Olfactory epithelium organization of the grass carp (Ctenopharyngodon idella) at the ultrastructural level: SEM and TEM observations

Olfaction is the major sense of smell in teleost involved in many physiological response and habitat acclimatization including food searching, migration for spawning, predator avoidance, reproduction behavior, as well as identification of fish of the same species. Our study illustrates the ultrastructure of the olfactory rosette of the grass carp Ctenopharyngodon idella (Cuvier and Valenciennes, 1844) by using Scanning Electron Microscope (SEM) and transmission Electron Microscope (TEM). Herein, the peripheral olfactory organs are represented by two olfactory rosettes lying in two nasal chambers, one on each side of fish snout. Each nasal chambers opens to the exterior by two nostrils a narrow inlet and wider outlet, segregated by a somewhat elevated, nasal bridge. The two nostrils are somewhat faraway as far as length of rosette’s length to permit entering and leave water flow bearing odorant molecules to the nasal cavities. The SEM revealed that each olfactory rosette is elongated oval-shaped and made up of 48-50 foliar lamellae transversely arranged on both sides of a narrow median raphe. Alongside, the magnitude of lamellae differs in relation to their location on the raphe, since the larger are in the middle whereas their dimensions gradually reduced towards both ends of the rosette indicating that the number and magnitude of lamellae increase as the fish grow. Moreover, the lamellar surface comprises sensory and non-sensory areas concealed in a mucous layer and not distributed uniformly within the epithelial surface of the olfactory lamellae. Accordingly, The TEM observations indicated that the sensory areas holds four main receptor neurons, two  are major including ciliated and microvillous receptor cells bearing either cilia or microvilli, respectively emitted from a dendritic knob. Additionally, two other minor rod-tipped and crypt cells bearing a compound rod cilium, or few microvilli and occult cilia emitted also from dendritic knob were rarely observed. From the other side, the non-sensory area comprises cylindrical flat top surface; ciliated non-sensory cells with motile long kinocilium and nonciliated stratified epithelial cells with fingerprint-like microridges both are mainly of supporting in addition of and ovoid goblet mucous cells in-between and stem basal cells. Collectively, our study revealed the general organization and ultrastructure of an important economic teleost fish that affects feeding habitat and has an important influence on the fish food intake

تركيز الكاتيكولامينات في الدماغ والحبل الشوكي لذكور الجرذان البيضاء المعالجة بالمبيد الحشري البيريثرويدي "سفلوثرين"

The principal objective of this study was to determine the modifications induced by the synthetic pyrethroid insecticide cyfluthrin in the concentrations of dopamine (DA), norepinephrine (NE) and epinephrine(E) in selected brain and spinal cord regions of male albino rats. A group of 30 rats were injected intraperitoneally every other day with cyfluthrin at 1/4 LD50 dose level for 18 days. Other two groups (30 rats each) were daily given cyfluthrin intraperitoneally at the dose levels of 1/8 LD50 and 1/50 LD50 for 18 days and 6 weeks respectively. All treated animals developed a time and dose dependent toxicity symptoms and behavioural changes representing the typical CS syndromes produced by a- cyano pyrethroids . These involve skin paresthesia , body tremor , motor incoordination , choreoathetotic writhing and profuse salivation . Clonic and tonic seizures appeared at the terminal stages . Concentrations of DA, NE and E were measured in the olfactory bulb, hypothalamus, cerebellum, medulla oblongata, thoracic and lumbar regions of the spinal cord homogenates of rats treated for 3, 6, 9, 12, 15 or 18 days every other day or daily with 1/4 or 1/8 LD50 dose levels respectively and of rats treated daily for 1, 2, 3, 4, 5 or 6 weeks with 1/50 LD50 dose level. It was found that cyfluthrin at all dose levels used induced a general increase of DA, NE and E in all studied brain and spinal cord regions. The pattern of this increase was both time and regional dependent. These data suggest that cyfluthrin is a mammalian neurotoxic agent, and the severity of its toxic action is dependent on the treatment period as well as the affected region of the central nervous system.تناول البحث دراسة تأثير الحقن المتكرر في التجويف البريتوني لذكور الجرذان البيضاء بالمبيد الحشري البيريثرويدي سفلوثرين على تركيزات الدوبامين والنورابينفرين و ا‏لابينفرين في مناطق محددة من ا‏لدماغ والحبل الشوكي . تم حقن الجرذان بثلاثة جرعات منفصلة من السلفوثرين تعادل 1/4 ،1/8 ، 1/50 الجرعة المميتة لنصف المجموعة ، حيث تم الحقن بالجرعة الاولى يوم بعد يوم لمدة ١٨ ‏يوم أو يوميا بأي من الجرعتين الثانية والثالثة لمدة ١٨ ‏يوم و ٦ ‏أسابيع على التوالي . تم قياس تركيزات الدوبامين والنورابينفرين والابينفرين في أنسجة الفص الشمي . تحت سرير الدماغ ( الهيبوثالامس ) ، المخيخ ، النخاع المستطيل‌، والمنطقتين الصدرية والقطنية من الحبل الشوكي بعد 18،15،12،9،6،3 ‏يوما من المعالجة بأي من الجرعتين 1/4 ١،1/8 ‏الجرعة المميتة لنصف المجموعة ، وبعد 6،5،4،3،2،1 ‏أسابيع من المعالجة بالجرعة 1/50 ‏الجرعة المميتة لنصف المجموعة . ‏أظهرت النتائج أن معالجة الجرذان بأي من الجرعات المستخدمة قد أحدث زيادة في تركيزات الدوبامين والنورابينفرين والابينفرين في جميع المناطق المدروسة من الدماغ والحبل الشوكي ، حيث اعتمدت مستويات الزيادة على فترات المعالجة بالحقن وأيضا على المنطقة المدروسة . اقترحت الدراسة أن للسفلوثرين تأثيرات سامة على الجهاز العصبي المركزي في الثدييات ء تتمثل في أحداث تغييرات في تركيز الكاتيوكولامينات في مناطق مختلفة من الدماغ والحبل الشوكي

