Chalcalburnus Chalcoides Research Articles

Biological characteristics of main commercial fish of the shamkir reservoir

In 2019-2022, an ichthyological study of six species of the main commercial fish was carried out at the Shamkir reservoir on the Kura River. Studies have shown that the ratio of males and females among the main fish species caught in this reservoir was approximately 1:1 for bream (Abramis brama orientalis), zander (Sander lucioperca) and carp (Cyprinus carpio), 2:3 for Prussian carp (Carassius auratus gibelio), 5:4 for Caspian roach (Rutilus caspicus), and 3:2 for Danubian bleak (Chalcalburnus chalcoides). In all fish species, the difference between the body weight of males and females without viscera was greater than the difference between their total body weight, which was due to the presence of eggs in females. For the same reason, the fullness according to Fulton of males and females more differs, than fullness according to Clark. Comparition of the different age groups shows that the growth speed of lenth and mass of the carp and zander were higher than of the rest fish. The growth rate of roach and Danubian bleak was the lowest compared to other fish.

Monitoring spawning migrations of potamodromous fish species via eDNA

Potamodromous fish are considered important indicators of habitat connectivity in freshwater ecosystems, but they are globally threatened by anthropogenic impacts. Hence, non-invasive techniques are necessary for monitoring during spawning migrations. The use of environmental DNA (eDNA) potentially facilitates these efforts, albeit quantitative examinations of spawning migrations remain so far mostly uncharted. Here, we investigated spawning migrations of Danube bleak, Alburnus mento, and Vimba bream, Vimba vimba, and found a strong correlation between daily visual fish counts and downstream eDNA signals obtained from filtered water samples analysed with digital PCR and end-point PCR coupled with capillary electrophoresis. By accounting for daily discharge fluctuations, it was possible to predict eDNA signal strength from the number of migrating fish: first, the whole spawning reach was taken into account. Second, the model was validated using eDNA signals and fish counts obtained from the upper half of the examined river stretch. Consequently, fish counts and their day-to-day changes could be described via an eDNA-based time series model for the whole migration period. Our findings highlight the capability of eDNA beyond delivering simple presence/absence data towards efficient and informative monitoring of highly dynamic aquatic processes such as spawning migrations of potamodromous fish species.

Trace and Macro Elements Bioaccumulation in the Muscle and Liver Tissues of <i>Alburnus chalcoides</i> from the South Caspian Sea and Potential Human Health Risk Assessment

Danube bleak Alburnus chalcoides (Guldenstadt, 1772) is a commercially important fish species in the southern part of the Caspian Sea. However, little is known about the concentrations of trace element (TE) in its muscles. To address the issue, we caught 77 A. chalcoides specimens at three different fishing regions (including Astara, Anzali, Kiashahr) of the southern shoreline of the Caspian Sea from September 2017 through June 2018. An inductively coupled plasma optical emission spectrometry (ICP-OES) was used to measure element concentrations in fish muscle and liver tissues. In the case of liver, 27 elements were detected. So that, 9 elements including Ag, Ba, Be, Ce, Co, Sc, U, V and Y which were not detected in liver. In the case of muscle tissue, 22 elements were detected and 14 elements including Ag, Ba, Be, Bi, Cd, Ce, Co, La, Li, Sc, U, V, W and Y. The element values in the muscle of A. chalcoides were significantly lower (p<0.05) than the maximum permitted levels suggested by International standards.

