fixative and in 70%ethanol until processed for identification.Results:Totally 1001 yellowfin tuna was examined out of 387(52.67%)hosts were infected with acanthocephalan(Echinorhynchus sp.).The proboscis Echinorhynchus sp.was long,cylindrical with cylindrical with a uniform width measured(0.41±0.02)mm in length and(0.12±0.03)mm in width.The endo parasite prevalence,intensity and abundance was recorded as 52.67%,12.46%,and 5.43%respectively.Conclusions:This current phenomena was carried out to report of acanthocephalan Echinorhynchus sp.attached the new host of yellowfin tuna from Nagapattinam coast.Moreover,parasitological investigations are required to determine endo parasites of host due to its importance and numerous occurring among most important marine food fishes in world wild.

Black gill disease of Paciifc white leg shrimp(Litopenaeus vannamei)byAspergillus lfavus

Objective:To study the epidemiology of black gill disease in white leg shrimp which is a major problem being faced by the commercial shrimp farmers who are culturing Litopenaeus vannamei(L.vannamei)in India.Methods:The normal and infected shrimps were collected from shrimp pond and the gill was preserved in appropriate preservative for histopathological examination and scanning electron microscope analysis.Pathogenic fungus was isolated from black gill of L.vannamei in potato dextrose agar medium.Morphological study and fungal strain identification were done by using light microscopy and scanning electron microscope.Fungal DNA was amplified by ITS4 and ITS5 primers and gene sequencing was done by Macrogen Inc.,Korea.Phylogenetic tree was prepared by using MEGA 6 software.Results:Fungal spores and hyphae were observed both in internal and external gill surface of infected shrimps.Fungal spores were round in shape and mature sporangium was observed.The histopathology study showed clearly that infected gill was damaged by the fungi.Scanning electron microscopic study showed adherence of fungi in infected gill.Internal transcribed spacer gene sequencing revealed that it was caused by Aspergillus flavus.Conclusions:The outcome of the present study would help to know the cause of black gill disease and to understand the effect of pathogenic fungi in shrimp culture.This study will initiate researchers for work in field of treatment or prevention of black gill disease in commercial L.vannamei culture.

Occurrence of a nematode Philometra(Costa,1845)in the ovaries of Epinephelus malabaricus(Bloch&Schneider,1801)in southeast coast of India

Objective:To study the prevalence of philometrid nematode,Philometra spp.infected in the ovaries of Epinephelus malabaricus(E.malabaricus)from southeast coast of India.Methods:Totally 4801 fishes were collected from Mandabam,Tuticorin and Kanyakumari.The normal and infected ovaries were carefully removed from dissected fishes and the prevalence of nematode infection for each fish was examined.Then the nematode were carefully removed and washed in a 0.6%saline solution and fixed in 70%ethanol.Representative nematodes were cleaned with glycerin and fixed in a solution of 95%glacial acitic acid and 5%formalin for identification under light microscopy.Results:Of which 16.8%,16.2%and 14.7%parasitic prevalence was observed from Mandabam,Tuticorin and Kanyakumari respectively.The intensity of parasitic worms per fish varied from 1 to 8 with an average of 6.33±0.84.Nematode length varies from 7-22 mm with in average of(18.70±4.57)mm.The average length and weight of E.malabaricus were(332.950±77.792)mm and(513.30±169.46)g respectively.Conclusions:It can be assumed that females of this nematode are unable to attain gravidity in this host species,and consequently,E.malabaricus does not serve as the true definitive host of Philometra spp.Prevalence of infection and intensity of the nematode are highly effected by sucking blood,causing atrophy of developing ova in the ovary,fibrosis of ovarian tissue,increasing granulocytes and haemorrhages,and thus negatively affecting the reproduction of some species of E.malabaricus.

Prevalance and pathology of gastric tumours in Indian oil sardine(Sardinella longiceps)from Parangipettai coastal waters,southeast coast of India

Objective:To carry out the survey of prevalence of gastric tumour in Sardinella longiceps of Parangipettai coastal waters,south east coast of India for a period of one year.Methods:Fish samples were directly collected from fishermen and also from auction yard.The prevalence of gastric tumour,gross pathology,radiography,histopathology,morphometric and meristic characters were investigated.Results:A total of 31 stomach tumour infected individuals were collected during the study period.The gross morphology showed distended abdomen and the radiograph exhibited enlargement of stomach.Autopsy of the infected fish exhibited reddish multilobed tumourous growth on the stomach.Histologically,the tumour lesions were characterized by the differential rate of glandular epitheloid and mesenchymal cells,polymorphic and hyperchromatic nuclei and mitotic activity.No evidence of local invasion and distinct metastases were observed in these cases.Conclusions:The tumours were diagnosed as gastric adenoma,myofibroblastoma,lipoma and fibrosarcoma.Among them myofibroblastoma is highly prevalent.