دراسات تطوريه مقارنة على جهاز القنوات الجانبية في سمكتي المبروك سيبرينس كاربيو والجامبوزيا جامبوزيا أفينس أفينس

The lateral line canals and the neuromasts situated inside their lumina are described in two fishes differing in their feeding habits. There are 20 canal neuromasts in the bottom feeder Cyprinus carpio, while in the surface feeder Gambusia affinis affinis there are 8 neuromasts only. Thus the canal system is well developed in the first species than in the second one. The canals open to the exterior through fine canaliculi with fine pore which are also great in number in Cyprinus carpio.تم دراسة وتوزيع قنوات الخط الجانبي لسمكتي المبروك والجمبوزيا حيث وجد ان جهاز الخط الجانبي متطور جداً ومعقد في المبروك ، بينما هذا الجهاز مختزل وبسيط في الجامبوزيا

A stereoscopic study of the mouthparts of the marine isopod, Cirolana bovina (Isopoda: Flabellifera)

The three-dimensional study of the mouthparts of the isopod crustacean Cirolana bovina is carried out for specimens collected from the Mediterranean Sea, Alexandria, Egypt, to reveal their morphology and related cuticular microstructures, especially setal types. The mouthparts consist of a labrum, paragnaths, paired mandibles, maxillules, maxillae and maxillipeds. The labrum and the paragnaths are the least developed but peculiarly the mandibles are asymmetrical, large, stout and highly modified. The possible functions of the mouthparts, especially in feeding are discussed in light of their structure. KEY WORDS: Crustacea, isopods, SEM, mouthparts, cuticular microstructures. Egyptian Journal of Biology Vol.3(2) 2001: 20-2

مشاهدات أولية على النمو النسبي وانتاج أسماك البلطي المستزرع في أقفاص بثلاث كثافات مختلفة