Parasitic protozoans of commercial fishes of the Kura river estuary

In 2014–2016 complete parasitological autopsy was used to examine 202 individuals of the Kura River estuary fish, belonging to the following 14 species: Caspian common sprat – Clupeonella delicatula caspia, Caspian shad – Alosa caspia caspia, black-backed shad – A. kessleri kessleri, Caspian roach – Rutilus rutilus caspius, kutum – R. frisii kutum, asp – Aspius aspius taeniatus, Kura shemaya – Chalcalburnus chalcoides, Transcaucasian silver bream – Blicca bjoerkna transcaucasica, bream – Abramis brama orientalis, Caspian vimba – Vimba vimba persa, carp – Cyprinus carpio, catfish – Silurus glanis, pike – Sander lucioperca, perch – Perca fluvistilis. As a result of the research there were found following 21 species of parasitic protozoa belonging to 5 phyla, 7 classes, 7 orders and 8 families: flagellates Trypanosoma carassii, Cryptobia borelli, Costia necatrix, coccidia Eimeria carpelli, microsporidium Pleistophora siluri, myxosporeans Myxobolus bliccae, M. bramae, M. cyprini, M. dispar, M. ellipsoides, M. muelleri, M. musculi, M. oviformis, M. pseudodispar, M. rotundus, infusorians Chilodonella hexasticha, Ch. piscicola, Ichthyophthirius multifiliis, Trichodina caspialosae, Ichthyophthirius multifiliis, Trichodina caspialosae, Trichodinella epizootica. The most frequent organ of localization of the parasites were the gills, in their tissues 7 species of myxosporeans, and on their surface 1 species of flagellates and 6 species of infusorians were found. In each of the remaining organs there were noted following numbers of species of parasitic protozoans: in the kidneys – 9 species, in the spleen – 7 species, in the muscles of the body – 6 species, in the skin and bladder – 5 species, in the liver – 4 species, on the surface of fins, in the bloodstream, intestinal walls and gall bladder – 2 species, in the heart, subcutaneous connective tissue, eyes and brain – 1 species. In the composition of protofauna, endoparasites (14 species) significantly prevailed over ectoparasites (7 species), and the forms that develop with a change of hosts (12 species), prevailed over forms that have a simple development cycle (9 species). Most of the parasites are of freshwater origin, so more species of parasites were found in fish caught in the highly desalinated part of the Kura estuary than in areas with more mineralized water. It has been established that, in contrast to ectoparasites, freshwater endoparasites, the infection by which occurs in fresh water, in the body of fish are also transferred to more mineralized sites. Among all discovered protozoa 7 species are the causative agents of fish diseases. However, due to not very high infection of fish, no pathogenic phenomena caused by these parasites were observed.

Effects of salinity and plasma prolactin on chloride cells in the gill of Chalcalburnus chalcoides

Gill chloride cells and prolactin hormone are of high importance in the adaptation of euryhaline fish. Guldenstati (Chalcalburnus chalcoides, 1772), an adromous fish, migrates from the Caspian Sea to rivers to have a more successful reproduction. The present study was aimed to evaluate the changes in the number and size of C. chalcoides gill chloride cells as well as to determine the relationship of its plasma prolactin with water salinity. Eighty-four individual C. chalcoides were collected from river (Lale Roud; 0.4 ppt), Lale Roud estuary (3.75 ppt), and Caspian Sea (9.71 ppt). The sampling was lasted for a-12 month period in 2014. The highest (1349±152) and lowest (881±37) number of gill chloride cells were observed in the animals collected from the Caspian Sea and in the river (Lale Roud), respectively. However, plasma prolactin demonstrated the highest level in C. chalcoides caught from the river (0.89±0.02 ng ml-1), but the lowest amount (0.70±0.03 ng ml-1) in the ones collected from the Caspian Sea. Overall, these results suggest that C. chalcoides migration across its habitats is an energy consuming ecological behavior, and the fish consumes high energy just after breeding and while returning to the Caspian Sea.

