DETERMINATION OF THE URVIVAL TEMPERATURE OF FRESH WATERFISH (Parachanna obscura) NEMATODES
E. M. Oden1 and O. J. Agada2
Department of Zoology and Environmental Biology
University of Calabar, Calabar Nigeria
E-mail: Estheroasis40@yahoo.com, oketeagada@yahoo.com
ABSTRACT
Parachana obscura is one of the major species of fishes that are most common in the Calabar Great Qua River. It is been consumed by about 70% of people within and without Cross River State almost every day. However, it has been noted from various literatures that this species of fish harbors a great number of nematodes. A total of 33 fishes (16larvae and 17adults) were bought from the Fishermen of Great Qua River Calabar, Cross River State –Nigeria, within the month of October and December 2011 respectively. The temperature range at which nematodes survive inthese fishes purchased from fishermen of Great Kwa River Calabar, Cross River state- Nigeria was investigated. One hundred and eighty-seven (187) nematodes were extracted from 33 fishes within the months of October and Dec ember 2011. Fifty-One percent (51%) adults and 49% larvae were observed; and the nematodes were identified as Contracaecum and Camallanus species. Generally, the larvae survive more than the adult nematode. And it was observed that decrease in temperature below 220C, decreases the survival rate and increase in temperature above 600C completely eliminates the nematodes. Also, the analysis of variance (ANOVA) of temperature and time carried out were highly significant at P (< 0.05). The public should subject P.obscura to a temperature range above 600C for 30minutes or more to ensure total elimination of nematodes from the fish before consumption.
Keywords: Parachana obscura,nematodes,temperature and time.