The present study attempts to identify some of the differences between the skull bones of two species Cyprinus carpio and Carassius carassius, which belong to the Cyprinidae family. The study is a taxonomic diagnostic study between the two species which are considered local fish abundant in the Iraqi aquatic environment

    The monogeneans Gyrodactylus dzhalilovi Ergens & Ashurova, 1984, G. magnus Konovalov, 1967 and G. matovi Ergens & Kakachava-Avramova, 1966 were recorded in this study for the first time in Iraq from gills of the common carp Cyprinus carpio Linnaeus, 1758 collected from Tigris River in Baghdad city. The description, measurements and illustrations of these parasites were given.

The development of thyroid gland in five developmental stages of common carp, Cyprinus carpio L. The thyroid originates from the pharyngeal floor as a median ventral keel in late embryos having four pairs of arches. It differentiates into profollicular aggergations and true follicles with flattened walls and empty lumina or with lumina filled with cotton waste-like material in three days-old elvers. Secretion of homogeneous eosinophilic colloid with a limited increase in the height of follicular wall is noted in five days-old elvers. In nine days-old individuals the follicles increase in size due to coallescence. The thyroid gland reaches its maximal activity as judged by its histology in one-two months-old individuals. The gland is of t

The acute toxicity effects of (2,4-D) pesticide to the common carp and grass carp was determined through 24, 48, 72 and 96 hr. Group of eight Common carp (Cyprinus carpio L., 1758; Pisces, Cyprinidae) and group of eight of grass carp (Ctenopharyngodon idella) were exposed to the 2,4-d. Lethal concentration (LC50) was determined with probit analysis. The median lethal concentration (LC50) values for common and grass carp were (157.77, 157.25, 156.41 and 152.62) and (115.92, 114.92, 112.94 and 96.52) respectively. Behavioral changes of the above mentioned species were examined for various herbicide concentrations.

  The present study aims to give some details about the normal anatomical and histological structure of the liver, pancreas and gall bladder in Cyprinus carpio Linnaeus, 1758 and Mesopotamichthys sharpeyi (Günther, 1874). Anatomical results revealed that the liver of C. carpio is a reddish-brown in color, located in the anterior part of abdominal cavity and dispersed between most of the intestines, which is divided into two lobes; while in M. sharpeyi the liver is light brown in color located in the anterior part of abdominal cavity and extends to the end of the intestinal tract with two lobs. The gallbladder situated in the right side of the liver in both species. Histological results in both species showed that the liver consists

In present study, an attempt has been made to investigate the effect of Chlorpyrifos insecticide on carp Cyprinus carpio L. through acute toxicity bioassay. The LC50 were estimated as 1897, 1266, 985 and 792 μg/L during 24 , 48, 72 and 96 hr. respectively by using the concentrations 500 , 1000, 1500 , 2000, 2500 and 3000 μg/L indicating high sensitivity of fish to chlorpyrifos. The behavioral response observed in the fish were erratic swimming, loss of reflex, hyperactivities, decrease in appetite secretion of mucus, increase movement of operculum and hyperventilation . These effects increased with increasing concentration of the chlorpyrifos and duration of exposure.

Hematological parameters were used as a biomarker of sub chronic effect of dursban  in Cyprinus carpio L. The common carp was exposed sub chronically to the 36, 53,113 µg /l concentrations of dursban for six weeks. During the experimental period the results showed a decrease  in the  red blood cell (RBC), white blood cell (WBC),  hemoglobin (Hb), mean corpuscular volume (MCV),  and packed cell volume (PCV)  in the  last two weeks of exposure, while the Mean corpuscular hemoglobin (MCH) and Mean corpuscular hemoglobin concentration (MCHC) were significantly increased. The present study indicates that sub chronic exposures of C.carpio to dursban alter the hematological parameters.

The study was conducted to show the effect of using dried rumen powder as a source of animal protein in the diets of common carp (Cyprinus carpio L.) on its performance, in the fish laboratory/College of Agricultural Engineering Sciences/University of Baghdad/ for a period of 70 d, 70 fingerlings were used with an average starting weight of 30±3 g, with a live mass rate of 202±2 g, randomly distributed among five treatments, two replicates for each treatment and seven fish for each replicate. Five diets of almost identical protein content and different percentages of addition of dried rumen powder were added. 25% was added to treatment T2 and 50% to treatment T3 and 75% of the treatment T4 and 100% of the treatment T5

A series of experiments were conducted for the first time in Iraq to evaluate the efficiency of five plant leaves extracts (Ibicella lutea, Nerium oleander, Clerodendron inerme, Allium cepa and Eucalyptus spp.) in treating the common carp (Cyprinus carpio) infected with monogenetic trematodes of genera Dactylogyrus. Five different concentrations of such extracts were used to bathe fishes for 5,10,15,20 and 25 minutes. A concentration of 15% A. cepa for 25 minutes of bath exposure was affective in trematode eradication. Extracts of both Eucalyptus and N. oleander at a concentration of 10% each were also affective for ten minutes exposure. Extracts of C. inerme had no any effect on such parasites. On the otherhand, extracts of 1. hitea caused