ОСОБЕННОСТИ МАЛЬКОВОГО ПЕРИОДА ШЕМАИ (CHALCALBURNUSCHALCOIDES) ПРИ ИСКУССТВЕННОМ ВЫРАЩИВАНИИ

The analysis of forming internal organs of shemaya ( Chalcalburnus chalcoides ) juvenile grown up in Temryuk fish breeding farm (Krasnodar region) showed that juveniles have got rather differentiated vital organs. Olfactory lobe looked like a small pair of growths on a forebrain; the third ventricle grew round; a formed epiphysis adjoined its upper part; an epithelial hypothesis adjoined its lower part. In the midbrain one could see visual lobe. The cerebellum contained considerable number of nerve cells; the medulla was shorter than a cerebellum; fossa rhomboidea was rather wide. The medulla narrowed into the spinal cord. Olfactory lobe was very wide, with open cavity, its epithelium gathered into rough longitudinal folds creating a socket. An eyeball had all well-differentiated scleras. All parts of a digestive tract had all three coats: mucous, muscular and connective; their thickness was different. The massive liver had well pronounced trabecular architectonics. Pancreas was actively producing enzymes. Shemaya juveniles have got completely formed gills that consist of filaments and lamellas. The heart of a shemaya juvenile has four well developed cameras: very wide auricle with thin walls; a ventricle; a small sinus venosus and an arterial cone. There are found species characteristics: gills have filaments of I and II orders, an arterial cone has a row of the pocket-style valves. Pathological changes are revealed in liver (fatty dystrophy) and gills (growths of a multilayered non-keratinized epithelium in the intervals between lamellas). This can be connected with violation of shemaya artificial cultivation technologies.

Biodiversity, the present ecological state of the Aral Sea and its impact on future development

The Aral sea used to be the fourth largest lake in the world. Its catchment area is huge, two main rivers (Amu Darya and Syr Darya) feed the lake. The balance of hydrological regime changed drastically after 1960 due to regulation of both main rivers and diversion of water for agricultural irrigation and intense cotton production. Salinity increased and most of invertebrate and fish species disappeared. A significant drop of water level has been recorded in the past 20 years and Aral Lake is presently divided into a small northern lake basin and a larger south basin. Kokaral dam construction resulted in increased water level and decreased salinity. Many invertebrate species reappeared in Small Aral and fish returned from Syr Darya river. Ecological situation in Large Aral is different, eastern part of this basin is completely dried out. The data on salinity levels, some chemical characteristics and above all the data about zooplankton, zoobenthos and fish in Small Aral have been recorded and presented in the article. Salinity ranges between 1 and 8 g/L, the lowest is near the river inlet. Five species of zooplankton (Keratella quadrata, Brachionus plicatilis, Evadne anonyx, Calanipeda aquaedulcis, Cyclops vicinus) and rotifers from the genus Synchaeta are very abundant, ten species are less numerous and seven summer species very rare. Different zoobenthos species are present, but only four abundant (Hediste diversicolor, Chironomus plumosus, Syndosmya segmentum and Cyprideis torosa). Zoobenthos mainly consist of Polychaeta, Mollusca, Crustacea and Diptera. The highest diversity was found near the Kokaral dam. Many fish species are commercially important: 14 of them are abundant, including endemic bream Abramis brama orientalis, Chalcalburnus chalcoides aralensis, carp Cyprinus carpio aralensis, and Aral roach Rutilus rutilus aralensis. White-eye bream Abramis sapa aralensis, silver carp Hypophtalmichthys molitrix, orfe Leuciscus idus oxianus, and snakehead Channa argus warpachowskii are less numerous. Aral barbel Barbus brachycephalus brachycephalus and Turkestan barbel Barbus capito conocephalus remain very rare. It can be concluded that significant positive changes occurred after Kokaral dam construction. Particularly, biocenoses and the Aral lake environment have been improved and fisheries returned. Today Kazakhstan Government is discussing an idea to improve this dam and dike and we support this discussion and advise to make it higher. All can lead to improve ecological state of the Small Aral.

The modern state of populations of Danube bleak Alburnus chalcoides and sabrefish Pelecus cultratus in the Syr Darya River watershed