Relative growth rate and productivity of Tilapia species (T. nilotica and T. galilaea) were studied for fish reared in cages in the Serow fish farm, Egypt. Both species were reared under three different stocking densities 100, 200 and 300 fish/ in^The fish were fed daily with supplementary food of 20% protein content at 5% of the stock weight-Control cages of each type of fish at the lowest stocking density were maintained without supplementary feeding. Results indicated that the individual growth rate of both species decreased with increased stocking densities with a best aggregate stocking rate of 200 fish/m3 for both species.The maximum production rates of 32.0 and 17.4 kg/m^six months and final average size of 178.7 and 108.7 gm/fish were recorded for T.nilotica and T. galilaea respectively.The range of food conversion ratios for T. nilotica were between 2.83 and 3.57 while for T. galilaea were 3.88 and 5.20 with efficiency decreasing with increasing stocking density. Survival rates at the three densities ranged between 97.5—100% indicating that Tilapia species are able to withstand a certain degree of crowding, which is an important characteristic in the intensive culture of the fish.اشتملت الدراسة على النمو النسبي وإنتاج أسماك البلطي (النيلي والجاليلي ) في أقفاص عائمة بمزرعة السرو - مصر - بثلاث كثافات مختلفة (100 ، 200 ، 300 سمكة/ متر مكعب ) وكل معدل كثافة جرب في أربعة أقفاص اثنين ذات حجم 1/م 3 والآخر ذات حجم 4 /م 3 - وغذيت الأسماك غذاء صناعي يحتوي على 20% بروتين بمعدل يومي 5% من الوزن الكلي للأسماك وأجريت تجربة معدل التحكم لكل نوع من الأسماك بدون غذاء إضافي . وقد تبين من نتائج هذه التجربة أن الزيادة في كثافة الأسماك لكلا النوعين ينتج عنها نقص في معدل النمو الفردي وكان أحسن معدل جماعي في كثافة 200 سمكة/متر مكعب حيث أعطى انتاج 32 كجم /المتر المكعب ،17.4كجم / المتر المكعب ووزن 178.7جرام /سمكة ، 108.1 جرام /سمكة لأسماك البلطي النيلي والجاليلي على الترتيب . وقد تفاوت معدل التحويل الغذائي إلى زيادة في الوزن في الكثافات الثلاث بين 2.83 ، 3.47 للبلطي النيلي ،3.88 ، 5.20 للبلطي الجاليلي . وكان المعدل بصفة عامة أقل قليلا في الكثافة العالية منه في الكثافات المنخفضة - وبلغ معدل البقاء بعد 180 يوم في كل من الكثافات الثلاث 100، 200 ، 300 سمكة/متر مكعب في كلا النوعين كما يلي : 99.5%، 99.8%، 97.9%للبلطي النيلي ،99.3%، 99.4%، 98.3% للبلطي الجاليلي على التوالي . ومما تبينه هذه الدراسة أيضا أن معدلات النمو لأسماك البلطي لا تتأثر بدرجة كبيرة حتى عندما تستزرع بكثافة عالية وذلك بمقارنتها بالكثافات الأقل مما يدل على أن هذه الأنواع من الأسماك لها القدرة على تحمل درجة معينة من الازدحام وهذه الخاصية يمكن الاستفادة منها كثيرا للزراعة المكثفة لهذه الأسماك

Zinc Oxide Nanoparticles (ZnO-NPs) Induce Cytotoxicity in the Zebrafish Olfactory Organs via Activating Oxidative Stress and Apoptosis at the Ultrastructure and Genetic Levels

Nanotechnology has gained tremendous attention because of its crucial characteristics and wide biomedical applications. Although zinc oxide nanoparticles (ZnO-NPs) are involved in many industrial applications, researchers pay more attention to their toxic effects on living organisms. Since the olfactory epithelium is exposed to the external environment, it is considered the first organ affected by ZnO-NPs. Herein, we demonstrated the cytotoxic effect of ZnO-NPs on the olfactory organ of adult zebrafish after 60 days post-treatment. We opted for this period when fishes stop eating their diet from the aquarium, appear feeble, and cannot swim freely. Our study demonstrated that ZnO-NPs induced significant malformations of the olfactory rosettes at histological, ultrastructural, and genetic levels. At the ultrastructure level, the olfactory lamellae appeared collapsed, malformed, and twisted with signs of degeneration and loss of intercellular connections. In addition, ZnO-NPs harmed sensory receptor and ciliated cells, microvilli, rodlet, crypt, and Kappe cells, with hyper-activity of mucous secretion from goblet cells. At the genetic level, ZnO-NPs could activate the reactive oxygen species (ROS) synthesis expected by the down-regulation of mRNA expression for the antioxidant-related genes and up-regulation of DNA damage, cell growth arrest, and apoptosis. Interestingly, ZnO-NPs affected the odor sensation at 60 days post-treatment (60-dpt) more than at 30-dpt, severely damaging the olfactory epithelium and irreparably affecting the cellular repairing mechanisms. This induced a dramatically adverse effect on the cellular endoplasmic reticulum (ER), revealed by higher CHOP protein expression, that suppresses the antioxidant effect of Nrf2 and is followed by the induction of apoptosis via the up-regulation of Bax expression and down-regulation of Bcl-2 protein