Event Abstract Back to Event The modern state of populations of Danube bleak Alburnus chalcoides and sabrefish Pelecus cultratus in the Syr Darya River watershed Fariza T. Amirbekova1* 1 Science Research Institute of Problems in Biology nd Biotechnology, Al-Farabi Kazakh National University, Kazakhstan Danube bleak and sabrefish were important commercial fish species before catastrophic changes in the Aral Sea. Measures undertaken by Government of the Republic of Kazakhstan since the end of XX-th century allowed improving the environment state here. Hence, investigation of the modern state of these fish populations was a goal of our investigations of fishes in the Syr Darya River in the borders of the Republic of Kazakhstan. Data were collected since 2007 from the Shardara water reservoir to the estuary in the Small Aral Sea. Now both species are ones of the most common species along the investigated part of the River. Environmental conditions are sufficient for their reproduction. By the known data of the XX-th century Danube bleak did not inhabit the middle reach of the Syr Darya River, but now it is usual here. Danube bleak was found in some tributaries of the Syr Darya River too, but sabrefish was not. Variation of many of measurements and counts for the population of Danube bleak remains in the same limits as in the past. Two forms of gill rakers were revealed. The maximal length and weight become smaller. The condition factor and grow rate are good. Some changes in body shape were revealed in the sabrefish population. The condition factor and grow rate became worse then earlier. Generally, the revealed differences in the state of two indigenous fish species can point to ecosystem changes in the investigated part of the Syr Darya River. Acknowledgements This investigation was supported by the Ministry of Education and Science of the Republic of Kazakhstan, the No 1380/GF4 grant. Keywords: Pelecus cultratus, Syr Darya River, Commercial, Counts, Measures Conference: XV European Congress of Ichthyology, Porto, Portugal, 7 Sep - 11 Sep, 2015. Presentation Type: Poster Presentation Topic: Phylogeny, Systematics and Genetics Citation: Amirbekova FT (2015). The modern state of populations of Danube bleak Alburnus chalcoides and sabrefish Pelecus cultratus in the Syr Darya River watershed. Front. Mar. Sci. Conference Abstract: XV European Congress of Ichthyology. doi: 10.3389/conf.fmars.2015.03.00086 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 16 Nov 2015; Published Online: 17 Nov 2015. * Correspondence: Ms. Fariza T Amirbekova, Science Research Institute of Problems in Biology nd Biotechnology, Al-Farabi Kazakh National University, Almaty, 050038, Kazakhstan, faryz-91@mail.ru Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Fariza T Amirbekova Google Fariza T Amirbekova Google Scholar Fariza T Amirbekova PubMed Fariza T Amirbekova Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Adaptive increase of level of serotonin-modulated anticonsolidational protein in tissues of semimigratory and migratory fish at increase of water salinity

The article deals with studies of serotonergic system activity in different tissues of semimigratory fish—the Caspian roach (Rutilus rutilus caspicus) and the carpbream (Abramis brama orientalis)—and of migratory fish—shemaya (Chalcalburnus chalcoides) caught in fresh and brackish waters, as well as in the common carp (Cyprinus carpio L.) tissues under effect of brackish water in model experiments. Using the indirect solid-phase ELISA-test, the serotonergic system activity was evaluated by measuring in the tissues of the studied fish the serotonin-modulated anticonsolidation protein (SMAP) which is in linear relationship with the serotonin level. There was found a significant elevation of SMAP levels in brains of the Caspian roach, carpbream, shemaya, and the common carp under action of increased water salinity. A revealed increase of the SMAP content in brain of the Caspian roach, carpbream, shemaya and the common carp under action of increased water salinity reflects the corresponding elevated activity of the serotoninergic system and indicates involvement of adaptive readjustments in the animals’ body.

Multifold obtaining of reproductive products of Azov Shemaya Chalcalburnus chalcoides during spawning season

In the framework of studies on the development of biotechnical norms of artificial cultivation of anadromous Azov-Black Sea shemaya Chalcalburnus chalcoides spawning by stages, the possibility of increasing the efficiency of using spawners by twofold obtaining of reproductive products during one fishery season was revealed. The working fecundity increases by 90% at obtaining from females of the second batch of eggs as compared to that in the case of obtaining of only one batch. The level of heat build-up required for obtaining the second batch of eggs without hormonal stimulation was determined. For males of shemaya, the possibility of the repeated obtaining of reproductive products upon one day after hypophysation was shown.

English

&nbsp; This study was carried out to determine fish species in &Ccedil;amlıg&ouml;ze Dam Lake located at Central Anatolian region of Turkey. Fish samples were caught seasonally with nets of various mesh sizes between April 2010 and January 2011 in &Ccedil;amlıg&ouml;ze Dam Lake. As a result of evaluated fish samples&nbsp;Oncorhynchus mykissbelonging to Salmonidae,&nbsp;Cyprinus carpio,&nbsp;Barbus plebejus,&nbsp;Capoeta sieboldii,&nbsp;Capoeta tinca,&nbsp;Chalcalburnus chalcoides,&nbsp;Chondrostoma nasus,&nbsp;Leuciscus cephalus&nbsp;belonging to Cyprinidae and&nbsp;Silurus glanis&nbsp;belonging to Siluridae were identified in this study area. All fish species were native except the&nbsp;Oncorhynchus mykiss&nbsp;andCyprinus carpio&nbsp;in &Ccedil;amlıg&ouml;ze Dam Lake. Some morphometric and meristic characteristics of the fish samples were examined in &Ccedil;amlıg&ouml;ze Dam Lake. &nbsp;Key words:&nbsp;Fish species, &Ccedil;amlıg&ouml;ze dam lake, Sivas, Turkey.

Condition factors of seven Cyprinid fish species from Çamligöze dam lake on central Anatolia, Turkey

In this study, condition factors were determined for seven Cyprinid fish species from Camligoze dam lake located at central Anatolian region of Turkey. The obtained results were compared with other studies from different habitats in Turkey. Fish samples were collected seasonally with nets of various mesh sizes from April 2010 to January 2011. Cyprinus carpio (1.6362 ± 0.2785) was determined to have the greatest mean condition factor followed by Capoeta tinca (1.3126 ± 0.1927), Leuciscus cephalus (1.2915 ± 0.3021), Barbus plebejus(1.1142 ± 0.1973), Chalcalburnus chalcoides (1.1138 ± 0.1251), Capoeta sieboldii (1.0214 ±0.1547) andChondrostoma nasus (0.9894 ± 0.2281) in Camligoze dam lake. For Camligoze dam lake, condition factors ofCyprinid fish species are given for the first time. Condition factors of seven Cyprinid fish species around “1” showed a good level of nutrition of fish and nutritional capacity in Camligoze dam lake. Key words: Camligoze dam lake, Turkey, condition factor, cyprinid fish species.

The Trace Element Analysis in Freshwater Fish Species, Water and Sediment in Iyidere Stream (Rize-Turkey)

Many environmental problems like dam construction, agricultural debris, flooding and industrial establishments threaten Iyidere stream (Rize, Turkey) on the southeastern coast of the Black Sea (Turkey). The trace element concentrations in water, fish and sediments in lyidere stream (Rize, Turkey) were investigated in this study. The concentration of six different elements in ten freshwater fish species and sediment was determined using energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied for the elemental analysis of fish and sediments. Water samples for trace metals were analyzed using standard spectrophotometry methods. A qualitative analysis of spectral peaks showed that ten different freshwater fish samples (Chondrostoma colchicum, Chalcalburnus chalcoides, Salmo trutta labrax, Alburnoides bipunctatus, Leuciscus cephalus, Barbus taurus escherichia, Capoeta tinca, Neogobius kessleri, Rutilus frisii, Lampetra lanceolata) and sediment contained phosphorus (P), sulphur (S), chlorine (Cl), potassium (K), calcium (Ca) and titanium (Ti). Heavy metals as toxic elements for biota (Pb, Cd, Hg, Zn and Mn etc.) were not detected in fish, water and sediments. Thus, It can be declared that freshwater fish of Iyidere does not contains health risks for consumers in terms of metal pollution.

Metazoan parasites of Alburnus chalcoides in Tödürge Lake (Zara/Sivas, Turkey)

Summary The metazoan parasites of the Danube bleak, Alburnus chalcoides (Guldenstadt, 1772), were determined in Todurge Lake, since the parasite fish fauna had not yet been studied in this system. A total of 106 specimens were collected from October 2004 to September 2005. Six parasite species were found: two monogeneans (Diplozoon paradoxum and Diplozoon megan), one digenean (Posthodiplostomum cuticola), one cestode (Bothriocephalus acheilognathi), one nematod (Rhabdochona sp.), and one copepod (Argulus foliaceus). About 87.7% of the Danube bleak examined were infected by at least one parasite: Rhabdochona sp. (4080 specimens), Posthodiplostomum cuticola (312 specimens) and Diplozoon megan (159 specimens) being the dominant parasites. Only 33% of the fish carried one parasitic species whilst the remainder had two (21.7%), three (17.9%) and four different species (15.1%). The frequency of infestation changed according to seasonal conditions, with a maximum 94.3% observed in spring. Occurrence, density, seasonal changes, and preferences of the parasites species for various ages and size groups of the bleak were identified, despite the limited overall sample size. D. paradoxum, D. megan, P. cuticola, B. acheilognathi, Rhabdochona sp. and A. foliaceus were determined for the first time as parasites of Danube bleak in Turkey. D. megan was also a new record for the fish parasite fauna of Turkey.

A fine structural review on the spermatozoa of Cyprinidae with attention to their phylogenetic implications.

The fine structural organization and dimensions of spermatozoa from species of 4 subfamilies of the Cyprinidae (Barbus barbus, Carassius carassius, Cyprinus carpio carpio, Cyprinus carpio haematopterus, Abramis brama, Alburnoides bipunctatus, Alburnus alburnus, Chalcalburnus chalcoides mento, Chondrostoma nasus, Hypophthalmichthys molitrix, Leuciscus cephalus, Phoxinus phoxinus, Rutilus rutilus, Rutilus meidingerii, Scardinius erythrophthalmus, Vimba vimba and Ctenopharyngodon idella) are compared with each other as well as with results from other studies. Based on these descriptions it is investigated whether sperm structure reveals correlations with the existing systematics and if it could be a useful taxonomical parameter. The scatter plots based on the discriminate analysis and the neighbour-joining trees based on a Mahalanobis distance matrix reveal that sperm organization is related with systematics in many aspects. However, in some cases there are also clear differences between relations found on the basis of sperm morphology and between the systematic relations.

Morphological discrimination between two populations of shemaya, Chalcalburnus chalcoides (Actinopterygii, Cyprinidae), using a truss network

Discriminación morfológica entre dos poblaciones del alburno del Danubio, Chalcalburnus chalcoides (Actinopterygii, Cyprinidae), utilizando una red en celosía Recientemente se han criticado diversos métodos de medición de parámetros corporales, que se utilizaban en la identificación de los linajes, debido a la debilidad y los sesgos inherentes a ellos. Como alternativa, cada vez se está usando más un nuevo sistema de medición morfométrica denomiado red en celosía, para la identificación de los linajes. Nosotros hemos estudiado las diferenciaciones morfométricas entre dos poblaciones y en los dos sexos del alburno del Danubio (Chalcalburnus chalcoides) utilizando este tipo de red. Se midieron las distancias entre 15 puntos determinados o nudos de la celosía en 66 especímenes. Se evaluaron las transformaciones del ajuste del tamaño dividiendo las características (distancias entre nudos) por el valor del centroide del espécimen. Se llevaron a cabo análisis de varianza multivariante (AMOVA), análisis de componentes principales y análisis de discriminación para investigar la distinción y los patrones de las variaciones morfológicas entre pobla­ciones y sexos. El AMOVA (test de Wilks) indicaba una diferencia significativa para los vectores medios entre poblaciones (? = 0,136; F = 7,76; P &lt; 0,001) y sexos (? = 0,120; F = 45,32; P &lt; 0,001). El análisis de discriminación clasificó correctamente el 97% y el 89,4% de las muestras en sus grupos originales de población y sexo, respectivamente. Nuestros resultados respaldan el uso de las redes en celosía para es­tudiar la variación morfológica entre poblaciones, ya que proporcionan perspectivas muy interesantes para el estudio de los patrones de diversidad.

Physiological and biochemical investigations on egg stickiness in common carp

The properties and behaviour of common carp, Cyprinus carpio, eggs in water and in ovarian fluids were studied at different temperature, pH, and with divalent cation concentrations. The biochemical composition of zona radiata externa (ZRE) was analyzed qualitatively and quantitatively on amino acids, carbohydrates, uronic acid and sialic acids using chemical assays; on proteins using electrophoresis. Comparative biochemical studies were performed on the chub, Leuciscus cephalus, the vimba, Vimba vimba and the bleak, Chalcalburnus chalcoides. Eggs of common carp became sticky within seconds after mixing with water. Egg stickiness was not affected by water pH in a range of 6–9, by water temperatures between 4 and 30 °C, by divalent cations in concentrations ≤20 mmol/l, and by sodium chloride concentrations ≤50 mmol/l. Our investigations indicated that specific proteins of the cyprinid ovarian fluid are controlling (inhibiting) the initiation of egg stickiness: egg stickiness did not develop as long as the eggs were incubated in ovarian fluid. When however the ovarian fluid proteins were removed from the ovarian fluid by heat treatment, eggs developed stickiness within seconds, like they do in water. Biochemically, the ZRE consisted of nine types of proteins whereby four of them were glycoproteins. Glucose, fructose, galactose, and uronic acids were the major carbohydrates. Treatment of the egg membrane with invertase or amyloglucosidase did not affect the egg stickiness. Treatment with protease prevented stickiness. From these results and from additional histochemical results, we conclude that glycoproteins are likely to be the molecules responsible for stickiness.

Effects of diazinon on female Chalcalburnus chalcoides Cyprinidae) serum estradiol levels

The effects of diazinon [O,O-diethyl O-(2-isopropyl 1-6-methyl-4 pryimidinyl)] (DZN) on serum estradiol levels in female Chalcalburnus chalcoides fish were studied. Five treatment aquaria were used as follows; control, DZN at 10, 20, 40, and 60 µg L−1 with 20 fish per aquarium. Each treatment was repeated for 24, 48, 72, 96, and 168 h (1 week). After exposure, fish were bled and serum estradiol levels determined by RIA (radioimmunoassay). Data showed a significant reduction in serum estradiol levels at all DZN concentrations used at all time periods. There did not seem to be a time or concentration dependent phenomenon.

Morphological differentiation between two populations of the Shemaya, Chalcalburnus chalcoides: a geometrical morphometric approach

Morphological differences (shape and size) among two populations of Shemaya (Danube Bleak), Chalcalburnus chalcoides,were studied by the geometric methods of shape PCA, thin-plate splines and multivariate analysis of partial warp scores. Measurements of Cartesian coordinates of 15 landmarks were obtained from 66 specimens from the Rivers Haraz and Shirud. For each specimen, centroid sizes were computed; sexual dimorphism and variation in size among sites were tested using t-test. Sexes differed significantly in size (P<0.001), with females being larger than males. Populations had significant size differences (P<0.001), with specimens from the River Shirud being larger than those from the River Haraz. Body shapes were significantly different between sexes (P<0.001) and populations (P<0.001), but interaction of sexes at sites were insignificant (P=358). TPS analysis showed a sexual dimorphism of shape, in particular the abdominal area, which appeared to be more enlarged in the females of the two populations. The canonical vitiate analysis CVA based on partial warps correctly identified all female specimens and 95% of male specimens at both locations. The results show thast the difference in body shape between the two populations is probably due to habitat influence (water flow speed).

A natural hybrid of Leuciscus cephalus (L.) and Chalcalburnus chalcoides (Güldenstädt)(Osteichthyes‐Cyprinidae) from Lake Tödürge (Sivas, Turkey)

Hybridization between Leuciscus cephalus and Chalcalburnus chalcoides was identified from biometrical features in 55 fish caught from Lake Tödürge, Sivas, Turkey, between April 1994 and November 1997. The hybrid index Vh for metric and meristic characters was intermediate (Vh = 45·6) compared with their parents (L. cephalus Vh = 0 or negative and C. chalcoides Vh ≥ 100). Morphological, metric and meristic features of L. cephalus × C. chalcoides also resembled those of the parents. The majority presented an intermediate position which was best shown by the shape of mouth, caudal fin, gill rakers and pharyngeal teeth, and also by the caudal peduncle depth, head and interorbital width, predorsal and preanal distance, height of anal fin, length of anal base and other characters.